Merge branch 'master' into ownJsonParsing

Gulpfile.ts

@@ -131,6 +131,7 @@ const es2017LibrarySource = [
     "es2017.object.d.ts",
     "es2017.sharedmemory.d.ts",
     "es2017.string.d.ts",
+    "es2017.intl.d.ts",
 ];
 
 const es2017LibrarySourceMap = es2017LibrarySource.map(function(source) {
@@ -935,7 +936,7 @@ gulp.task(loggedIOJsPath, /*help*/ false, [], (done) => {
     const temp = path.join(builtLocalDirectory, "temp");
     mkdirP(temp, (err) => {
         if (err) { console.error(err); done(err); process.exit(1); }
-        exec(host, [LKGCompiler, "--types --outdir", temp, loggedIOpath], () => {
+        exec(host, [LKGCompiler, "--types", "--target es5", "--lib es5", "--outdir", temp, loggedIOpath], () => {
             fs.renameSync(path.join(temp, "/harness/loggedIO.js"), loggedIOJsPath);
             del(temp).then(() => done(), done);
         }, done);
@@ -946,7 +947,13 @@ const instrumenterPath = path.join(harnessDirectory, "instrumenter.ts");
 const instrumenterJsPath = path.join(builtLocalDirectory, "instrumenter.js");
 gulp.task(instrumenterJsPath, /*help*/ false, [servicesFile], () => {
     const settings: tsc.Settings = getCompilerSettings({
-        outFile: instrumenterJsPath
+        outFile: instrumenterJsPath,
+        target: "es5",
+        lib: [
+            "es6",
+            "dom",
+            "scripthost"
+        ]
     }, /*useBuiltCompiler*/ true);
     return gulp.src(instrumenterPath)
         .pipe(newer(instrumenterJsPath))

Jakefile.js

@@ -172,7 +172,8 @@ var es2016LibrarySourceMap = es2016LibrarySource.map(function (source) {
 var es2017LibrarySource = [
     "es2017.object.d.ts",
     "es2017.sharedmemory.d.ts",
-    "es2017.string.d.ts"
+    "es2017.string.d.ts",
+    "es2017.intl.d.ts"
 ];
 
 var es2017LibrarySourceMap = es2017LibrarySource.map(function (source) {

lib/cancellationToken.js

@@ -69,3 +69,5 @@ function createCancellationToken(args) {
     }
 }
 module.exports = createCancellationToken;
+
+//# sourceMappingURL=cancellationToken.js.map

lib/lib.d.ts

@@ -1406,6 +1406,14 @@ interface ArrayBuffer {
     slice(begin: number, end?: number): ArrayBuffer;
 }
 
+/**
+ * Allowed ArrayBuffer types for the buffer of an ArrayBufferView and related Typed Arrays.
+ */
+interface ArrayBufferTypes {
+    ArrayBuffer: ArrayBuffer;
+}
+type ArrayBufferLike = ArrayBufferTypes[keyof ArrayBufferTypes];
+
 interface ArrayBufferConstructor {
     readonly prototype: ArrayBuffer;
     new (byteLength: number): ArrayBuffer;
@@ -1417,7 +1425,7 @@ interface ArrayBufferView {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    buffer: ArrayBuffer;
+    buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -1559,7 +1567,7 @@ interface DataView {
 }
 
 interface DataViewConstructor {
-    new (buffer: ArrayBuffer, byteOffset?: number, byteLength?: number): DataView;
+    new (buffer: ArrayBufferLike, byteOffset?: number, byteLength?: number): DataView;
 }
 declare const DataView: DataViewConstructor;
 
@@ -1576,7 +1584,7 @@ interface Int8Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -1819,7 +1827,7 @@ interface Int8ArrayConstructor {
     readonly prototype: Int8Array;
     new (length: number): Int8Array;
     new (array: ArrayLike<number>): Int8Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Int8Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Int8Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -1860,7 +1868,7 @@ interface Uint8Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -2104,7 +2112,7 @@ interface Uint8ArrayConstructor {
     readonly prototype: Uint8Array;
     new (length: number): Uint8Array;
     new (array: ArrayLike<number>): Uint8Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Uint8Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Uint8Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -2145,7 +2153,7 @@ interface Uint8ClampedArray {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -2389,7 +2397,7 @@ interface Uint8ClampedArrayConstructor {
     readonly prototype: Uint8ClampedArray;
     new (length: number): Uint8ClampedArray;
     new (array: ArrayLike<number>): Uint8ClampedArray;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Uint8ClampedArray;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Uint8ClampedArray;
 
     /**
       * The size in bytes of each element in the array.
@@ -2429,7 +2437,7 @@ interface Int16Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -2673,7 +2681,7 @@ interface Int16ArrayConstructor {
     readonly prototype: Int16Array;
     new (length: number): Int16Array;
     new (array: ArrayLike<number>): Int16Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Int16Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Int16Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -2714,7 +2722,7 @@ interface Uint16Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -2958,7 +2966,7 @@ interface Uint16ArrayConstructor {
     readonly prototype: Uint16Array;
     new (length: number): Uint16Array;
     new (array: ArrayLike<number>): Uint16Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Uint16Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Uint16Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -2998,7 +3006,7 @@ interface Int32Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -3242,7 +3250,7 @@ interface Int32ArrayConstructor {
     readonly prototype: Int32Array;
     new (length: number): Int32Array;
     new (array: ArrayLike<number>): Int32Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Int32Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Int32Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -3282,7 +3290,7 @@ interface Uint32Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -3526,7 +3534,7 @@ interface Uint32ArrayConstructor {
     readonly prototype: Uint32Array;
     new (length: number): Uint32Array;
     new (array: ArrayLike<number>): Uint32Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Uint32Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Uint32Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -3566,7 +3574,7 @@ interface Float32Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -3810,7 +3818,7 @@ interface Float32ArrayConstructor {
     readonly prototype: Float32Array;
     new (length: number): Float32Array;
     new (array: ArrayLike<number>): Float32Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Float32Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Float32Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -3851,7 +3859,7 @@ interface Float64Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -4095,7 +4103,7 @@ interface Float64ArrayConstructor {
     readonly prototype: Float64Array;
     new (length: number): Float64Array;
     new (array: ArrayLike<number>): Float64Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Float64Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Float64Array;
 
     /**
       * The size in bytes of each element in the array.

lib/lib.es2015.iterable.d.ts

@@ -52,17 +52,17 @@ interface Array<T> {
     [Symbol.iterator](): IterableIterator<T>;
 
     /**
-     * Returns an array of key, value pairs for every entry in the array
+     * Returns an iterable of key, value pairs for every entry in the array
      */
     entries(): IterableIterator<[number, T]>;
 
     /**
-     * Returns an list of keys in the array
+     * Returns an iterable of keys in the array
      */
     keys(): IterableIterator<number>;
 
     /**
-     * Returns an list of values in the array
+     * Returns an iterable of values in the array
      */
     values(): IterableIterator<T>;
 }
@@ -86,21 +86,21 @@ interface ArrayConstructor {
 }
 
 interface ReadonlyArray<T> {
-    /** Iterator */
+    /** Iterator of values in the array. */
     [Symbol.iterator](): IterableIterator<T>;
 
     /**
-     * Returns an array of key, value pairs for every entry in the array
+     * Returns an iterable of key, value pairs for every entry in the array
      */
     entries(): IterableIterator<[number, T]>;
 
     /**
-     * Returns an list of keys in the array
+     * Returns an iterable of keys in the array
      */
     keys(): IterableIterator<number>;
 
     /**
-     * Returns an list of values in the array
+     * Returns an iterable of values in the array
      */
     values(): IterableIterator<T>;
 }
@@ -111,9 +111,42 @@ interface IArguments {
 }
 
 interface Map<K, V> {
+    /** Returns an iterable of entries in the map. */
     [Symbol.iterator](): IterableIterator<[K, V]>;
+
+    /**
+     * Returns an iterable of key, value pairs for every entry in the map.
+     */
     entries(): IterableIterator<[K, V]>;
+
+    /**
+     * Returns an iterable of keys in the map
+     */
     keys(): IterableIterator<K>;
+
+    /**
+     * Returns an iterable of values in the map
+     */
+    values(): IterableIterator<V>;
+}
+
+interface ReadonlyMap<K, V> {
+    /** Returns an iterable of entries in the map. */
+    [Symbol.iterator](): IterableIterator<[K, V]>;
+
+    /**
+     * Returns an iterable of key, value pairs for every entry in the map.
+     */
+    entries(): IterableIterator<[K, V]>;
+
+    /**
+     * Returns an iterable of keys in the map
+     */
+    keys(): IterableIterator<K>;
+
+    /**
+     * Returns an iterable of values in the map
+     */
     values(): IterableIterator<V>;
 }
 
@@ -128,9 +161,40 @@ interface WeakMapConstructor {
 }
 
 interface Set<T> {
+    /** Iterates over values in the set. */
     [Symbol.iterator](): IterableIterator<T>;
+    /**
+     * Returns an iterable of [v,v] pairs for every value `v` in the set.
+     */
     entries(): IterableIterator<[T, T]>;
+    /**
+     * Despite its name, returns an iterable of the values in the set,
+     */
     keys(): IterableIterator<T>;
+
+    /**
+     * Returns an iterable of values in the set.
+     */
+    values(): IterableIterator<T>;
+}
+
+interface ReadonlySet<T> {
+    /** Iterates over values in the set. */
+    [Symbol.iterator](): IterableIterator<T>;
+
+    /**
+     * Returns an iterable of [v,v] pairs for every value `v` in the set.
+     */
+    entries(): IterableIterator<[T, T]>;
+
+    /**
+     * Despite its name, returns an iterable of the values in the set,
+     */
+    keys(): IterableIterator<T>;
+
+    /**
+     * Returns an iterable of values in the set.
+     */
     values(): IterableIterator<T>;
 }
 

lib/lib.es2015.proxy.d.ts

@@ -23,7 +23,7 @@ interface ProxyHandler<T extends object> {
     setPrototypeOf? (target: T, v: any): boolean;
     isExtensible? (target: T): boolean;
     preventExtensions? (target: T): boolean;
-    getOwnPropertyDescriptor? (target: T, p: PropertyKey): PropertyDescriptor;
+    getOwnPropertyDescriptor? (target: T, p: PropertyKey): PropertyDescriptor | undefined;
     has? (target: T, p: PropertyKey): boolean;
     get? (target: T, p: PropertyKey, receiver: any): any;
     set? (target: T, p: PropertyKey, value: any, receiver: any): boolean;

lib/lib.es2017.d.ts

@@ -21,4 +21,5 @@ and limitations under the License.
 /// <reference path="lib.es2016.d.ts" />
 /// <reference path="lib.es2017.object.d.ts" />
 /// <reference path="lib.es2017.sharedmemory.d.ts" />
-/// <reference path="lib.es2017.string.d.ts" />
+/// <reference path="lib.es2017.string.d.ts" />
+/// <reference path="lib.es2017.intl.d.ts" />

lib/lib.es2017.sharedmemory.d.ts

@@ -43,5 +43,96 @@ interface SharedArrayBufferConstructor {
     readonly prototype: SharedArrayBuffer;
     new (byteLength: number): SharedArrayBuffer;
 }
+declare var SharedArrayBuffer: SharedArrayBufferConstructor;
 
-declare var SharedArrayBuffer: SharedArrayBufferConstructor;
+interface ArrayBufferTypes {
+    SharedArrayBuffer: SharedArrayBuffer;
+}
+
+interface Atomics {
+    /**
+     * Adds a value to the value at the given position in the array, returning the original value.
+     * Until this atomic operation completes, any other read or write operation against the array
+     * will block.
+     */
+    add(typedArray: Int8Array | Uint8Array | Int16Array | Uint16Array | Int32Array | Uint32Array, index: number, value: number): number;
+
+    /**
+     * Stores the bitwise AND of a value with the value at the given position in the array,
+     * returning the original value. Until this atomic operation completes, any other read or
+     * write operation against the array will block.
+     */
+    and(typedArray: Int8Array | Uint8Array | Int16Array | Uint16Array | Int32Array | Uint32Array, index: number, value: number): number;
+
+    /**
+     * Replaces the value at the given position in the array if the original value equals the given
+     * expected value, returning the original value. Until this atomic operation completes, any
+     * other read or write operation against the array will block.
+     */
+    compareExchange(typedArray: Int8Array | Uint8Array | Int16Array | Uint16Array | Int32Array | Uint32Array, index: number, expectedValue: number, replacementValue: number): number;
+
+    /**
+     * Replaces the value at the given position in the array, returning the original value. Until
+     * this atomic operation completes, any other read or write operation against the array will
+     * block.
+     */
+    exchange(typedArray: Int8Array | Uint8Array | Int16Array | Uint16Array | Int32Array | Uint32Array, index: number, value: number): number;
+
+    /**
+     * Returns a value indicating whether high-performance algorithms can use atomic operations
+     * (`true`) or must use locks (`false`) for the given number of bytes-per-element of a typed
+     * array.
+     */
+    isLockFree(size: number): boolean;
+
+    /**
+     * Returns the value at the given position in the array. Until this atomic operation completes,
+     * any other read or write operation against the array will block.
+     */
+    load(typedArray: Int8Array | Uint8Array | Int16Array | Uint16Array | Int32Array | Uint32Array, index: number): number;
+
+    /**
+     * Stores the bitwise OR of a value with the value at the given position in the array,
+     * returning the original value. Until this atomic operation completes, any other read or write
+     * operation against the array will block.
+     */
+    or(typedArray: Int8Array | Uint8Array | Int16Array | Uint16Array | Int32Array | Uint32Array, index: number, value: number): number;
+
+    /**
+     * Stores a value at the given position in the array, returning the new value. Until this
+     * atomic operation completes, any other read or write operation against the array will block.
+     */
+    store(typedArray: Int8Array | Uint8Array | Int16Array | Uint16Array | Int32Array | Uint32Array, index: number, value: number): number;
+
+    /**
+     * Subtracts a value from the value at the given position in the array, returning the original
+     * value. Until this atomic operation completes, any other read or write operation against the
+     * array will block.
+     */
+    sub(typedArray: Int8Array | Uint8Array | Int16Array | Uint16Array | Int32Array | Uint32Array, index: number, value: number): number;
+
+    /**
+     * If the value at the given position in the array is equal to the provided value, the current
+     * agent is put to sleep causing execution to suspend until the timeout expires (returning
+     * `"timed-out"`) or until the agent is awoken (returning `"ok"`); otherwise, returns
+     * `"not-equal"`.
+     */
+    wait(typedArray: Int32Array, index: number, value: number, timeout?: number): "ok" | "not-equal" | "timed-out";
+
+    /**
+     * Wakes up sleeping agents that are waiting on the given index of the array, returning the
+     * number of agents that were awoken.
+     */
+    wake(typedArray: Int32Array, index: number, count: number): number;
+
+    /**
+     * Stores the bitwise XOR of a value with the value at the given position in the array,
+     * returning the original value. Until this atomic operation completes, any other read or write
+     * operation against the array will block.
+     */
+    xor(typedArray: Int8Array | Uint8Array | Int16Array | Uint16Array | Int32Array | Uint32Array, index: number, value: number): number;
+
+    readonly [Symbol.toStringTag]: "Atomics";
+}
+
+declare var Atomics: Atomics;

lib/lib.es5.d.ts

@@ -1406,6 +1406,14 @@ interface ArrayBuffer {
     slice(begin: number, end?: number): ArrayBuffer;
 }
 
+/**
+ * Allowed ArrayBuffer types for the buffer of an ArrayBufferView and related Typed Arrays.
+ */
+interface ArrayBufferTypes {
+    ArrayBuffer: ArrayBuffer;
+}
+type ArrayBufferLike = ArrayBufferTypes[keyof ArrayBufferTypes];
+
 interface ArrayBufferConstructor {
     readonly prototype: ArrayBuffer;
     new (byteLength: number): ArrayBuffer;
@@ -1417,7 +1425,7 @@ interface ArrayBufferView {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    buffer: ArrayBuffer;
+    buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -1559,7 +1567,7 @@ interface DataView {
 }
 
 interface DataViewConstructor {
-    new (buffer: ArrayBuffer, byteOffset?: number, byteLength?: number): DataView;
+    new (buffer: ArrayBufferLike, byteOffset?: number, byteLength?: number): DataView;
 }
 declare const DataView: DataViewConstructor;
 
@@ -1576,7 +1584,7 @@ interface Int8Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -1819,7 +1827,7 @@ interface Int8ArrayConstructor {
     readonly prototype: Int8Array;
     new (length: number): Int8Array;
     new (array: ArrayLike<number>): Int8Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Int8Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Int8Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -1860,7 +1868,7 @@ interface Uint8Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -2104,7 +2112,7 @@ interface Uint8ArrayConstructor {
     readonly prototype: Uint8Array;
     new (length: number): Uint8Array;
     new (array: ArrayLike<number>): Uint8Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Uint8Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Uint8Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -2145,7 +2153,7 @@ interface Uint8ClampedArray {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -2389,7 +2397,7 @@ interface Uint8ClampedArrayConstructor {
     readonly prototype: Uint8ClampedArray;
     new (length: number): Uint8ClampedArray;
     new (array: ArrayLike<number>): Uint8ClampedArray;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Uint8ClampedArray;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Uint8ClampedArray;
 
     /**
       * The size in bytes of each element in the array.
@@ -2429,7 +2437,7 @@ interface Int16Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -2673,7 +2681,7 @@ interface Int16ArrayConstructor {
     readonly prototype: Int16Array;
     new (length: number): Int16Array;
     new (array: ArrayLike<number>): Int16Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Int16Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Int16Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -2714,7 +2722,7 @@ interface Uint16Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -2958,7 +2966,7 @@ interface Uint16ArrayConstructor {
     readonly prototype: Uint16Array;
     new (length: number): Uint16Array;
     new (array: ArrayLike<number>): Uint16Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Uint16Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Uint16Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -2998,7 +3006,7 @@ interface Int32Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -3242,7 +3250,7 @@ interface Int32ArrayConstructor {
     readonly prototype: Int32Array;
     new (length: number): Int32Array;
     new (array: ArrayLike<number>): Int32Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Int32Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Int32Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -3282,7 +3290,7 @@ interface Uint32Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -3526,7 +3534,7 @@ interface Uint32ArrayConstructor {
     readonly prototype: Uint32Array;
     new (length: number): Uint32Array;
     new (array: ArrayLike<number>): Uint32Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Uint32Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Uint32Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -3566,7 +3574,7 @@ interface Float32Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -3810,7 +3818,7 @@ interface Float32ArrayConstructor {
     readonly prototype: Float32Array;
     new (length: number): Float32Array;
     new (array: ArrayLike<number>): Float32Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Float32Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Float32Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -3851,7 +3859,7 @@ interface Float64Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -4095,7 +4103,7 @@ interface Float64ArrayConstructor {
     readonly prototype: Float64Array;
     new (length: number): Float64Array;
     new (array: ArrayLike<number>): Float64Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Float64Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Float64Array;
 
     /**
       * The size in bytes of each element in the array.

lib/lib.es6.d.ts

@@ -1406,6 +1406,14 @@ interface ArrayBuffer {
     slice(begin: number, end?: number): ArrayBuffer;
 }
 
+/**
+ * Allowed ArrayBuffer types for the buffer of an ArrayBufferView and related Typed Arrays.
+ */
+interface ArrayBufferTypes {
+    ArrayBuffer: ArrayBuffer;
+}
+type ArrayBufferLike = ArrayBufferTypes[keyof ArrayBufferTypes];
+
 interface ArrayBufferConstructor {
     readonly prototype: ArrayBuffer;
     new (byteLength: number): ArrayBuffer;
@@ -1417,7 +1425,7 @@ interface ArrayBufferView {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    buffer: ArrayBuffer;
+    buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -1559,7 +1567,7 @@ interface DataView {
 }
 
 interface DataViewConstructor {
-    new (buffer: ArrayBuffer, byteOffset?: number, byteLength?: number): DataView;
+    new (buffer: ArrayBufferLike, byteOffset?: number, byteLength?: number): DataView;
 }
 declare const DataView: DataViewConstructor;
 
@@ -1576,7 +1584,7 @@ interface Int8Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -1819,7 +1827,7 @@ interface Int8ArrayConstructor {
     readonly prototype: Int8Array;
     new (length: number): Int8Array;
     new (array: ArrayLike<number>): Int8Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Int8Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Int8Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -1860,7 +1868,7 @@ interface Uint8Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -2104,7 +2112,7 @@ interface Uint8ArrayConstructor {
     readonly prototype: Uint8Array;
     new (length: number): Uint8Array;
     new (array: ArrayLike<number>): Uint8Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Uint8Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Uint8Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -2145,7 +2153,7 @@ interface Uint8ClampedArray {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -2389,7 +2397,7 @@ interface Uint8ClampedArrayConstructor {
     readonly prototype: Uint8ClampedArray;
     new (length: number): Uint8ClampedArray;
     new (array: ArrayLike<number>): Uint8ClampedArray;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Uint8ClampedArray;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Uint8ClampedArray;
 
     /**
       * The size in bytes of each element in the array.
@@ -2429,7 +2437,7 @@ interface Int16Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -2673,7 +2681,7 @@ interface Int16ArrayConstructor {
     readonly prototype: Int16Array;
     new (length: number): Int16Array;
     new (array: ArrayLike<number>): Int16Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Int16Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Int16Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -2714,7 +2722,7 @@ interface Uint16Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -2958,7 +2966,7 @@ interface Uint16ArrayConstructor {
     readonly prototype: Uint16Array;
     new (length: number): Uint16Array;
     new (array: ArrayLike<number>): Uint16Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Uint16Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Uint16Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -2998,7 +3006,7 @@ interface Int32Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -3242,7 +3250,7 @@ interface Int32ArrayConstructor {
     readonly prototype: Int32Array;
     new (length: number): Int32Array;
     new (array: ArrayLike<number>): Int32Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Int32Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Int32Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -3282,7 +3290,7 @@ interface Uint32Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -3526,7 +3534,7 @@ interface Uint32ArrayConstructor {
     readonly prototype: Uint32Array;
     new (length: number): Uint32Array;
     new (array: ArrayLike<number>): Uint32Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Uint32Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Uint32Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -3566,7 +3574,7 @@ interface Float32Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -3810,7 +3818,7 @@ interface Float32ArrayConstructor {
     readonly prototype: Float32Array;
     new (length: number): Float32Array;
     new (array: ArrayLike<number>): Float32Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Float32Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Float32Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -3851,7 +3859,7 @@ interface Float64Array {
     /**
       * The ArrayBuffer instance referenced by the array.
       */
-    readonly buffer: ArrayBuffer;
+    readonly buffer: ArrayBufferLike;
 
     /**
       * The length in bytes of the array.
@@ -4095,7 +4103,7 @@ interface Float64ArrayConstructor {
     readonly prototype: Float64Array;
     new (length: number): Float64Array;
     new (array: ArrayLike<number>): Float64Array;
-    new (buffer: ArrayBuffer, byteOffset?: number, length?: number): Float64Array;
+    new (buffer: ArrayBufferLike, byteOffset?: number, length?: number): Float64Array;
 
     /**
       * The size in bytes of each element in the array.
@@ -4977,17 +4985,17 @@ interface Array<T> {
     [Symbol.iterator](): IterableIterator<T>;
 
     /**
-     * Returns an array of key, value pairs for every entry in the array
+     * Returns an iterable of key, value pairs for every entry in the array
      */
     entries(): IterableIterator<[number, T]>;
 
     /**
-     * Returns an list of keys in the array
+     * Returns an iterable of keys in the array
      */
     keys(): IterableIterator<number>;
 
     /**
-     * Returns an list of values in the array
+     * Returns an iterable of values in the array
      */
     values(): IterableIterator<T>;
 }
@@ -5011,21 +5019,21 @@ interface ArrayConstructor {
 }
 
 interface ReadonlyArray<T> {
-    /** Iterator */
+    /** Iterator of values in the array. */
     [Symbol.iterator](): IterableIterator<T>;
 
     /**
-     * Returns an array of key, value pairs for every entry in the array
+     * Returns an iterable of key, value pairs for every entry in the array
      */
     entries(): IterableIterator<[number, T]>;
 
     /**
-     * Returns an list of keys in the array
+     * Returns an iterable of keys in the array
      */
     keys(): IterableIterator<number>;
 
     /**
-     * Returns an list of values in the array
+     * Returns an iterable of values in the array
      */
     values(): IterableIterator<T>;
 }
@@ -5036,9 +5044,42 @@ interface IArguments {
 }
 
 interface Map<K, V> {
+    /** Returns an iterable of entries in the map. */
     [Symbol.iterator](): IterableIterator<[K, V]>;
+
+    /**
+     * Returns an iterable of key, value pairs for every entry in the map.
+     */
     entries(): IterableIterator<[K, V]>;
+
+    /**
+     * Returns an iterable of keys in the map
+     */
     keys(): IterableIterator<K>;
+
+    /**
+     * Returns an iterable of values in the map
+     */
+    values(): IterableIterator<V>;
+}
+
+interface ReadonlyMap<K, V> {
+    /** Returns an iterable of entries in the map. */
+    [Symbol.iterator](): IterableIterator<[K, V]>;
+
+    /**
+     * Returns an iterable of key, value pairs for every entry in the map.
+     */
+    entries(): IterableIterator<[K, V]>;
+
+    /**
+     * Returns an iterable of keys in the map
+     */
+    keys(): IterableIterator<K>;
+
+    /**
+     * Returns an iterable of values in the map
+     */
     values(): IterableIterator<V>;
 }
 
@@ -5053,9 +5094,40 @@ interface WeakMapConstructor {
 }
 
 interface Set<T> {
+    /** Iterates over values in the set. */
     [Symbol.iterator](): IterableIterator<T>;
+    /**
+     * Returns an iterable of [v,v] pairs for every value `v` in the set.
+     */
     entries(): IterableIterator<[T, T]>;
+    /**
+     * Despite its name, returns an iterable of the values in the set,
+     */
     keys(): IterableIterator<T>;
+
+    /**
+     * Returns an iterable of values in the set.
+     */
+    values(): IterableIterator<T>;
+}
+
+interface ReadonlySet<T> {
+    /** Iterates over values in the set. */
+    [Symbol.iterator](): IterableIterator<T>;
+
+    /**
+     * Returns an iterable of [v,v] pairs for every value `v` in the set.
+     */
+    entries(): IterableIterator<[T, T]>;
+
+    /**
+     * Despite its name, returns an iterable of the values in the set,
+     */
+    keys(): IterableIterator<T>;
+
+    /**
+     * Returns an iterable of values in the set.
+     */
     values(): IterableIterator<T>;
 }
 
@@ -5637,7 +5709,7 @@ interface ProxyHandler<T extends object> {
     setPrototypeOf? (target: T, v: any): boolean;
     isExtensible? (target: T): boolean;
     preventExtensions? (target: T): boolean;
-    getOwnPropertyDescriptor? (target: T, p: PropertyKey): PropertyDescriptor;
+    getOwnPropertyDescriptor? (target: T, p: PropertyKey): PropertyDescriptor | undefined;
     has? (target: T, p: PropertyKey): boolean;
     get? (target: T, p: PropertyKey, receiver: any): any;
     set? (target: T, p: PropertyKey, value: any, receiver: any): boolean;

lib/tsserverlibrary.d.ts

@@ -352,9 +352,10 @@ declare namespace ts {
         SyntaxList = 294,
         NotEmittedStatement = 295,
         PartiallyEmittedExpression = 296,
-        MergeDeclarationMarker = 297,
-        EndOfDeclarationMarker = 298,
-        Count = 299,
+        CommaListExpression = 297,
+        MergeDeclarationMarker = 298,
+        EndOfDeclarationMarker = 299,
+        Count = 300,
         FirstAssignment = 58,
         LastAssignment = 70,
         FirstCompoundAssignment = 59,
@@ -482,9 +483,11 @@ declare namespace ts {
     type DeclarationName = Identifier | StringLiteral | NumericLiteral | ComputedPropertyName | BindingPattern;
     interface Declaration extends Node {
         _declarationBrand: any;
+    }
+    interface NamedDeclaration extends Declaration {
         name?: DeclarationName;
     }
-    interface DeclarationStatement extends Declaration, Statement {
+    interface DeclarationStatement extends NamedDeclaration, Statement {
         name?: Identifier | StringLiteral | NumericLiteral;
     }
     interface ComputedPropertyName extends Node {
@@ -495,7 +498,7 @@ declare namespace ts {
         kind: SyntaxKind.Decorator;
         expression: LeftHandSideExpression;
     }
-    interface TypeParameterDeclaration extends Declaration {
+    interface TypeParameterDeclaration extends NamedDeclaration {
         kind: SyntaxKind.TypeParameter;
         parent?: DeclarationWithTypeParameters;
         name: Identifier;
@@ -503,7 +506,7 @@ declare namespace ts {
         default?: TypeNode;
         expression?: Expression;
     }
-    interface SignatureDeclaration extends Declaration {
+    interface SignatureDeclaration extends NamedDeclaration {
         name?: PropertyName;
         typeParameters?: NodeArray<TypeParameterDeclaration>;
         parameters: NodeArray<ParameterDeclaration>;
@@ -516,7 +519,7 @@ declare namespace ts {
         kind: SyntaxKind.ConstructSignature;
     }
     type BindingName = Identifier | BindingPattern;
-    interface VariableDeclaration extends Declaration {
+    interface VariableDeclaration extends NamedDeclaration {
         kind: SyntaxKind.VariableDeclaration;
         parent?: VariableDeclarationList | CatchClause;
         name: BindingName;
@@ -528,7 +531,7 @@ declare namespace ts {
         parent?: VariableStatement | ForStatement | ForOfStatement | ForInStatement;
         declarations: NodeArray<VariableDeclaration>;
     }
-    interface ParameterDeclaration extends Declaration {
+    interface ParameterDeclaration extends NamedDeclaration {
         kind: SyntaxKind.Parameter;
         parent?: SignatureDeclaration;
         dotDotDotToken?: DotDotDotToken;
@@ -537,7 +540,7 @@ declare namespace ts {
         type?: TypeNode;
         initializer?: Expression;
     }
-    interface BindingElement extends Declaration {
+    interface BindingElement extends NamedDeclaration {
         kind: SyntaxKind.BindingElement;
         parent?: BindingPattern;
         propertyName?: PropertyName;
@@ -559,7 +562,7 @@ declare namespace ts {
         type?: TypeNode;
         initializer?: Expression;
     }
-    interface ObjectLiteralElement extends Declaration {
+    interface ObjectLiteralElement extends NamedDeclaration {
         _objectLiteralBrandBrand: any;
         name?: PropertyName;
     }
@@ -581,7 +584,7 @@ declare namespace ts {
         kind: SyntaxKind.SpreadAssignment;
         expression: Expression;
     }
-    interface VariableLikeDeclaration extends Declaration {
+    interface VariableLikeDeclaration extends NamedDeclaration {
         propertyName?: PropertyName;
         dotDotDotToken?: DotDotDotToken;
         name: DeclarationName;
@@ -589,7 +592,7 @@ declare namespace ts {
         type?: TypeNode;
         initializer?: Expression;
     }
-    interface PropertyLikeDeclaration extends Declaration {
+    interface PropertyLikeDeclaration extends NamedDeclaration {
         name: PropertyName;
     }
     interface ObjectBindingPattern extends Node {
@@ -926,7 +929,7 @@ declare namespace ts {
     }
     type EntityNameExpression = Identifier | PropertyAccessEntityNameExpression | ParenthesizedExpression;
     type EntityNameOrEntityNameExpression = EntityName | EntityNameExpression;
-    interface PropertyAccessExpression extends MemberExpression, Declaration {
+    interface PropertyAccessExpression extends MemberExpression, NamedDeclaration {
         kind: SyntaxKind.PropertyAccessExpression;
         expression: LeftHandSideExpression;
         name: Identifier;
@@ -991,7 +994,7 @@ declare namespace ts {
     }
     interface MetaProperty extends PrimaryExpression {
         kind: SyntaxKind.MetaProperty;
-        keywordToken: SyntaxKind;
+        keywordToken: SyntaxKind.NewKeyword;
         name: Identifier;
     }
     interface JsxElement extends PrimaryExpression {
@@ -1051,6 +1054,10 @@ declare namespace ts {
     interface NotEmittedStatement extends Statement {
         kind: SyntaxKind.NotEmittedStatement;
     }
+    interface CommaListExpression extends Expression {
+        kind: SyntaxKind.CommaListExpression;
+        elements: NodeArray<Expression>;
+    }
     interface EmptyStatement extends Statement {
         kind: SyntaxKind.EmptyStatement;
     }
@@ -1172,7 +1179,7 @@ declare namespace ts {
         block: Block;
     }
     type DeclarationWithTypeParameters = SignatureDeclaration | ClassLikeDeclaration | InterfaceDeclaration | TypeAliasDeclaration;
-    interface ClassLikeDeclaration extends Declaration {
+    interface ClassLikeDeclaration extends NamedDeclaration {
         name?: Identifier;
         typeParameters?: NodeArray<TypeParameterDeclaration>;
         heritageClauses?: NodeArray<HeritageClause>;
@@ -1185,11 +1192,11 @@ declare namespace ts {
     interface ClassExpression extends ClassLikeDeclaration, PrimaryExpression {
         kind: SyntaxKind.ClassExpression;
     }
-    interface ClassElement extends Declaration {
+    interface ClassElement extends NamedDeclaration {
         _classElementBrand: any;
         name?: PropertyName;
     }
-    interface TypeElement extends Declaration {
+    interface TypeElement extends NamedDeclaration {
         _typeElementBrand: any;
         name?: PropertyName;
         questionToken?: QuestionToken;
@@ -1213,7 +1220,7 @@ declare namespace ts {
         typeParameters?: NodeArray<TypeParameterDeclaration>;
         type: TypeNode;
     }
-    interface EnumMember extends Declaration {
+    interface EnumMember extends NamedDeclaration {
         kind: SyntaxKind.EnumMember;
         parent?: EnumDeclaration;
         name: PropertyName;
@@ -1266,13 +1273,13 @@ declare namespace ts {
         moduleSpecifier: Expression;
     }
     type NamedImportBindings = NamespaceImport | NamedImports;
-    interface ImportClause extends Declaration {
+    interface ImportClause extends NamedDeclaration {
         kind: SyntaxKind.ImportClause;
         parent?: ImportDeclaration;
         name?: Identifier;
         namedBindings?: NamedImportBindings;
     }
-    interface NamespaceImport extends Declaration {
+    interface NamespaceImport extends NamedDeclaration {
         kind: SyntaxKind.NamespaceImport;
         parent?: ImportClause;
         name: Identifier;
@@ -1298,13 +1305,13 @@ declare namespace ts {
         elements: NodeArray<ExportSpecifier>;
     }
     type NamedImportsOrExports = NamedImports | NamedExports;
-    interface ImportSpecifier extends Declaration {
+    interface ImportSpecifier extends NamedDeclaration {
         kind: SyntaxKind.ImportSpecifier;
         parent?: NamedImports;
         propertyName?: Identifier;
         name: Identifier;
     }
-    interface ExportSpecifier extends Declaration {
+    interface ExportSpecifier extends NamedDeclaration {
         kind: SyntaxKind.ExportSpecifier;
         parent?: NamedExports;
         propertyName?: Identifier;
@@ -1435,7 +1442,7 @@ declare namespace ts {
         kind: SyntaxKind.JSDocTypeTag;
         typeExpression: JSDocTypeExpression;
     }
-    interface JSDocTypedefTag extends JSDocTag, Declaration {
+    interface JSDocTypedefTag extends JSDocTag, NamedDeclaration {
         kind: SyntaxKind.JSDocTypedefTag;
         fullName?: JSDocNamespaceDeclaration | Identifier;
         name?: Identifier;
@@ -1626,11 +1633,11 @@ declare namespace ts {
         signatureToSignatureDeclaration(signature: Signature, kind: SyntaxKind, enclosingDeclaration?: Node, flags?: NodeBuilderFlags): SignatureDeclaration;
         indexInfoToIndexSignatureDeclaration(indexInfo: IndexInfo, kind: IndexKind, enclosingDeclaration?: Node, flags?: NodeBuilderFlags): IndexSignatureDeclaration;
         getSymbolsInScope(location: Node, meaning: SymbolFlags): Symbol[];
-        getSymbolAtLocation(node: Node): Symbol;
+        getSymbolAtLocation(node: Node): Symbol | undefined;
         getSymbolsOfParameterPropertyDeclaration(parameter: ParameterDeclaration, parameterName: string): Symbol[];
-        getShorthandAssignmentValueSymbol(location: Node): Symbol;
-        getExportSpecifierLocalTargetSymbol(location: ExportSpecifier): Symbol;
-        getPropertySymbolOfDestructuringAssignment(location: Identifier): Symbol;
+        getShorthandAssignmentValueSymbol(location: Node): Symbol | undefined;
+        getExportSpecifierLocalTargetSymbol(location: ExportSpecifier): Symbol | undefined;
+        getPropertySymbolOfDestructuringAssignment(location: Identifier): Symbol | undefined;
         getTypeAtLocation(node: Node): Type;
         getTypeFromTypeNode(node: TypeNode): Type;
         signatureToString(signature: Signature, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): string;
@@ -1640,37 +1647,47 @@ declare namespace ts {
         getFullyQualifiedName(symbol: Symbol): string;
         getAugmentedPropertiesOfType(type: Type): Symbol[];
         getRootSymbols(symbol: Symbol): Symbol[];
-        getContextualType(node: Expression): Type;
-        getResolvedSignature(node: CallLikeExpression, candidatesOutArray?: Signature[]): Signature;
-        getSignatureFromDeclaration(declaration: SignatureDeclaration): Signature;
-        isImplementationOfOverload(node: FunctionLikeDeclaration): boolean;
+        getContextualType(node: Expression): Type | undefined;
+        getResolvedSignature(node: CallLikeExpression, candidatesOutArray?: Signature[]): Signature | undefined;
+        getSignatureFromDeclaration(declaration: SignatureDeclaration): Signature | undefined;
+        isImplementationOfOverload(node: FunctionLikeDeclaration): boolean | undefined;
         isUndefinedSymbol(symbol: Symbol): boolean;
         isArgumentsSymbol(symbol: Symbol): boolean;
         isUnknownSymbol(symbol: Symbol): boolean;
-        getConstantValue(node: EnumMember | PropertyAccessExpression | ElementAccessExpression): number;
+        getConstantValue(node: EnumMember | PropertyAccessExpression | ElementAccessExpression): string | number | undefined;
         isValidPropertyAccess(node: PropertyAccessExpression | QualifiedName, propertyName: string): boolean;
         getAliasedSymbol(symbol: Symbol): Symbol;
         getExportsOfModule(moduleSymbol: Symbol): Symbol[];
-        getAllAttributesTypeFromJsxOpeningLikeElement(elementNode: JsxOpeningLikeElement): Type;
+        getAllAttributesTypeFromJsxOpeningLikeElement(elementNode: JsxOpeningLikeElement): Type | undefined;
         getJsxIntrinsicTagNames(): Symbol[];
         isOptionalParameter(node: ParameterDeclaration): boolean;
         getAmbientModules(): Symbol[];
         tryGetMemberInModuleExports(memberName: string, moduleSymbol: Symbol): Symbol | undefined;
         getApparentType(type: Type): Type;
+        getSuggestionForNonexistentProperty(node: Identifier, containingType: Type): string | undefined;
+        getSuggestionForNonexistentSymbol(location: Node, name: string, meaning: SymbolFlags): string | undefined;
     }
     enum NodeBuilderFlags {
         None = 0,
-        allowThisInObjectLiteral = 1,
-        allowQualifedNameInPlaceOfIdentifier = 2,
-        allowTypeParameterInQualifiedName = 4,
-        allowAnonymousIdentifier = 8,
-        allowEmptyUnionOrIntersection = 16,
-        allowEmptyTuple = 32,
+        NoTruncation = 1,
+        WriteArrayAsGenericType = 2,
+        WriteTypeArgumentsOfSignature = 32,
+        UseFullyQualifiedType = 64,
+        SuppressAnyReturnType = 256,
+        WriteTypeParametersInQualifiedName = 512,
+        AllowThisInObjectLiteral = 1024,
+        AllowQualifedNameInPlaceOfIdentifier = 2048,
+        AllowAnonymousIdentifier = 8192,
+        AllowEmptyUnionOrIntersection = 16384,
+        AllowEmptyTuple = 32768,
+        IgnoreErrors = 60416,
+        InObjectTypeLiteral = 1048576,
+        InTypeAlias = 8388608,
     }
     interface SymbolDisplayBuilder {
         buildTypeDisplay(type: Type, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
         buildSymbolDisplay(symbol: Symbol, writer: SymbolWriter, enclosingDeclaration?: Node, meaning?: SymbolFlags, flags?: SymbolFormatFlags): void;
-        buildSignatureDisplay(signatures: Signature, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): void;
+        buildSignatureDisplay(signature: Signature, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): void;
         buildIndexSignatureDisplay(info: IndexInfo, writer: SymbolWriter, kind: IndexKind, enclosingDeclaration?: Node, globalFlags?: TypeFormatFlags, symbolStack?: Symbol[]): void;
         buildParameterDisplay(parameter: Symbol, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
         buildTypeParameterDisplay(tp: TypeParameter, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
@@ -1831,18 +1848,18 @@ declare namespace ts {
         Index = 262144,
         IndexedAccess = 524288,
         NonPrimitive = 16777216,
-        Literal = 480,
+        Literal = 224,
         StringOrNumberLiteral = 96,
         PossiblyFalsy = 7406,
         StringLike = 262178,
-        NumberLike = 340,
+        NumberLike = 84,
         BooleanLike = 136,
         EnumLike = 272,
         UnionOrIntersection = 196608,
         StructuredType = 229376,
         StructuredOrTypeVariable = 1032192,
         TypeVariable = 540672,
-        Narrowable = 17810431,
+        Narrowable = 17810175,
         NotUnionOrUnit = 16810497,
     }
     type DestructuringPattern = BindingPattern | ObjectLiteralExpression | ArrayLiteralExpression;
@@ -1854,15 +1871,17 @@ declare namespace ts {
         aliasTypeArguments?: Type[];
     }
     interface LiteralType extends Type {
-        text: string;
+        value: string | number;
         freshType?: LiteralType;
         regularType?: LiteralType;
     }
-    interface EnumType extends Type {
-        memberTypes: EnumLiteralType[];
+    interface StringLiteralType extends LiteralType {
+        value: string;
     }
-    interface EnumLiteralType extends LiteralType {
-        baseType: EnumType & UnionType;
+    interface NumberLiteralType extends LiteralType {
+        value: number;
+    }
+    interface EnumType extends Type {
     }
     const enum ObjectFlags {
         Class = 1,
@@ -1896,7 +1915,7 @@ declare namespace ts {
     }
     interface TypeReference extends ObjectType {
         target: GenericType;
-        typeArguments: Type[];
+        typeArguments?: Type[];
     }
     interface GenericType extends InterfaceType, TypeReference {
     }
@@ -1932,7 +1951,7 @@ declare namespace ts {
     }
     interface Signature {
         declaration: SignatureDeclaration;
-        typeParameters: TypeParameter[];
+        typeParameters?: TypeParameter[];
         parameters: Symbol[];
     }
     const enum IndexKind {
@@ -1961,9 +1980,9 @@ declare namespace ts {
         next?: DiagnosticMessageChain;
     }
     interface Diagnostic {
-        file: SourceFile;
-        start: number;
-        length: number;
+        file: SourceFile | undefined;
+        start: number | undefined;
+        length: number | undefined;
         messageText: string | DiagnosticMessageChain;
         category: DiagnosticCategory;
         code: number;
@@ -2204,6 +2223,7 @@ declare namespace ts {
         NoHoisting = 2097152,
         HasEndOfDeclarationMarker = 4194304,
         Iterator = 8388608,
+        NoAsciiEscaping = 16777216,
     }
     interface EmitHelper {
         readonly name: string;
@@ -2362,13 +2382,13 @@ declare namespace ts {
     function isWhiteSpaceSingleLine(ch: number): boolean;
     function isLineBreak(ch: number): boolean;
     function couldStartTrivia(text: string, pos: number): boolean;
-    function forEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U;
-    function forEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U;
+    function forEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U | undefined;
+    function forEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U | undefined;
     function reduceEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T, memo: U) => U, state: T, initial: U): U;
     function reduceEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T, memo: U) => U, state: T, initial: U): U;
     function getLeadingCommentRanges(text: string, pos: number): CommentRange[] | undefined;
     function getTrailingCommentRanges(text: string, pos: number): CommentRange[] | undefined;
-    function getShebang(text: string): string;
+    function getShebang(text: string): string | undefined;
     function isIdentifierStart(ch: number, languageVersion: ScriptTarget): boolean;
     function isIdentifierPart(ch: number, languageVersion: ScriptTarget): boolean;
     function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean, languageVariant?: LanguageVariant, text?: string, onError?: ErrorCallback, start?: number, length?: number): Scanner;
@@ -2384,7 +2404,7 @@ declare namespace ts {
         error?: Diagnostic;
     };
     function parseJsonConfigFileContent(json: any, host: ParseConfigHost, basePath: string, existingOptions?: CompilerOptions, configFileName?: string, resolutionStack?: Path[], extraFileExtensions?: JsFileExtensionInfo[]): ParsedCommandLine;
-    function convertCompileOnSaveOptionFromJson(jsonOption: any, basePath: string, errors: Diagnostic[]): boolean | undefined;
+    function convertCompileOnSaveOptionFromJson(jsonOption: any, basePath: string, errors: Diagnostic[]): boolean;
     function convertCompilerOptionsFromJson(jsonOptions: any, basePath: string, configFileName?: string): {
         options: CompilerOptions;
         errors: Diagnostic[];
@@ -2395,9 +2415,6 @@ declare namespace ts {
     };
 }
 declare namespace ts {
-    interface Push<T> {
-        push(value: T): void;
-    }
     function moduleHasNonRelativeName(moduleName: string): boolean;
     function getEffectiveTypeRoots(options: CompilerOptions, host: {
         directoryExists?: (directoryName: string) => boolean;
@@ -2466,6 +2483,7 @@ declare namespace ts {
     function createLiteral(value: string | number | boolean): PrimaryExpression;
     function createNumericLiteral(value: string): NumericLiteral;
     function createIdentifier(text: string): Identifier;
+    function updateIdentifier(node: Identifier, typeArguments: NodeArray<TypeNode> | undefined): Identifier;
     function createTempVariable(recordTempVariable: ((node: Identifier) => void) | undefined): Identifier;
     function createLoopVariable(): Identifier;
     function createUniqueName(text: string): Identifier;
@@ -2480,58 +2498,19 @@ declare namespace ts {
     function updateQualifiedName(node: QualifiedName, left: EntityName, right: Identifier): QualifiedName;
     function createComputedPropertyName(expression: Expression): ComputedPropertyName;
     function updateComputedPropertyName(node: ComputedPropertyName, expression: Expression): ComputedPropertyName;
-    function createSignatureDeclaration(kind: SyntaxKind, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): SignatureDeclaration;
-    function createFunctionTypeNode(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): FunctionTypeNode;
-    function updateFunctionTypeNode(node: FunctionTypeNode, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): FunctionTypeNode;
-    function createConstructorTypeNode(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): ConstructorTypeNode;
-    function updateConstructorTypeNode(node: ConstructorTypeNode, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): ConstructorTypeNode;
-    function createCallSignatureDeclaration(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): CallSignatureDeclaration;
-    function updateCallSignatureDeclaration(node: CallSignatureDeclaration, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): CallSignatureDeclaration;
-    function createConstructSignatureDeclaration(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): ConstructSignatureDeclaration;
-    function updateConstructSignatureDeclaration(node: ConstructSignatureDeclaration, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): ConstructSignatureDeclaration;
-    function createMethodSignature(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined): MethodSignature;
-    function updateMethodSignature(node: MethodSignature, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined, name: PropertyName, questionToken: QuestionToken | undefined): MethodSignature;
-    function createKeywordTypeNode(kind: KeywordTypeNode["kind"]): KeywordTypeNode;
-    function createThisTypeNode(): ThisTypeNode;
-    function createLiteralTypeNode(literal: Expression): LiteralTypeNode;
-    function updateLiteralTypeNode(node: LiteralTypeNode, literal: Expression): LiteralTypeNode;
-    function createTypeReferenceNode(typeName: string | EntityName, typeArguments: TypeNode[] | undefined): TypeReferenceNode;
-    function updateTypeReferenceNode(node: TypeReferenceNode, typeName: EntityName, typeArguments: NodeArray<TypeNode> | undefined): TypeReferenceNode;
-    function createTypePredicateNode(parameterName: Identifier | ThisTypeNode | string, type: TypeNode): TypePredicateNode;
-    function updateTypePredicateNode(node: TypePredicateNode, parameterName: Identifier | ThisTypeNode, type: TypeNode): TypePredicateNode;
-    function createTypeQueryNode(exprName: EntityName): TypeQueryNode;
-    function updateTypeQueryNode(node: TypeQueryNode, exprName: EntityName): TypeQueryNode;
-    function createArrayTypeNode(elementType: TypeNode): ArrayTypeNode;
-    function updateArrayTypeNode(node: ArrayTypeNode, elementType: TypeNode): ArrayTypeNode;
-    function createUnionOrIntersectionTypeNode(kind: SyntaxKind.UnionType, types: TypeNode[]): UnionTypeNode;
-    function createUnionOrIntersectionTypeNode(kind: SyntaxKind.IntersectionType, types: TypeNode[]): IntersectionTypeNode;
-    function createUnionOrIntersectionTypeNode(kind: SyntaxKind.UnionType | SyntaxKind.IntersectionType, types: TypeNode[]): UnionOrIntersectionTypeNode;
-    function updateUnionOrIntersectionTypeNode(node: UnionOrIntersectionTypeNode, types: NodeArray<TypeNode>): UnionOrIntersectionTypeNode;
-    function createParenthesizedType(type: TypeNode): ParenthesizedTypeNode;
-    function updateParenthesizedType(node: ParenthesizedTypeNode, type: TypeNode): ParenthesizedTypeNode;
-    function createTypeLiteralNode(members: TypeElement[]): TypeLiteralNode;
-    function updateTypeLiteralNode(node: TypeLiteralNode, members: NodeArray<TypeElement>): TypeLiteralNode;
-    function createTupleTypeNode(elementTypes: TypeNode[]): TupleTypeNode;
-    function updateTypleTypeNode(node: TupleTypeNode, elementTypes: TypeNode[]): TupleTypeNode;
-    function createMappedTypeNode(readonlyToken: ReadonlyToken | undefined, typeParameter: TypeParameterDeclaration, questionToken: QuestionToken | undefined, type: TypeNode | undefined): MappedTypeNode;
-    function updateMappedTypeNode(node: MappedTypeNode, readonlyToken: ReadonlyToken | undefined, typeParameter: TypeParameterDeclaration, questionToken: QuestionToken | undefined, type: TypeNode | undefined): MappedTypeNode;
-    function createTypeOperatorNode(type: TypeNode): TypeOperatorNode;
-    function updateTypeOperatorNode(node: TypeOperatorNode, type: TypeNode): TypeOperatorNode;
-    function createIndexedAccessTypeNode(objectType: TypeNode, indexType: TypeNode): IndexedAccessTypeNode;
-    function updateIndexedAccessTypeNode(node: IndexedAccessTypeNode, objectType: TypeNode, indexType: TypeNode): IndexedAccessTypeNode;
     function createTypeParameterDeclaration(name: string | Identifier, constraint: TypeNode | undefined, defaultType: TypeNode | undefined): TypeParameterDeclaration;
     function updateTypeParameterDeclaration(node: TypeParameterDeclaration, name: Identifier, constraint: TypeNode | undefined, defaultType: TypeNode | undefined): TypeParameterDeclaration;
-    function createPropertySignature(name: PropertyName | string, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature;
-    function updatePropertySignature(node: PropertySignature, name: PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature;
-    function createIndexSignatureDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], type: TypeNode): IndexSignatureDeclaration;
-    function updateIndexSignatureDeclaration(node: IndexSignatureDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], type: TypeNode): IndexSignatureDeclaration;
     function createParameter(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, dotDotDotToken: DotDotDotToken | undefined, name: string | BindingName, questionToken?: QuestionToken, type?: TypeNode, initializer?: Expression): ParameterDeclaration;
     function updateParameter(node: ParameterDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, dotDotDotToken: DotDotDotToken | undefined, name: string | BindingName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): ParameterDeclaration;
     function createDecorator(expression: Expression): Decorator;
     function updateDecorator(node: Decorator, expression: Expression): Decorator;
+    function createPropertySignature(modifiers: Modifier[] | undefined, name: PropertyName | string, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature;
+    function updatePropertySignature(node: PropertySignature, modifiers: Modifier[] | undefined, name: PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature;
     function createProperty(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression): PropertyDeclaration;
     function updateProperty(node: PropertyDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: PropertyName, type: TypeNode | undefined, initializer: Expression): PropertyDeclaration;
-    function createMethodDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): MethodDeclaration;
+    function createMethodSignature(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined): MethodSignature;
+    function updateMethodSignature(node: MethodSignature, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined, name: PropertyName, questionToken: QuestionToken | undefined): MethodSignature;
+    function createMethod(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): MethodDeclaration;
     function updateMethod(node: MethodDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: PropertyName, questionToken: QuestionToken | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): MethodDeclaration;
     function createConstructor(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], body: Block | undefined): ConstructorDeclaration;
     function updateConstructor(node: ConstructorDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], body: Block | undefined): ConstructorDeclaration;
@@ -2539,6 +2518,45 @@ declare namespace ts {
     function updateGetAccessor(node: GetAccessorDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: PropertyName, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): GetAccessorDeclaration;
     function createSetAccessor(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | PropertyName, parameters: ParameterDeclaration[], body: Block | undefined): SetAccessorDeclaration;
     function updateSetAccessor(node: SetAccessorDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: PropertyName, parameters: ParameterDeclaration[], body: Block | undefined): SetAccessorDeclaration;
+    function createCallSignature(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): CallSignatureDeclaration;
+    function updateCallSignature(node: CallSignatureDeclaration, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): CallSignatureDeclaration;
+    function createConstructSignature(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): ConstructSignatureDeclaration;
+    function updateConstructSignature(node: ConstructSignatureDeclaration, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): ConstructSignatureDeclaration;
+    function createIndexSignature(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], type: TypeNode): IndexSignatureDeclaration;
+    function updateIndexSignature(node: IndexSignatureDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], type: TypeNode): IndexSignatureDeclaration;
+    function createKeywordTypeNode(kind: KeywordTypeNode["kind"]): KeywordTypeNode;
+    function createTypePredicateNode(parameterName: Identifier | ThisTypeNode | string, type: TypeNode): TypePredicateNode;
+    function updateTypePredicateNode(node: TypePredicateNode, parameterName: Identifier | ThisTypeNode, type: TypeNode): TypePredicateNode;
+    function createTypeReferenceNode(typeName: string | EntityName, typeArguments: TypeNode[] | undefined): TypeReferenceNode;
+    function updateTypeReferenceNode(node: TypeReferenceNode, typeName: EntityName, typeArguments: NodeArray<TypeNode> | undefined): TypeReferenceNode;
+    function createFunctionTypeNode(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): FunctionTypeNode;
+    function updateFunctionTypeNode(node: FunctionTypeNode, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): FunctionTypeNode;
+    function createConstructorTypeNode(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): ConstructorTypeNode;
+    function updateConstructorTypeNode(node: ConstructorTypeNode, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): ConstructorTypeNode;
+    function createTypeQueryNode(exprName: EntityName): TypeQueryNode;
+    function updateTypeQueryNode(node: TypeQueryNode, exprName: EntityName): TypeQueryNode;
+    function createTypeLiteralNode(members: TypeElement[]): TypeLiteralNode;
+    function updateTypeLiteralNode(node: TypeLiteralNode, members: NodeArray<TypeElement>): TypeLiteralNode;
+    function createArrayTypeNode(elementType: TypeNode): ArrayTypeNode;
+    function updateArrayTypeNode(node: ArrayTypeNode, elementType: TypeNode): ArrayTypeNode;
+    function createTupleTypeNode(elementTypes: TypeNode[]): TupleTypeNode;
+    function updateTypleTypeNode(node: TupleTypeNode, elementTypes: TypeNode[]): TupleTypeNode;
+    function createUnionTypeNode(types: TypeNode[]): UnionTypeNode;
+    function updateUnionTypeNode(node: UnionTypeNode, types: NodeArray<TypeNode>): UnionTypeNode;
+    function createIntersectionTypeNode(types: TypeNode[]): IntersectionTypeNode;
+    function updateIntersectionTypeNode(node: IntersectionTypeNode, types: NodeArray<TypeNode>): IntersectionTypeNode;
+    function createUnionOrIntersectionTypeNode(kind: SyntaxKind.UnionType | SyntaxKind.IntersectionType, types: TypeNode[]): UnionTypeNode | IntersectionTypeNode;
+    function createParenthesizedType(type: TypeNode): ParenthesizedTypeNode;
+    function updateParenthesizedType(node: ParenthesizedTypeNode, type: TypeNode): ParenthesizedTypeNode;
+    function createThisTypeNode(): ThisTypeNode;
+    function createTypeOperatorNode(type: TypeNode): TypeOperatorNode;
+    function updateTypeOperatorNode(node: TypeOperatorNode, type: TypeNode): TypeOperatorNode;
+    function createIndexedAccessTypeNode(objectType: TypeNode, indexType: TypeNode): IndexedAccessTypeNode;
+    function updateIndexedAccessTypeNode(node: IndexedAccessTypeNode, objectType: TypeNode, indexType: TypeNode): IndexedAccessTypeNode;
+    function createMappedTypeNode(readonlyToken: ReadonlyToken | undefined, typeParameter: TypeParameterDeclaration, questionToken: QuestionToken | undefined, type: TypeNode | undefined): MappedTypeNode;
+    function updateMappedTypeNode(node: MappedTypeNode, readonlyToken: ReadonlyToken | undefined, typeParameter: TypeParameterDeclaration, questionToken: QuestionToken | undefined, type: TypeNode | undefined): MappedTypeNode;
+    function createLiteralTypeNode(literal: Expression): LiteralTypeNode;
+    function updateLiteralTypeNode(node: LiteralTypeNode, literal: Expression): LiteralTypeNode;
     function createObjectBindingPattern(elements: BindingElement[]): ObjectBindingPattern;
     function updateObjectBindingPattern(node: ObjectBindingPattern, elements: BindingElement[]): ObjectBindingPattern;
     function createArrayBindingPattern(elements: ArrayBindingElement[]): ArrayBindingPattern;
@@ -2580,7 +2598,7 @@ declare namespace ts {
     function createPostfix(operand: Expression, operator: PostfixUnaryOperator): PostfixUnaryExpression;
     function updatePostfix(node: PostfixUnaryExpression, operand: Expression): PostfixUnaryExpression;
     function createBinary(left: Expression, operator: BinaryOperator | BinaryOperatorToken, right: Expression): BinaryExpression;
-    function updateBinary(node: BinaryExpression, left: Expression, right: Expression): BinaryExpression;
+    function updateBinary(node: BinaryExpression, left: Expression, right: Expression, operator?: BinaryOperator | BinaryOperatorToken): BinaryExpression;
     function createConditional(condition: Expression, whenTrue: Expression, whenFalse: Expression): ConditionalExpression;
     function createConditional(condition: Expression, questionToken: QuestionToken, whenTrue: Expression, colonToken: ColonToken, whenFalse: Expression): ConditionalExpression;
     function updateConditional(node: ConditionalExpression, condition: Expression, whenTrue: Expression, whenFalse: Expression): ConditionalExpression;
@@ -2600,16 +2618,15 @@ declare namespace ts {
     function updateAsExpression(node: AsExpression, expression: Expression, type: TypeNode): AsExpression;
     function createNonNullExpression(expression: Expression): NonNullExpression;
     function updateNonNullExpression(node: NonNullExpression, expression: Expression): NonNullExpression;
+    function createMetaProperty(keywordToken: MetaProperty["keywordToken"], name: Identifier): MetaProperty;
+    function updateMetaProperty(node: MetaProperty, name: Identifier): MetaProperty;
     function createTemplateSpan(expression: Expression, literal: TemplateMiddle | TemplateTail): TemplateSpan;
     function updateTemplateSpan(node: TemplateSpan, expression: Expression, literal: TemplateMiddle | TemplateTail): TemplateSpan;
+    function createSemicolonClassElement(): SemicolonClassElement;
     function createBlock(statements: Statement[], multiLine?: boolean): Block;
     function updateBlock(node: Block, statements: Statement[]): Block;
     function createVariableStatement(modifiers: Modifier[] | undefined, declarationList: VariableDeclarationList | VariableDeclaration[]): VariableStatement;
     function updateVariableStatement(node: VariableStatement, modifiers: Modifier[] | undefined, declarationList: VariableDeclarationList): VariableStatement;
-    function createVariableDeclarationList(declarations: VariableDeclaration[], flags?: NodeFlags): VariableDeclarationList;
-    function updateVariableDeclarationList(node: VariableDeclarationList, declarations: VariableDeclaration[]): VariableDeclarationList;
-    function createVariableDeclaration(name: string | BindingName, type?: TypeNode, initializer?: Expression): VariableDeclaration;
-    function updateVariableDeclaration(node: VariableDeclaration, name: BindingName, type: TypeNode | undefined, initializer: Expression | undefined): VariableDeclaration;
     function createEmptyStatement(): EmptyStatement;
     function createStatement(expression: Expression): ExpressionStatement;
     function updateStatement(node: ExpressionStatement, expression: Expression): ExpressionStatement;
@@ -2641,10 +2658,19 @@ declare namespace ts {
     function updateThrow(node: ThrowStatement, expression: Expression): ThrowStatement;
     function createTry(tryBlock: Block, catchClause: CatchClause | undefined, finallyBlock: Block | undefined): TryStatement;
     function updateTry(node: TryStatement, tryBlock: Block, catchClause: CatchClause | undefined, finallyBlock: Block | undefined): TryStatement;
+    function createDebuggerStatement(): DebuggerStatement;
+    function createVariableDeclaration(name: string | BindingName, type?: TypeNode, initializer?: Expression): VariableDeclaration;
+    function updateVariableDeclaration(node: VariableDeclaration, name: BindingName, type: TypeNode | undefined, initializer: Expression | undefined): VariableDeclaration;
+    function createVariableDeclarationList(declarations: VariableDeclaration[], flags?: NodeFlags): VariableDeclarationList;
+    function updateVariableDeclarationList(node: VariableDeclarationList, declarations: VariableDeclaration[]): VariableDeclarationList;
     function createFunctionDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: string | Identifier | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): FunctionDeclaration;
     function updateFunctionDeclaration(node: FunctionDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: Identifier | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): FunctionDeclaration;
     function createClassDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier | undefined, typeParameters: TypeParameterDeclaration[] | undefined, heritageClauses: HeritageClause[], members: ClassElement[]): ClassDeclaration;
     function updateClassDeclaration(node: ClassDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier | undefined, typeParameters: TypeParameterDeclaration[] | undefined, heritageClauses: HeritageClause[], members: ClassElement[]): ClassDeclaration;
+    function createInterfaceDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, typeParameters: TypeParameterDeclaration[] | undefined, heritageClauses: HeritageClause[] | undefined, members: TypeElement[]): InterfaceDeclaration;
+    function updateInterfaceDeclaration(node: InterfaceDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, typeParameters: TypeParameterDeclaration[] | undefined, heritageClauses: HeritageClause[] | undefined, members: TypeElement[]): InterfaceDeclaration;
+    function createTypeAliasDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, typeParameters: TypeParameterDeclaration[] | undefined, type: TypeNode): TypeAliasDeclaration;
+    function updateTypeAliasDeclaration(node: TypeAliasDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, typeParameters: TypeParameterDeclaration[] | undefined, type: TypeNode): TypeAliasDeclaration;
     function createEnumDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, members: EnumMember[]): EnumDeclaration;
     function updateEnumDeclaration(node: EnumDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, members: EnumMember[]): EnumDeclaration;
     function createModuleDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: ModuleName, body: ModuleBody | undefined, flags?: NodeFlags): ModuleDeclaration;
@@ -2653,6 +2679,8 @@ declare namespace ts {
     function updateModuleBlock(node: ModuleBlock, statements: Statement[]): ModuleBlock;
     function createCaseBlock(clauses: CaseOrDefaultClause[]): CaseBlock;
     function updateCaseBlock(node: CaseBlock, clauses: CaseOrDefaultClause[]): CaseBlock;
+    function createNamespaceExportDeclaration(name: string | Identifier): NamespaceExportDeclaration;
+    function updateNamespaceExportDeclaration(node: NamespaceExportDeclaration, name: Identifier): NamespaceExportDeclaration;
     function createImportEqualsDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, moduleReference: ModuleReference): ImportEqualsDeclaration;
     function updateImportEqualsDeclaration(node: ImportEqualsDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, moduleReference: ModuleReference): ImportEqualsDeclaration;
     function createImportDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, importClause: ImportClause | undefined, moduleSpecifier?: Expression): ImportDeclaration;
@@ -2683,20 +2711,20 @@ declare namespace ts {
     function updateJsxOpeningElement(node: JsxOpeningElement, tagName: JsxTagNameExpression, attributes: JsxAttributes): JsxOpeningElement;
     function createJsxClosingElement(tagName: JsxTagNameExpression): JsxClosingElement;
     function updateJsxClosingElement(node: JsxClosingElement, tagName: JsxTagNameExpression): JsxClosingElement;
-    function createJsxAttributes(properties: JsxAttributeLike[]): JsxAttributes;
-    function updateJsxAttributes(jsxAttributes: JsxAttributes, properties: JsxAttributeLike[]): JsxAttributes;
     function createJsxAttribute(name: Identifier, initializer: StringLiteral | JsxExpression): JsxAttribute;
     function updateJsxAttribute(node: JsxAttribute, name: Identifier, initializer: StringLiteral | JsxExpression): JsxAttribute;
+    function createJsxAttributes(properties: JsxAttributeLike[]): JsxAttributes;
+    function updateJsxAttributes(node: JsxAttributes, properties: JsxAttributeLike[]): JsxAttributes;
     function createJsxSpreadAttribute(expression: Expression): JsxSpreadAttribute;
     function updateJsxSpreadAttribute(node: JsxSpreadAttribute, expression: Expression): JsxSpreadAttribute;
     function createJsxExpression(dotDotDotToken: DotDotDotToken | undefined, expression: Expression | undefined): JsxExpression;
     function updateJsxExpression(node: JsxExpression, expression: Expression | undefined): JsxExpression;
-    function createHeritageClause(token: HeritageClause["token"], types: ExpressionWithTypeArguments[]): HeritageClause;
-    function updateHeritageClause(node: HeritageClause, types: ExpressionWithTypeArguments[]): HeritageClause;
     function createCaseClause(expression: Expression, statements: Statement[]): CaseClause;
     function updateCaseClause(node: CaseClause, expression: Expression, statements: Statement[]): CaseClause;
     function createDefaultClause(statements: Statement[]): DefaultClause;
     function updateDefaultClause(node: DefaultClause, statements: Statement[]): DefaultClause;
+    function createHeritageClause(token: HeritageClause["token"], types: ExpressionWithTypeArguments[]): HeritageClause;
+    function updateHeritageClause(node: HeritageClause, types: ExpressionWithTypeArguments[]): HeritageClause;
     function createCatchClause(variableDeclaration: string | VariableDeclaration, block: Block): CatchClause;
     function updateCatchClause(node: CatchClause, variableDeclaration: VariableDeclaration, block: Block): CatchClause;
     function createPropertyAssignment(name: string | PropertyName, initializer: Expression): PropertyAssignment;
@@ -2712,6 +2740,8 @@ declare namespace ts {
     function createNotEmittedStatement(original: Node): NotEmittedStatement;
     function createPartiallyEmittedExpression(expression: Expression, original?: Node): PartiallyEmittedExpression;
     function updatePartiallyEmittedExpression(node: PartiallyEmittedExpression, expression: Expression): PartiallyEmittedExpression;
+    function createCommaList(elements: Expression[]): CommaListExpression;
+    function updateCommaList(node: CommaListExpression, elements: Expression[]): CommaListExpression;
     function createBundle(sourceFiles: SourceFile[]): Bundle;
     function updateBundle(node: Bundle, sourceFiles: SourceFile[]): Bundle;
     function createComma(left: Expression, right: Expression): Expression;
@@ -2745,8 +2775,8 @@ declare namespace ts {
     function getSyntheticTrailingComments(node: Node): SynthesizedComment[] | undefined;
     function setSyntheticTrailingComments<T extends Node>(node: T, comments: SynthesizedComment[]): T;
     function addSyntheticTrailingComment<T extends Node>(node: T, kind: SyntaxKind.SingleLineCommentTrivia | SyntaxKind.MultiLineCommentTrivia, text: string, hasTrailingNewLine?: boolean): T;
-    function getConstantValue(node: PropertyAccessExpression | ElementAccessExpression): number;
-    function setConstantValue(node: PropertyAccessExpression | ElementAccessExpression, value: number): PropertyAccessExpression | ElementAccessExpression;
+    function getConstantValue(node: PropertyAccessExpression | ElementAccessExpression): string | number;
+    function setConstantValue(node: PropertyAccessExpression | ElementAccessExpression, value: string | number): PropertyAccessExpression | ElementAccessExpression;
     function addEmitHelper<T extends Node>(node: T, helper: EmitHelper): T;
     function addEmitHelpers<T extends Node>(node: T, helpers: EmitHelper[] | undefined): T;
     function removeEmitHelper(node: Node, helper: EmitHelper): boolean;
@@ -2756,7 +2786,7 @@ declare namespace ts {
 }
 declare namespace ts {
     function createNode(kind: SyntaxKind, pos?: number, end?: number): Node;
-    function forEachChild<T>(node: Node, cbNode: (node: Node) => T, cbNodeArray?: (nodes: Node[]) => T): T;
+    function forEachChild<T>(node: Node, cbNode: (node: Node) => T, cbNodeArray?: (nodes: Node[]) => T): T | undefined;
     function createSourceFile(fileName: string, sourceText: string, languageVersion: ScriptTarget, setParentNodes?: boolean, scriptKind?: ScriptKind): SourceFile;
     function parseIsolatedEntityName(text: string, languageVersion: ScriptTarget): EntityName;
     function isExternalModule(file: SourceFile): boolean;
@@ -2789,6 +2819,7 @@ declare namespace ts {
         getNewLine(): string;
     }
     function formatDiagnostics(diagnostics: Diagnostic[], host: FormatDiagnosticsHost): string;
+    function formatDiagnosticsWithColorAndContext(diagnostics: Diagnostic[], host: FormatDiagnosticsHost): string;
     function flattenDiagnosticMessageText(messageText: string | DiagnosticMessageChain, newLine: string): string;
     function createProgram(rootNames: string[], options: CompilerOptions, host?: CompilerHost, oldProgram?: Program): Program;
 }
@@ -2931,6 +2962,8 @@ declare namespace ts {
         getDocCommentTemplateAtPosition(fileName: string, position: number): TextInsertion;
         isValidBraceCompletionAtPosition(fileName: string, position: number, openingBrace: number): boolean;
         getCodeFixesAtPosition(fileName: string, start: number, end: number, errorCodes: number[], formatOptions: FormatCodeSettings): CodeAction[];
+        getApplicableRefactors(fileName: string, positionOrRaneg: number | TextRange): ApplicableRefactorInfo[];
+        getRefactorCodeActions(fileName: string, formatOptions: FormatCodeSettings, positionOrRange: number | TextRange, refactorName: string): CodeAction[] | undefined;
         getEmitOutput(fileName: string, emitOnlyDtsFiles?: boolean): EmitOutput;
         getProgram(): Program;
         dispose(): void;
@@ -2981,6 +3014,10 @@ declare namespace ts {
         description: string;
         changes: FileTextChanges[];
     }
+    interface ApplicableRefactorInfo {
+        name: string;
+        description: string;
+    }
     interface TextInsertion {
         newText: string;
         caretOffset: number;
@@ -3367,6 +3404,7 @@ declare namespace ts {
         reportDiagnostics?: boolean;
         moduleName?: string;
         renamedDependencies?: MapLike<string>;
+        transformers?: CustomTransformers;
     }
     interface TranspileOutput {
         outputText: string;
@@ -3610,6 +3648,9 @@ declare namespace ts.server.protocol {
         type CompilerOptionsForInferredProjects = "compilerOptionsForInferredProjects";
         type GetCodeFixes = "getCodeFixes";
         type GetSupportedCodeFixes = "getSupportedCodeFixes";
+        type GetApplicableRefactors = "getApplicableRefactors";
+        type GetRefactorCodeActions = "getRefactorCodeActions";
+        type GetRefactorCodeActionsFull = "getRefactorCodeActions-full";
     }
     interface Message {
         seq: number;
@@ -3704,15 +3745,44 @@ declare namespace ts.server.protocol {
         line: number;
         offset: number;
     }
+    type FileLocationOrRangeRequestArgs = FileLocationRequestArgs | FileRangeRequestArgs;
+    interface GetApplicableRefactorsRequest extends Request {
+        command: CommandTypes.GetApplicableRefactors;
+        arguments: GetApplicableRefactorsRequestArgs;
+    }
+    type GetApplicableRefactorsRequestArgs = FileLocationOrRangeRequestArgs;
+    interface ApplicableRefactorInfo {
+        name: string;
+        description: string;
+    }
+    interface GetApplicableRefactorsResponse extends Response {
+        body?: ApplicableRefactorInfo[];
+    }
+    interface GetRefactorCodeActionsRequest extends Request {
+        command: CommandTypes.GetRefactorCodeActions;
+        arguments: GetRefactorCodeActionsRequestArgs;
+    }
+    type GetRefactorCodeActionsRequestArgs = FileLocationOrRangeRequestArgs & {
+        refactorName: string;
+    };
+    type RefactorCodeActions = {
+        actions: protocol.CodeAction[];
+        renameLocation?: number;
+    };
+    interface GetRefactorCodeActionsResponse extends Response {
+        body: RefactorCodeActions;
+    }
     interface CodeFixRequest extends Request {
         command: CommandTypes.GetCodeFixes;
         arguments: CodeFixRequestArgs;
     }
-    interface CodeFixRequestArgs extends FileRequestArgs {
+    interface FileRangeRequestArgs extends FileRequestArgs {
         startLine: number;
         startOffset: number;
         endLine: number;
         endOffset: number;
+    }
+    interface CodeFixRequestArgs extends FileRangeRequestArgs {
         errorCodes?: number[];
     }
     interface GetCodeFixesResponse extends Response {
@@ -4291,6 +4361,7 @@ declare namespace ts.server.protocol {
         insertSpaceAfterOpeningAndBeforeClosingNonemptyBraces?: boolean;
         insertSpaceAfterOpeningAndBeforeClosingTemplateStringBraces?: boolean;
         insertSpaceAfterOpeningAndBeforeClosingJsxExpressionBraces?: boolean;
+        insertSpaceAfterTypeAssertion?: boolean;
         insertSpaceBeforeFunctionParenthesis?: boolean;
         placeOpenBraceOnNewLineForFunctions?: boolean;
         placeOpenBraceOnNewLineForControlBlocks?: boolean;
@@ -4408,7 +4479,7 @@ declare namespace ts.server {
         project: Project;
     }
     interface EventSender {
-        event(payload: any, eventName: string): void;
+        event<T>(payload: T, eventName: string): void;
     }
     namespace CommandNames {
         const Brace: protocol.CommandTypes.Brace;
@@ -4455,6 +4526,9 @@ declare namespace ts.server {
         const CompilerOptionsForInferredProjects: protocol.CommandTypes.CompilerOptionsForInferredProjects;
         const GetCodeFixes: protocol.CommandTypes.GetCodeFixes;
         const GetSupportedCodeFixes: protocol.CommandTypes.GetSupportedCodeFixes;
+        const GetApplicableRefactors: protocol.CommandTypes.GetApplicableRefactors;
+        const GetRefactorCodeActions: protocol.CommandTypes.GetRefactorCodeActions;
+        const GetRefactorCodeActionsFull: protocol.CommandTypes.GetRefactorCodeActionsFull;
     }
     function formatMessage<T extends protocol.Message>(msg: T, logger: server.Logger, byteLength: (s: string, encoding: string) => number, newLine: string): string;
     interface SessionOptions {
@@ -4470,6 +4544,7 @@ declare namespace ts.server {
         throttleWaitMilliseconds?: number;
         globalPlugins?: string[];
         pluginProbeLocations?: string[];
+        allowLocalPluginLoads?: boolean;
     }
     class Session implements EventSender {
         private readonly gcTimer;
@@ -4491,7 +4566,7 @@ declare namespace ts.server {
         logError(err: Error, cmd: string): void;
         send(msg: protocol.Message): void;
         configFileDiagnosticEvent(triggerFile: string, configFile: string, diagnostics: ts.Diagnostic[]): void;
-        event(info: any, eventName: string): void;
+        event<T>(info: T, eventName: string): void;
         output(info: any, cmdName: string, reqSeq?: number, errorMsg?: string): void;
         private semanticCheck(file, project);
         private syntacticCheck(file, project);
@@ -4554,7 +4629,12 @@ declare namespace ts.server {
         private getNavigationTree(args, simplifiedResult);
         private getNavigateToItems(args, simplifiedResult);
         private getSupportedCodeFixes();
+        private isLocation(locationOrSpan);
+        private extractPositionAndRange(args, scriptInfo);
+        private getApplicableRefactors(args);
+        private getRefactorCodeActions(args, simplifiedResult);
         private getCodeFixes(args, simplifiedResult);
+        private getStartAndEndPosition(args, scriptInfo);
         private mapCodeAction(codeAction, scriptInfo);
         private convertTextChangeToCodeEdit(change, scriptInfo);
         private getBraceMatching(args, simplifiedResult);
@@ -5047,6 +5127,7 @@ declare namespace ts.server {
         throttleWaitMilliseconds?: number;
         globalPlugins?: string[];
         pluginProbeLocations?: string[];
+        allowLocalPluginLoads?: boolean;
     }
     class ProjectService {
         readonly typingsCache: TypingsCache;
@@ -5076,6 +5157,7 @@ declare namespace ts.server {
         private readonly eventHandler?;
         readonly globalPlugins: ReadonlyArray<string>;
         readonly pluginProbeLocations: ReadonlyArray<string>;
+        readonly allowLocalPluginLoads: boolean;
         constructor(opts: ProjectServiceOptions);
         ensureInferredProjectsUpToDate_TestOnly(): void;
         getCompilerOptionsForInferredProjects(): CompilerOptions;

lib/typescript.d.ts

@@ -359,9 +359,10 @@ declare namespace ts {
         SyntaxList = 294,
         NotEmittedStatement = 295,
         PartiallyEmittedExpression = 296,
-        MergeDeclarationMarker = 297,
-        EndOfDeclarationMarker = 298,
-        Count = 299,
+        CommaListExpression = 297,
+        MergeDeclarationMarker = 298,
+        EndOfDeclarationMarker = 299,
+        Count = 300,
         FirstAssignment = 58,
         LastAssignment = 70,
         FirstCompoundAssignment = 59,
@@ -474,6 +475,10 @@ declare namespace ts {
     type ModifiersArray = NodeArray<Modifier>;
     interface Identifier extends PrimaryExpression {
         kind: SyntaxKind.Identifier;
+        /**
+         * Text of identifier (with escapes converted to characters).
+         * If the identifier begins with two underscores, this will begin with three.
+         */
         text: string;
         originalKeywordKind?: SyntaxKind;
         isInJSDocNamespace?: boolean;
@@ -491,9 +496,11 @@ declare namespace ts {
     type DeclarationName = Identifier | StringLiteral | NumericLiteral | ComputedPropertyName | BindingPattern;
     interface Declaration extends Node {
         _declarationBrand: any;
+    }
+    interface NamedDeclaration extends Declaration {
         name?: DeclarationName;
     }
-    interface DeclarationStatement extends Declaration, Statement {
+    interface DeclarationStatement extends NamedDeclaration, Statement {
         name?: Identifier | StringLiteral | NumericLiteral;
     }
     interface ComputedPropertyName extends Node {
@@ -504,7 +511,7 @@ declare namespace ts {
         kind: SyntaxKind.Decorator;
         expression: LeftHandSideExpression;
     }
-    interface TypeParameterDeclaration extends Declaration {
+    interface TypeParameterDeclaration extends NamedDeclaration {
         kind: SyntaxKind.TypeParameter;
         parent?: DeclarationWithTypeParameters;
         name: Identifier;
@@ -512,7 +519,7 @@ declare namespace ts {
         default?: TypeNode;
         expression?: Expression;
     }
-    interface SignatureDeclaration extends Declaration {
+    interface SignatureDeclaration extends NamedDeclaration {
         name?: PropertyName;
         typeParameters?: NodeArray<TypeParameterDeclaration>;
         parameters: NodeArray<ParameterDeclaration>;
@@ -525,7 +532,7 @@ declare namespace ts {
         kind: SyntaxKind.ConstructSignature;
     }
     type BindingName = Identifier | BindingPattern;
-    interface VariableDeclaration extends Declaration {
+    interface VariableDeclaration extends NamedDeclaration {
         kind: SyntaxKind.VariableDeclaration;
         parent?: VariableDeclarationList | CatchClause;
         name: BindingName;
@@ -537,7 +544,7 @@ declare namespace ts {
         parent?: VariableStatement | ForStatement | ForOfStatement | ForInStatement;
         declarations: NodeArray<VariableDeclaration>;
     }
-    interface ParameterDeclaration extends Declaration {
+    interface ParameterDeclaration extends NamedDeclaration {
         kind: SyntaxKind.Parameter;
         parent?: SignatureDeclaration;
         dotDotDotToken?: DotDotDotToken;
@@ -546,7 +553,7 @@ declare namespace ts {
         type?: TypeNode;
         initializer?: Expression;
     }
-    interface BindingElement extends Declaration {
+    interface BindingElement extends NamedDeclaration {
         kind: SyntaxKind.BindingElement;
         parent?: BindingPattern;
         propertyName?: PropertyName;
@@ -568,7 +575,7 @@ declare namespace ts {
         type?: TypeNode;
         initializer?: Expression;
     }
-    interface ObjectLiteralElement extends Declaration {
+    interface ObjectLiteralElement extends NamedDeclaration {
         _objectLiteralBrandBrand: any;
         name?: PropertyName;
     }
@@ -590,7 +597,7 @@ declare namespace ts {
         kind: SyntaxKind.SpreadAssignment;
         expression: Expression;
     }
-    interface VariableLikeDeclaration extends Declaration {
+    interface VariableLikeDeclaration extends NamedDeclaration {
         propertyName?: PropertyName;
         dotDotDotToken?: DotDotDotToken;
         name: DeclarationName;
@@ -598,7 +605,7 @@ declare namespace ts {
         type?: TypeNode;
         initializer?: Expression;
     }
-    interface PropertyLikeDeclaration extends Declaration {
+    interface PropertyLikeDeclaration extends NamedDeclaration {
         name: PropertyName;
     }
     interface ObjectBindingPattern extends Node {
@@ -950,7 +957,7 @@ declare namespace ts {
     }
     type EntityNameExpression = Identifier | PropertyAccessEntityNameExpression | ParenthesizedExpression;
     type EntityNameOrEntityNameExpression = EntityName | EntityNameExpression;
-    interface PropertyAccessExpression extends MemberExpression, Declaration {
+    interface PropertyAccessExpression extends MemberExpression, NamedDeclaration {
         kind: SyntaxKind.PropertyAccessExpression;
         expression: LeftHandSideExpression;
         name: Identifier;
@@ -1016,7 +1023,7 @@ declare namespace ts {
     }
     interface MetaProperty extends PrimaryExpression {
         kind: SyntaxKind.MetaProperty;
-        keywordToken: SyntaxKind;
+        keywordToken: SyntaxKind.NewKeyword;
         name: Identifier;
     }
     interface JsxElement extends PrimaryExpression {
@@ -1076,6 +1083,13 @@ declare namespace ts {
     interface NotEmittedStatement extends Statement {
         kind: SyntaxKind.NotEmittedStatement;
     }
+    /**
+     * A list of comma-seperated expressions. This node is only created by transformations.
+     */
+    interface CommaListExpression extends Expression {
+        kind: SyntaxKind.CommaListExpression;
+        elements: NodeArray<Expression>;
+    }
     interface EmptyStatement extends Statement {
         kind: SyntaxKind.EmptyStatement;
     }
@@ -1197,7 +1211,7 @@ declare namespace ts {
         block: Block;
     }
     type DeclarationWithTypeParameters = SignatureDeclaration | ClassLikeDeclaration | InterfaceDeclaration | TypeAliasDeclaration;
-    interface ClassLikeDeclaration extends Declaration {
+    interface ClassLikeDeclaration extends NamedDeclaration {
         name?: Identifier;
         typeParameters?: NodeArray<TypeParameterDeclaration>;
         heritageClauses?: NodeArray<HeritageClause>;
@@ -1210,11 +1224,11 @@ declare namespace ts {
     interface ClassExpression extends ClassLikeDeclaration, PrimaryExpression {
         kind: SyntaxKind.ClassExpression;
     }
-    interface ClassElement extends Declaration {
+    interface ClassElement extends NamedDeclaration {
         _classElementBrand: any;
         name?: PropertyName;
     }
-    interface TypeElement extends Declaration {
+    interface TypeElement extends NamedDeclaration {
         _typeElementBrand: any;
         name?: PropertyName;
         questionToken?: QuestionToken;
@@ -1238,7 +1252,7 @@ declare namespace ts {
         typeParameters?: NodeArray<TypeParameterDeclaration>;
         type: TypeNode;
     }
-    interface EnumMember extends Declaration {
+    interface EnumMember extends NamedDeclaration {
         kind: SyntaxKind.EnumMember;
         parent?: EnumDeclaration;
         name: PropertyName;
@@ -1297,13 +1311,13 @@ declare namespace ts {
         moduleSpecifier: Expression;
     }
     type NamedImportBindings = NamespaceImport | NamedImports;
-    interface ImportClause extends Declaration {
+    interface ImportClause extends NamedDeclaration {
         kind: SyntaxKind.ImportClause;
         parent?: ImportDeclaration;
         name?: Identifier;
         namedBindings?: NamedImportBindings;
     }
-    interface NamespaceImport extends Declaration {
+    interface NamespaceImport extends NamedDeclaration {
         kind: SyntaxKind.NamespaceImport;
         parent?: ImportClause;
         name: Identifier;
@@ -1330,13 +1344,13 @@ declare namespace ts {
         elements: NodeArray<ExportSpecifier>;
     }
     type NamedImportsOrExports = NamedImports | NamedExports;
-    interface ImportSpecifier extends Declaration {
+    interface ImportSpecifier extends NamedDeclaration {
         kind: SyntaxKind.ImportSpecifier;
         parent?: NamedImports;
         propertyName?: Identifier;
         name: Identifier;
     }
-    interface ExportSpecifier extends Declaration {
+    interface ExportSpecifier extends NamedDeclaration {
         kind: SyntaxKind.ExportSpecifier;
         parent?: NamedExports;
         propertyName?: Identifier;
@@ -1467,7 +1481,7 @@ declare namespace ts {
         kind: SyntaxKind.JSDocTypeTag;
         typeExpression: JSDocTypeExpression;
     }
-    interface JSDocTypedefTag extends JSDocTag, Declaration {
+    interface JSDocTypedefTag extends JSDocTag, NamedDeclaration {
         kind: SyntaxKind.JSDocTypedefTag;
         fullName?: JSDocNamespaceDeclaration | Identifier;
         name?: Identifier;
@@ -1706,11 +1720,11 @@ declare namespace ts {
         /** Note that the resulting nodes cannot be checked. */
         indexInfoToIndexSignatureDeclaration(indexInfo: IndexInfo, kind: IndexKind, enclosingDeclaration?: Node, flags?: NodeBuilderFlags): IndexSignatureDeclaration;
         getSymbolsInScope(location: Node, meaning: SymbolFlags): Symbol[];
-        getSymbolAtLocation(node: Node): Symbol;
+        getSymbolAtLocation(node: Node): Symbol | undefined;
         getSymbolsOfParameterPropertyDeclaration(parameter: ParameterDeclaration, parameterName: string): Symbol[];
-        getShorthandAssignmentValueSymbol(location: Node): Symbol;
-        getExportSpecifierLocalTargetSymbol(location: ExportSpecifier): Symbol;
-        getPropertySymbolOfDestructuringAssignment(location: Identifier): Symbol;
+        getShorthandAssignmentValueSymbol(location: Node): Symbol | undefined;
+        getExportSpecifierLocalTargetSymbol(location: ExportSpecifier): Symbol | undefined;
+        getPropertySymbolOfDestructuringAssignment(location: Identifier): Symbol | undefined;
         getTypeAtLocation(node: Node): Type;
         getTypeFromTypeNode(node: TypeNode): Type;
         signatureToString(signature: Signature, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): string;
@@ -1720,38 +1734,48 @@ declare namespace ts {
         getFullyQualifiedName(symbol: Symbol): string;
         getAugmentedPropertiesOfType(type: Type): Symbol[];
         getRootSymbols(symbol: Symbol): Symbol[];
-        getContextualType(node: Expression): Type;
-        getResolvedSignature(node: CallLikeExpression, candidatesOutArray?: Signature[]): Signature;
-        getSignatureFromDeclaration(declaration: SignatureDeclaration): Signature;
-        isImplementationOfOverload(node: FunctionLikeDeclaration): boolean;
+        getContextualType(node: Expression): Type | undefined;
+        getResolvedSignature(node: CallLikeExpression, candidatesOutArray?: Signature[]): Signature | undefined;
+        getSignatureFromDeclaration(declaration: SignatureDeclaration): Signature | undefined;
+        isImplementationOfOverload(node: FunctionLikeDeclaration): boolean | undefined;
         isUndefinedSymbol(symbol: Symbol): boolean;
         isArgumentsSymbol(symbol: Symbol): boolean;
         isUnknownSymbol(symbol: Symbol): boolean;
-        getConstantValue(node: EnumMember | PropertyAccessExpression | ElementAccessExpression): number;
+        getConstantValue(node: EnumMember | PropertyAccessExpression | ElementAccessExpression): string | number | undefined;
         isValidPropertyAccess(node: PropertyAccessExpression | QualifiedName, propertyName: string): boolean;
         /** Follow all aliases to get the original symbol. */
         getAliasedSymbol(symbol: Symbol): Symbol;
         getExportsOfModule(moduleSymbol: Symbol): Symbol[];
-        getAllAttributesTypeFromJsxOpeningLikeElement(elementNode: JsxOpeningLikeElement): Type;
+        getAllAttributesTypeFromJsxOpeningLikeElement(elementNode: JsxOpeningLikeElement): Type | undefined;
         getJsxIntrinsicTagNames(): Symbol[];
         isOptionalParameter(node: ParameterDeclaration): boolean;
         getAmbientModules(): Symbol[];
         tryGetMemberInModuleExports(memberName: string, moduleSymbol: Symbol): Symbol | undefined;
         getApparentType(type: Type): Type;
+        getSuggestionForNonexistentProperty(node: Identifier, containingType: Type): string | undefined;
+        getSuggestionForNonexistentSymbol(location: Node, name: string, meaning: SymbolFlags): string | undefined;
     }
     enum NodeBuilderFlags {
         None = 0,
-        allowThisInObjectLiteral = 1,
-        allowQualifedNameInPlaceOfIdentifier = 2,
-        allowTypeParameterInQualifiedName = 4,
-        allowAnonymousIdentifier = 8,
-        allowEmptyUnionOrIntersection = 16,
-        allowEmptyTuple = 32,
+        NoTruncation = 1,
+        WriteArrayAsGenericType = 2,
+        WriteTypeArgumentsOfSignature = 32,
+        UseFullyQualifiedType = 64,
+        SuppressAnyReturnType = 256,
+        WriteTypeParametersInQualifiedName = 512,
+        AllowThisInObjectLiteral = 1024,
+        AllowQualifedNameInPlaceOfIdentifier = 2048,
+        AllowAnonymousIdentifier = 8192,
+        AllowEmptyUnionOrIntersection = 16384,
+        AllowEmptyTuple = 32768,
+        IgnoreErrors = 60416,
+        InObjectTypeLiteral = 1048576,
+        InTypeAlias = 8388608,
     }
     interface SymbolDisplayBuilder {
         buildTypeDisplay(type: Type, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
         buildSymbolDisplay(symbol: Symbol, writer: SymbolWriter, enclosingDeclaration?: Node, meaning?: SymbolFlags, flags?: SymbolFormatFlags): void;
-        buildSignatureDisplay(signatures: Signature, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): void;
+        buildSignatureDisplay(signature: Signature, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): void;
         buildIndexSignatureDisplay(info: IndexInfo, writer: SymbolWriter, kind: IndexKind, enclosingDeclaration?: Node, globalFlags?: TypeFormatFlags, symbolStack?: Symbol[]): void;
         buildParameterDisplay(parameter: Symbol, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
         buildTypeParameterDisplay(tp: TypeParameter, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
@@ -1912,18 +1936,18 @@ declare namespace ts {
         Index = 262144,
         IndexedAccess = 524288,
         NonPrimitive = 16777216,
-        Literal = 480,
+        Literal = 224,
         StringOrNumberLiteral = 96,
         PossiblyFalsy = 7406,
         StringLike = 262178,
-        NumberLike = 340,
+        NumberLike = 84,
         BooleanLike = 136,
         EnumLike = 272,
         UnionOrIntersection = 196608,
         StructuredType = 229376,
         StructuredOrTypeVariable = 1032192,
         TypeVariable = 540672,
-        Narrowable = 17810431,
+        Narrowable = 17810175,
         NotUnionOrUnit = 16810497,
     }
     type DestructuringPattern = BindingPattern | ObjectLiteralExpression | ArrayLiteralExpression;
@@ -1935,15 +1959,17 @@ declare namespace ts {
         aliasTypeArguments?: Type[];
     }
     interface LiteralType extends Type {
-        text: string;
+        value: string | number;
         freshType?: LiteralType;
         regularType?: LiteralType;
     }
-    interface EnumType extends Type {
-        memberTypes: EnumLiteralType[];
+    interface StringLiteralType extends LiteralType {
+        value: string;
     }
-    interface EnumLiteralType extends LiteralType {
-        baseType: EnumType & UnionType;
+    interface NumberLiteralType extends LiteralType {
+        value: number;
+    }
+    interface EnumType extends Type {
     }
     enum ObjectFlags {
         Class = 1,
@@ -1988,7 +2014,7 @@ declare namespace ts {
      */
     interface TypeReference extends ObjectType {
         target: GenericType;
-        typeArguments: Type[];
+        typeArguments?: Type[];
     }
     interface GenericType extends InterfaceType, TypeReference {
     }
@@ -2024,7 +2050,7 @@ declare namespace ts {
     }
     interface Signature {
         declaration: SignatureDeclaration;
-        typeParameters: TypeParameter[];
+        typeParameters?: TypeParameter[];
         parameters: Symbol[];
     }
     enum IndexKind {
@@ -2059,9 +2085,9 @@ declare namespace ts {
         next?: DiagnosticMessageChain;
     }
     interface Diagnostic {
-        file: SourceFile;
-        start: number;
-        length: number;
+        file: SourceFile | undefined;
+        start: number | undefined;
+        length: number | undefined;
         messageText: string | DiagnosticMessageChain;
         category: DiagnosticCategory;
         code: number;
@@ -2329,6 +2355,7 @@ declare namespace ts {
         NoHoisting = 2097152,
         HasEndOfDeclarationMarker = 4194304,
         Iterator = 8388608,
+        NoAsciiEscaping = 16777216,
     }
     interface EmitHelper {
         readonly name: string;
@@ -2611,14 +2638,14 @@ declare namespace ts {
     function isWhiteSpaceSingleLine(ch: number): boolean;
     function isLineBreak(ch: number): boolean;
     function couldStartTrivia(text: string, pos: number): boolean;
-    function forEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U;
-    function forEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U;
+    function forEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U | undefined;
+    function forEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U | undefined;
     function reduceEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T, memo: U) => U, state: T, initial: U): U;
     function reduceEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T, memo: U) => U, state: T, initial: U): U;
     function getLeadingCommentRanges(text: string, pos: number): CommentRange[] | undefined;
     function getTrailingCommentRanges(text: string, pos: number): CommentRange[] | undefined;
     /** Optionally, get the shebang */
-    function getShebang(text: string): string;
+    function getShebang(text: string): string | undefined;
     function isIdentifierStart(ch: number, languageVersion: ScriptTarget): boolean;
     function isIdentifierPart(ch: number, languageVersion: ScriptTarget): boolean;
     function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean, languageVariant?: LanguageVariant, text?: string, onError?: ErrorCallback, start?: number, length?: number): Scanner;
@@ -2709,6 +2736,7 @@ declare namespace ts {
     function createLiteral(value: string | number | boolean): PrimaryExpression;
     function createNumericLiteral(value: string): NumericLiteral;
     function createIdentifier(text: string): Identifier;
+    function updateIdentifier(node: Identifier, typeArguments: NodeArray<TypeNode> | undefined): Identifier;
     /** Create a unique temporary variable. */
     function createTempVariable(recordTempVariable: ((node: Identifier) => void) | undefined): Identifier;
     /** Create a unique temporary variable for use in a loop. */
@@ -2727,58 +2755,19 @@ declare namespace ts {
     function updateQualifiedName(node: QualifiedName, left: EntityName, right: Identifier): QualifiedName;
     function createComputedPropertyName(expression: Expression): ComputedPropertyName;
     function updateComputedPropertyName(node: ComputedPropertyName, expression: Expression): ComputedPropertyName;
-    function createSignatureDeclaration(kind: SyntaxKind, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): SignatureDeclaration;
-    function createFunctionTypeNode(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): FunctionTypeNode;
-    function updateFunctionTypeNode(node: FunctionTypeNode, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): FunctionTypeNode;
-    function createConstructorTypeNode(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): ConstructorTypeNode;
-    function updateConstructorTypeNode(node: ConstructorTypeNode, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): ConstructorTypeNode;
-    function createCallSignatureDeclaration(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): CallSignatureDeclaration;
-    function updateCallSignatureDeclaration(node: CallSignatureDeclaration, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): CallSignatureDeclaration;
-    function createConstructSignatureDeclaration(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): ConstructSignatureDeclaration;
-    function updateConstructSignatureDeclaration(node: ConstructSignatureDeclaration, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): ConstructSignatureDeclaration;
-    function createMethodSignature(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined): MethodSignature;
-    function updateMethodSignature(node: MethodSignature, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined, name: PropertyName, questionToken: QuestionToken | undefined): MethodSignature;
-    function createKeywordTypeNode(kind: KeywordTypeNode["kind"]): KeywordTypeNode;
-    function createThisTypeNode(): ThisTypeNode;
-    function createLiteralTypeNode(literal: Expression): LiteralTypeNode;
-    function updateLiteralTypeNode(node: LiteralTypeNode, literal: Expression): LiteralTypeNode;
-    function createTypeReferenceNode(typeName: string | EntityName, typeArguments: TypeNode[] | undefined): TypeReferenceNode;
-    function updateTypeReferenceNode(node: TypeReferenceNode, typeName: EntityName, typeArguments: NodeArray<TypeNode> | undefined): TypeReferenceNode;
-    function createTypePredicateNode(parameterName: Identifier | ThisTypeNode | string, type: TypeNode): TypePredicateNode;
-    function updateTypePredicateNode(node: TypePredicateNode, parameterName: Identifier | ThisTypeNode, type: TypeNode): TypePredicateNode;
-    function createTypeQueryNode(exprName: EntityName): TypeQueryNode;
-    function updateTypeQueryNode(node: TypeQueryNode, exprName: EntityName): TypeQueryNode;
-    function createArrayTypeNode(elementType: TypeNode): ArrayTypeNode;
-    function updateArrayTypeNode(node: ArrayTypeNode, elementType: TypeNode): ArrayTypeNode;
-    function createUnionOrIntersectionTypeNode(kind: SyntaxKind.UnionType, types: TypeNode[]): UnionTypeNode;
-    function createUnionOrIntersectionTypeNode(kind: SyntaxKind.IntersectionType, types: TypeNode[]): IntersectionTypeNode;
-    function createUnionOrIntersectionTypeNode(kind: SyntaxKind.UnionType | SyntaxKind.IntersectionType, types: TypeNode[]): UnionOrIntersectionTypeNode;
-    function updateUnionOrIntersectionTypeNode(node: UnionOrIntersectionTypeNode, types: NodeArray<TypeNode>): UnionOrIntersectionTypeNode;
-    function createParenthesizedType(type: TypeNode): ParenthesizedTypeNode;
-    function updateParenthesizedType(node: ParenthesizedTypeNode, type: TypeNode): ParenthesizedTypeNode;
-    function createTypeLiteralNode(members: TypeElement[]): TypeLiteralNode;
-    function updateTypeLiteralNode(node: TypeLiteralNode, members: NodeArray<TypeElement>): TypeLiteralNode;
-    function createTupleTypeNode(elementTypes: TypeNode[]): TupleTypeNode;
-    function updateTypleTypeNode(node: TupleTypeNode, elementTypes: TypeNode[]): TupleTypeNode;
-    function createMappedTypeNode(readonlyToken: ReadonlyToken | undefined, typeParameter: TypeParameterDeclaration, questionToken: QuestionToken | undefined, type: TypeNode | undefined): MappedTypeNode;
-    function updateMappedTypeNode(node: MappedTypeNode, readonlyToken: ReadonlyToken | undefined, typeParameter: TypeParameterDeclaration, questionToken: QuestionToken | undefined, type: TypeNode | undefined): MappedTypeNode;
-    function createTypeOperatorNode(type: TypeNode): TypeOperatorNode;
-    function updateTypeOperatorNode(node: TypeOperatorNode, type: TypeNode): TypeOperatorNode;
-    function createIndexedAccessTypeNode(objectType: TypeNode, indexType: TypeNode): IndexedAccessTypeNode;
-    function updateIndexedAccessTypeNode(node: IndexedAccessTypeNode, objectType: TypeNode, indexType: TypeNode): IndexedAccessTypeNode;
     function createTypeParameterDeclaration(name: string | Identifier, constraint: TypeNode | undefined, defaultType: TypeNode | undefined): TypeParameterDeclaration;
     function updateTypeParameterDeclaration(node: TypeParameterDeclaration, name: Identifier, constraint: TypeNode | undefined, defaultType: TypeNode | undefined): TypeParameterDeclaration;
-    function createPropertySignature(name: PropertyName | string, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature;
-    function updatePropertySignature(node: PropertySignature, name: PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature;
-    function createIndexSignatureDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], type: TypeNode): IndexSignatureDeclaration;
-    function updateIndexSignatureDeclaration(node: IndexSignatureDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], type: TypeNode): IndexSignatureDeclaration;
     function createParameter(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, dotDotDotToken: DotDotDotToken | undefined, name: string | BindingName, questionToken?: QuestionToken, type?: TypeNode, initializer?: Expression): ParameterDeclaration;
     function updateParameter(node: ParameterDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, dotDotDotToken: DotDotDotToken | undefined, name: string | BindingName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): ParameterDeclaration;
     function createDecorator(expression: Expression): Decorator;
     function updateDecorator(node: Decorator, expression: Expression): Decorator;
+    function createPropertySignature(modifiers: Modifier[] | undefined, name: PropertyName | string, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature;
+    function updatePropertySignature(node: PropertySignature, modifiers: Modifier[] | undefined, name: PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature;
     function createProperty(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression): PropertyDeclaration;
     function updateProperty(node: PropertyDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: PropertyName, type: TypeNode | undefined, initializer: Expression): PropertyDeclaration;
-    function createMethodDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): MethodDeclaration;
+    function createMethodSignature(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined): MethodSignature;
+    function updateMethodSignature(node: MethodSignature, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined, name: PropertyName, questionToken: QuestionToken | undefined): MethodSignature;
+    function createMethod(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): MethodDeclaration;
     function updateMethod(node: MethodDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: PropertyName, questionToken: QuestionToken | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): MethodDeclaration;
     function createConstructor(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], body: Block | undefined): ConstructorDeclaration;
     function updateConstructor(node: ConstructorDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], body: Block | undefined): ConstructorDeclaration;
@@ -2786,6 +2775,45 @@ declare namespace ts {
     function updateGetAccessor(node: GetAccessorDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: PropertyName, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): GetAccessorDeclaration;
     function createSetAccessor(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | PropertyName, parameters: ParameterDeclaration[], body: Block | undefined): SetAccessorDeclaration;
     function updateSetAccessor(node: SetAccessorDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: PropertyName, parameters: ParameterDeclaration[], body: Block | undefined): SetAccessorDeclaration;
+    function createCallSignature(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): CallSignatureDeclaration;
+    function updateCallSignature(node: CallSignatureDeclaration, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): CallSignatureDeclaration;
+    function createConstructSignature(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): ConstructSignatureDeclaration;
+    function updateConstructSignature(node: ConstructSignatureDeclaration, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): ConstructSignatureDeclaration;
+    function createIndexSignature(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], type: TypeNode): IndexSignatureDeclaration;
+    function updateIndexSignature(node: IndexSignatureDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], type: TypeNode): IndexSignatureDeclaration;
+    function createKeywordTypeNode(kind: KeywordTypeNode["kind"]): KeywordTypeNode;
+    function createTypePredicateNode(parameterName: Identifier | ThisTypeNode | string, type: TypeNode): TypePredicateNode;
+    function updateTypePredicateNode(node: TypePredicateNode, parameterName: Identifier | ThisTypeNode, type: TypeNode): TypePredicateNode;
+    function createTypeReferenceNode(typeName: string | EntityName, typeArguments: TypeNode[] | undefined): TypeReferenceNode;
+    function updateTypeReferenceNode(node: TypeReferenceNode, typeName: EntityName, typeArguments: NodeArray<TypeNode> | undefined): TypeReferenceNode;
+    function createFunctionTypeNode(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): FunctionTypeNode;
+    function updateFunctionTypeNode(node: FunctionTypeNode, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): FunctionTypeNode;
+    function createConstructorTypeNode(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): ConstructorTypeNode;
+    function updateConstructorTypeNode(node: ConstructorTypeNode, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): ConstructorTypeNode;
+    function createTypeQueryNode(exprName: EntityName): TypeQueryNode;
+    function updateTypeQueryNode(node: TypeQueryNode, exprName: EntityName): TypeQueryNode;
+    function createTypeLiteralNode(members: TypeElement[]): TypeLiteralNode;
+    function updateTypeLiteralNode(node: TypeLiteralNode, members: NodeArray<TypeElement>): TypeLiteralNode;
+    function createArrayTypeNode(elementType: TypeNode): ArrayTypeNode;
+    function updateArrayTypeNode(node: ArrayTypeNode, elementType: TypeNode): ArrayTypeNode;
+    function createTupleTypeNode(elementTypes: TypeNode[]): TupleTypeNode;
+    function updateTypleTypeNode(node: TupleTypeNode, elementTypes: TypeNode[]): TupleTypeNode;
+    function createUnionTypeNode(types: TypeNode[]): UnionTypeNode;
+    function updateUnionTypeNode(node: UnionTypeNode, types: NodeArray<TypeNode>): UnionTypeNode;
+    function createIntersectionTypeNode(types: TypeNode[]): IntersectionTypeNode;
+    function updateIntersectionTypeNode(node: IntersectionTypeNode, types: NodeArray<TypeNode>): IntersectionTypeNode;
+    function createUnionOrIntersectionTypeNode(kind: SyntaxKind.UnionType | SyntaxKind.IntersectionType, types: TypeNode[]): UnionTypeNode | IntersectionTypeNode;
+    function createParenthesizedType(type: TypeNode): ParenthesizedTypeNode;
+    function updateParenthesizedType(node: ParenthesizedTypeNode, type: TypeNode): ParenthesizedTypeNode;
+    function createThisTypeNode(): ThisTypeNode;
+    function createTypeOperatorNode(type: TypeNode): TypeOperatorNode;
+    function updateTypeOperatorNode(node: TypeOperatorNode, type: TypeNode): TypeOperatorNode;
+    function createIndexedAccessTypeNode(objectType: TypeNode, indexType: TypeNode): IndexedAccessTypeNode;
+    function updateIndexedAccessTypeNode(node: IndexedAccessTypeNode, objectType: TypeNode, indexType: TypeNode): IndexedAccessTypeNode;
+    function createMappedTypeNode(readonlyToken: ReadonlyToken | undefined, typeParameter: TypeParameterDeclaration, questionToken: QuestionToken | undefined, type: TypeNode | undefined): MappedTypeNode;
+    function updateMappedTypeNode(node: MappedTypeNode, readonlyToken: ReadonlyToken | undefined, typeParameter: TypeParameterDeclaration, questionToken: QuestionToken | undefined, type: TypeNode | undefined): MappedTypeNode;
+    function createLiteralTypeNode(literal: Expression): LiteralTypeNode;
+    function updateLiteralTypeNode(node: LiteralTypeNode, literal: Expression): LiteralTypeNode;
     function createObjectBindingPattern(elements: BindingElement[]): ObjectBindingPattern;
     function updateObjectBindingPattern(node: ObjectBindingPattern, elements: BindingElement[]): ObjectBindingPattern;
     function createArrayBindingPattern(elements: ArrayBindingElement[]): ArrayBindingPattern;
@@ -2827,7 +2855,7 @@ declare namespace ts {
     function createPostfix(operand: Expression, operator: PostfixUnaryOperator): PostfixUnaryExpression;
     function updatePostfix(node: PostfixUnaryExpression, operand: Expression): PostfixUnaryExpression;
     function createBinary(left: Expression, operator: BinaryOperator | BinaryOperatorToken, right: Expression): BinaryExpression;
-    function updateBinary(node: BinaryExpression, left: Expression, right: Expression): BinaryExpression;
+    function updateBinary(node: BinaryExpression, left: Expression, right: Expression, operator?: BinaryOperator | BinaryOperatorToken): BinaryExpression;
     function createConditional(condition: Expression, whenTrue: Expression, whenFalse: Expression): ConditionalExpression;
     function createConditional(condition: Expression, questionToken: QuestionToken, whenTrue: Expression, colonToken: ColonToken, whenFalse: Expression): ConditionalExpression;
     function updateConditional(node: ConditionalExpression, condition: Expression, whenTrue: Expression, whenFalse: Expression): ConditionalExpression;
@@ -2847,16 +2875,15 @@ declare namespace ts {
     function updateAsExpression(node: AsExpression, expression: Expression, type: TypeNode): AsExpression;
     function createNonNullExpression(expression: Expression): NonNullExpression;
     function updateNonNullExpression(node: NonNullExpression, expression: Expression): NonNullExpression;
+    function createMetaProperty(keywordToken: MetaProperty["keywordToken"], name: Identifier): MetaProperty;
+    function updateMetaProperty(node: MetaProperty, name: Identifier): MetaProperty;
     function createTemplateSpan(expression: Expression, literal: TemplateMiddle | TemplateTail): TemplateSpan;
     function updateTemplateSpan(node: TemplateSpan, expression: Expression, literal: TemplateMiddle | TemplateTail): TemplateSpan;
+    function createSemicolonClassElement(): SemicolonClassElement;
     function createBlock(statements: Statement[], multiLine?: boolean): Block;
     function updateBlock(node: Block, statements: Statement[]): Block;
     function createVariableStatement(modifiers: Modifier[] | undefined, declarationList: VariableDeclarationList | VariableDeclaration[]): VariableStatement;
     function updateVariableStatement(node: VariableStatement, modifiers: Modifier[] | undefined, declarationList: VariableDeclarationList): VariableStatement;
-    function createVariableDeclarationList(declarations: VariableDeclaration[], flags?: NodeFlags): VariableDeclarationList;
-    function updateVariableDeclarationList(node: VariableDeclarationList, declarations: VariableDeclaration[]): VariableDeclarationList;
-    function createVariableDeclaration(name: string | BindingName, type?: TypeNode, initializer?: Expression): VariableDeclaration;
-    function updateVariableDeclaration(node: VariableDeclaration, name: BindingName, type: TypeNode | undefined, initializer: Expression | undefined): VariableDeclaration;
     function createEmptyStatement(): EmptyStatement;
     function createStatement(expression: Expression): ExpressionStatement;
     function updateStatement(node: ExpressionStatement, expression: Expression): ExpressionStatement;
@@ -2888,10 +2915,19 @@ declare namespace ts {
     function updateThrow(node: ThrowStatement, expression: Expression): ThrowStatement;
     function createTry(tryBlock: Block, catchClause: CatchClause | undefined, finallyBlock: Block | undefined): TryStatement;
     function updateTry(node: TryStatement, tryBlock: Block, catchClause: CatchClause | undefined, finallyBlock: Block | undefined): TryStatement;
+    function createDebuggerStatement(): DebuggerStatement;
+    function createVariableDeclaration(name: string | BindingName, type?: TypeNode, initializer?: Expression): VariableDeclaration;
+    function updateVariableDeclaration(node: VariableDeclaration, name: BindingName, type: TypeNode | undefined, initializer: Expression | undefined): VariableDeclaration;
+    function createVariableDeclarationList(declarations: VariableDeclaration[], flags?: NodeFlags): VariableDeclarationList;
+    function updateVariableDeclarationList(node: VariableDeclarationList, declarations: VariableDeclaration[]): VariableDeclarationList;
     function createFunctionDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: string | Identifier | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): FunctionDeclaration;
     function updateFunctionDeclaration(node: FunctionDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: Identifier | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): FunctionDeclaration;
     function createClassDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier | undefined, typeParameters: TypeParameterDeclaration[] | undefined, heritageClauses: HeritageClause[], members: ClassElement[]): ClassDeclaration;
     function updateClassDeclaration(node: ClassDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier | undefined, typeParameters: TypeParameterDeclaration[] | undefined, heritageClauses: HeritageClause[], members: ClassElement[]): ClassDeclaration;
+    function createInterfaceDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, typeParameters: TypeParameterDeclaration[] | undefined, heritageClauses: HeritageClause[] | undefined, members: TypeElement[]): InterfaceDeclaration;
+    function updateInterfaceDeclaration(node: InterfaceDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, typeParameters: TypeParameterDeclaration[] | undefined, heritageClauses: HeritageClause[] | undefined, members: TypeElement[]): InterfaceDeclaration;
+    function createTypeAliasDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, typeParameters: TypeParameterDeclaration[] | undefined, type: TypeNode): TypeAliasDeclaration;
+    function updateTypeAliasDeclaration(node: TypeAliasDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, typeParameters: TypeParameterDeclaration[] | undefined, type: TypeNode): TypeAliasDeclaration;
     function createEnumDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, members: EnumMember[]): EnumDeclaration;
     function updateEnumDeclaration(node: EnumDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, members: EnumMember[]): EnumDeclaration;
     function createModuleDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: ModuleName, body: ModuleBody | undefined, flags?: NodeFlags): ModuleDeclaration;
@@ -2900,6 +2936,8 @@ declare namespace ts {
     function updateModuleBlock(node: ModuleBlock, statements: Statement[]): ModuleBlock;
     function createCaseBlock(clauses: CaseOrDefaultClause[]): CaseBlock;
     function updateCaseBlock(node: CaseBlock, clauses: CaseOrDefaultClause[]): CaseBlock;
+    function createNamespaceExportDeclaration(name: string | Identifier): NamespaceExportDeclaration;
+    function updateNamespaceExportDeclaration(node: NamespaceExportDeclaration, name: Identifier): NamespaceExportDeclaration;
     function createImportEqualsDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, moduleReference: ModuleReference): ImportEqualsDeclaration;
     function updateImportEqualsDeclaration(node: ImportEqualsDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, moduleReference: ModuleReference): ImportEqualsDeclaration;
     function createImportDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, importClause: ImportClause | undefined, moduleSpecifier?: Expression): ImportDeclaration;
@@ -2930,20 +2968,20 @@ declare namespace ts {
     function updateJsxOpeningElement(node: JsxOpeningElement, tagName: JsxTagNameExpression, attributes: JsxAttributes): JsxOpeningElement;
     function createJsxClosingElement(tagName: JsxTagNameExpression): JsxClosingElement;
     function updateJsxClosingElement(node: JsxClosingElement, tagName: JsxTagNameExpression): JsxClosingElement;
-    function createJsxAttributes(properties: JsxAttributeLike[]): JsxAttributes;
-    function updateJsxAttributes(jsxAttributes: JsxAttributes, properties: JsxAttributeLike[]): JsxAttributes;
     function createJsxAttribute(name: Identifier, initializer: StringLiteral | JsxExpression): JsxAttribute;
     function updateJsxAttribute(node: JsxAttribute, name: Identifier, initializer: StringLiteral | JsxExpression): JsxAttribute;
+    function createJsxAttributes(properties: JsxAttributeLike[]): JsxAttributes;
+    function updateJsxAttributes(node: JsxAttributes, properties: JsxAttributeLike[]): JsxAttributes;
     function createJsxSpreadAttribute(expression: Expression): JsxSpreadAttribute;
     function updateJsxSpreadAttribute(node: JsxSpreadAttribute, expression: Expression): JsxSpreadAttribute;
     function createJsxExpression(dotDotDotToken: DotDotDotToken | undefined, expression: Expression | undefined): JsxExpression;
     function updateJsxExpression(node: JsxExpression, expression: Expression | undefined): JsxExpression;
-    function createHeritageClause(token: HeritageClause["token"], types: ExpressionWithTypeArguments[]): HeritageClause;
-    function updateHeritageClause(node: HeritageClause, types: ExpressionWithTypeArguments[]): HeritageClause;
     function createCaseClause(expression: Expression, statements: Statement[]): CaseClause;
     function updateCaseClause(node: CaseClause, expression: Expression, statements: Statement[]): CaseClause;
     function createDefaultClause(statements: Statement[]): DefaultClause;
     function updateDefaultClause(node: DefaultClause, statements: Statement[]): DefaultClause;
+    function createHeritageClause(token: HeritageClause["token"], types: ExpressionWithTypeArguments[]): HeritageClause;
+    function updateHeritageClause(node: HeritageClause, types: ExpressionWithTypeArguments[]): HeritageClause;
     function createCatchClause(variableDeclaration: string | VariableDeclaration, block: Block): CatchClause;
     function updateCatchClause(node: CatchClause, variableDeclaration: VariableDeclaration, block: Block): CatchClause;
     function createPropertyAssignment(name: string | PropertyName, initializer: Expression): PropertyAssignment;
@@ -2976,6 +3014,8 @@ declare namespace ts {
      */
     function createPartiallyEmittedExpression(expression: Expression, original?: Node): PartiallyEmittedExpression;
     function updatePartiallyEmittedExpression(node: PartiallyEmittedExpression, expression: Expression): PartiallyEmittedExpression;
+    function createCommaList(elements: Expression[]): CommaListExpression;
+    function updateCommaList(node: CommaListExpression, elements: Expression[]): CommaListExpression;
     function createBundle(sourceFiles: SourceFile[]): Bundle;
     function updateBundle(node: Bundle, sourceFiles: SourceFile[]): Bundle;
     function createComma(left: Expression, right: Expression): Expression;
@@ -3040,11 +3080,11 @@ declare namespace ts {
     /**
      * Gets the constant value to emit for an expression.
      */
-    function getConstantValue(node: PropertyAccessExpression | ElementAccessExpression): number;
+    function getConstantValue(node: PropertyAccessExpression | ElementAccessExpression): string | number;
     /**
      * Sets the constant value to emit for an expression.
      */
-    function setConstantValue(node: PropertyAccessExpression | ElementAccessExpression, value: number): PropertyAccessExpression | ElementAccessExpression;
+    function setConstantValue(node: PropertyAccessExpression | ElementAccessExpression, value: string | number): PropertyAccessExpression | ElementAccessExpression;
     /**
      * Adds an EmitHelper to a node.
      */
@@ -3069,17 +3109,13 @@ declare namespace ts {
 }
 declare namespace ts {
     function createNode(kind: SyntaxKind, pos?: number, end?: number): Node;
-    function forEachChild<T>(node: Node, cbNode: (node: Node) => T, cbNodeArray?: (nodes: Node[]) => T): T;
+    function forEachChild<T>(node: Node, cbNode: (node: Node) => T, cbNodeArray?: (nodes: Node[]) => T): T | undefined;
     function createSourceFile(fileName: string, sourceText: string, languageVersion: ScriptTarget, setParentNodes?: boolean, scriptKind?: ScriptKind): SourceFile;
     function parseIsolatedEntityName(text: string, languageVersion: ScriptTarget): EntityName;
     function isExternalModule(file: SourceFile): boolean;
     function updateSourceFile(sourceFile: SourceFile, newText: string, textChangeRange: TextChangeRange, aggressiveChecks?: boolean): SourceFile;
 }
 declare namespace ts {
-    /** Array that is only intended to be pushed to, never read. */
-    interface Push<T> {
-        push(value: T): void;
-    }
     function moduleHasNonRelativeName(moduleName: string): boolean;
     function getEffectiveTypeRoots(options: CompilerOptions, host: {
         directoryExists?: (directoryName: string) => boolean;
@@ -3218,6 +3254,7 @@ declare namespace ts {
         getNewLine(): string;
     }
     function formatDiagnostics(diagnostics: Diagnostic[], host: FormatDiagnosticsHost): string;
+    function formatDiagnosticsWithColorAndContext(diagnostics: Diagnostic[], host: FormatDiagnosticsHost): string;
     function flattenDiagnosticMessageText(messageText: string | DiagnosticMessageChain, newLine: string): string;
     function createProgram(rootNames: string[], options: CompilerOptions, host?: CompilerHost, oldProgram?: Program): Program;
 }
@@ -3246,9 +3283,10 @@ declare namespace ts {
      * @param host Instance of ParseConfigHost used to enumerate files in folder.
      * @param basePath A root directory to resolve relative path entries in the config
      *    file to. e.g. outDir
+     * @param resolutionStack Only present for backwards-compatibility. Should be empty.
      */
     function parseJsonConfigFileContent(json: any, host: ParseConfigHost, basePath: string, existingOptions?: CompilerOptions, configFileName?: string, resolutionStack?: Path[], extraFileExtensions?: JsFileExtensionInfo[]): ParsedCommandLine;
-    function convertCompileOnSaveOptionFromJson(jsonOption: any, basePath: string, errors: Diagnostic[]): boolean | undefined;
+    function convertCompileOnSaveOptionFromJson(jsonOption: any, basePath: string, errors: Diagnostic[]): boolean;
     function convertCompilerOptionsFromJson(jsonOptions: any, basePath: string, configFileName?: string): {
         options: CompilerOptions;
         errors: Diagnostic[];
@@ -3422,6 +3460,8 @@ declare namespace ts {
         getDocCommentTemplateAtPosition(fileName: string, position: number): TextInsertion;
         isValidBraceCompletionAtPosition(fileName: string, position: number, openingBrace: number): boolean;
         getCodeFixesAtPosition(fileName: string, start: number, end: number, errorCodes: number[], formatOptions: FormatCodeSettings): CodeAction[];
+        getApplicableRefactors(fileName: string, positionOrRaneg: number | TextRange): ApplicableRefactorInfo[];
+        getRefactorCodeActions(fileName: string, formatOptions: FormatCodeSettings, positionOrRange: number | TextRange, refactorName: string): CodeAction[] | undefined;
         getEmitOutput(fileName: string, emitOnlyDtsFiles?: boolean): EmitOutput;
         getProgram(): Program;
         dispose(): void;
@@ -3492,6 +3532,10 @@ declare namespace ts {
         /** Text changes to apply to each file as part of the code action */
         changes: FileTextChanges[];
     }
+    interface ApplicableRefactorInfo {
+        name: string;
+        description: string;
+    }
     interface TextInsertion {
         newText: string;
         /** The position in newText the caret should point to after the insertion. */
@@ -4006,6 +4050,7 @@ declare namespace ts {
         reportDiagnostics?: boolean;
         moduleName?: string;
         renamedDependencies?: MapLike<string>;
+        transformers?: CustomTransformers;
     }
     interface TranspileOutput {
         outputText: string;

lib/typescriptServices.d.ts

@@ -359,9 +359,10 @@ declare namespace ts {
         SyntaxList = 294,
         NotEmittedStatement = 295,
         PartiallyEmittedExpression = 296,
-        MergeDeclarationMarker = 297,
-        EndOfDeclarationMarker = 298,
-        Count = 299,
+        CommaListExpression = 297,
+        MergeDeclarationMarker = 298,
+        EndOfDeclarationMarker = 299,
+        Count = 300,
         FirstAssignment = 58,
         LastAssignment = 70,
         FirstCompoundAssignment = 59,
@@ -474,6 +475,10 @@ declare namespace ts {
     type ModifiersArray = NodeArray<Modifier>;
     interface Identifier extends PrimaryExpression {
         kind: SyntaxKind.Identifier;
+        /**
+         * Text of identifier (with escapes converted to characters).
+         * If the identifier begins with two underscores, this will begin with three.
+         */
         text: string;
         originalKeywordKind?: SyntaxKind;
         isInJSDocNamespace?: boolean;
@@ -491,9 +496,11 @@ declare namespace ts {
     type DeclarationName = Identifier | StringLiteral | NumericLiteral | ComputedPropertyName | BindingPattern;
     interface Declaration extends Node {
         _declarationBrand: any;
+    }
+    interface NamedDeclaration extends Declaration {
         name?: DeclarationName;
     }
-    interface DeclarationStatement extends Declaration, Statement {
+    interface DeclarationStatement extends NamedDeclaration, Statement {
         name?: Identifier | StringLiteral | NumericLiteral;
     }
     interface ComputedPropertyName extends Node {
@@ -504,7 +511,7 @@ declare namespace ts {
         kind: SyntaxKind.Decorator;
         expression: LeftHandSideExpression;
     }
-    interface TypeParameterDeclaration extends Declaration {
+    interface TypeParameterDeclaration extends NamedDeclaration {
         kind: SyntaxKind.TypeParameter;
         parent?: DeclarationWithTypeParameters;
         name: Identifier;
@@ -512,7 +519,7 @@ declare namespace ts {
         default?: TypeNode;
         expression?: Expression;
     }
-    interface SignatureDeclaration extends Declaration {
+    interface SignatureDeclaration extends NamedDeclaration {
         name?: PropertyName;
         typeParameters?: NodeArray<TypeParameterDeclaration>;
         parameters: NodeArray<ParameterDeclaration>;
@@ -525,7 +532,7 @@ declare namespace ts {
         kind: SyntaxKind.ConstructSignature;
     }
     type BindingName = Identifier | BindingPattern;
-    interface VariableDeclaration extends Declaration {
+    interface VariableDeclaration extends NamedDeclaration {
         kind: SyntaxKind.VariableDeclaration;
         parent?: VariableDeclarationList | CatchClause;
         name: BindingName;
@@ -537,7 +544,7 @@ declare namespace ts {
         parent?: VariableStatement | ForStatement | ForOfStatement | ForInStatement;
         declarations: NodeArray<VariableDeclaration>;
     }
-    interface ParameterDeclaration extends Declaration {
+    interface ParameterDeclaration extends NamedDeclaration {
         kind: SyntaxKind.Parameter;
         parent?: SignatureDeclaration;
         dotDotDotToken?: DotDotDotToken;
@@ -546,7 +553,7 @@ declare namespace ts {
         type?: TypeNode;
         initializer?: Expression;
     }
-    interface BindingElement extends Declaration {
+    interface BindingElement extends NamedDeclaration {
         kind: SyntaxKind.BindingElement;
         parent?: BindingPattern;
         propertyName?: PropertyName;
@@ -568,7 +575,7 @@ declare namespace ts {
         type?: TypeNode;
         initializer?: Expression;
     }
-    interface ObjectLiteralElement extends Declaration {
+    interface ObjectLiteralElement extends NamedDeclaration {
         _objectLiteralBrandBrand: any;
         name?: PropertyName;
     }
@@ -590,7 +597,7 @@ declare namespace ts {
         kind: SyntaxKind.SpreadAssignment;
         expression: Expression;
     }
-    interface VariableLikeDeclaration extends Declaration {
+    interface VariableLikeDeclaration extends NamedDeclaration {
         propertyName?: PropertyName;
         dotDotDotToken?: DotDotDotToken;
         name: DeclarationName;
@@ -598,7 +605,7 @@ declare namespace ts {
         type?: TypeNode;
         initializer?: Expression;
     }
-    interface PropertyLikeDeclaration extends Declaration {
+    interface PropertyLikeDeclaration extends NamedDeclaration {
         name: PropertyName;
     }
     interface ObjectBindingPattern extends Node {
@@ -950,7 +957,7 @@ declare namespace ts {
     }
     type EntityNameExpression = Identifier | PropertyAccessEntityNameExpression | ParenthesizedExpression;
     type EntityNameOrEntityNameExpression = EntityName | EntityNameExpression;
-    interface PropertyAccessExpression extends MemberExpression, Declaration {
+    interface PropertyAccessExpression extends MemberExpression, NamedDeclaration {
         kind: SyntaxKind.PropertyAccessExpression;
         expression: LeftHandSideExpression;
         name: Identifier;
@@ -1016,7 +1023,7 @@ declare namespace ts {
     }
     interface MetaProperty extends PrimaryExpression {
         kind: SyntaxKind.MetaProperty;
-        keywordToken: SyntaxKind;
+        keywordToken: SyntaxKind.NewKeyword;
         name: Identifier;
     }
     interface JsxElement extends PrimaryExpression {
@@ -1076,6 +1083,13 @@ declare namespace ts {
     interface NotEmittedStatement extends Statement {
         kind: SyntaxKind.NotEmittedStatement;
     }
+    /**
+     * A list of comma-seperated expressions. This node is only created by transformations.
+     */
+    interface CommaListExpression extends Expression {
+        kind: SyntaxKind.CommaListExpression;
+        elements: NodeArray<Expression>;
+    }
     interface EmptyStatement extends Statement {
         kind: SyntaxKind.EmptyStatement;
     }
@@ -1197,7 +1211,7 @@ declare namespace ts {
         block: Block;
     }
     type DeclarationWithTypeParameters = SignatureDeclaration | ClassLikeDeclaration | InterfaceDeclaration | TypeAliasDeclaration;
-    interface ClassLikeDeclaration extends Declaration {
+    interface ClassLikeDeclaration extends NamedDeclaration {
         name?: Identifier;
         typeParameters?: NodeArray<TypeParameterDeclaration>;
         heritageClauses?: NodeArray<HeritageClause>;
@@ -1210,11 +1224,11 @@ declare namespace ts {
     interface ClassExpression extends ClassLikeDeclaration, PrimaryExpression {
         kind: SyntaxKind.ClassExpression;
     }
-    interface ClassElement extends Declaration {
+    interface ClassElement extends NamedDeclaration {
         _classElementBrand: any;
         name?: PropertyName;
     }
-    interface TypeElement extends Declaration {
+    interface TypeElement extends NamedDeclaration {
         _typeElementBrand: any;
         name?: PropertyName;
         questionToken?: QuestionToken;
@@ -1238,7 +1252,7 @@ declare namespace ts {
         typeParameters?: NodeArray<TypeParameterDeclaration>;
         type: TypeNode;
     }
-    interface EnumMember extends Declaration {
+    interface EnumMember extends NamedDeclaration {
         kind: SyntaxKind.EnumMember;
         parent?: EnumDeclaration;
         name: PropertyName;
@@ -1297,13 +1311,13 @@ declare namespace ts {
         moduleSpecifier: Expression;
     }
     type NamedImportBindings = NamespaceImport | NamedImports;
-    interface ImportClause extends Declaration {
+    interface ImportClause extends NamedDeclaration {
         kind: SyntaxKind.ImportClause;
         parent?: ImportDeclaration;
         name?: Identifier;
         namedBindings?: NamedImportBindings;
     }
-    interface NamespaceImport extends Declaration {
+    interface NamespaceImport extends NamedDeclaration {
         kind: SyntaxKind.NamespaceImport;
         parent?: ImportClause;
         name: Identifier;
@@ -1330,13 +1344,13 @@ declare namespace ts {
         elements: NodeArray<ExportSpecifier>;
     }
     type NamedImportsOrExports = NamedImports | NamedExports;
-    interface ImportSpecifier extends Declaration {
+    interface ImportSpecifier extends NamedDeclaration {
         kind: SyntaxKind.ImportSpecifier;
         parent?: NamedImports;
         propertyName?: Identifier;
         name: Identifier;
     }
-    interface ExportSpecifier extends Declaration {
+    interface ExportSpecifier extends NamedDeclaration {
         kind: SyntaxKind.ExportSpecifier;
         parent?: NamedExports;
         propertyName?: Identifier;
@@ -1467,7 +1481,7 @@ declare namespace ts {
         kind: SyntaxKind.JSDocTypeTag;
         typeExpression: JSDocTypeExpression;
     }
-    interface JSDocTypedefTag extends JSDocTag, Declaration {
+    interface JSDocTypedefTag extends JSDocTag, NamedDeclaration {
         kind: SyntaxKind.JSDocTypedefTag;
         fullName?: JSDocNamespaceDeclaration | Identifier;
         name?: Identifier;
@@ -1706,11 +1720,11 @@ declare namespace ts {
         /** Note that the resulting nodes cannot be checked. */
         indexInfoToIndexSignatureDeclaration(indexInfo: IndexInfo, kind: IndexKind, enclosingDeclaration?: Node, flags?: NodeBuilderFlags): IndexSignatureDeclaration;
         getSymbolsInScope(location: Node, meaning: SymbolFlags): Symbol[];
-        getSymbolAtLocation(node: Node): Symbol;
+        getSymbolAtLocation(node: Node): Symbol | undefined;
         getSymbolsOfParameterPropertyDeclaration(parameter: ParameterDeclaration, parameterName: string): Symbol[];
-        getShorthandAssignmentValueSymbol(location: Node): Symbol;
-        getExportSpecifierLocalTargetSymbol(location: ExportSpecifier): Symbol;
-        getPropertySymbolOfDestructuringAssignment(location: Identifier): Symbol;
+        getShorthandAssignmentValueSymbol(location: Node): Symbol | undefined;
+        getExportSpecifierLocalTargetSymbol(location: ExportSpecifier): Symbol | undefined;
+        getPropertySymbolOfDestructuringAssignment(location: Identifier): Symbol | undefined;
         getTypeAtLocation(node: Node): Type;
         getTypeFromTypeNode(node: TypeNode): Type;
         signatureToString(signature: Signature, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): string;
@@ -1720,38 +1734,48 @@ declare namespace ts {
         getFullyQualifiedName(symbol: Symbol): string;
         getAugmentedPropertiesOfType(type: Type): Symbol[];
         getRootSymbols(symbol: Symbol): Symbol[];
-        getContextualType(node: Expression): Type;
-        getResolvedSignature(node: CallLikeExpression, candidatesOutArray?: Signature[]): Signature;
-        getSignatureFromDeclaration(declaration: SignatureDeclaration): Signature;
-        isImplementationOfOverload(node: FunctionLikeDeclaration): boolean;
+        getContextualType(node: Expression): Type | undefined;
+        getResolvedSignature(node: CallLikeExpression, candidatesOutArray?: Signature[]): Signature | undefined;
+        getSignatureFromDeclaration(declaration: SignatureDeclaration): Signature | undefined;
+        isImplementationOfOverload(node: FunctionLikeDeclaration): boolean | undefined;
         isUndefinedSymbol(symbol: Symbol): boolean;
         isArgumentsSymbol(symbol: Symbol): boolean;
         isUnknownSymbol(symbol: Symbol): boolean;
-        getConstantValue(node: EnumMember | PropertyAccessExpression | ElementAccessExpression): number;
+        getConstantValue(node: EnumMember | PropertyAccessExpression | ElementAccessExpression): string | number | undefined;
         isValidPropertyAccess(node: PropertyAccessExpression | QualifiedName, propertyName: string): boolean;
         /** Follow all aliases to get the original symbol. */
         getAliasedSymbol(symbol: Symbol): Symbol;
         getExportsOfModule(moduleSymbol: Symbol): Symbol[];
-        getAllAttributesTypeFromJsxOpeningLikeElement(elementNode: JsxOpeningLikeElement): Type;
+        getAllAttributesTypeFromJsxOpeningLikeElement(elementNode: JsxOpeningLikeElement): Type | undefined;
         getJsxIntrinsicTagNames(): Symbol[];
         isOptionalParameter(node: ParameterDeclaration): boolean;
         getAmbientModules(): Symbol[];
         tryGetMemberInModuleExports(memberName: string, moduleSymbol: Symbol): Symbol | undefined;
         getApparentType(type: Type): Type;
+        getSuggestionForNonexistentProperty(node: Identifier, containingType: Type): string | undefined;
+        getSuggestionForNonexistentSymbol(location: Node, name: string, meaning: SymbolFlags): string | undefined;
     }
     enum NodeBuilderFlags {
         None = 0,
-        allowThisInObjectLiteral = 1,
-        allowQualifedNameInPlaceOfIdentifier = 2,
-        allowTypeParameterInQualifiedName = 4,
-        allowAnonymousIdentifier = 8,
-        allowEmptyUnionOrIntersection = 16,
-        allowEmptyTuple = 32,
+        NoTruncation = 1,
+        WriteArrayAsGenericType = 2,
+        WriteTypeArgumentsOfSignature = 32,
+        UseFullyQualifiedType = 64,
+        SuppressAnyReturnType = 256,
+        WriteTypeParametersInQualifiedName = 512,
+        AllowThisInObjectLiteral = 1024,
+        AllowQualifedNameInPlaceOfIdentifier = 2048,
+        AllowAnonymousIdentifier = 8192,
+        AllowEmptyUnionOrIntersection = 16384,
+        AllowEmptyTuple = 32768,
+        IgnoreErrors = 60416,
+        InObjectTypeLiteral = 1048576,
+        InTypeAlias = 8388608,
     }
     interface SymbolDisplayBuilder {
         buildTypeDisplay(type: Type, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
         buildSymbolDisplay(symbol: Symbol, writer: SymbolWriter, enclosingDeclaration?: Node, meaning?: SymbolFlags, flags?: SymbolFormatFlags): void;
-        buildSignatureDisplay(signatures: Signature, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): void;
+        buildSignatureDisplay(signature: Signature, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): void;
         buildIndexSignatureDisplay(info: IndexInfo, writer: SymbolWriter, kind: IndexKind, enclosingDeclaration?: Node, globalFlags?: TypeFormatFlags, symbolStack?: Symbol[]): void;
         buildParameterDisplay(parameter: Symbol, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
         buildTypeParameterDisplay(tp: TypeParameter, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
@@ -1912,18 +1936,18 @@ declare namespace ts {
         Index = 262144,
         IndexedAccess = 524288,
         NonPrimitive = 16777216,
-        Literal = 480,
+        Literal = 224,
         StringOrNumberLiteral = 96,
         PossiblyFalsy = 7406,
         StringLike = 262178,
-        NumberLike = 340,
+        NumberLike = 84,
         BooleanLike = 136,
         EnumLike = 272,
         UnionOrIntersection = 196608,
         StructuredType = 229376,
         StructuredOrTypeVariable = 1032192,
         TypeVariable = 540672,
-        Narrowable = 17810431,
+        Narrowable = 17810175,
         NotUnionOrUnit = 16810497,
     }
     type DestructuringPattern = BindingPattern | ObjectLiteralExpression | ArrayLiteralExpression;
@@ -1935,15 +1959,17 @@ declare namespace ts {
         aliasTypeArguments?: Type[];
     }
     interface LiteralType extends Type {
-        text: string;
+        value: string | number;
         freshType?: LiteralType;
         regularType?: LiteralType;
     }
-    interface EnumType extends Type {
-        memberTypes: EnumLiteralType[];
+    interface StringLiteralType extends LiteralType {
+        value: string;
     }
-    interface EnumLiteralType extends LiteralType {
-        baseType: EnumType & UnionType;
+    interface NumberLiteralType extends LiteralType {
+        value: number;
+    }
+    interface EnumType extends Type {
     }
     enum ObjectFlags {
         Class = 1,
@@ -1988,7 +2014,7 @@ declare namespace ts {
      */
     interface TypeReference extends ObjectType {
         target: GenericType;
-        typeArguments: Type[];
+        typeArguments?: Type[];
     }
     interface GenericType extends InterfaceType, TypeReference {
     }
@@ -2024,7 +2050,7 @@ declare namespace ts {
     }
     interface Signature {
         declaration: SignatureDeclaration;
-        typeParameters: TypeParameter[];
+        typeParameters?: TypeParameter[];
         parameters: Symbol[];
     }
     enum IndexKind {
@@ -2059,9 +2085,9 @@ declare namespace ts {
         next?: DiagnosticMessageChain;
     }
     interface Diagnostic {
-        file: SourceFile;
-        start: number;
-        length: number;
+        file: SourceFile | undefined;
+        start: number | undefined;
+        length: number | undefined;
         messageText: string | DiagnosticMessageChain;
         category: DiagnosticCategory;
         code: number;
@@ -2329,6 +2355,7 @@ declare namespace ts {
         NoHoisting = 2097152,
         HasEndOfDeclarationMarker = 4194304,
         Iterator = 8388608,
+        NoAsciiEscaping = 16777216,
     }
     interface EmitHelper {
         readonly name: string;
@@ -2611,14 +2638,14 @@ declare namespace ts {
     function isWhiteSpaceSingleLine(ch: number): boolean;
     function isLineBreak(ch: number): boolean;
     function couldStartTrivia(text: string, pos: number): boolean;
-    function forEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U;
-    function forEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U;
+    function forEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U | undefined;
+    function forEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U | undefined;
     function reduceEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T, memo: U) => U, state: T, initial: U): U;
     function reduceEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T, memo: U) => U, state: T, initial: U): U;
     function getLeadingCommentRanges(text: string, pos: number): CommentRange[] | undefined;
     function getTrailingCommentRanges(text: string, pos: number): CommentRange[] | undefined;
     /** Optionally, get the shebang */
-    function getShebang(text: string): string;
+    function getShebang(text: string): string | undefined;
     function isIdentifierStart(ch: number, languageVersion: ScriptTarget): boolean;
     function isIdentifierPart(ch: number, languageVersion: ScriptTarget): boolean;
     function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean, languageVariant?: LanguageVariant, text?: string, onError?: ErrorCallback, start?: number, length?: number): Scanner;
@@ -2709,6 +2736,7 @@ declare namespace ts {
     function createLiteral(value: string | number | boolean): PrimaryExpression;
     function createNumericLiteral(value: string): NumericLiteral;
     function createIdentifier(text: string): Identifier;
+    function updateIdentifier(node: Identifier, typeArguments: NodeArray<TypeNode> | undefined): Identifier;
     /** Create a unique temporary variable. */
     function createTempVariable(recordTempVariable: ((node: Identifier) => void) | undefined): Identifier;
     /** Create a unique temporary variable for use in a loop. */
@@ -2727,58 +2755,19 @@ declare namespace ts {
     function updateQualifiedName(node: QualifiedName, left: EntityName, right: Identifier): QualifiedName;
     function createComputedPropertyName(expression: Expression): ComputedPropertyName;
     function updateComputedPropertyName(node: ComputedPropertyName, expression: Expression): ComputedPropertyName;
-    function createSignatureDeclaration(kind: SyntaxKind, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): SignatureDeclaration;
-    function createFunctionTypeNode(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): FunctionTypeNode;
-    function updateFunctionTypeNode(node: FunctionTypeNode, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): FunctionTypeNode;
-    function createConstructorTypeNode(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): ConstructorTypeNode;
-    function updateConstructorTypeNode(node: ConstructorTypeNode, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): ConstructorTypeNode;
-    function createCallSignatureDeclaration(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): CallSignatureDeclaration;
-    function updateCallSignatureDeclaration(node: CallSignatureDeclaration, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): CallSignatureDeclaration;
-    function createConstructSignatureDeclaration(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): ConstructSignatureDeclaration;
-    function updateConstructSignatureDeclaration(node: ConstructSignatureDeclaration, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): ConstructSignatureDeclaration;
-    function createMethodSignature(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined): MethodSignature;
-    function updateMethodSignature(node: MethodSignature, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined, name: PropertyName, questionToken: QuestionToken | undefined): MethodSignature;
-    function createKeywordTypeNode(kind: KeywordTypeNode["kind"]): KeywordTypeNode;
-    function createThisTypeNode(): ThisTypeNode;
-    function createLiteralTypeNode(literal: Expression): LiteralTypeNode;
-    function updateLiteralTypeNode(node: LiteralTypeNode, literal: Expression): LiteralTypeNode;
-    function createTypeReferenceNode(typeName: string | EntityName, typeArguments: TypeNode[] | undefined): TypeReferenceNode;
-    function updateTypeReferenceNode(node: TypeReferenceNode, typeName: EntityName, typeArguments: NodeArray<TypeNode> | undefined): TypeReferenceNode;
-    function createTypePredicateNode(parameterName: Identifier | ThisTypeNode | string, type: TypeNode): TypePredicateNode;
-    function updateTypePredicateNode(node: TypePredicateNode, parameterName: Identifier | ThisTypeNode, type: TypeNode): TypePredicateNode;
-    function createTypeQueryNode(exprName: EntityName): TypeQueryNode;
-    function updateTypeQueryNode(node: TypeQueryNode, exprName: EntityName): TypeQueryNode;
-    function createArrayTypeNode(elementType: TypeNode): ArrayTypeNode;
-    function updateArrayTypeNode(node: ArrayTypeNode, elementType: TypeNode): ArrayTypeNode;
-    function createUnionOrIntersectionTypeNode(kind: SyntaxKind.UnionType, types: TypeNode[]): UnionTypeNode;
-    function createUnionOrIntersectionTypeNode(kind: SyntaxKind.IntersectionType, types: TypeNode[]): IntersectionTypeNode;
-    function createUnionOrIntersectionTypeNode(kind: SyntaxKind.UnionType | SyntaxKind.IntersectionType, types: TypeNode[]): UnionOrIntersectionTypeNode;
-    function updateUnionOrIntersectionTypeNode(node: UnionOrIntersectionTypeNode, types: NodeArray<TypeNode>): UnionOrIntersectionTypeNode;
-    function createParenthesizedType(type: TypeNode): ParenthesizedTypeNode;
-    function updateParenthesizedType(node: ParenthesizedTypeNode, type: TypeNode): ParenthesizedTypeNode;
-    function createTypeLiteralNode(members: TypeElement[]): TypeLiteralNode;
-    function updateTypeLiteralNode(node: TypeLiteralNode, members: NodeArray<TypeElement>): TypeLiteralNode;
-    function createTupleTypeNode(elementTypes: TypeNode[]): TupleTypeNode;
-    function updateTypleTypeNode(node: TupleTypeNode, elementTypes: TypeNode[]): TupleTypeNode;
-    function createMappedTypeNode(readonlyToken: ReadonlyToken | undefined, typeParameter: TypeParameterDeclaration, questionToken: QuestionToken | undefined, type: TypeNode | undefined): MappedTypeNode;
-    function updateMappedTypeNode(node: MappedTypeNode, readonlyToken: ReadonlyToken | undefined, typeParameter: TypeParameterDeclaration, questionToken: QuestionToken | undefined, type: TypeNode | undefined): MappedTypeNode;
-    function createTypeOperatorNode(type: TypeNode): TypeOperatorNode;
-    function updateTypeOperatorNode(node: TypeOperatorNode, type: TypeNode): TypeOperatorNode;
-    function createIndexedAccessTypeNode(objectType: TypeNode, indexType: TypeNode): IndexedAccessTypeNode;
-    function updateIndexedAccessTypeNode(node: IndexedAccessTypeNode, objectType: TypeNode, indexType: TypeNode): IndexedAccessTypeNode;
     function createTypeParameterDeclaration(name: string | Identifier, constraint: TypeNode | undefined, defaultType: TypeNode | undefined): TypeParameterDeclaration;
     function updateTypeParameterDeclaration(node: TypeParameterDeclaration, name: Identifier, constraint: TypeNode | undefined, defaultType: TypeNode | undefined): TypeParameterDeclaration;
-    function createPropertySignature(name: PropertyName | string, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature;
-    function updatePropertySignature(node: PropertySignature, name: PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature;
-    function createIndexSignatureDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], type: TypeNode): IndexSignatureDeclaration;
-    function updateIndexSignatureDeclaration(node: IndexSignatureDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], type: TypeNode): IndexSignatureDeclaration;
     function createParameter(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, dotDotDotToken: DotDotDotToken | undefined, name: string | BindingName, questionToken?: QuestionToken, type?: TypeNode, initializer?: Expression): ParameterDeclaration;
     function updateParameter(node: ParameterDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, dotDotDotToken: DotDotDotToken | undefined, name: string | BindingName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): ParameterDeclaration;
     function createDecorator(expression: Expression): Decorator;
     function updateDecorator(node: Decorator, expression: Expression): Decorator;
+    function createPropertySignature(modifiers: Modifier[] | undefined, name: PropertyName | string, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature;
+    function updatePropertySignature(node: PropertySignature, modifiers: Modifier[] | undefined, name: PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature;
     function createProperty(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression): PropertyDeclaration;
     function updateProperty(node: PropertyDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: PropertyName, type: TypeNode | undefined, initializer: Expression): PropertyDeclaration;
-    function createMethodDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): MethodDeclaration;
+    function createMethodSignature(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined): MethodSignature;
+    function updateMethodSignature(node: MethodSignature, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined, name: PropertyName, questionToken: QuestionToken | undefined): MethodSignature;
+    function createMethod(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): MethodDeclaration;
     function updateMethod(node: MethodDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: PropertyName, questionToken: QuestionToken | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): MethodDeclaration;
     function createConstructor(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], body: Block | undefined): ConstructorDeclaration;
     function updateConstructor(node: ConstructorDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], body: Block | undefined): ConstructorDeclaration;
@@ -2786,6 +2775,45 @@ declare namespace ts {
     function updateGetAccessor(node: GetAccessorDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: PropertyName, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): GetAccessorDeclaration;
     function createSetAccessor(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | PropertyName, parameters: ParameterDeclaration[], body: Block | undefined): SetAccessorDeclaration;
     function updateSetAccessor(node: SetAccessorDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: PropertyName, parameters: ParameterDeclaration[], body: Block | undefined): SetAccessorDeclaration;
+    function createCallSignature(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): CallSignatureDeclaration;
+    function updateCallSignature(node: CallSignatureDeclaration, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): CallSignatureDeclaration;
+    function createConstructSignature(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): ConstructSignatureDeclaration;
+    function updateConstructSignature(node: ConstructSignatureDeclaration, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): ConstructSignatureDeclaration;
+    function createIndexSignature(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], type: TypeNode): IndexSignatureDeclaration;
+    function updateIndexSignature(node: IndexSignatureDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, parameters: ParameterDeclaration[], type: TypeNode): IndexSignatureDeclaration;
+    function createKeywordTypeNode(kind: KeywordTypeNode["kind"]): KeywordTypeNode;
+    function createTypePredicateNode(parameterName: Identifier | ThisTypeNode | string, type: TypeNode): TypePredicateNode;
+    function updateTypePredicateNode(node: TypePredicateNode, parameterName: Identifier | ThisTypeNode, type: TypeNode): TypePredicateNode;
+    function createTypeReferenceNode(typeName: string | EntityName, typeArguments: TypeNode[] | undefined): TypeReferenceNode;
+    function updateTypeReferenceNode(node: TypeReferenceNode, typeName: EntityName, typeArguments: NodeArray<TypeNode> | undefined): TypeReferenceNode;
+    function createFunctionTypeNode(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): FunctionTypeNode;
+    function updateFunctionTypeNode(node: FunctionTypeNode, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): FunctionTypeNode;
+    function createConstructorTypeNode(typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined): ConstructorTypeNode;
+    function updateConstructorTypeNode(node: ConstructorTypeNode, typeParameters: NodeArray<TypeParameterDeclaration> | undefined, parameters: NodeArray<ParameterDeclaration>, type: TypeNode | undefined): ConstructorTypeNode;
+    function createTypeQueryNode(exprName: EntityName): TypeQueryNode;
+    function updateTypeQueryNode(node: TypeQueryNode, exprName: EntityName): TypeQueryNode;
+    function createTypeLiteralNode(members: TypeElement[]): TypeLiteralNode;
+    function updateTypeLiteralNode(node: TypeLiteralNode, members: NodeArray<TypeElement>): TypeLiteralNode;
+    function createArrayTypeNode(elementType: TypeNode): ArrayTypeNode;
+    function updateArrayTypeNode(node: ArrayTypeNode, elementType: TypeNode): ArrayTypeNode;
+    function createTupleTypeNode(elementTypes: TypeNode[]): TupleTypeNode;
+    function updateTypleTypeNode(node: TupleTypeNode, elementTypes: TypeNode[]): TupleTypeNode;
+    function createUnionTypeNode(types: TypeNode[]): UnionTypeNode;
+    function updateUnionTypeNode(node: UnionTypeNode, types: NodeArray<TypeNode>): UnionTypeNode;
+    function createIntersectionTypeNode(types: TypeNode[]): IntersectionTypeNode;
+    function updateIntersectionTypeNode(node: IntersectionTypeNode, types: NodeArray<TypeNode>): IntersectionTypeNode;
+    function createUnionOrIntersectionTypeNode(kind: SyntaxKind.UnionType | SyntaxKind.IntersectionType, types: TypeNode[]): UnionTypeNode | IntersectionTypeNode;
+    function createParenthesizedType(type: TypeNode): ParenthesizedTypeNode;
+    function updateParenthesizedType(node: ParenthesizedTypeNode, type: TypeNode): ParenthesizedTypeNode;
+    function createThisTypeNode(): ThisTypeNode;
+    function createTypeOperatorNode(type: TypeNode): TypeOperatorNode;
+    function updateTypeOperatorNode(node: TypeOperatorNode, type: TypeNode): TypeOperatorNode;
+    function createIndexedAccessTypeNode(objectType: TypeNode, indexType: TypeNode): IndexedAccessTypeNode;
+    function updateIndexedAccessTypeNode(node: IndexedAccessTypeNode, objectType: TypeNode, indexType: TypeNode): IndexedAccessTypeNode;
+    function createMappedTypeNode(readonlyToken: ReadonlyToken | undefined, typeParameter: TypeParameterDeclaration, questionToken: QuestionToken | undefined, type: TypeNode | undefined): MappedTypeNode;
+    function updateMappedTypeNode(node: MappedTypeNode, readonlyToken: ReadonlyToken | undefined, typeParameter: TypeParameterDeclaration, questionToken: QuestionToken | undefined, type: TypeNode | undefined): MappedTypeNode;
+    function createLiteralTypeNode(literal: Expression): LiteralTypeNode;
+    function updateLiteralTypeNode(node: LiteralTypeNode, literal: Expression): LiteralTypeNode;
     function createObjectBindingPattern(elements: BindingElement[]): ObjectBindingPattern;
     function updateObjectBindingPattern(node: ObjectBindingPattern, elements: BindingElement[]): ObjectBindingPattern;
     function createArrayBindingPattern(elements: ArrayBindingElement[]): ArrayBindingPattern;
@@ -2827,7 +2855,7 @@ declare namespace ts {
     function createPostfix(operand: Expression, operator: PostfixUnaryOperator): PostfixUnaryExpression;
     function updatePostfix(node: PostfixUnaryExpression, operand: Expression): PostfixUnaryExpression;
     function createBinary(left: Expression, operator: BinaryOperator | BinaryOperatorToken, right: Expression): BinaryExpression;
-    function updateBinary(node: BinaryExpression, left: Expression, right: Expression): BinaryExpression;
+    function updateBinary(node: BinaryExpression, left: Expression, right: Expression, operator?: BinaryOperator | BinaryOperatorToken): BinaryExpression;
     function createConditional(condition: Expression, whenTrue: Expression, whenFalse: Expression): ConditionalExpression;
     function createConditional(condition: Expression, questionToken: QuestionToken, whenTrue: Expression, colonToken: ColonToken, whenFalse: Expression): ConditionalExpression;
     function updateConditional(node: ConditionalExpression, condition: Expression, whenTrue: Expression, whenFalse: Expression): ConditionalExpression;
@@ -2847,16 +2875,15 @@ declare namespace ts {
     function updateAsExpression(node: AsExpression, expression: Expression, type: TypeNode): AsExpression;
     function createNonNullExpression(expression: Expression): NonNullExpression;
     function updateNonNullExpression(node: NonNullExpression, expression: Expression): NonNullExpression;
+    function createMetaProperty(keywordToken: MetaProperty["keywordToken"], name: Identifier): MetaProperty;
+    function updateMetaProperty(node: MetaProperty, name: Identifier): MetaProperty;
     function createTemplateSpan(expression: Expression, literal: TemplateMiddle | TemplateTail): TemplateSpan;
     function updateTemplateSpan(node: TemplateSpan, expression: Expression, literal: TemplateMiddle | TemplateTail): TemplateSpan;
+    function createSemicolonClassElement(): SemicolonClassElement;
     function createBlock(statements: Statement[], multiLine?: boolean): Block;
     function updateBlock(node: Block, statements: Statement[]): Block;
     function createVariableStatement(modifiers: Modifier[] | undefined, declarationList: VariableDeclarationList | VariableDeclaration[]): VariableStatement;
     function updateVariableStatement(node: VariableStatement, modifiers: Modifier[] | undefined, declarationList: VariableDeclarationList): VariableStatement;
-    function createVariableDeclarationList(declarations: VariableDeclaration[], flags?: NodeFlags): VariableDeclarationList;
-    function updateVariableDeclarationList(node: VariableDeclarationList, declarations: VariableDeclaration[]): VariableDeclarationList;
-    function createVariableDeclaration(name: string | BindingName, type?: TypeNode, initializer?: Expression): VariableDeclaration;
-    function updateVariableDeclaration(node: VariableDeclaration, name: BindingName, type: TypeNode | undefined, initializer: Expression | undefined): VariableDeclaration;
     function createEmptyStatement(): EmptyStatement;
     function createStatement(expression: Expression): ExpressionStatement;
     function updateStatement(node: ExpressionStatement, expression: Expression): ExpressionStatement;
@@ -2888,10 +2915,19 @@ declare namespace ts {
     function updateThrow(node: ThrowStatement, expression: Expression): ThrowStatement;
     function createTry(tryBlock: Block, catchClause: CatchClause | undefined, finallyBlock: Block | undefined): TryStatement;
     function updateTry(node: TryStatement, tryBlock: Block, catchClause: CatchClause | undefined, finallyBlock: Block | undefined): TryStatement;
+    function createDebuggerStatement(): DebuggerStatement;
+    function createVariableDeclaration(name: string | BindingName, type?: TypeNode, initializer?: Expression): VariableDeclaration;
+    function updateVariableDeclaration(node: VariableDeclaration, name: BindingName, type: TypeNode | undefined, initializer: Expression | undefined): VariableDeclaration;
+    function createVariableDeclarationList(declarations: VariableDeclaration[], flags?: NodeFlags): VariableDeclarationList;
+    function updateVariableDeclarationList(node: VariableDeclarationList, declarations: VariableDeclaration[]): VariableDeclarationList;
     function createFunctionDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: string | Identifier | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): FunctionDeclaration;
     function updateFunctionDeclaration(node: FunctionDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, asteriskToken: AsteriskToken | undefined, name: Identifier | undefined, typeParameters: TypeParameterDeclaration[] | undefined, parameters: ParameterDeclaration[], type: TypeNode | undefined, body: Block | undefined): FunctionDeclaration;
     function createClassDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier | undefined, typeParameters: TypeParameterDeclaration[] | undefined, heritageClauses: HeritageClause[], members: ClassElement[]): ClassDeclaration;
     function updateClassDeclaration(node: ClassDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier | undefined, typeParameters: TypeParameterDeclaration[] | undefined, heritageClauses: HeritageClause[], members: ClassElement[]): ClassDeclaration;
+    function createInterfaceDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, typeParameters: TypeParameterDeclaration[] | undefined, heritageClauses: HeritageClause[] | undefined, members: TypeElement[]): InterfaceDeclaration;
+    function updateInterfaceDeclaration(node: InterfaceDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, typeParameters: TypeParameterDeclaration[] | undefined, heritageClauses: HeritageClause[] | undefined, members: TypeElement[]): InterfaceDeclaration;
+    function createTypeAliasDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, typeParameters: TypeParameterDeclaration[] | undefined, type: TypeNode): TypeAliasDeclaration;
+    function updateTypeAliasDeclaration(node: TypeAliasDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, typeParameters: TypeParameterDeclaration[] | undefined, type: TypeNode): TypeAliasDeclaration;
     function createEnumDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, members: EnumMember[]): EnumDeclaration;
     function updateEnumDeclaration(node: EnumDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, members: EnumMember[]): EnumDeclaration;
     function createModuleDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: ModuleName, body: ModuleBody | undefined, flags?: NodeFlags): ModuleDeclaration;
@@ -2900,6 +2936,8 @@ declare namespace ts {
     function updateModuleBlock(node: ModuleBlock, statements: Statement[]): ModuleBlock;
     function createCaseBlock(clauses: CaseOrDefaultClause[]): CaseBlock;
     function updateCaseBlock(node: CaseBlock, clauses: CaseOrDefaultClause[]): CaseBlock;
+    function createNamespaceExportDeclaration(name: string | Identifier): NamespaceExportDeclaration;
+    function updateNamespaceExportDeclaration(node: NamespaceExportDeclaration, name: Identifier): NamespaceExportDeclaration;
     function createImportEqualsDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, moduleReference: ModuleReference): ImportEqualsDeclaration;
     function updateImportEqualsDeclaration(node: ImportEqualsDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, moduleReference: ModuleReference): ImportEqualsDeclaration;
     function createImportDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, importClause: ImportClause | undefined, moduleSpecifier?: Expression): ImportDeclaration;
@@ -2930,20 +2968,20 @@ declare namespace ts {
     function updateJsxOpeningElement(node: JsxOpeningElement, tagName: JsxTagNameExpression, attributes: JsxAttributes): JsxOpeningElement;
     function createJsxClosingElement(tagName: JsxTagNameExpression): JsxClosingElement;
     function updateJsxClosingElement(node: JsxClosingElement, tagName: JsxTagNameExpression): JsxClosingElement;
-    function createJsxAttributes(properties: JsxAttributeLike[]): JsxAttributes;
-    function updateJsxAttributes(jsxAttributes: JsxAttributes, properties: JsxAttributeLike[]): JsxAttributes;
     function createJsxAttribute(name: Identifier, initializer: StringLiteral | JsxExpression): JsxAttribute;
     function updateJsxAttribute(node: JsxAttribute, name: Identifier, initializer: StringLiteral | JsxExpression): JsxAttribute;
+    function createJsxAttributes(properties: JsxAttributeLike[]): JsxAttributes;
+    function updateJsxAttributes(node: JsxAttributes, properties: JsxAttributeLike[]): JsxAttributes;
     function createJsxSpreadAttribute(expression: Expression): JsxSpreadAttribute;
     function updateJsxSpreadAttribute(node: JsxSpreadAttribute, expression: Expression): JsxSpreadAttribute;
     function createJsxExpression(dotDotDotToken: DotDotDotToken | undefined, expression: Expression | undefined): JsxExpression;
     function updateJsxExpression(node: JsxExpression, expression: Expression | undefined): JsxExpression;
-    function createHeritageClause(token: HeritageClause["token"], types: ExpressionWithTypeArguments[]): HeritageClause;
-    function updateHeritageClause(node: HeritageClause, types: ExpressionWithTypeArguments[]): HeritageClause;
     function createCaseClause(expression: Expression, statements: Statement[]): CaseClause;
     function updateCaseClause(node: CaseClause, expression: Expression, statements: Statement[]): CaseClause;
     function createDefaultClause(statements: Statement[]): DefaultClause;
     function updateDefaultClause(node: DefaultClause, statements: Statement[]): DefaultClause;
+    function createHeritageClause(token: HeritageClause["token"], types: ExpressionWithTypeArguments[]): HeritageClause;
+    function updateHeritageClause(node: HeritageClause, types: ExpressionWithTypeArguments[]): HeritageClause;
     function createCatchClause(variableDeclaration: string | VariableDeclaration, block: Block): CatchClause;
     function updateCatchClause(node: CatchClause, variableDeclaration: VariableDeclaration, block: Block): CatchClause;
     function createPropertyAssignment(name: string | PropertyName, initializer: Expression): PropertyAssignment;
@@ -2976,6 +3014,8 @@ declare namespace ts {
      */
     function createPartiallyEmittedExpression(expression: Expression, original?: Node): PartiallyEmittedExpression;
     function updatePartiallyEmittedExpression(node: PartiallyEmittedExpression, expression: Expression): PartiallyEmittedExpression;
+    function createCommaList(elements: Expression[]): CommaListExpression;
+    function updateCommaList(node: CommaListExpression, elements: Expression[]): CommaListExpression;
     function createBundle(sourceFiles: SourceFile[]): Bundle;
     function updateBundle(node: Bundle, sourceFiles: SourceFile[]): Bundle;
     function createComma(left: Expression, right: Expression): Expression;
@@ -3040,11 +3080,11 @@ declare namespace ts {
     /**
      * Gets the constant value to emit for an expression.
      */
-    function getConstantValue(node: PropertyAccessExpression | ElementAccessExpression): number;
+    function getConstantValue(node: PropertyAccessExpression | ElementAccessExpression): string | number;
     /**
      * Sets the constant value to emit for an expression.
      */
-    function setConstantValue(node: PropertyAccessExpression | ElementAccessExpression, value: number): PropertyAccessExpression | ElementAccessExpression;
+    function setConstantValue(node: PropertyAccessExpression | ElementAccessExpression, value: string | number): PropertyAccessExpression | ElementAccessExpression;
     /**
      * Adds an EmitHelper to a node.
      */
@@ -3069,17 +3109,13 @@ declare namespace ts {
 }
 declare namespace ts {
     function createNode(kind: SyntaxKind, pos?: number, end?: number): Node;
-    function forEachChild<T>(node: Node, cbNode: (node: Node) => T, cbNodeArray?: (nodes: Node[]) => T): T;
+    function forEachChild<T>(node: Node, cbNode: (node: Node) => T, cbNodeArray?: (nodes: Node[]) => T): T | undefined;
     function createSourceFile(fileName: string, sourceText: string, languageVersion: ScriptTarget, setParentNodes?: boolean, scriptKind?: ScriptKind): SourceFile;
     function parseIsolatedEntityName(text: string, languageVersion: ScriptTarget): EntityName;
     function isExternalModule(file: SourceFile): boolean;
     function updateSourceFile(sourceFile: SourceFile, newText: string, textChangeRange: TextChangeRange, aggressiveChecks?: boolean): SourceFile;
 }
 declare namespace ts {
-    /** Array that is only intended to be pushed to, never read. */
-    interface Push<T> {
-        push(value: T): void;
-    }
     function moduleHasNonRelativeName(moduleName: string): boolean;
     function getEffectiveTypeRoots(options: CompilerOptions, host: {
         directoryExists?: (directoryName: string) => boolean;
@@ -3218,6 +3254,7 @@ declare namespace ts {
         getNewLine(): string;
     }
     function formatDiagnostics(diagnostics: Diagnostic[], host: FormatDiagnosticsHost): string;
+    function formatDiagnosticsWithColorAndContext(diagnostics: Diagnostic[], host: FormatDiagnosticsHost): string;
     function flattenDiagnosticMessageText(messageText: string | DiagnosticMessageChain, newLine: string): string;
     function createProgram(rootNames: string[], options: CompilerOptions, host?: CompilerHost, oldProgram?: Program): Program;
 }
@@ -3246,9 +3283,10 @@ declare namespace ts {
      * @param host Instance of ParseConfigHost used to enumerate files in folder.
      * @param basePath A root directory to resolve relative path entries in the config
      *    file to. e.g. outDir
+     * @param resolutionStack Only present for backwards-compatibility. Should be empty.
      */
     function parseJsonConfigFileContent(json: any, host: ParseConfigHost, basePath: string, existingOptions?: CompilerOptions, configFileName?: string, resolutionStack?: Path[], extraFileExtensions?: JsFileExtensionInfo[]): ParsedCommandLine;
-    function convertCompileOnSaveOptionFromJson(jsonOption: any, basePath: string, errors: Diagnostic[]): boolean | undefined;
+    function convertCompileOnSaveOptionFromJson(jsonOption: any, basePath: string, errors: Diagnostic[]): boolean;
     function convertCompilerOptionsFromJson(jsonOptions: any, basePath: string, configFileName?: string): {
         options: CompilerOptions;
         errors: Diagnostic[];
@@ -3422,6 +3460,8 @@ declare namespace ts {
         getDocCommentTemplateAtPosition(fileName: string, position: number): TextInsertion;
         isValidBraceCompletionAtPosition(fileName: string, position: number, openingBrace: number): boolean;
         getCodeFixesAtPosition(fileName: string, start: number, end: number, errorCodes: number[], formatOptions: FormatCodeSettings): CodeAction[];
+        getApplicableRefactors(fileName: string, positionOrRaneg: number | TextRange): ApplicableRefactorInfo[];
+        getRefactorCodeActions(fileName: string, formatOptions: FormatCodeSettings, positionOrRange: number | TextRange, refactorName: string): CodeAction[] | undefined;
         getEmitOutput(fileName: string, emitOnlyDtsFiles?: boolean): EmitOutput;
         getProgram(): Program;
         dispose(): void;
@@ -3492,6 +3532,10 @@ declare namespace ts {
         /** Text changes to apply to each file as part of the code action */
         changes: FileTextChanges[];
     }
+    interface ApplicableRefactorInfo {
+        name: string;
+        description: string;
+    }
     interface TextInsertion {
         newText: string;
         /** The position in newText the caret should point to after the insertion. */
@@ -4006,6 +4050,7 @@ declare namespace ts {
         reportDiagnostics?: boolean;
         moduleName?: string;
         renamedDependencies?: MapLike<string>;
+        transformers?: CustomTransformers;
     }
     interface TranspileOutput {
         outputText: string;

src/compiler/binder.ts

@@ -149,7 +149,7 @@ namespace ts {
             inStrictMode = bindInStrictMode(file, opts);
             classifiableNames = createMap<string>();
             symbolCount = 0;
-            skipTransformFlagAggregation = isDeclarationFile(file);
+            skipTransformFlagAggregation = file.isDeclarationFile;
 
             Symbol = objectAllocator.getSymbolConstructor();
 
@@ -182,7 +182,7 @@ namespace ts {
         return bindSourceFile;
 
         function bindInStrictMode(file: SourceFile, opts: CompilerOptions): boolean {
-            if ((opts.alwaysStrict === undefined ? opts.strict : opts.alwaysStrict) && !isDeclarationFile(file)) {
+            if ((opts.alwaysStrict === undefined ? opts.strict : opts.alwaysStrict) && !file.isDeclarationFile) {
                 // bind in strict mode source files with alwaysStrict option
                 return true;
             }
@@ -260,18 +260,9 @@ namespace ts {
                 case SyntaxKind.ExportAssignment:
                     return (<ExportAssignment>node).isExportEquals ? "export=" : "default";
                 case SyntaxKind.BinaryExpression:
-                    switch (getSpecialPropertyAssignmentKind(node as BinaryExpression)) {
-                        case SpecialPropertyAssignmentKind.ModuleExports:
-                            // module.exports = ...
-                            return "export=";
-                        case SpecialPropertyAssignmentKind.ExportsProperty:
-                        case SpecialPropertyAssignmentKind.ThisProperty:
-                        case SpecialPropertyAssignmentKind.Property:
-                            // exports.x = ... or this.y = ...
-                            return ((node as BinaryExpression).left as PropertyAccessExpression).name.text;
-                        case SpecialPropertyAssignmentKind.PrototypeProperty:
-                            // className.prototype.methodName = ...
-                            return (((node as BinaryExpression).left as PropertyAccessExpression).expression as PropertyAccessExpression).name.text;
+                    if (getSpecialPropertyAssignmentKind(node as BinaryExpression) === SpecialPropertyAssignmentKind.ModuleExports) {
+                        // module.exports = ...
+                        return "export=";
                     }
                     Debug.fail("Unknown binary declaration kind");
                     break;
@@ -439,6 +430,7 @@ namespace ts {
                 //       during global merging in the checker. Why? The only case when ambient module is permitted inside another module is module augmentation
                 //       and this case is specially handled. Module augmentations should only be merged with original module definition
                 //       and should never be merged directly with other augmentation, and the latter case would be possible if automatic merge is allowed.
+                if (node.kind === SyntaxKind.JSDocTypedefTag) Debug.assert(isInJavaScriptFile(node)); // We shouldn't add symbols for JSDoc nodes if not in a JS file.
                 const isJSDocTypedefInJSDocNamespace = node.kind === SyntaxKind.JSDocTypedefTag &&
                     (node as JSDocTypedefTag).name &&
                     (node as JSDocTypedefTag).name.kind === SyntaxKind.Identifier &&
@@ -603,9 +595,7 @@ namespace ts {
             // Binding of JsDocComment should be done before the current block scope container changes.
             // because the scope of JsDocComment should not be affected by whether the current node is a
             // container or not.
-            if (isInJavaScriptFile(node) && node.jsDoc) {
-                forEach(node.jsDoc, bind);
-            }
+            forEach(node.jsDoc, bind);
             if (checkUnreachable(node)) {
                 bindEachChild(node);
                 return;
@@ -1913,9 +1903,7 @@ namespace ts {
             // Here the current node is "foo", which is a container, but the scope of "MyType" should
             // not be inside "foo". Therefore we always bind @typedef before bind the parent node,
             // and skip binding this tag later when binding all the other jsdoc tags.
-            if (isInJavaScriptFile(node)) {
-                bindJSDocTypedefTagIfAny(node);
-            }
+            bindJSDocTypedefTagIfAny(node);
 
             // First we bind declaration nodes to a symbol if possible. We'll both create a symbol
             // and then potentially add the symbol to an appropriate symbol table. Possible
@@ -2003,7 +1991,7 @@ namespace ts {
                     // for typedef type names with namespaces, bind the new jsdoc type symbol here
                     // because it requires all containing namespaces to be in effect, namely the
                     // current "blockScopeContainer" needs to be set to its immediate namespace parent.
-                    if ((<Identifier>node).isInJSDocNamespace) {
+                    if (isInJavaScriptFile(node) && (<Identifier>node).isInJSDocNamespace) {
                         let parentNode = node.parent;
                         while (parentNode && parentNode.kind !== SyntaxKind.JSDocTypedefTag) {
                             parentNode = parentNode.parent;
@@ -2073,10 +2061,7 @@ namespace ts {
                     return bindVariableDeclarationOrBindingElement(<VariableDeclaration | BindingElement>node);
                 case SyntaxKind.PropertyDeclaration:
                 case SyntaxKind.PropertySignature:
-                case SyntaxKind.JSDocRecordMember:
-                    return bindPropertyOrMethodOrAccessor(<Declaration>node, SymbolFlags.Property | ((<PropertyDeclaration>node).questionToken ? SymbolFlags.Optional : SymbolFlags.None), SymbolFlags.PropertyExcludes);
-                case SyntaxKind.JSDocPropertyTag:
-                    return bindJSDocProperty(<JSDocPropertyTag>node);
+                    return bindPropertyWorker(node as PropertyDeclaration | PropertySignature);
                 case SyntaxKind.PropertyAssignment:
                 case SyntaxKind.ShorthandPropertyAssignment:
                     return bindPropertyOrMethodOrAccessor(<Declaration>node, SymbolFlags.Property, SymbolFlags.PropertyExcludes);
@@ -2121,13 +2106,10 @@ namespace ts {
                     return bindPropertyOrMethodOrAccessor(<Declaration>node, SymbolFlags.SetAccessor, SymbolFlags.SetAccessorExcludes);
                 case SyntaxKind.FunctionType:
                 case SyntaxKind.ConstructorType:
-                case SyntaxKind.JSDocFunctionType:
                     return bindFunctionOrConstructorType(<SignatureDeclaration>node);
                 case SyntaxKind.TypeLiteral:
                 case SyntaxKind.MappedType:
-                case SyntaxKind.JSDocTypeLiteral:
-                case SyntaxKind.JSDocRecordType:
-                    return bindAnonymousDeclaration(<Declaration>node, SymbolFlags.TypeLiteral, "__type");
+                    return bindAnonymousTypeWorker(node as TypeLiteralNode | MappedTypeNode);
                 case SyntaxKind.ObjectLiteralExpression:
                     return bindObjectLiteralExpression(<ObjectLiteralExpression>node);
                 case SyntaxKind.FunctionExpression:
@@ -2148,11 +2130,6 @@ namespace ts {
                     return bindClassLikeDeclaration(<ClassLikeDeclaration>node);
                 case SyntaxKind.InterfaceDeclaration:
                     return bindBlockScopedDeclaration(<Declaration>node, SymbolFlags.Interface, SymbolFlags.InterfaceExcludes);
-                case SyntaxKind.JSDocTypedefTag:
-                    if (!(<JSDocTypedefTag>node).fullName || (<JSDocTypedefTag>node).fullName.kind === SyntaxKind.Identifier) {
-                        return bindBlockScopedDeclaration(<Declaration>node, SymbolFlags.TypeAlias, SymbolFlags.TypeAliasExcludes);
-                    }
-                    break;
                 case SyntaxKind.TypeAliasDeclaration:
                     return bindBlockScopedDeclaration(<Declaration>node, SymbolFlags.TypeAlias, SymbolFlags.TypeAliasExcludes);
                 case SyntaxKind.EnumDeclaration:
@@ -2190,9 +2167,41 @@ namespace ts {
                 // falls through
                 case SyntaxKind.ModuleBlock:
                     return updateStrictModeStatementList((<Block | ModuleBlock>node).statements);
+
+                default:
+                    if (isInJavaScriptFile(node)) return bindJSDocWorker(node);
             }
         }
 
+        function bindJSDocWorker(node: Node) {
+            switch (node.kind) {
+                case SyntaxKind.JSDocRecordMember:
+                    return bindPropertyWorker(node as JSDocRecordMember);
+                case SyntaxKind.JSDocPropertyTag:
+                    return declareSymbolAndAddToSymbolTable(node as JSDocPropertyTag, SymbolFlags.Property, SymbolFlags.PropertyExcludes);
+                case SyntaxKind.JSDocFunctionType:
+                    return bindFunctionOrConstructorType(<SignatureDeclaration>node);
+                case SyntaxKind.JSDocTypeLiteral:
+                case SyntaxKind.JSDocRecordType:
+                    return bindAnonymousTypeWorker(node as JSDocTypeLiteral | JSDocRecordType);
+                case SyntaxKind.JSDocTypedefTag: {
+                    const { fullName } = node as JSDocTypedefTag;
+                    if (!fullName || fullName.kind === SyntaxKind.Identifier) {
+                        return bindBlockScopedDeclaration(<Declaration>node, SymbolFlags.TypeAlias, SymbolFlags.TypeAliasExcludes);
+                    }
+                    break;
+                }
+            }
+        }
+
+        function bindPropertyWorker(node: PropertyDeclaration | PropertySignature) {
+            return bindPropertyOrMethodOrAccessor(node, SymbolFlags.Property | (node.questionToken ? SymbolFlags.Optional : SymbolFlags.None), SymbolFlags.PropertyExcludes);
+        }
+
+        function bindAnonymousTypeWorker(node: TypeLiteralNode | MappedTypeNode | JSDocTypeLiteral | JSDocRecordType) {
+            return bindAnonymousDeclaration(<Declaration>node, SymbolFlags.TypeLiteral, "__type");
+        }
+
         function checkTypePredicate(node: TypePredicateNode) {
             const { parameterName, type } = node;
             if (parameterName && parameterName.kind === SyntaxKind.Identifier) {
@@ -2527,7 +2536,7 @@ namespace ts {
         }
 
         function bindFunctionDeclaration(node: FunctionDeclaration) {
-            if (!isDeclarationFile(file) && !isInAmbientContext(node)) {
+            if (!file.isDeclarationFile && !isInAmbientContext(node)) {
                 if (isAsyncFunction(node)) {
                     emitFlags |= NodeFlags.HasAsyncFunctions;
                 }
@@ -2544,7 +2553,7 @@ namespace ts {
         }
 
         function bindFunctionExpression(node: FunctionExpression) {
-            if (!isDeclarationFile(file) && !isInAmbientContext(node)) {
+            if (!file.isDeclarationFile && !isInAmbientContext(node)) {
                 if (isAsyncFunction(node)) {
                     emitFlags |= NodeFlags.HasAsyncFunctions;
                 }
@@ -2558,10 +2567,8 @@ namespace ts {
         }
 
         function bindPropertyOrMethodOrAccessor(node: Declaration, symbolFlags: SymbolFlags, symbolExcludes: SymbolFlags) {
-            if (!isDeclarationFile(file) && !isInAmbientContext(node)) {
-                if (isAsyncFunction(node)) {
-                    emitFlags |= NodeFlags.HasAsyncFunctions;
-                }
+            if (!file.isDeclarationFile && !isInAmbientContext(node) && isAsyncFunction(node)) {
+                emitFlags |= NodeFlags.HasAsyncFunctions;
             }
 
             if (currentFlow && isObjectLiteralOrClassExpressionMethod(node)) {
@@ -2573,10 +2580,6 @@ namespace ts {
                 : declareSymbolAndAddToSymbolTable(node, symbolFlags, symbolExcludes);
         }
 
-        function bindJSDocProperty(node: JSDocPropertyTag) {
-            return declareSymbolAndAddToSymbolTable(node, SymbolFlags.Property, SymbolFlags.PropertyExcludes);
-        }
-
         // reachability checks
 
         function shouldReportErrorOnModuleDeclaration(node: ModuleDeclaration): boolean {
@@ -3395,6 +3398,7 @@ namespace ts {
             case SyntaxKind.IndexedAccessType:
             case SyntaxKind.MappedType:
             case SyntaxKind.LiteralType:
+            case SyntaxKind.NamespaceExportDeclaration:
                 // Types and signatures are TypeScript syntax, and exclude all other facts.
                 transformFlags = TransformFlags.AssertTypeScript;
                 excludeFlags = TransformFlags.TypeExcludes;

src/compiler/commandLineParser.ts

@@ -139,6 +139,7 @@ namespace ts {
                     "es2017.object": "lib.es2017.object.d.ts",
                     "es2017.sharedmemory": "lib.es2017.sharedmemory.d.ts",
                     "es2017.string": "lib.es2017.string.d.ts",
+                    "es2017.intl": "lib.es2017.intl.d.ts",
                     "esnext.asynciterable": "lib.esnext.asynciterable.d.ts",
                 }),
             },

src/compiler/comments.ts

@@ -58,8 +58,10 @@ namespace ts {
                     }
 
                     const isEmittedNode = node.kind !== SyntaxKind.NotEmittedStatement;
-                    const skipLeadingComments = pos < 0 || (emitFlags & EmitFlags.NoLeadingComments) !== 0;
-                    const skipTrailingComments = end < 0 || (emitFlags & EmitFlags.NoTrailingComments) !== 0;
+                    // We have to explicitly check that the node is JsxText because if the compilerOptions.jsx is "preserve" we will not do any transformation.
+                    // It is expensive to walk entire tree just to set one kind of node to have no comments.
+                    const skipLeadingComments = pos < 0 || (emitFlags & EmitFlags.NoLeadingComments) !== 0 || node.kind === SyntaxKind.JsxText;
+                    const skipTrailingComments = end < 0 || (emitFlags & EmitFlags.NoTrailingComments) !== 0 || node.kind === SyntaxKind.JsxText;
 
                     // Emit leading comments if the position is not synthesized and the node
                     // has not opted out from emitting leading comments.

src/compiler/core.ts

@@ -230,6 +230,8 @@ namespace ts {
      * If no such value is found, it applies the callback until the parent pointer is undefined or the callback returns "quit"
      * At that point findAncestor returns undefined.
      */
+    export function findAncestor<T extends Node>(node: Node, callback: (element: Node) => element is T): T | undefined;
+    export function findAncestor(node: Node, callback: (element: Node) => boolean | "quit"): Node | undefined;
     export function findAncestor(node: Node, callback: (element: Node) => boolean | "quit"): Node {
         while (node) {
             const result = callback(node);
@@ -1762,6 +1764,11 @@ namespace ts {
         return str.lastIndexOf(prefix, 0) === 0;
     }
 
+    /* @internal */
+    export function removePrefix(str: string, prefix: string): string {
+        return startsWith(str, prefix) ? str.substr(prefix.length) : str;
+    }
+
     /* @internal */
     export function endsWith(str: string, suffix: string): boolean {
         const expectedPos = str.length - suffix.length;
@@ -1776,7 +1783,8 @@ namespace ts {
         return path.length > extension.length && endsWith(path, extension);
     }
 
-    export function fileExtensionIsAny(path: string, extensions: string[]): boolean {
+    /* @internal */
+    export function fileExtensionIsOneOf(path: string, extensions: string[]): boolean {
         for (const extension of extensions) {
             if (fileExtensionIs(path, extension)) {
                 return true;
@@ -1976,7 +1984,7 @@ namespace ts {
             for (const current of files) {
                 const name = combinePaths(path, current);
                 const absoluteName = combinePaths(absolutePath, current);
-                if (extensions && !fileExtensionIsAny(name, extensions)) continue;
+                if (extensions && !fileExtensionIsOneOf(name, extensions)) continue;
                 if (excludeRegex && excludeRegex.test(absoluteName)) continue;
                 if (!includeFileRegexes) {
                     results[0].push(name);

src/compiler/declarationEmitter.ts

@@ -190,7 +190,7 @@ namespace ts {
             const writer = <EmitTextWriterWithSymbolWriter>createTextWriter(newLine);
             writer.trackSymbol = trackSymbol;
             writer.reportInaccessibleThisError = reportInaccessibleThisError;
-            writer.reportIllegalExtends = reportIllegalExtends;
+            writer.reportPrivateInBaseOfClassExpression = reportPrivateInBaseOfClassExpression;
             writer.writeKeyword = writer.write;
             writer.writeOperator = writer.write;
             writer.writePunctuation = writer.write;
@@ -314,11 +314,11 @@ namespace ts {
             recordTypeReferenceDirectivesIfNecessary(resolver.getTypeReferenceDirectivesForSymbol(symbol, meaning));
         }
 
-        function reportIllegalExtends() {
+        function reportPrivateInBaseOfClassExpression(propertyName: string) {
             if (errorNameNode) {
                 reportedDeclarationError = true;
-                emitterDiagnostics.add(createDiagnosticForNode(errorNameNode, Diagnostics.extends_clause_of_exported_class_0_refers_to_a_type_whose_name_cannot_be_referenced,
-                    declarationNameToString(errorNameNode)));
+                emitterDiagnostics.add(
+                    createDiagnosticForNode(errorNameNode, Diagnostics.Property_0_of_exported_class_expression_may_not_be_private_or_protected, propertyName));
             }
         }
 
@@ -344,7 +344,9 @@ namespace ts {
             }
             else {
                 errorNameNode = declaration.name;
-                const format = TypeFormatFlags.UseTypeOfFunction | TypeFormatFlags.UseTypeAliasValue |
+                const format = TypeFormatFlags.UseTypeOfFunction |
+                    TypeFormatFlags.WriteClassExpressionAsTypeLiteral |
+                    TypeFormatFlags.UseTypeAliasValue |
                     (shouldUseResolverType ? TypeFormatFlags.AddUndefined : 0);
                 resolver.writeTypeOfDeclaration(declaration, enclosingDeclaration, format, writer);
                 errorNameNode = undefined;
@@ -360,7 +362,11 @@ namespace ts {
             }
             else {
                 errorNameNode = signature.name;
-                resolver.writeReturnTypeOfSignatureDeclaration(signature, enclosingDeclaration, TypeFormatFlags.UseTypeOfFunction | TypeFormatFlags.UseTypeAliasValue, writer);
+                resolver.writeReturnTypeOfSignatureDeclaration(
+                    signature,
+                    enclosingDeclaration,
+                    TypeFormatFlags.UseTypeOfFunction | TypeFormatFlags.UseTypeAliasValue | TypeFormatFlags.WriteClassExpressionAsTypeLiteral,
+                    writer);
                 errorNameNode = undefined;
             }
         }
@@ -621,7 +627,11 @@ namespace ts {
             write(tempVarName);
             write(": ");
             writer.getSymbolAccessibilityDiagnostic = () => diagnostic;
-            resolver.writeTypeOfExpression(expr, enclosingDeclaration, TypeFormatFlags.UseTypeOfFunction | TypeFormatFlags.UseTypeAliasValue, writer);
+            resolver.writeTypeOfExpression(
+                expr,
+                enclosingDeclaration,
+                TypeFormatFlags.UseTypeOfFunction | TypeFormatFlags.UseTypeAliasValue | TypeFormatFlags.WriteClassExpressionAsTypeLiteral,
+                writer);
             write(";");
             writeLine();
             return tempVarName;
@@ -984,7 +994,7 @@ namespace ts {
             const enumMemberValue = resolver.getConstantValue(node);
             if (enumMemberValue !== undefined) {
                 write(" = ");
-                write(enumMemberValue.toString());
+                write(getTextOfConstantValue(enumMemberValue));
             }
             write(",");
             writeLine();
@@ -1840,7 +1850,7 @@ namespace ts {
         function writeReferencePath(referencedFile: SourceFile, addBundledFileReference: boolean, emitOnlyDtsFiles: boolean): boolean {
             let declFileName: string;
             let addedBundledEmitReference = false;
-            if (isDeclarationFile(referencedFile)) {
+            if (referencedFile.isDeclarationFile) {
                 // Declaration file, use declaration file name
                 declFileName = referencedFile.fileName;
             }

src/compiler/diagnosticMessages.json

@@ -1075,7 +1075,7 @@
         "category": "Error",
         "code": 2345
     },
-    "Supplied parameters do not match any signature of call target.": {
+    "Call target does not contain any signatures.": {
         "category": "Error",
         "code": 2346
     },
@@ -1863,6 +1863,30 @@
         "category": "Error",
         "code": 2552
     },
+    "Computed values are not permitted in an enum with string valued members.": {
+        "category": "Error",
+        "code": 2553
+    },
+    "Expected {0} arguments, but got {1}.": {
+        "category": "Error",
+        "code": 2554
+    },
+    "Expected at least {0} arguments, but got {1}.": {
+        "category": "Error",
+        "code": 2555
+    },
+    "Expected {0} arguments, but got a minimum of {1}.": {
+        "category": "Error",
+        "code": 2556
+    },
+    "Expected at least {0} arguments, but got a minimum of {1}.": {
+        "category": "Error",
+        "code": 2557
+    },
+    "Expected {0} type arguments, but got {1}.": {
+        "category": "Error",
+        "code": 2558
+    },
     "JSX element attributes type '{0}' may not be a union type.": {
         "category": "Error",
         "code": 2600
@@ -2440,9 +2464,9 @@
         "category": "Error",
         "code": 4092
     },
-    "'extends' clause of exported class '{0}' refers to a type whose name cannot be referenced.": {
+    "Property '{0}' of exported class expression may not be private or protected.": {
         "category": "Error",
-        "code": 4093
+        "code": 4094
     },
 
     "The current host does not support the '{0}' option.": {
@@ -3045,6 +3069,10 @@
         "category": "Message",
         "code": 6136
     },
+    "Cannot import type declaration files. Consider importing '{0}' instead of '{1}'.": {
+        "category": "Error",
+        "code": 6137
+    },
     "Property '{0}' is declared but never used.": {
         "category": "Error",
         "code": 6138
@@ -3564,6 +3592,15 @@
         "code": 90022
     },
 
+    "Convert function to an ES2015 class": {
+        "category": "Message",
+        "code": 95001
+    },
+    "Convert function '{0}' to class": {
+        "category": "Message",
+        "code": 95002
+    },
+
     "Octal literal types must use ES2015 syntax. Use the syntax '{0}'.": {
         "category": "Error",
         "code": 8017

src/compiler/emitter.ts

@@ -153,7 +153,7 @@ namespace ts {
             for (let i = 0; i < numNodes; i++) {
                 const currentNode = bundle ? bundle.sourceFiles[i] : node;
                 const sourceFile = isSourceFile(currentNode) ? currentNode : currentSourceFile;
-                const shouldSkip = compilerOptions.noEmitHelpers || (sourceFile && getExternalHelpersModuleName(sourceFile) !== undefined);
+                const shouldSkip = compilerOptions.noEmitHelpers || getExternalHelpersModuleName(sourceFile) !== undefined;
                 const shouldBundle = isSourceFile(currentNode) && !isOwnFileEmit;
                 const helpers = getEmitHelpers(currentNode);
                 if (helpers) {
@@ -200,7 +200,9 @@ namespace ts {
             onSetSourceFile,
             substituteNode,
             onBeforeEmitNodeArray,
-            onAfterEmitNodeArray
+            onAfterEmitNodeArray,
+            onBeforeEmitToken,
+            onAfterEmitToken
         } = handlers;
 
         const newLine = getNewLineCharacter(printerOptions);
@@ -212,7 +214,7 @@ namespace ts {
             emitLeadingCommentsOfPosition,
         } = comments;
 
-        let currentSourceFile: SourceFile;
+        let currentSourceFile: SourceFile | undefined;
         let nodeIdToGeneratedName: string[]; // Map of generated names for specific nodes.
         let autoGeneratedIdToGeneratedName: string[]; // Map of generated names for temp and loop variables.
         let generatedNames: Map<string>; // Set of names generated by the NameGenerator.
@@ -264,7 +266,12 @@ namespace ts {
             return endPrint();
         }
 
-        function writeNode(hint: EmitHint, node: Node, sourceFile: SourceFile, output: EmitTextWriter) {
+        /**
+         * If `sourceFile` is `undefined`, `node` must be a synthesized `TypeNode`.
+         */
+        function writeNode(hint: EmitHint, node: TypeNode, sourceFile: undefined, output: EmitTextWriter): void;
+        function writeNode(hint: EmitHint, node: Node, sourceFile: SourceFile, output: EmitTextWriter): void;
+        function writeNode(hint: EmitHint, node: Node, sourceFile: SourceFile | undefined, output: EmitTextWriter) {
             const previousWriter = writer;
             setWriter(output);
             print(hint, node, sourceFile);
@@ -305,8 +312,10 @@ namespace ts {
             return text;
         }
 
-        function print(hint: EmitHint, node: Node, sourceFile: SourceFile) {
-            setSourceFile(sourceFile);
+        function print(hint: EmitHint, node: Node, sourceFile: SourceFile | undefined) {
+            if (sourceFile) {
+                setSourceFile(sourceFile);
+            }
             pipelineEmitWithNotification(hint, node);
         }
 
@@ -399,7 +408,7 @@ namespace ts {
             // Strict mode reserved words
             // Contextual keywords
             if (isKeyword(kind)) {
-                writeTokenText(kind);
+                writeTokenNode(node);
                 return;
             }
 
@@ -562,6 +571,8 @@ namespace ts {
                     return emitModuleBlock(<ModuleBlock>node);
                 case SyntaxKind.CaseBlock:
                     return emitCaseBlock(<CaseBlock>node);
+                case SyntaxKind.NamespaceExportDeclaration:
+                    return emitNamespaceExportDeclaration(<NamespaceExportDeclaration>node);
                 case SyntaxKind.ImportEqualsDeclaration:
                     return emitImportEqualsDeclaration(<ImportEqualsDeclaration>node);
                 case SyntaxKind.ImportDeclaration:
@@ -638,7 +649,7 @@ namespace ts {
             }
 
             if (isToken(node)) {
-                writeTokenText(kind);
+                writeTokenNode(node);
                 return;
             }
         }
@@ -665,7 +676,7 @@ namespace ts {
                 case SyntaxKind.SuperKeyword:
                 case SyntaxKind.TrueKeyword:
                 case SyntaxKind.ThisKeyword:
-                    writeTokenText(kind);
+                    writeTokenNode(node);
                     return;
 
                 // Expressions
@@ -781,6 +792,7 @@ namespace ts {
 
         function emitIdentifier(node: Identifier) {
             write(getTextOfNode(node, /*includeTrivia*/ false));
+            emitTypeArguments(node, node.typeArguments);
         }
 
         //
@@ -815,6 +827,7 @@ namespace ts {
         function emitTypeParameter(node: TypeParameterDeclaration) {
             emit(node.name);
             emitWithPrefix(" extends ", node.constraint);
+            emitWithPrefix(" = ", node.default);
         }
 
         function emitParameter(node: ParameterDeclaration) {
@@ -849,6 +862,7 @@ namespace ts {
             emitDecorators(node, node.decorators);
             emitModifiers(node, node.modifiers);
             emit(node.name);
+            writeIfPresent(node.questionToken, "?");
             emitWithPrefix(": ", node.type);
             emitExpressionWithPrefix(" = ", node.initializer);
             write(";");
@@ -870,6 +884,7 @@ namespace ts {
             emitModifiers(node, node.modifiers);
             writeIfPresent(node.asteriskToken, "*");
             emit(node.name);
+            writeIfPresent(node.questionToken, "?");
             emitSignatureAndBody(node, emitSignatureHead);
         }
 
@@ -955,7 +970,10 @@ namespace ts {
 
         function emitTypeLiteral(node: TypeLiteralNode) {
             write("{");
-            emitList(node, node.members, ListFormat.TypeLiteralMembers);
+            // If the literal is empty, do not add spaces between braces.
+            if (node.members.length > 0) {
+                emitList(node, node.members, getEmitFlags(node) & EmitFlags.SingleLine ? ListFormat.SingleLineTypeLiteralMembers : ListFormat.MultiLineTypeLiteralMembers);
+            }
             write("}");
         }
 
@@ -1002,9 +1020,15 @@ namespace ts {
         }
 
         function emitMappedType(node: MappedTypeNode) {
+            const emitFlags = getEmitFlags(node);
             write("{");
-            writeLine();
-            increaseIndent();
+            if (emitFlags & EmitFlags.SingleLine) {
+                write(" ");
+            }
+            else {
+                writeLine();
+                increaseIndent();
+            }
             writeIfPresent(node.readonlyToken, "readonly ");
             write("[");
             emit(node.typeParameter.name);
@@ -1015,8 +1039,13 @@ namespace ts {
             write(": ");
             emit(node.type);
             write(";");
-            writeLine();
-            decreaseIndent();
+            if (emitFlags & EmitFlags.SingleLine) {
+                write(" ");
+            }
+            else {
+                writeLine();
+                decreaseIndent();
+            }
             write("}");
         }
 
@@ -1131,7 +1160,7 @@ namespace ts {
                 // check if constant enum value is integer
                 const constantValue = getConstantValue(expression);
                 // isFinite handles cases when constantValue is undefined
-                return isFinite(constantValue)
+                return typeof constantValue === "number" && isFinite(constantValue)
                     && Math.floor(constantValue) === constantValue
                     && printerOptions.removeComments;
             }
@@ -1237,7 +1266,7 @@ namespace ts {
             const operand = node.operand;
             return operand.kind === SyntaxKind.PrefixUnaryExpression
                 && ((node.operator === SyntaxKind.PlusToken && ((<PrefixUnaryExpression>operand).operator === SyntaxKind.PlusToken || (<PrefixUnaryExpression>operand).operator === SyntaxKind.PlusPlusToken))
-                || (node.operator === SyntaxKind.MinusToken && ((<PrefixUnaryExpression>operand).operator === SyntaxKind.MinusToken || (<PrefixUnaryExpression>operand).operator === SyntaxKind.MinusMinusToken)));
+                    || (node.operator === SyntaxKind.MinusToken && ((<PrefixUnaryExpression>operand).operator === SyntaxKind.MinusToken || (<PrefixUnaryExpression>operand).operator === SyntaxKind.MinusMinusToken)));
         }
 
         function emitPostfixUnaryExpression(node: PostfixUnaryExpression) {
@@ -1252,7 +1281,7 @@ namespace ts {
 
             emitExpression(node.left);
             increaseIndentIf(indentBeforeOperator, isCommaOperator ? " " : undefined);
-            writeTokenText(node.operatorToken.kind);
+            writeTokenNode(node.operatorToken);
             increaseIndentIf(indentAfterOperator, " ");
             emitExpression(node.right);
             decreaseIndentIf(indentBeforeOperator, indentAfterOperator);
@@ -1859,6 +1888,12 @@ namespace ts {
             write(";");
         }
 
+        function emitNamespaceExportDeclaration(node: NamespaceExportDeclaration) {
+            write("export as namespace ");
+            emit(node.name);
+            write(";");
+        }
+
         function emitNamedExports(node: NamedExports) {
             emitNamedImportsOrExports(node);
         }
@@ -1996,6 +2031,22 @@ namespace ts {
                     rangeStartPositionsAreOnSameLine(parentNode, statements[0], currentSourceFile)
                 );
 
+            // e.g:
+            //      case 0: // Zero
+            //      case 1: // One
+            //      case 2: // two
+            //          return "hi";
+            // If there is no statements, emitNodeWithComments of the parentNode which is caseClause will take care of trailing comment.
+            // So in example above, comment "// Zero" and "// One" will be emit in emitTrailingComments in emitNodeWithComments.
+            // However, for "case 2", because parentNode which is caseClause has an "end" property to be end of the statements (in this case return statement)
+            // comment "// two" will not be emitted in emitNodeWithComments.
+            // Therefore, we have to do the check here to emit such comment.
+            if (statements.length > 0) {
+                // We use emitTrailingCommentsOfPosition instead of emitLeadingCommentsOfPosition because leading comments is defined as comments before the node after newline character separating it from previous line
+                // Note: we can't use parentNode.end as such position includes statements.
+                emitTrailingCommentsOfPosition(statements.pos);
+            }
+
             if (emitAsSingleStatement) {
                 write(" ");
                 emit(statements[0]);
@@ -2432,6 +2483,16 @@ namespace ts {
                 : writeTokenText(token, pos);
         }
 
+        function writeTokenNode(node: Node) {
+            if (onBeforeEmitToken) {
+                onBeforeEmitToken(node);
+            }
+            writeTokenText(node.kind);
+            if (onAfterEmitToken) {
+                onAfterEmitToken(node);
+            }
+        }
+
         function writeTokenText(token: SyntaxKind, pos?: number) {
             const tokenString = tokenToString(token);
             write(tokenString);
@@ -2637,7 +2698,9 @@ namespace ts {
             if (node.kind === SyntaxKind.StringLiteral && (<StringLiteral>node).textSourceNode) {
                 const textSourceNode = (<StringLiteral>node).textSourceNode;
                 if (isIdentifier(textSourceNode)) {
-                    return "\"" + escapeNonAsciiCharacters(escapeString(getTextOfNode(textSourceNode))) + "\"";
+                    return getEmitFlags(node) & EmitFlags.NoAsciiEscaping ?
+                        `"${escapeString(getTextOfNode(textSourceNode))}"` :
+                        `"${escapeNonAsciiString(getTextOfNode(textSourceNode))}"`;
                 }
                 else {
                     return getLiteralTextOfNode(textSourceNode);
@@ -2903,9 +2966,9 @@ namespace ts {
 
     // Flags enum to track count of temp variables and a few dedicated names
     const enum TempFlags {
-        Auto      = 0x00000000,  // No preferred name
+        Auto = 0x00000000,  // No preferred name
         CountMask = 0x0FFFFFFF,  // Temp variable counter
-        _i        = 0x10000000,  // Use/preference flag for '_i'
+        _i = 0x10000000,  // Use/preference flag for '_i'
     }
 
     const enum ListFormat {
@@ -2948,9 +3011,11 @@ namespace ts {
         NoInterveningComments = 1 << 17, // Do not emit comments between each node
 
         // Precomputed Formats
-        Modifiers = SingleLine | SpaceBetweenSiblings,
+        Modifiers = SingleLine | SpaceBetweenSiblings | NoInterveningComments,
         HeritageClauses = SingleLine | SpaceBetweenSiblings,
-        TypeLiteralMembers = MultiLine | Indented,
+        SingleLineTypeLiteralMembers = SingleLine | SpaceBetweenBraces | SpaceBetweenSiblings | Indented,
+        MultiLineTypeLiteralMembers = MultiLine | Indented,
+
         TupleTypeElements = CommaDelimited | SpaceBetweenSiblings | SingleLine | Indented,
         UnionTypeConstituents = BarDelimited | SpaceBetweenSiblings | SingleLine,
         IntersectionTypeConstituents = AmpersandDelimited | SpaceBetweenSiblings | SingleLine,

src/compiler/factory.ts

@@ -107,15 +107,27 @@ namespace ts {
 
     // Identifiers
 
-    export function createIdentifier(text: string): Identifier {
+    export function createIdentifier(text: string): Identifier;
+    /* @internal */
+    export function createIdentifier(text: string, typeArguments: TypeNode[]): Identifier;
+    export function createIdentifier(text: string, typeArguments?: TypeNode[]): Identifier {
         const node = <Identifier>createSynthesizedNode(SyntaxKind.Identifier);
         node.text = escapeIdentifier(text);
         node.originalKeywordKind = text ? stringToToken(text) : SyntaxKind.Unknown;
         node.autoGenerateKind = GeneratedIdentifierKind.None;
         node.autoGenerateId = 0;
+        if (typeArguments) {
+            node.typeArguments = createNodeArray(typeArguments);
+        }
         return node;
     }
 
+    export function updateIdentifier(node: Identifier, typeArguments: NodeArray<TypeNode> | undefined): Identifier {
+        return node.typeArguments !== typeArguments
+        ? updateNode(createIdentifier(node.text, typeArguments), node)
+        : node;
+    }
+
     let nextAutoGenerateId = 0;
 
     /** Create a unique temporary variable. */
@@ -271,8 +283,9 @@ namespace ts {
 
     // Type Elements
 
-    export function createPropertySignature(name: PropertyName | string, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature {
+    export function createPropertySignature(modifiers: Modifier[] | undefined, name: PropertyName | string, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined): PropertySignature {
         const node = createSynthesizedNode(SyntaxKind.PropertySignature) as PropertySignature;
+        node.modifiers = asNodeArray(modifiers);
         node.name = asName(name);
         node.questionToken = questionToken;
         node.type = type;
@@ -280,12 +293,13 @@ namespace ts {
         return node;
     }
 
-    export function updatePropertySignature(node: PropertySignature, name: PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined) {
-        return node.name !== name
+    export function updatePropertySignature(node: PropertySignature, modifiers: Modifier[] | undefined, name: PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined) {
+        return node.modifiers !== modifiers
+            || node.name !== name
             || node.questionToken !== questionToken
             || node.type !== type
             || node.initializer !== initializer
-            ? updateNode(createPropertySignature(name, questionToken, type, initializer), node)
+            ? updateNode(createPropertySignature(modifiers, name, questionToken, type, initializer), node)
             : node;
     }
 
@@ -492,7 +506,7 @@ namespace ts {
     export function createTypeReferenceNode(typeName: string | EntityName, typeArguments: TypeNode[] | undefined) {
         const node = createSynthesizedNode(SyntaxKind.TypeReference) as TypeReferenceNode;
         node.typeName = asName(typeName);
-        node.typeArguments = asNodeArray(typeArguments);
+        node.typeArguments = typeArguments && parenthesizeTypeParameters(typeArguments);
         return node;
     }
 
@@ -545,7 +559,7 @@ namespace ts {
 
     export function createArrayTypeNode(elementType: TypeNode) {
         const node = createSynthesizedNode(SyntaxKind.ArrayType) as ArrayTypeNode;
-        node.elementType = elementType;
+        node.elementType = parenthesizeElementTypeMember(elementType);
         return node;
     }
 
@@ -585,7 +599,7 @@ namespace ts {
 
     export function createUnionOrIntersectionTypeNode(kind: SyntaxKind.UnionType | SyntaxKind.IntersectionType, types: TypeNode[]) {
         const node = createSynthesizedNode(kind) as UnionTypeNode | IntersectionTypeNode;
-        node.types = createNodeArray(types);
+        node.types = parenthesizeElementTypeMembers(types);
         return node;
     }
 
@@ -614,7 +628,7 @@ namespace ts {
     export function createTypeOperatorNode(type: TypeNode) {
         const node = createSynthesizedNode(SyntaxKind.TypeOperator) as TypeOperatorNode;
         node.operator = SyntaxKind.KeyOfKeyword;
-        node.type = type;
+        node.type = parenthesizeElementTypeMember(type);
         return node;
     }
 
@@ -624,7 +638,7 @@ namespace ts {
 
     export function createIndexedAccessTypeNode(objectType: TypeNode, indexType: TypeNode) {
         const node = createSynthesizedNode(SyntaxKind.IndexedAccessType) as IndexedAccessTypeNode;
-        node.objectType = objectType;
+        node.objectType = parenthesizeElementTypeMember(objectType);
         node.indexType = indexType;
         return node;
     }
@@ -970,10 +984,10 @@ namespace ts {
         return node;
     }
 
-    export function updateBinary(node: BinaryExpression, left: Expression, right: Expression) {
+    export function updateBinary(node: BinaryExpression, left: Expression, right: Expression, operator?: BinaryOperator | BinaryOperatorToken) {
         return node.left !== left
             || node.right !== right
-            ? updateNode(createBinary(left, node.operatorToken, right), node)
+            ? updateNode(createBinary(left, operator || node.operatorToken, right), node)
             : node;
     }
 
@@ -1488,19 +1502,23 @@ namespace ts {
             : node;
     }
 
-    export function createTypeAliasDeclaration(name: string | Identifier, typeParameters: TypeParameterDeclaration[] | undefined, type: TypeNode) {
+    export function createTypeAliasDeclaration(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | Identifier, typeParameters: TypeParameterDeclaration[] | undefined, type: TypeNode) {
         const node = <TypeAliasDeclaration>createSynthesizedNode(SyntaxKind.TypeAliasDeclaration);
+        node.decorators = asNodeArray(decorators);
+        node.modifiers = asNodeArray(modifiers);
         node.name = asName(name);
         node.typeParameters = asNodeArray(typeParameters);
         node.type = type;
         return node;
     }
 
-    export function updateTypeAliasDeclaration(node: TypeAliasDeclaration, name: Identifier, typeParameters: TypeParameterDeclaration[] | undefined, type: TypeNode) {
-        return node.name !== name
+    export function updateTypeAliasDeclaration(node: TypeAliasDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: Identifier, typeParameters: TypeParameterDeclaration[] | undefined, type: TypeNode) {
+        return node.decorators !== decorators
+            || node.modifiers !== modifiers
+            || node.name !== name
             || node.typeParameters !== typeParameters
             || node.type !== type
-            ? updateNode(createTypeAliasDeclaration(name, typeParameters, type), node)
+            ? updateNode(createTypeAliasDeclaration(decorators, modifiers, name, typeParameters, type), node)
             : node;
     }
 
@@ -1613,14 +1631,14 @@ namespace ts {
             : node;
     }
 
-    export function createImportClause(name: Identifier, namedBindings: NamedImportBindings): ImportClause {
+    export function createImportClause(name: Identifier | undefined, namedBindings: NamedImportBindings | undefined): ImportClause {
         const node = <ImportClause>createSynthesizedNode(SyntaxKind.ImportClause);
         node.name = name;
         node.namedBindings = namedBindings;
         return node;
     }
 
-    export function updateImportClause(node: ImportClause, name: Identifier, namedBindings: NamedImportBindings) {
+    export function updateImportClause(node: ImportClause, name: Identifier | undefined, namedBindings: NamedImportBindings | undefined) {
         return node.name !== name
             || node.namedBindings !== namedBindings
             ? updateNode(createImportClause(name, namedBindings), node)
@@ -2344,7 +2362,7 @@ namespace ts {
     /**
      * Sets the constant value to emit for an expression.
      */
-    export function setConstantValue(node: PropertyAccessExpression | ElementAccessExpression, value: number) {
+    export function setConstantValue(node: PropertyAccessExpression | ElementAccessExpression, value: string | number) {
         const emitNode = getOrCreateEmitNode(node);
         emitNode.constantValue = value;
         return node;
@@ -2476,6 +2494,25 @@ namespace ts {
 
 /* @internal */
 namespace ts {
+    export const nullTransformationContext: TransformationContext = {
+        enableEmitNotification: noop,
+        enableSubstitution: noop,
+        endLexicalEnvironment: () => undefined,
+        getCompilerOptions: notImplemented,
+        getEmitHost: notImplemented,
+        getEmitResolver: notImplemented,
+        hoistFunctionDeclaration: noop,
+        hoistVariableDeclaration: noop,
+        isEmitNotificationEnabled: notImplemented,
+        isSubstitutionEnabled: notImplemented,
+        onEmitNode: noop,
+        onSubstituteNode: notImplemented,
+        readEmitHelpers: notImplemented,
+        requestEmitHelper: noop,
+        resumeLexicalEnvironment: noop,
+        startLexicalEnvironment: noop,
+        suspendLexicalEnvironment: noop
+    };
 
     // Compound nodes
 
@@ -3276,16 +3313,6 @@ namespace ts {
         return statements;
     }
 
-    export function parenthesizeConditionalHead(condition: Expression) {
-        const conditionalPrecedence = getOperatorPrecedence(SyntaxKind.ConditionalExpression, SyntaxKind.QuestionToken);
-        const emittedCondition = skipPartiallyEmittedExpressions(condition);
-        const conditionPrecedence = getExpressionPrecedence(emittedCondition);
-        if (compareValues(conditionPrecedence, conditionalPrecedence) === Comparison.LessThan) {
-            return createParen(condition);
-        }
-        return condition;
-    }
-
     /**
      * Wraps the operand to a BinaryExpression in parentheses if they are needed to preserve the intended
      * order of operations.
@@ -3587,6 +3614,35 @@ namespace ts {
         return expression;
     }
 
+    export function parenthesizeElementTypeMember(member: TypeNode) {
+        switch (member.kind) {
+            case SyntaxKind.UnionType:
+            case SyntaxKind.IntersectionType:
+            case SyntaxKind.FunctionType:
+            case SyntaxKind.ConstructorType:
+                return createParenthesizedType(member);
+        }
+        return member;
+    }
+
+    export function parenthesizeElementTypeMembers(members: TypeNode[]) {
+        return createNodeArray(sameMap(members, parenthesizeElementTypeMember));
+    }
+
+    export function parenthesizeTypeParameters(typeParameters: TypeNode[]) {
+        if (some(typeParameters)) {
+            const nodeArray = createNodeArray() as NodeArray<TypeNode>;
+            for (let i = 0; i < typeParameters.length; ++i) {
+                const entry = typeParameters[i];
+                nodeArray.push(i === 0 && isFunctionOrConstructorTypeNode(entry) && entry.typeParameters ?
+                    createParenthesizedType(entry) :
+                    entry);
+            }
+
+            return nodeArray;
+        }
+    }
+
     /**
      * Clones a series of not-emitted expressions with a new inner expression.
      *
@@ -3783,7 +3839,7 @@ namespace ts {
         if (file.moduleName) {
             return createLiteral(file.moduleName);
         }
-        if (!isDeclarationFile(file) && (options.out || options.outFile)) {
+        if (!file.isDeclarationFile && (options.out || options.outFile)) {
             return createLiteral(getExternalModuleNameFromPath(host, file.fileName));
         }
         return undefined;

src/compiler/moduleNameResolver.ts

@@ -653,11 +653,13 @@ namespace ts {
                 if (state.traceEnabled) {
                     trace(state.host, Diagnostics.Trying_substitution_0_candidate_module_location_Colon_1, subst, path);
                 }
-                // A path mapping may have a ".ts" extension; in contrast to an import, which should omit it.
-                const tsExtension = tryGetExtensionFromPath(candidate);
-                if (tsExtension !== undefined) {
+                // A path mapping may have an extension, in contrast to an import, which should omit it.
+                const extension = tryGetExtensionFromPath(candidate);
+                if (extension !== undefined) {
                     const path = tryFile(candidate, failedLookupLocations, /*onlyRecordFailures*/ false, state);
-                    return path && { path, extension: tsExtension };
+                    if (path !== undefined) {
+                        return { path, extension };
+                    }
                 }
 
                 return loader(extensions, candidate, failedLookupLocations, !directoryProbablyExists(getDirectoryPath(candidate), state.host), state);
@@ -971,10 +973,13 @@ namespace ts {
         }
     }
 
+    /** Double underscores are used in DefinitelyTyped to delimit scoped packages. */
+    const mangledScopedPackageSeparator = "__";
+
     /** For a scoped package, we must look in `@types/foo__bar` instead of `@types/@foo/bar`. */
     function mangleScopedPackage(moduleName: string, state: ModuleResolutionState): string {
         if (startsWith(moduleName, "@")) {
-            const replaceSlash = moduleName.replace(ts.directorySeparator, "__");
+            const replaceSlash = moduleName.replace(ts.directorySeparator, mangledScopedPackageSeparator);
             if (replaceSlash !== moduleName) {
                 const mangled = replaceSlash.slice(1); // Take off the "@"
                 if (state.traceEnabled) {
@@ -986,6 +991,17 @@ namespace ts {
         return moduleName;
     }
 
+    /* @internal */
+    export function getPackageNameFromAtTypesDirectory(mangledName: string): string {
+        const withoutAtTypePrefix = removePrefix(mangledName, "@types/");
+        if (withoutAtTypePrefix !== mangledName) {
+            return withoutAtTypePrefix.indexOf("__") !== -1 ?
+                "@" + withoutAtTypePrefix.replace(mangledScopedPackageSeparator, ts.directorySeparator) :
+                withoutAtTypePrefix;
+        }
+        return mangledName;
+    }
+
     function tryFindNonRelativeModuleNameInCache(cache: PerModuleNameCache | undefined, moduleName: string, containingDirectory: string, traceEnabled: boolean, host: ModuleResolutionHost): SearchResult<Resolved> {
         const result = cache && cache.get(containingDirectory);
         if (result) {

src/compiler/parser.ts

@@ -22,19 +22,19 @@ namespace ts {
         }
     }
 
-    function visitNode<T>(cbNode: (node: Node) => T, node: Node): T {
+    function visitNode<T>(cbNode: (node: Node) => T, node?: Node): T | undefined {
         if (node) {
             return cbNode(node);
         }
     }
 
-    function visitNodeArray<T>(cbNodes: (nodes: Node[]) => T, nodes: Node[]) {
+    function visitNodeArray<T>(cbNodes: (nodes: Node[]) => T, nodes?: Node[]): T | undefined {
         if (nodes) {
             return cbNodes(nodes);
         }
     }
 
-    function visitEachNode<T>(cbNode: (node: Node) => T, nodes: Node[]) {
+    function visitEachNode<T>(cbNode: (node: Node) => T, nodes?: Node[]): T | undefined {
         if (nodes) {
             for (const node of nodes) {
                 const result = cbNode(node);
@@ -49,14 +49,14 @@ namespace ts {
     // stored in properties. If a 'cbNodes' callback is specified, it is invoked for embedded arrays; otherwise,
     // embedded arrays are flattened and the 'cbNode' callback is invoked for each element. If a callback returns
     // a truthy value, iteration stops and that value is returned. Otherwise, undefined is returned.
-    export function forEachChild<T>(node: Node, cbNode: (node: Node) => T, cbNodeArray?: (nodes: Node[]) => T): T {
+    export function forEachChild<T>(node: Node, cbNode: (node: Node) => T | undefined, cbNodeArray?: (nodes: NodeArray<Node>) => T | undefined): T | undefined {
         if (!node) {
             return;
         }
         // The visitXXX functions could be written as local functions that close over the cbNode and cbNodeArray
         // callback parameters, but that causes a closure allocation for each invocation with noticeable effects
         // on performance.
-        const visitNodes: (cb: ((node: Node) => T) | ((node: Node[]) => T), nodes: Node[]) => T = cbNodeArray ? visitNodeArray : visitEachNode;
+        const visitNodes: (cb: ((node?: Node) => T | undefined) | ((node?: Node[]) => T | undefined), nodes?: Node[]) => T | undefined = cbNodeArray ? visitNodeArray : visitEachNode;
         const cbNodes = cbNodeArray || cbNode;
         switch (node.kind) {
             case SyntaxKind.QualifiedName:
@@ -1273,12 +1273,12 @@ namespace ts {
             if (token() === SyntaxKind.ExportKeyword) {
                 nextToken();
                 if (token() === SyntaxKind.DefaultKeyword) {
-                    return lookAhead(nextTokenIsClassOrFunctionOrAsync);
+                    return lookAhead(nextTokenCanFollowDefaultKeyword);
                 }
                 return token() !== SyntaxKind.AsteriskToken && token() !== SyntaxKind.AsKeyword && token() !== SyntaxKind.OpenBraceToken && canFollowModifier();
             }
             if (token() === SyntaxKind.DefaultKeyword) {
-                return nextTokenIsClassOrFunctionOrAsync();
+                return nextTokenCanFollowDefaultKeyword();
             }
             if (token() === SyntaxKind.StaticKeyword) {
                 nextToken();
@@ -1300,9 +1300,10 @@ namespace ts {
                 || isLiteralPropertyName();
         }
 
-        function nextTokenIsClassOrFunctionOrAsync(): boolean {
+        function nextTokenCanFollowDefaultKeyword(): boolean {
             nextToken();
             return token() === SyntaxKind.ClassKeyword || token() === SyntaxKind.FunctionKeyword ||
+                token() === SyntaxKind.InterfaceKeyword ||
                 (token() === SyntaxKind.AbstractKeyword && lookAhead(nextTokenIsClassKeywordOnSameLine)) ||
                 (token() === SyntaxKind.AsyncKeyword && lookAhead(nextTokenIsFunctionKeywordOnSameLine));
         }

src/compiler/program.ts

@@ -386,6 +386,19 @@ namespace ts {
         allDiagnostics?: Diagnostic[];
     }
 
+    /**
+     * Create a new 'Program' instance. A Program is an immutable collection of 'SourceFile's and a 'CompilerOptions'
+     * that represent a compilation unit.
+     *
+     * Creating a program proceeds from a set of root files, expanding the set of inputs by following imports and
+     * triple-slash-reference-path directives transitively. '@types' and triple-slash-reference-types are also pulled in.
+     *
+     * @param rootNames - A set of root files.
+     * @param options - The compiler options which should be used.
+     * @param host - The host interacts with the underlying file system.
+     * @param oldProgram - Reuses an old program structure.
+     * @returns A 'Program' object.
+     */
     export function createProgram(rootNames: string[], options: CompilerOptions, host?: CompilerHost, oldProgram?: Program): Program {
         let program: Program;
         let files: SourceFile[] = [];
@@ -530,7 +543,8 @@ namespace ts {
             getFileProcessingDiagnostics: () => fileProcessingDiagnostics,
             getResolvedTypeReferenceDirectives: () => resolvedTypeReferenceDirectives,
             isSourceFileFromExternalLibrary,
-            dropDiagnosticsProducingTypeChecker
+            dropDiagnosticsProducingTypeChecker,
+            getSourceFileFromReference,
         };
 
         verifyCompilerOptions();
@@ -1310,7 +1324,7 @@ namespace ts {
         }
 
         function getDeclarationDiagnosticsForFile(sourceFile: SourceFile, cancellationToken: CancellationToken): Diagnostic[] {
-            return isDeclarationFile(sourceFile) ? [] : getDeclarationDiagnosticsWorker(sourceFile, cancellationToken);
+            return sourceFile.isDeclarationFile ? [] : getDeclarationDiagnosticsWorker(sourceFile, cancellationToken);
         }
 
         function getOptionsDiagnostics(): Diagnostic[] {
@@ -1352,7 +1366,6 @@ namespace ts {
 
             const isJavaScriptFile = isSourceFileJavaScript(file);
             const isExternalModuleFile = isExternalModule(file);
-            const isDtsFile = isDeclarationFile(file);
 
             let imports: LiteralExpression[];
             let moduleAugmentations: LiteralExpression[];
@@ -1405,7 +1418,7 @@ namespace ts {
                         }
                         break;
                     case SyntaxKind.ModuleDeclaration:
-                        if (isAmbientModule(<ModuleDeclaration>node) && (inAmbientModule || hasModifier(node, ModifierFlags.Ambient) || isDeclarationFile(file))) {
+                        if (isAmbientModule(<ModuleDeclaration>node) && (inAmbientModule || hasModifier(node, ModifierFlags.Ambient) || file.isDeclarationFile)) {
                             const moduleName = <LiteralExpression>(<ModuleDeclaration>node).name;
                             // Ambient module declarations can be interpreted as augmentations for some existing external modules.
                             // This will happen in two cases:
@@ -1416,7 +1429,7 @@ namespace ts {
                                 (moduleAugmentations || (moduleAugmentations = [])).push(moduleName);
                             }
                             else if (!inAmbientModule) {
-                                if (isDtsFile) {
+                                if (file.isDeclarationFile) {
                                     // for global .d.ts files record name of ambient module
                                     (ambientModules || (ambientModules = [])).push(moduleName.text);
                                 }
@@ -1447,48 +1460,60 @@ namespace ts {
             }
         }
 
-        function processSourceFile(fileName: string, isDefaultLib: boolean, refFile?: SourceFile, refPos?: number, refEnd?: number) {
-            let diagnosticArgument: string[];
-            let diagnostic: DiagnosticMessage;
+        /** This should have similar behavior to 'processSourceFile' without diagnostics or mutation. */
+        function getSourceFileFromReference(referencingFile: SourceFile, ref: FileReference): SourceFile | undefined {
+            return getSourceFileFromReferenceWorker(resolveTripleslashReference(ref.fileName, referencingFile.fileName), fileName => filesByName.get(toPath(fileName, currentDirectory, getCanonicalFileName)));
+        }
+
+        function getSourceFileFromReferenceWorker(
+                fileName: string,
+                getSourceFile: (fileName: string) => SourceFile | undefined,
+                fail?: (diagnostic: DiagnosticMessage, ...argument: string[]) => void,
+                refFile?: SourceFile): SourceFile | undefined {
+
             if (hasExtension(fileName)) {
                 if (!options.allowNonTsExtensions && !forEach(supportedExtensions, extension => fileExtensionIs(host.getCanonicalFileName(fileName), extension))) {
-                    diagnostic = Diagnostics.File_0_has_unsupported_extension_The_only_supported_extensions_are_1;
-                    diagnosticArgument = [fileName, "'" + supportedExtensions.join("', '") + "'"];
+                    if (fail) fail(Diagnostics.File_0_has_unsupported_extension_The_only_supported_extensions_are_1, fileName, "'" + supportedExtensions.join("', '") + "'");
+                    return undefined;
                 }
-                else if (!findSourceFile(fileName, toPath(fileName, currentDirectory, getCanonicalFileName), isDefaultLib, refFile, refPos, refEnd)) {
-                    diagnostic = Diagnostics.File_0_not_found;
-                    diagnosticArgument = [fileName];
-                }
-                else if (refFile && host.getCanonicalFileName(fileName) === host.getCanonicalFileName(refFile.fileName)) {
-                    diagnostic = Diagnostics.A_file_cannot_have_a_reference_to_itself;
-                    diagnosticArgument = [fileName];
-                }
-            }
-            else {
-                const nonTsFile: SourceFile = options.allowNonTsExtensions && findSourceFile(fileName, toPath(fileName, currentDirectory, getCanonicalFileName), isDefaultLib, refFile, refPos, refEnd);
-                if (!nonTsFile) {
-                    if (options.allowNonTsExtensions) {
-                        diagnostic = Diagnostics.File_0_not_found;
-                        diagnosticArgument = [fileName];
-                    }
-                    else if (!forEach(supportedExtensions, extension => findSourceFile(fileName + extension, toPath(fileName + extension, currentDirectory, getCanonicalFileName), isDefaultLib, refFile, refPos, refEnd))) {
-                        diagnostic = Diagnostics.File_0_not_found;
-                        fileName += ".ts";
-                        diagnosticArgument = [fileName];
-                    }
-                }
-            }
 
-            if (diagnostic) {
-                if (refFile !== undefined && refEnd !== undefined && refPos !== undefined) {
-                    fileProcessingDiagnostics.add(createFileDiagnostic(refFile, refPos, refEnd - refPos, diagnostic, ...diagnosticArgument));
+                const sourceFile = getSourceFile(fileName);
+                if (fail) {
+                    if (!sourceFile) {
+                        fail(Diagnostics.File_0_not_found, fileName);
+                    }
+                    else if (refFile && host.getCanonicalFileName(fileName) === host.getCanonicalFileName(refFile.fileName)) {
+                        fail(Diagnostics.A_file_cannot_have_a_reference_to_itself, fileName);
+                    }
                 }
-                else {
-                    fileProcessingDiagnostics.add(createCompilerDiagnostic(diagnostic, ...diagnosticArgument));
+                return sourceFile;
+            } else {
+                const sourceFileNoExtension = options.allowNonTsExtensions && getSourceFile(fileName);
+                if (sourceFileNoExtension) return sourceFileNoExtension;
+
+                if (fail && options.allowNonTsExtensions) {
+                    fail(Diagnostics.File_0_not_found, fileName);
+                    return undefined;
                 }
+
+                const sourceFileWithAddedExtension = forEach(supportedExtensions, extension => getSourceFile(fileName + extension));
+                if (fail && !sourceFileWithAddedExtension) fail(Diagnostics.File_0_not_found, fileName + ".ts");
+                return sourceFileWithAddedExtension;
             }
         }
 
+        /** This has side effects through `findSourceFile`. */
+        function processSourceFile(fileName: string, isDefaultLib: boolean, refFile?: SourceFile, refPos?: number, refEnd?: number): void {
+            getSourceFileFromReferenceWorker(fileName,
+                fileName => findSourceFile(fileName, toPath(fileName, currentDirectory, getCanonicalFileName), isDefaultLib, refFile, refPos, refEnd),
+                (diagnostic, ...args) => {
+                    fileProcessingDiagnostics.add(refFile !== undefined && refEnd !== undefined && refPos !== undefined
+                        ? createFileDiagnostic(refFile, refPos, refEnd - refPos, diagnostic, ...args)
+                        : createCompilerDiagnostic(diagnostic, ...args));
+                },
+                refFile);
+        }
+
         function reportFileNamesDifferOnlyInCasingError(fileName: string, existingFileName: string, refFile: SourceFile, refPos: number, refEnd: number): void {
             if (refFile !== undefined && refPos !== undefined && refEnd !== undefined) {
                 fileProcessingDiagnostics.add(createFileDiagnostic(refFile, refPos, refEnd - refPos,
@@ -1734,7 +1759,7 @@ namespace ts {
                 const absoluteRootDirectoryPath = host.getCanonicalFileName(getNormalizedAbsolutePath(rootDirectory, currentDirectory));
 
                 for (const sourceFile of sourceFiles) {
-                    if (!isDeclarationFile(sourceFile)) {
+                    if (!sourceFile.isDeclarationFile) {
                         const absoluteSourceFilePath = host.getCanonicalFileName(getNormalizedAbsolutePath(sourceFile.fileName, currentDirectory));
                         if (absoluteSourceFilePath.indexOf(absoluteRootDirectoryPath) !== 0) {
                             programDiagnostics.add(createCompilerDiagnostic(Diagnostics.File_0_is_not_under_rootDir_1_rootDir_is_expected_to_contain_all_source_files, sourceFile.fileName, options.rootDir));
@@ -1849,13 +1874,13 @@ namespace ts {
             const languageVersion = options.target || ScriptTarget.ES3;
             const outFile = options.outFile || options.out;
 
-            const firstNonAmbientExternalModuleSourceFile = forEach(files, f => isExternalModule(f) && !isDeclarationFile(f) ? f : undefined);
+            const firstNonAmbientExternalModuleSourceFile = forEach(files, f => isExternalModule(f) && !f.isDeclarationFile ? f : undefined);
             if (options.isolatedModules) {
                 if (options.module === ModuleKind.None && languageVersion < ScriptTarget.ES2015) {
                     createDiagnosticForOptionName(Diagnostics.Option_isolatedModules_can_only_be_used_when_either_option_module_is_provided_or_option_target_is_ES2015_or_higher, "isolatedModules", "target");
                 }
 
-                const firstNonExternalModuleSourceFile = forEach(files, f => !isExternalModule(f) && !isDeclarationFile(f) ? f : undefined);
+                const firstNonExternalModuleSourceFile = forEach(files, f => !isExternalModule(f) && !f.isDeclarationFile ? f : undefined);
                 if (firstNonExternalModuleSourceFile) {
                     const span = getErrorSpanForNode(firstNonExternalModuleSourceFile, firstNonExternalModuleSourceFile);
                     programDiagnostics.add(createFileDiagnostic(firstNonExternalModuleSourceFile, span.start, span.length, Diagnostics.Cannot_compile_namespaces_when_the_isolatedModules_flag_is_provided));

src/compiler/scanner.ts

@@ -712,11 +712,11 @@ namespace ts {
         return accumulator;
     }
 
-    export function forEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T) {
+    export function forEachLeadingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U | undefined {
         return iterateCommentRanges(/*reduce*/ false, text, pos, /*trailing*/ false, cb, state);
     }
 
-    export function forEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T) {
+    export function forEachTrailingCommentRange<T, U>(text: string, pos: number, cb: (pos: number, end: number, kind: CommentKind, hasTrailingNewLine: boolean, state: T) => U, state?: T): U | undefined {
         return iterateCommentRanges(/*reduce*/ false, text, pos, /*trailing*/ true, cb, state);
     }
 
@@ -746,10 +746,11 @@ namespace ts {
     }
 
     /** Optionally, get the shebang */
-    export function getShebang(text: string): string {
-        return shebangTriviaRegex.test(text)
-            ? shebangTriviaRegex.exec(text)[0]
-            : undefined;
+    export function getShebang(text: string): string | undefined {
+        const match = shebangTriviaRegex.exec(text);
+        if (match) {
+            return match[0];
+        }
     }
 
     export function isIdentifierStart(ch: number, languageVersion: ScriptTarget): boolean {

src/compiler/transformer.ts

@@ -166,7 +166,7 @@ namespace ts {
         };
 
         function transformRoot(node: T) {
-            return node && (!isSourceFile(node) || !isDeclarationFile(node)) ? transformation(node) : node;
+            return node && (!isSourceFile(node) || !node.isDeclarationFile) ? transformation(node) : node;
         }
 
         /**

src/compiler/transformers/es2015.ts

@@ -295,7 +295,7 @@ namespace ts {
         return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
-            if (isDeclarationFile(node)) {
+            if (node.isDeclarationFile) {
                 return node;
             }
 

src/compiler/transformers/es2016.ts

@@ -9,7 +9,7 @@ namespace ts {
         return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
-            if (isDeclarationFile(node)) {
+            if (node.isDeclarationFile) {
                 return node;
             }
 

src/compiler/transformers/es2017.ts

@@ -47,7 +47,7 @@ namespace ts {
         return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
-            if (isDeclarationFile(node)) {
+            if (node.isDeclarationFile) {
                 return node;
             }
 

src/compiler/transformers/esnext.ts

@@ -33,7 +33,7 @@ namespace ts {
         return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
-            if (isDeclarationFile(node)) {
+            if (node.isDeclarationFile) {
                 return node;
             }
 
@@ -929,8 +929,8 @@ namespace ts {
         text: `
             var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
                 var i, p;
-                return i = {}, verb("next"), verb("throw"), verb("return"), i[Symbol.iterator] = function () { return this; }, i;
-                function verb(n) { if (o[n]) i[n] = function (v) { return (p = !p) ? { value: __await(o[n](v)), done: n === "return" } : v; }; }
+                return i = {}, verb("next"), verb("throw", function (e) { throw e; }), verb("return"), i[Symbol.iterator] = function () { return this; }, i;
+                function verb(n, f) { if (o[n]) i[n] = function (v) { return (p = !p) ? { value: __await(o[n](v)), done: n === "return" } : f ? f(v) : v; }; }
             };
         `
     };

src/compiler/transformers/generators.ts

@@ -293,8 +293,7 @@ namespace ts {
         return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
-            if (isDeclarationFile(node)
-                || (node.transformFlags & TransformFlags.ContainsGenerator) === 0) {
+            if (node.isDeclarationFile || (node.transformFlags & TransformFlags.ContainsGenerator) === 0) {
                 return node;
             }
 

src/compiler/transformers/jsx.ts

@@ -15,7 +15,7 @@ namespace ts {
          * @param node A SourceFile node.
          */
         function transformSourceFile(node: SourceFile) {
-            if (isDeclarationFile(node)) {
+            if (node.isDeclarationFile) {
                 return node;
             }
 

src/compiler/transformers/module/es2015.ts

@@ -16,7 +16,7 @@ namespace ts {
         return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
-            if (isDeclarationFile(node)) {
+            if (node.isDeclarationFile) {
                 return node;
             }
 

src/compiler/transformers/module/module.ts

@@ -55,7 +55,7 @@ namespace ts {
          * @param node The SourceFile node.
          */
         function transformSourceFile(node: SourceFile) {
-            if (isDeclarationFile(node) || !(isExternalModule(node) || compilerOptions.isolatedModules)) {
+            if (node.isDeclarationFile || !(isExternalModule(node) || compilerOptions.isolatedModules)) {
                 return node;
             }
 

src/compiler/transformers/module/system.ts

@@ -50,9 +50,7 @@ namespace ts {
          * @param node The SourceFile node.
          */
         function transformSourceFile(node: SourceFile) {
-            if (isDeclarationFile(node)
-                || !(isExternalModule(node)
-                    || compilerOptions.isolatedModules)) {
+            if (node.isDeclarationFile || !(isExternalModule(node) || compilerOptions.isolatedModules)) {
                 return node;
             }
 

src/compiler/transformers/ts.ts

@@ -76,7 +76,7 @@ namespace ts {
          * @param node A SourceFile node.
          */
         function transformSourceFile(node: SourceFile) {
-            if (isDeclarationFile(node)) {
+            if (node.isDeclarationFile) {
                 return node;
             }
 
@@ -345,6 +345,9 @@ namespace ts {
 
                 case SyntaxKind.PropertyDeclaration:
                     // TypeScript property declarations are elided.
+
+                case SyntaxKind.NamespaceExportDeclaration:
+                    // TypeScript namespace export declarations are elided.
                     return undefined;
 
                 case SyntaxKind.Constructor:
@@ -2494,22 +2497,27 @@ namespace ts {
             // we pass false as 'generateNameForComputedPropertyName' for a backward compatibility purposes
             // old emitter always generate 'expression' part of the name as-is.
             const name = getExpressionForPropertyName(member, /*generateNameForComputedPropertyName*/ false);
+            const valueExpression = transformEnumMemberDeclarationValue(member);
+            const innerAssignment = createAssignment(
+                createElementAccess(
+                    currentNamespaceContainerName,
+                    name
+                ),
+                valueExpression
+            );
+            const outerAssignment = valueExpression.kind === SyntaxKind.StringLiteral ?
+                innerAssignment :
+                createAssignment(
+                    createElementAccess(
+                        currentNamespaceContainerName,
+                        innerAssignment
+                    ),
+                    name
+                );
             return setTextRange(
                 createStatement(
                     setTextRange(
-                        createAssignment(
-                            createElementAccess(
-                                currentNamespaceContainerName,
-                                createAssignment(
-                                    createElementAccess(
-                                        currentNamespaceContainerName,
-                                        name
-                                    ),
-                                    transformEnumMemberDeclarationValue(member)
-                                )
-                            ),
-                            name
-                        ),
+                        outerAssignment,
                         member
                     )
                 ),
@@ -3349,7 +3357,7 @@ namespace ts {
             return node;
         }
 
-        function tryGetConstEnumValue(node: Node): number {
+        function tryGetConstEnumValue(node: Node): string | number {
             if (compilerOptions.isolatedModules) {
                 return undefined;
             }

src/compiler/types.ts

@@ -577,10 +577,11 @@ namespace ts {
          * If the identifier begins with two underscores, this will begin with three.
          */
         text: string;
-        originalKeywordKind?: SyntaxKind;              // Original syntaxKind which get set so that we can report an error later
+        originalKeywordKind?: SyntaxKind;                         // Original syntaxKind which get set so that we can report an error later
         /*@internal*/ autoGenerateKind?: GeneratedIdentifierKind; // Specifies whether to auto-generate the text for an identifier.
-        /*@internal*/ autoGenerateId?: number;         // Ensures unique generated identifiers get unique names, but clones get the same name.
-        isInJSDocNamespace?: boolean;                  // if the node is a member in a JSDoc namespace
+        /*@internal*/ autoGenerateId?: number;                    // Ensures unique generated identifiers get unique names, but clones get the same name.
+        isInJSDocNamespace?: boolean;                             // if the node is a member in a JSDoc namespace
+        /*@internal*/ typeArguments?: NodeArray<TypeNode>;        // Only defined on synthesized nodes. Though not syntactically valid, used in emitting diagnostics.
     }
 
     // Transient identifier node (marked by id === -1)
@@ -891,6 +892,8 @@ namespace ts {
         kind: SyntaxKind.ConstructorType;
     }
 
+    export type TypeReferenceType = TypeReferenceNode | ExpressionWithTypeArguments | JSDocTypeReference;
+
     export interface TypeReferenceNode extends TypeNode {
         kind: SyntaxKind.TypeReference;
         typeName: EntityName;
@@ -2429,6 +2432,8 @@ namespace ts {
         /* @internal */ isSourceFileFromExternalLibrary(file: SourceFile): boolean;
         // For testing purposes only.
         /* @internal */ structureIsReused?: StructureIsReused;
+
+        /* @internal */ getSourceFileFromReference(referencingFile: SourceFile, ref: FileReference): SourceFile | undefined;
     }
 
     /* @internal */
@@ -2508,10 +2513,10 @@ namespace ts {
         getTypeOfSymbolAtLocation(symbol: Symbol, node: Node): Type;
         getDeclaredTypeOfSymbol(symbol: Symbol): Type;
         getPropertiesOfType(type: Type): Symbol[];
-        getPropertyOfType(type: Type, propertyName: string): Symbol;
-        getIndexInfoOfType(type: Type, kind: IndexKind): IndexInfo;
+        getPropertyOfType(type: Type, propertyName: string): Symbol | undefined;
+        getIndexInfoOfType(type: Type, kind: IndexKind): IndexInfo | undefined;
         getSignaturesOfType(type: Type, kind: SignatureKind): Signature[];
-        getIndexTypeOfType(type: Type, kind: IndexKind): Type;
+        getIndexTypeOfType(type: Type, kind: IndexKind): Type | undefined;
         getBaseTypes(type: InterfaceType): BaseType[];
         getBaseTypeOfLiteralType(type: Type): Type;
         getWidenedType(type: Type): Type;
@@ -2532,11 +2537,11 @@ namespace ts {
         indexInfoToIndexSignatureDeclaration(indexInfo: IndexInfo, kind: IndexKind, enclosingDeclaration?: Node, flags?: NodeBuilderFlags): IndexSignatureDeclaration;
 
         getSymbolsInScope(location: Node, meaning: SymbolFlags): Symbol[];
-        getSymbolAtLocation(node: Node): Symbol;
+        getSymbolAtLocation(node: Node): Symbol | undefined;
         getSymbolsOfParameterPropertyDeclaration(parameter: ParameterDeclaration, parameterName: string): Symbol[];
-        getShorthandAssignmentValueSymbol(location: Node): Symbol;
-        getExportSpecifierLocalTargetSymbol(location: ExportSpecifier): Symbol;
-        getPropertySymbolOfDestructuringAssignment(location: Identifier): Symbol;
+        getShorthandAssignmentValueSymbol(location: Node): Symbol | undefined;
+        getExportSpecifierLocalTargetSymbol(location: ExportSpecifier): Symbol | undefined;
+        getPropertySymbolOfDestructuringAssignment(location: Identifier): Symbol | undefined;
         getTypeAtLocation(node: Node): Type;
         getTypeFromTypeNode(node: TypeNode): Type;
         signatureToString(signature: Signature, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): string;
@@ -2547,15 +2552,15 @@ namespace ts {
         getAugmentedPropertiesOfType(type: Type): Symbol[];
         getRootSymbols(symbol: Symbol): Symbol[];
         getContextualType(node: Expression): Type | undefined;
-        getResolvedSignature(node: CallLikeExpression, candidatesOutArray?: Signature[]): Signature;
-        getSignatureFromDeclaration(declaration: SignatureDeclaration): Signature;
-        isImplementationOfOverload(node: FunctionLikeDeclaration): boolean;
+        getResolvedSignature(node: CallLikeExpression, candidatesOutArray?: Signature[]): Signature | undefined;
+        getSignatureFromDeclaration(declaration: SignatureDeclaration): Signature | undefined;
+        isImplementationOfOverload(node: FunctionLikeDeclaration): boolean | undefined;
         isUndefinedSymbol(symbol: Symbol): boolean;
         isArgumentsSymbol(symbol: Symbol): boolean;
         isUnknownSymbol(symbol: Symbol): boolean;
         /* @internal */ getMergedSymbol(symbol: Symbol): Symbol;
 
-        getConstantValue(node: EnumMember | PropertyAccessExpression | ElementAccessExpression): number;
+        getConstantValue(node: EnumMember | PropertyAccessExpression | ElementAccessExpression): string | number | undefined;
         isValidPropertyAccess(node: PropertyAccessExpression | QualifiedName, propertyName: string): boolean;
         /** Follow all aliases to get the original symbol. */
         getAliasedSymbol(symbol: Symbol): Symbol;
@@ -2565,7 +2570,7 @@ namespace ts {
         /** Unlike `getExportsOfModule`, this includes properties of an `export =` value. */
         /* @internal */ getExportsAndPropertiesOfModule(moduleSymbol: Symbol): Symbol[];
 
-        getAllAttributesTypeFromJsxOpeningLikeElement(elementNode: JsxOpeningLikeElement): Type;
+        getAllAttributesTypeFromJsxOpeningLikeElement(elementNode: JsxOpeningLikeElement): Type | undefined;
         getJsxIntrinsicTagNames(): Symbol[];
         isOptionalParameter(node: ParameterDeclaration): boolean;
         getAmbientModules(): Symbol[];
@@ -2573,10 +2578,10 @@ namespace ts {
         tryGetMemberInModuleExports(memberName: string, moduleSymbol: Symbol): Symbol | undefined;
         getApparentType(type: Type): Type;
         getSuggestionForNonexistentProperty(node: Identifier, containingType: Type): string | undefined;
-        getSuggestionForNonexistentSymbol(location: Node, name: string, meaning: SymbolFlags): string;
-        /* @internal */ getBaseConstraintOfType(type: Type): Type;
+        getSuggestionForNonexistentSymbol(location: Node, name: string, meaning: SymbolFlags): string | undefined;
+        /* @internal */ getBaseConstraintOfType(type: Type): Type | undefined;
 
-        /* @internal */ tryFindAmbientModuleWithoutAugmentations(moduleName: string): Symbol;
+        /* @internal */ tryFindAmbientModuleWithoutAugmentations(moduleName: string): Symbol | undefined;
 
         // Should not be called directly.  Should only be accessed through the Program instance.
         /* @internal */ getDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationToken): Diagnostic[];
@@ -2591,24 +2596,39 @@ namespace ts {
         /**
          * For a union, will include a property if it's defined in *any* of the member types.
          * So for `{ a } | { b }`, this will include both `a` and `b`.
+         * Does not include properties of primitive types.
          */
         /* @internal */ getAllPossiblePropertiesOfType(type: Type): Symbol[];
     }
 
     export enum NodeBuilderFlags {
         None                                    = 0,
-        allowThisInObjectLiteral                = 1 << 0,
-        allowQualifedNameInPlaceOfIdentifier    = 1 << 1,
-        allowTypeParameterInQualifiedName       = 1 << 2,
-        allowAnonymousIdentifier                = 1 << 3,
-        allowEmptyUnionOrIntersection           = 1 << 4,
-        allowEmptyTuple                         = 1 << 5
+        // Options
+        NoTruncation                            = 1 << 0,   // Don't truncate result
+        WriteArrayAsGenericType                 = 1 << 1,   // Write Array<T> instead T[]
+        WriteTypeArgumentsOfSignature           = 1 << 5,   // Write the type arguments instead of type parameters of the signature
+        UseFullyQualifiedType                   = 1 << 6,   // Write out the fully qualified type name (eg. Module.Type, instead of Type)
+        SuppressAnyReturnType                   = 1 << 8,   // If the return type is any-like, don't offer a return type.
+        WriteTypeParametersInQualifiedName      = 1 << 9,
+
+        // Error handling
+        AllowThisInObjectLiteral                = 1 << 10,
+        AllowQualifedNameInPlaceOfIdentifier    = 1 << 11,
+        AllowAnonymousIdentifier                = 1 << 13,
+        AllowEmptyUnionOrIntersection           = 1 << 14,
+        AllowEmptyTuple                         = 1 << 15,
+
+        IgnoreErrors = AllowThisInObjectLiteral | AllowQualifedNameInPlaceOfIdentifier | AllowAnonymousIdentifier | AllowEmptyUnionOrIntersection | AllowEmptyTuple,
+
+        // State
+        InObjectTypeLiteral                     = 1 << 20,
+        InTypeAlias                             = 1 << 23,    // Writing type in type alias declaration
     }
 
     export interface SymbolDisplayBuilder {
         buildTypeDisplay(type: Type, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
         buildSymbolDisplay(symbol: Symbol, writer: SymbolWriter, enclosingDeclaration?: Node, meaning?: SymbolFlags, flags?: SymbolFormatFlags): void;
-        buildSignatureDisplay(signatures: Signature, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): void;
+        buildSignatureDisplay(signature: Signature, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags, kind?: SignatureKind): void;
         buildIndexSignatureDisplay(info: IndexInfo, writer: SymbolWriter, kind: IndexKind, enclosingDeclaration?: Node, globalFlags?: TypeFormatFlags, symbolStack?: Symbol[]): void;
         buildParameterDisplay(parameter: Symbol, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
         buildTypeParameterDisplay(tp: TypeParameter, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
@@ -2638,24 +2658,25 @@ namespace ts {
         // with import statements it previously saw (but chose not to emit).
         trackSymbol(symbol: Symbol, enclosingDeclaration?: Node, meaning?: SymbolFlags): void;
         reportInaccessibleThisError(): void;
-        reportIllegalExtends(): void;
+        reportPrivateInBaseOfClassExpression(propertyName: string): void;
     }
 
     export const enum TypeFormatFlags {
-        None                            = 0x00000000,
-        WriteArrayAsGenericType         = 0x00000001,  // Write Array<T> instead T[]
-        UseTypeOfFunction               = 0x00000002,  // Write typeof instead of function type literal
-        NoTruncation                    = 0x00000004,  // Don't truncate typeToString result
-        WriteArrowStyleSignature        = 0x00000008,  // Write arrow style signature
-        WriteOwnNameForAnyLike          = 0x00000010,  // Write symbol's own name instead of 'any' for any like types (eg. unknown, __resolving__ etc)
-        WriteTypeArgumentsOfSignature   = 0x00000020,  // Write the type arguments instead of type parameters of the signature
-        InElementType                   = 0x00000040,  // Writing an array or union element type
-        UseFullyQualifiedType           = 0x00000080,  // Write out the fully qualified type name (eg. Module.Type, instead of Type)
-        InFirstTypeArgument             = 0x00000100,  // Writing first type argument of the instantiated type
-        InTypeAlias                     = 0x00000200,  // Writing type in type alias declaration
-        UseTypeAliasValue               = 0x00000400,  // Serialize the type instead of using type-alias. This is needed when we emit declaration file.
-        SuppressAnyReturnType           = 0x00000800,  // If the return type is any-like, don't offer a return type.
-        AddUndefined                    = 0x00001000,  // Add undefined to types of initialized, non-optional parameters
+        None                            = 0,
+        WriteArrayAsGenericType         = 1 << 0,  // Write Array<T> instead T[]
+        UseTypeOfFunction               = 1 << 2,  // Write typeof instead of function type literal
+        NoTruncation                    = 1 << 3,  // Don't truncate typeToString result
+        WriteArrowStyleSignature        = 1 << 4,  // Write arrow style signature
+        WriteOwnNameForAnyLike          = 1 << 5,  // Write symbol's own name instead of 'any' for any like types (eg. unknown, __resolving__ etc)
+        WriteTypeArgumentsOfSignature   = 1 << 6,  // Write the type arguments instead of type parameters of the signature
+        InElementType                   = 1 << 7,  // Writing an array or union element type
+        UseFullyQualifiedType           = 1 << 8,  // Write out the fully qualified type name (eg. Module.Type, instead of Type)
+        InFirstTypeArgument             = 1 << 9,  // Writing first type argument of the instantiated type
+        InTypeAlias                     = 1 << 10,  // Writing type in type alias declaration
+        UseTypeAliasValue               = 1 << 11,  // Serialize the type instead of using type-alias. This is needed when we emit declaration file.
+        SuppressAnyReturnType           = 1 << 12,  // If the return type is any-like, don't offer a return type.
+        AddUndefined                    = 1 << 13,  // Add undefined to types of initialized, non-optional parameters
+        WriteClassExpressionAsTypeLiteral = 1 << 14, // Write a type literal instead of (Anonymous class)
     }
 
     export const enum SymbolFormatFlags {
@@ -2758,7 +2779,7 @@ namespace ts {
         getNodeCheckFlags(node: Node): NodeCheckFlags;
         isDeclarationVisible(node: Declaration): boolean;
         collectLinkedAliases(node: Identifier): Node[];
-        isImplementationOfOverload(node: FunctionLikeDeclaration): boolean;
+        isImplementationOfOverload(node: FunctionLikeDeclaration): boolean | undefined;
         isRequiredInitializedParameter(node: ParameterDeclaration): boolean;
         writeTypeOfDeclaration(declaration: AccessorDeclaration | VariableLikeDeclaration, enclosingDeclaration: Node, flags: TypeFormatFlags, writer: SymbolWriter): void;
         writeReturnTypeOfSignatureDeclaration(signatureDeclaration: SignatureDeclaration, enclosingDeclaration: Node, flags: TypeFormatFlags, writer: SymbolWriter): void;
@@ -2766,7 +2787,7 @@ namespace ts {
         isSymbolAccessible(symbol: Symbol, enclosingDeclaration: Node, meaning: SymbolFlags, shouldComputeAliasToMarkVisible: boolean): SymbolAccessibilityResult;
         isEntityNameVisible(entityName: EntityNameOrEntityNameExpression, enclosingDeclaration: Node): SymbolVisibilityResult;
         // Returns the constant value this property access resolves to, or 'undefined' for a non-constant
-        getConstantValue(node: EnumMember | PropertyAccessExpression | ElementAccessExpression): number;
+        getConstantValue(node: EnumMember | PropertyAccessExpression | ElementAccessExpression): string | number;
         getReferencedValueDeclaration(reference: Identifier): Declaration;
         getTypeReferenceSerializationKind(typeName: EntityName, location?: Node): TypeReferenceSerializationKind;
         isOptionalParameter(node: ParameterDeclaration): boolean;
@@ -2904,6 +2925,13 @@ namespace ts {
         isDeclarationWithCollidingName?: boolean;    // True if symbol is block scoped redeclaration
         bindingElement?: BindingElement;    // Binding element associated with property symbol
         exportsSomeValue?: boolean;         // True if module exports some value (not just types)
+        enumKind?: EnumKind;                // Enum declaration classification
+    }
+
+    /* @internal */
+    export const enum EnumKind {
+        Numeric,                            // Numeric enum (each member has a TypeFlags.Enum type)
+        Literal                             // Literal enum (each member has a TypeFlags.EnumLiteral type)
     }
 
     /* @internal */
@@ -2976,7 +3004,7 @@ namespace ts {
         resolvedSymbol?: Symbol;          // Cached name resolution result
         resolvedIndexInfo?: IndexInfo;    // Cached indexing info resolution result
         maybeTypePredicate?: boolean;     // Cached check whether call expression might reference a type predicate
-        enumMemberValue?: number;         // Constant value of enum member
+        enumMemberValue?: string | number;  // Constant value of enum member
         isVisible?: boolean;              // Is this node visible
         containsArgumentsReference?: boolean; // Whether a function-like declaration contains an 'arguments' reference
         hasReportedStatementInAmbientContext?: boolean;  // Cache boolean if we report statements in ambient context
@@ -2996,7 +3024,7 @@ namespace ts {
         StringLiteral           = 1 << 5,
         NumberLiteral           = 1 << 6,
         BooleanLiteral          = 1 << 7,
-        EnumLiteral             = 1 << 8,
+        EnumLiteral             = 1 << 8,   // Always combined with StringLiteral, NumberLiteral, or Union
         ESSymbol                = 1 << 9,   // Type of symbol primitive introduced in ES6
         Void                    = 1 << 10,
         Undefined               = 1 << 11,
@@ -3022,7 +3050,7 @@ namespace ts {
 
         /* @internal */
         Nullable = Undefined | Null,
-        Literal = StringLiteral | NumberLiteral | BooleanLiteral | EnumLiteral,
+        Literal = StringLiteral | NumberLiteral | BooleanLiteral,
         StringOrNumberLiteral = StringLiteral | NumberLiteral,
         /* @internal */
         DefinitelyFalsy = StringLiteral | NumberLiteral | BooleanLiteral | Void | Undefined | Null,
@@ -3030,9 +3058,9 @@ namespace ts {
         /* @internal */
         Intrinsic = Any | String | Number | Boolean | BooleanLiteral | ESSymbol | Void | Undefined | Null | Never | NonPrimitive,
         /* @internal */
-        Primitive = String | Number | Boolean | Enum | ESSymbol | Void | Undefined | Null | Literal,
+        Primitive = String | Number | Boolean | Enum | EnumLiteral | ESSymbol | Void | Undefined | Null | Literal,
         StringLike = String | StringLiteral | Index,
-        NumberLike = Number | NumberLiteral | Enum | EnumLiteral,
+        NumberLike = Number | NumberLiteral | Enum,
         BooleanLike = Boolean | BooleanLiteral,
         EnumLike = Enum | EnumLiteral,
         UnionOrIntersection = Union | Intersection,
@@ -3071,19 +3099,21 @@ namespace ts {
     // String literal types (TypeFlags.StringLiteral)
     // Numeric literal types (TypeFlags.NumberLiteral)
     export interface LiteralType extends Type {
-        text: string;               // Text of literal
+        value: string | number;     // Value of literal
         freshType?: LiteralType;    // Fresh version of type
         regularType?: LiteralType;  // Regular version of type
     }
 
-    // Enum types (TypeFlags.Enum)
-    export interface EnumType extends Type {
-        memberTypes: EnumLiteralType[];
+    export interface StringLiteralType extends LiteralType {
+        value: string;
     }
 
-    // Enum types (TypeFlags.EnumLiteral)
-    export interface EnumLiteralType extends LiteralType {
-        baseType: EnumType & UnionType;  // Base enum type
+    export interface NumberLiteralType extends LiteralType {
+        value: number;
+    }
+
+    // Enum types (TypeFlags.Enum)
+    export interface EnumType extends Type {
     }
 
     export const enum ObjectFlags {
@@ -3140,7 +3170,7 @@ namespace ts {
      */
     export interface TypeReference extends ObjectType {
         target: GenericType;    // Type reference target
-        typeArguments: Type[];  // Type reference type arguments (undefined if none)
+        typeArguments?: Type[];  // Type reference type arguments (undefined if none)
     }
 
     // Generic class and interface types
@@ -3270,7 +3300,7 @@ namespace ts {
 
     export interface Signature {
         declaration: SignatureDeclaration;  // Originating declaration
-        typeParameters: TypeParameter[];    // Type parameters (undefined if non-generic)
+        typeParameters?: TypeParameter[];   // Type parameters (undefined if non-generic)
         parameters: Symbol[];               // Parameters
         /* @internal */
         thisParameter?: Symbol;             // symbol of this-type parameter
@@ -3393,7 +3423,7 @@ namespace ts {
     export enum DiagnosticCategory {
         Warning,
         Error,
-        Message,
+        Message
     }
 
     export enum ModuleResolutionKind {
@@ -3533,7 +3563,7 @@ namespace ts {
 
     export const enum NewLineKind {
         CarriageReturnLineFeed = 0,
-        LineFeed = 1,
+        LineFeed = 1
     }
 
     export interface LineAndCharacter {
@@ -3955,7 +3985,7 @@ namespace ts {
         commentRange?: TextRange;               // The text range to use when emitting leading or trailing comments
         sourceMapRange?: TextRange;             // The text range to use when emitting leading or trailing source mappings
         tokenSourceMapRanges?: TextRange[];     // The text range to use when emitting source mappings for tokens
-        constantValue?: number;                 // The constant value of an expression
+        constantValue?: string | number;        // The constant value of an expression
         externalHelpersModuleName?: Identifier; // The local name for an imported helpers module
         helpers?: EmitHelper[];                 // Emit helpers for the node
     }
@@ -3988,6 +4018,7 @@ namespace ts {
         NoHoisting = 1 << 21,                    // Do not hoist this declaration in --module system
         HasEndOfDeclarationMarker = 1 << 22,     // Declaration has an associated NotEmittedStatement to mark the end of the declaration
         Iterator = 1 << 23,                      // The expression to a `yield*` should be treated as an Iterator when down-leveling, not an Iterable.
+        NoAsciiEscaping = 1 << 24,               // When synthesizing nodes that lack an original node or textSourceNode, we want to write the text on the node with ASCII escaping substitutions.
     }
 
     export interface EmitHelper {
@@ -4200,7 +4231,7 @@ namespace ts {
          * Prints a bundle of source files as-is, without any emit transformations.
          */
         printBundle(bundle: Bundle): string;
-        /*@internal*/ writeNode(hint: EmitHint, node: Node, sourceFile: SourceFile, writer: EmitTextWriter): void;
+        /*@internal*/ writeNode(hint: EmitHint, node: Node, sourceFile: SourceFile | undefined, writer: EmitTextWriter): void;
         /*@internal*/ writeFile(sourceFile: SourceFile, writer: EmitTextWriter): void;
         /*@internal*/ writeBundle(bundle: Bundle, writer: EmitTextWriter): void;
     }
@@ -4254,6 +4285,8 @@ namespace ts {
         /*@internal*/ onSetSourceFile?: (node: SourceFile) => void;
         /*@internal*/ onBeforeEmitNodeArray?: (nodes: NodeArray<any>) => void;
         /*@internal*/ onAfterEmitNodeArray?: (nodes: NodeArray<any>) => void;
+        /*@internal*/ onBeforeEmitToken?: (node: Node) => void;
+        /*@internal*/ onAfterEmitToken?: (node: Node) => void;
     }
 
     export interface PrinterOptions {

src/compiler/utilities.ts

@@ -11,12 +11,12 @@ namespace ts {
         isTypeReferenceDirective?: boolean;
     }
 
-    export function getDeclarationOfKind(symbol: Symbol, kind: SyntaxKind): Declaration {
+    export function getDeclarationOfKind<T extends Declaration>(symbol: Symbol, kind: T["kind"]): T {
         const declarations = symbol.declarations;
         if (declarations) {
             for (const declaration of declarations) {
                 if (declaration.kind === kind) {
-                    return declaration;
+                    return declaration as T;
                 }
             }
         }
@@ -68,7 +68,7 @@ namespace ts {
                 clear: () => str = "",
                 trackSymbol: noop,
                 reportInaccessibleThisError: noop,
-                reportIllegalExtends: noop
+                reportPrivateInBaseOfClassExpression: noop,
             };
         }
 
@@ -328,19 +328,21 @@ namespace ts {
             return getSourceTextOfNodeFromSourceFile(sourceFile, node);
         }
 
+        const escapeText = getEmitFlags(node) & EmitFlags.NoAsciiEscaping ? escapeString : escapeNonAsciiString;
+
         // If we can't reach the original source text, use the canonical form if it's a number,
-        // or an escaped quoted form of the original text if it's string-like.
+        // or a (possibly escaped) quoted form of the original text if it's string-like.
         switch (node.kind) {
             case SyntaxKind.StringLiteral:
-                return getQuotedEscapedLiteralText('"', node.text, '"');
+                return '"' + escapeText(node.text) + '"';
             case SyntaxKind.NoSubstitutionTemplateLiteral:
-                return getQuotedEscapedLiteralText("`", node.text, "`");
+                return "`" + escapeText(node.text) + "`";
             case SyntaxKind.TemplateHead:
-                return getQuotedEscapedLiteralText("`", node.text, "${");
+                return "`" + escapeText(node.text) + "${";
             case SyntaxKind.TemplateMiddle:
-                return getQuotedEscapedLiteralText("}", node.text, "${");
+                return "}" + escapeText(node.text) + "${";
             case SyntaxKind.TemplateTail:
-                return getQuotedEscapedLiteralText("}", node.text, "`");
+                return "}" + escapeText(node.text) + "`";
             case SyntaxKind.NumericLiteral:
                 return node.text;
         }
@@ -348,8 +350,8 @@ namespace ts {
         Debug.fail(`Literal kind '${node.kind}' not accounted for.`);
     }
 
-    function getQuotedEscapedLiteralText(leftQuote: string, text: string, rightQuote: string) {
-        return leftQuote + escapeNonAsciiCharacters(escapeString(text)) + rightQuote;
+    export function getTextOfConstantValue(value: string | number) {
+        return typeof value === "string" ? '"' + escapeNonAsciiString(value) + '"' : "" + value;
     }
 
     // Add an extra underscore to identifiers that start with two underscores to avoid issues with magic names like '__proto__'
@@ -465,7 +467,7 @@ namespace ts {
         return getFullWidth(name) === 0 ? "(Missing)" : getTextOfNode(name);
     }
 
-    export function getNameFromIndexInfo(info: IndexInfo) {
+    export function getNameFromIndexInfo(info: IndexInfo): string | undefined {
         return info.declaration ? declarationNameToString(info.declaration.parameters[0].name) : undefined;
     }
 
@@ -589,10 +591,6 @@ namespace ts {
         return (file.externalModuleIndicator || file.commonJsModuleIndicator) !== undefined;
     }
 
-    export function isDeclarationFile(file: SourceFile): boolean {
-        return file.isDeclarationFile;
-    }
-
     export function isConstEnumDeclaration(node: Node): boolean {
         return node.kind === SyntaxKind.EnumDeclaration && isConst(node);
     }
@@ -881,6 +879,16 @@ namespace ts {
         return false;
     }
 
+    export function isFunctionOrConstructorTypeNode(node: Node): node is FunctionTypeNode | ConstructorTypeNode {
+        switch (node.kind) {
+            case SyntaxKind.FunctionType:
+            case SyntaxKind.ConstructorType:
+                return true;
+        }
+
+        return false;
+    }
+
     export function introducesArgumentsExoticObject(node: Node) {
         switch (node.kind) {
             case SyntaxKind.MethodDeclaration:
@@ -1594,7 +1602,7 @@ namespace ts {
 
             // Pull parameter comments from declaring function as well
             if (node.kind === SyntaxKind.Parameter) {
-                cache = concatenate(cache, getJSDocParameterTags(node));
+                cache = concatenate(cache, getJSDocParameterTags(node as ParameterDeclaration));
             }
 
             if (isVariableLike(node) && node.initializer) {
@@ -1605,11 +1613,8 @@ namespace ts {
         }
     }
 
-    export function getJSDocParameterTags(param: Node): JSDocParameterTag[] {
-        if (!isParameter(param)) {
-            return undefined;
-        }
-        const func = param.parent as FunctionLikeDeclaration;
+    export function getJSDocParameterTags(param: ParameterDeclaration): JSDocParameterTag[] {
+        const func = param.parent;
         const tags = getJSDocTags(func, SyntaxKind.JSDocParameterTag) as JSDocParameterTag[];
         if (!param.name) {
             // this is an anonymous jsdoc param from a `function(type1, type2): type3` specification
@@ -1630,10 +1635,22 @@ namespace ts {
         }
     }
 
+    /** Does the opposite of `getJSDocParameterTags`: given a JSDoc parameter, finds the parameter corresponding to it. */
+    export function getParameterFromJSDoc(node: JSDocParameterTag): ParameterDeclaration | undefined {
+        const name = node.parameterName.text;
+        const grandParent = node.parent!.parent!;
+        Debug.assert(node.parent!.kind === SyntaxKind.JSDocComment);
+        if (!isFunctionLike(grandParent)) {
+            return undefined;
+        }
+        return find(grandParent.parameters, p =>
+            p.name.kind === SyntaxKind.Identifier && p.name.text === name);
+    }
+
     export function getJSDocType(node: Node): JSDocType {
         let tag: JSDocTypeTag | JSDocParameterTag = getFirstJSDocTag(node, SyntaxKind.JSDocTypeTag) as JSDocTypeTag;
         if (!tag && node.kind === SyntaxKind.Parameter) {
-            const paramTags = getJSDocParameterTags(node);
+            const paramTags = getJSDocParameterTags(node as ParameterDeclaration);
             if (paramTags) {
                 tag = find(paramTags, tag => !!tag.typeExpression);
             }
@@ -1771,33 +1788,20 @@ namespace ts {
         }
     }
 
-    export function getNameOfDeclaration(declaration: Declaration): DeclarationName {
-        if (!declaration) {
-            return undefined;
-        }
-        if (declaration.kind === SyntaxKind.BinaryExpression) {
-            const kind = getSpecialPropertyAssignmentKind(declaration as BinaryExpression);
-            const lhs = (declaration as BinaryExpression).left;
-            switch (kind) {
-                case SpecialPropertyAssignmentKind.None:
-                case SpecialPropertyAssignmentKind.ModuleExports:
-                    return undefined;
-                case SpecialPropertyAssignmentKind.ExportsProperty:
-                    if (lhs.kind === SyntaxKind.Identifier) {
-                        return (lhs as PropertyAccessExpression).name;
-                    }
-                    else {
-                        return ((lhs as PropertyAccessExpression).expression as PropertyAccessExpression).name;
-                    }
-                case SpecialPropertyAssignmentKind.ThisProperty:
-                case SpecialPropertyAssignmentKind.Property:
-                    return (lhs as PropertyAccessExpression).name;
-                case SpecialPropertyAssignmentKind.PrototypeProperty:
-                    return ((lhs as PropertyAccessExpression).expression as PropertyAccessExpression).name;
-            }
-        }
-        else {
-            return (declaration as NamedDeclaration).name;
+    /* @internal */
+    // See GH#16030
+    export function isAnyDeclarationName(name: Node): boolean {
+        switch (name.kind) {
+            case SyntaxKind.Identifier:
+            case SyntaxKind.StringLiteral:
+            case SyntaxKind.NumericLiteral:
+                if (isDeclaration(name.parent)) {
+                    return name.parent.name === name;
+                }
+                const binExp = name.parent.parent;
+                return isBinaryExpression(binExp) && getSpecialPropertyAssignmentKind(binExp) !== SpecialPropertyAssignmentKind.None && getNameOfDeclaration(binExp) === name;
+            default:
+                return false;
         }
     }
 
@@ -1913,21 +1917,19 @@ namespace ts {
         const isNoDefaultLibRegEx = /^(\/\/\/\s*<reference\s+no-default-lib\s*=\s*)('|")(.+?)\2\s*\/>/gim;
         if (simpleReferenceRegEx.test(comment)) {
             if (isNoDefaultLibRegEx.test(comment)) {
-                return {
-                    isNoDefaultLib: true
-                };
+                return { isNoDefaultLib: true };
             }
             else {
                 const refMatchResult = fullTripleSlashReferencePathRegEx.exec(comment);
                 const refLibResult = !refMatchResult && fullTripleSlashReferenceTypeReferenceDirectiveRegEx.exec(comment);
-                if (refMatchResult || refLibResult) {
-                    const start = commentRange.pos;
-                    const end = commentRange.end;
+                const match = refMatchResult || refLibResult;
+                if (match) {
+                    const pos = commentRange.pos + match[1].length + match[2].length;
                     return {
                         fileReference: {
-                            pos: start,
-                            end: end,
-                            fileName: (refMatchResult || refLibResult)[3]
+                            pos,
+                            end: pos + match[3].length,
+                            fileName: match[3]
                         },
                         isNoDefaultLib: false,
                         isTypeReferenceDirective: !!refLibResult
@@ -2473,7 +2475,8 @@ namespace ts {
     }
 
     const nonAsciiCharacters = /[^\u0000-\u007F]/g;
-    export function escapeNonAsciiCharacters(s: string): string {
+    export function escapeNonAsciiString(s: string): string {
+        s = escapeString(s);
         // Replace non-ASCII characters with '\uNNNN' escapes if any exist.
         // Otherwise just return the original string.
         return nonAsciiCharacters.test(s) ?
@@ -2577,7 +2580,7 @@ namespace ts {
 
     export function getExternalModuleNameFromDeclaration(host: EmitHost, resolver: EmitResolver, declaration: ImportEqualsDeclaration | ImportDeclaration | ExportDeclaration | ModuleDeclaration): string {
         const file = resolver.getExternalModuleFileFromDeclaration(declaration);
-        if (!file || isDeclarationFile(file)) {
+        if (!file || file.isDeclarationFile) {
             return undefined;
         }
         return getResolvedExternalModuleName(host, file);
@@ -2650,7 +2653,7 @@ namespace ts {
 
     /** Don't call this for `--outFile`, just for `--outDir` or plain emit. `--outFile` needs additional checks. */
     export function sourceFileMayBeEmitted(sourceFile: SourceFile, options: CompilerOptions, isSourceFileFromExternalLibrary: (file: SourceFile) => boolean) {
-        return !(options.noEmitForJsFiles && isSourceFileJavaScript(sourceFile)) && !isDeclarationFile(sourceFile) && !isSourceFileFromExternalLibrary(sourceFile);
+        return !(options.noEmitForJsFiles && isSourceFileJavaScript(sourceFile)) && !sourceFile.isDeclarationFile && !isSourceFileFromExternalLibrary(sourceFile);
     }
 
     /**
@@ -3176,11 +3179,11 @@ namespace ts {
     }
 
     export function getLocalSymbolForExportDefault(symbol: Symbol) {
-        return isExportDefaultSymbol(symbol) ? symbol.valueDeclaration.localSymbol : undefined;
+        return isExportDefaultSymbol(symbol) ? symbol.declarations[0].localSymbol : undefined;
     }
 
     function isExportDefaultSymbol(symbol: Symbol): boolean {
-        return symbol && symbol.valueDeclaration && hasModifier(symbol.valueDeclaration, ModifierFlags.Default);
+        return symbol && length(symbol.declarations) > 0 && hasModifier(symbol.declarations[0], ModifierFlags.Default);
     }
 
     /** Return ".ts", ".d.ts", or ".tsx", if that is the extension. */
@@ -3266,13 +3269,13 @@ namespace ts {
     const carriageReturnLineFeed = "\r\n";
     const lineFeed = "\n";
     export function getNewLineCharacter(options: CompilerOptions | PrinterOptions): string {
-        if (options.newLine === NewLineKind.CarriageReturnLineFeed) {
-            return carriageReturnLineFeed;
+        switch (options.newLine) {
+            case NewLineKind.CarriageReturnLineFeed:
+                return carriageReturnLineFeed;
+            case NewLineKind.LineFeed:
+                return lineFeed;
         }
-        else if (options.newLine === NewLineKind.LineFeed) {
-            return lineFeed;
-        }
-        else if (sys) {
+        if (sys) {
             return sys.newLine;
         }
         return carriageReturnLineFeed;
@@ -4031,6 +4034,10 @@ namespace ts {
         return node.kind === SyntaxKind.ImportEqualsDeclaration;
     }
 
+    export function isImportDeclaration(node: Node): node is ImportDeclaration {
+        return node.kind === SyntaxKind.ImportDeclaration;
+    }
+
     export function isImportClause(node: Node): node is ImportClause {
         return node.kind === SyntaxKind.ImportClause;
     }
@@ -4739,4 +4746,25 @@ namespace ts {
     export function unescapeIdentifier(identifier: string): string {
         return identifier.length >= 3 && identifier.charCodeAt(0) === CharacterCodes._ && identifier.charCodeAt(1) === CharacterCodes._ && identifier.charCodeAt(2) === CharacterCodes._ ? identifier.substr(1) : identifier;
     }
+
+    export function getNameOfDeclaration(declaration: Declaration): DeclarationName | undefined {
+        if (!declaration) {
+            return undefined;
+        }
+        if (declaration.kind === SyntaxKind.BinaryExpression) {
+            const expr = declaration as BinaryExpression;
+            switch (getSpecialPropertyAssignmentKind(expr)) {
+                case SpecialPropertyAssignmentKind.ExportsProperty:
+                case SpecialPropertyAssignmentKind.ThisProperty:
+                case SpecialPropertyAssignmentKind.Property:
+                case SpecialPropertyAssignmentKind.PrototypeProperty:
+                    return (expr.left as PropertyAccessExpression).name;
+                default:
+                    return undefined;
+            }
+        }
+        else {
+            return (declaration as NamedDeclaration).name;
+        }
+    }
 }

src/compiler/visitor.ts

@@ -220,6 +220,10 @@ namespace ts {
 
         switch (kind) {
             // Names
+
+            case SyntaxKind.Identifier:
+                return updateIdentifier(<Identifier>node, nodesVisitor((<Identifier>node).typeArguments, visitor, isTypeNode));
+
             case SyntaxKind.QualifiedName:
                 return updateQualifiedName(<QualifiedName>node,
                     visitNode((<QualifiedName>node).left, visitor, isEntityName),
@@ -255,6 +259,7 @@ namespace ts {
 
             case SyntaxKind.PropertySignature:
                 return updatePropertySignature((<PropertySignature>node),
+                    nodesVisitor((<PropertySignature>node).modifiers, visitor, isToken),
                     visitNode((<PropertySignature>node).name, visitor, isPropertyName),
                     visitNode((<PropertySignature>node).questionToken, tokenVisitor, isToken),
                     visitNode((<PropertySignature>node).type, visitor, isTypeNode),
@@ -511,7 +516,8 @@ namespace ts {
             case SyntaxKind.BinaryExpression:
                 return updateBinary(<BinaryExpression>node,
                     visitNode((<BinaryExpression>node).left, visitor, isExpression),
-                    visitNode((<BinaryExpression>node).right, visitor, isExpression));
+                    visitNode((<BinaryExpression>node).right, visitor, isExpression),
+                    visitNode((<BinaryExpression>node).operatorToken, visitor, isToken));
 
             case SyntaxKind.ConditionalExpression:
                 return updateConditional(<ConditionalExpression>node,
@@ -695,6 +701,8 @@ namespace ts {
 
             case SyntaxKind.TypeAliasDeclaration:
                 return updateTypeAliasDeclaration(<TypeAliasDeclaration>node,
+                    nodesVisitor((<TypeAliasDeclaration>node).decorators, visitor, isDecorator),
+                    nodesVisitor((<TypeAliasDeclaration>node).modifiers, visitor, isModifier),
                     visitNode((<TypeAliasDeclaration>node).name, visitor, isIdentifier),
                     nodesVisitor((<TypeAliasDeclaration>node).typeParameters, visitor, isTypeParameter),
                     visitNode((<TypeAliasDeclaration>node).type, visitor, isTypeNode));
@@ -970,6 +978,15 @@ namespace ts {
                 break;
 
             // Type member
+
+            case SyntaxKind.PropertySignature:
+                result = reduceNodes((<PropertySignature>node).modifiers, cbNodes, result);
+                result = reduceNode((<PropertySignature>node).name, cbNode, result);
+                result = reduceNode((<PropertySignature>node).questionToken, cbNode, result);
+                result = reduceNode((<PropertySignature>node).type, cbNode, result);
+                result = reduceNode((<PropertySignature>node).initializer, cbNode, result);
+                break;
+
             case SyntaxKind.PropertyDeclaration:
                 result = reduceNodes((<PropertyDeclaration>node).decorators, cbNodes, result);
                 result = reduceNodes((<PropertyDeclaration>node).modifiers, cbNodes, result);

src/harness/fourslash.ts

@@ -916,7 +916,7 @@ namespace FourSlash {
         }
 
         private getNode(): ts.Node {
-            return ts.getTouchingPropertyName(this.getSourceFile(), this.currentCaretPosition);
+            return ts.getTouchingPropertyName(this.getSourceFile(), this.currentCaretPosition, /*includeJsDocComment*/ false);
         }
 
         private goToAndGetNode(range: Range): ts.Node {
@@ -994,17 +994,15 @@ namespace FourSlash {
         }
 
         public verifyReferenceGroups(startRanges: Range | Range[], parts: Array<{ definition: string, ranges: Range[] }>): void {
-            interface ReferenceJson { definition: string; ranges: ts.ReferenceEntry[]; }
-            type ReferencesJson = ReferenceJson[];
-            const fullExpected = parts.map<ReferenceJson>(({ definition, ranges }) => ({ definition, ranges: ranges.map(rangeToReferenceEntry) }));
+            const fullExpected = ts.map(parts, ({ definition, ranges }) => ({ definition, ranges: ranges.map(rangeToReferenceEntry) }));
 
             for (const startRange of toArray(startRanges)) {
                 this.goToRangeStart(startRange);
-                const fullActual = ts.map<ts.ReferencedSymbol, ReferenceJson>(this.findReferencesAtCaret(), ({ definition, references }) => ({
+                const fullActual = ts.map(this.findReferencesAtCaret(), ({ definition, references }) => ({
                     definition: definition.displayParts.map(d => d.text).join(""),
                     ranges: references
                 }));
-                this.assertObjectsEqual<ReferencesJson>(fullActual, fullExpected);
+                this.assertObjectsEqual(fullActual, fullExpected);
             }
 
             function rangeToReferenceEntry(r: Range): ts.ReferenceEntry {
@@ -1047,6 +1045,10 @@ namespace FourSlash {
                     this.raiseError(`${msgPrefix}At ${path}: ${msg}`);
                 };
 
+                if ((actual === undefined) !== (expected === undefined)) {
+                    fail(`Expected ${expected}, got ${actual}`);
+                }
+
                 for (const key in actual) if (ts.hasProperty(actual as any, key)) {
                     const ak = actual[key], ek = expected[key];
                     if (typeof ak === "object" && typeof ek === "object") {
@@ -1062,6 +1064,14 @@ namespace FourSlash {
                     }
                 }
             };
+            if (fullActual === undefined || fullExpected === undefined) {
+                if (fullActual === fullExpected) {
+                    return;
+                }
+                console.log("Expected:", stringify(fullExpected));
+                console.log("Actual: ", stringify(fullActual));
+                this.raiseError(msgPrefix);
+            }
             recur(fullActual, fullExpected, "");
 
         }
@@ -2167,7 +2177,7 @@ namespace FourSlash {
             }
 
             ts.zipWith(expected, actual, (expectedClassification, actualClassification) => {
-                const expectedType: string = (<any>ts.ClassificationTypeNames)[expectedClassification.classificationType];
+                const expectedType = expectedClassification.classificationType;
                 if (expectedType !== actualClassification.classificationType) {
                     this.raiseError("verifyClassifications failed - expected classifications type to be " +
                         expectedType + ", but was " +
@@ -2347,7 +2357,8 @@ namespace FourSlash {
         private applyCodeAction(fileName: string, actions: ts.CodeAction[], index?: number): void {
             if (index === undefined) {
                 if (!(actions && actions.length === 1)) {
-                    this.raiseError(`Should find exactly one codefix, but ${actions ? actions.length : "none"} found.`);
+                    const actionText = (actions && actions.length) ? JSON.stringify(actions) : "none";
+                    this.raiseError(`Should find exactly one codefix, but found ${actionText}`);
                 }
                 index = 0;
             }
@@ -2701,6 +2712,60 @@ namespace FourSlash {
             }
         }
 
+        public verifyApplicableRefactorAvailableAtMarker(negative: boolean, markerName: string) {
+            const marker = this.getMarkerByName(markerName);
+            const applicableRefactors = this.languageService.getApplicableRefactors(this.activeFile.fileName, marker.position);
+            const isAvailable = applicableRefactors && applicableRefactors.length > 0;
+            if (negative && isAvailable) {
+                this.raiseError(`verifyApplicableRefactorAvailableAtMarker failed - expected no refactor at marker ${markerName} but found some.`);
+            }
+            if (!negative && !isAvailable) {
+                this.raiseError(`verifyApplicableRefactorAvailableAtMarker failed - expected a refactor at marker ${markerName} but found none.`);
+            }
+        }
+
+        public verifyApplicableRefactorAvailableForRange(negative: boolean) {
+            const ranges = this.getRanges();
+            if (!(ranges && ranges.length === 1)) {
+                throw new Error("Exactly one refactor range is allowed per test.");
+            }
+
+            const applicableRefactors = this.languageService.getApplicableRefactors(this.activeFile.fileName, { pos: ranges[0].start, end: ranges[0].end });
+            const isAvailable = applicableRefactors && applicableRefactors.length > 0;
+            if (negative && isAvailable) {
+                this.raiseError(`verifyApplicableRefactorAvailableForRange failed - expected no refactor but found some.`);
+            }
+            if (!negative && !isAvailable) {
+                this.raiseError(`verifyApplicableRefactorAvailableForRange failed - expected a refactor but found none.`);
+            }
+        }
+
+        public verifyFileAfterApplyingRefactorAtMarker(
+            markerName: string,
+            expectedContent: string,
+            refactorNameToApply: string,
+            formattingOptions?: ts.FormatCodeSettings) {
+
+            formattingOptions = formattingOptions || this.formatCodeSettings;
+            const markerPos = this.getMarkerByName(markerName).position;
+
+            const applicableRefactors = this.languageService.getApplicableRefactors(this.activeFile.fileName, markerPos);
+            const applicableRefactorToApply = ts.find(applicableRefactors, refactor => refactor.name === refactorNameToApply);
+
+            if (!applicableRefactorToApply) {
+                this.raiseError(`The expected refactor: ${refactorNameToApply} is not available at the marker location.`);
+            }
+
+            const codeActions = this.languageService.getRefactorCodeActions(this.activeFile.fileName, formattingOptions, markerPos, refactorNameToApply);
+
+            this.applyCodeAction(this.activeFile.fileName, codeActions);
+            const actualContent = this.getFileContent(this.activeFile.fileName);
+
+            if (this.normalizeNewlines(actualContent) !== this.normalizeNewlines(expectedContent)) {
+                this.raiseError(`verifyFileAfterApplyingRefactors failed: expected:\n${expectedContent}\nactual:\n${actualContent}`);
+            }
+        }
+
         public printAvailableCodeFixes() {
             const codeFixes = this.getCodeFixActions(this.activeFile.fileName);
             Harness.IO.log(stringify(codeFixes));
@@ -3514,6 +3579,14 @@ namespace FourSlashInterface {
         public codeFixAvailable() {
             this.state.verifyCodeFixAvailable(this.negative);
         }
+
+        public applicableRefactorAvailableAtMarker(markerName: string) {
+            this.state.verifyApplicableRefactorAvailableAtMarker(this.negative, markerName);
+        }
+
+        public applicableRefactorAvailableForRange() {
+            this.state.verifyApplicableRefactorAvailableForRange(this.negative);
+        }
     }
 
     export class Verify extends VerifyNegatable {
@@ -3728,6 +3801,10 @@ namespace FourSlashInterface {
             this.state.verifyRangeAfterCodeFix(expectedText, includeWhiteSpace, errorCode, index);
         }
 
+        public fileAfterApplyingRefactorAtMarker(markerName: string, expectedContent: string, refactorNameToApply: string, formattingOptions?: ts.FormatCodeSettings): void {
+            this.state.verifyFileAfterApplyingRefactorAtMarker(markerName, expectedContent, refactorNameToApply, formattingOptions);
+        }
+
         public importFixAtPosition(expectedTextArray: string[], errorCode?: number): void {
             this.state.verifyImportFixAtPosition(expectedTextArray, errorCode);
         }
@@ -3802,7 +3879,7 @@ namespace FourSlashInterface {
         /**
          * This method *requires* an ordered stream of classifications for a file, and spans are highly recommended.
          */
-        public semanticClassificationsAre(...classifications: { classificationType: string; text: string; textSpan?: FourSlash.TextSpan }[]) {
+        public semanticClassificationsAre(...classifications: Classification[]) {
             this.state.verifySemanticClassifications(classifications);
         }
 
@@ -3997,102 +4074,107 @@ namespace FourSlashInterface {
         }
     }
 
+    interface Classification {
+        classificationType: ts.ClassificationTypeNames;
+        text: string;
+        textSpan?: FourSlash.TextSpan;
+    }
     export namespace Classification {
-        export function comment(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("comment", text, position);
+        export function comment(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.comment, text, position);
         }
 
-        export function identifier(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("identifier", text, position);
+        export function identifier(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.identifier, text, position);
         }
 
-        export function keyword(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("keyword", text, position);
+        export function keyword(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.keyword, text, position);
         }
 
-        export function numericLiteral(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("numericLiteral", text, position);
+        export function numericLiteral(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.numericLiteral, text, position);
         }
 
-        export function operator(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("operator", text, position);
+        export function operator(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.operator, text, position);
         }
 
-        export function stringLiteral(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("stringLiteral", text, position);
+        export function stringLiteral(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.stringLiteral, text, position);
         }
 
-        export function whiteSpace(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("whiteSpace", text, position);
+        export function whiteSpace(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.whiteSpace, text, position);
         }
 
-        export function text(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("text", text, position);
+        export function text(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.text, text, position);
         }
 
-        export function punctuation(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("punctuation", text, position);
+        export function punctuation(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.punctuation, text, position);
         }
 
-        export function docCommentTagName(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("docCommentTagName", text, position);
+        export function docCommentTagName(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.docCommentTagName, text, position);
         }
 
-        export function className(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("className", text, position);
+        export function className(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.className, text, position);
         }
 
-        export function enumName(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("enumName", text, position);
+        export function enumName(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.enumName, text, position);
         }
 
-        export function interfaceName(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("interfaceName", text, position);
+        export function interfaceName(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.interfaceName, text, position);
         }
 
-        export function moduleName(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("moduleName", text, position);
+        export function moduleName(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.moduleName, text, position);
         }
 
-        export function typeParameterName(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("typeParameterName", text, position);
+        export function typeParameterName(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.typeParameterName, text, position);
         }
 
-        export function parameterName(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("parameterName", text, position);
+        export function parameterName(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.parameterName, text, position);
         }
 
-        export function typeAliasName(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("typeAliasName", text, position);
+        export function typeAliasName(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.typeAliasName, text, position);
         }
 
-        export function jsxOpenTagName(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("jsxOpenTagName", text, position);
+        export function jsxOpenTagName(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.jsxOpenTagName, text, position);
         }
 
-        export function jsxCloseTagName(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("jsxCloseTagName", text, position);
+        export function jsxCloseTagName(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.jsxCloseTagName, text, position);
         }
 
-        export function jsxSelfClosingTagName(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("jsxSelfClosingTagName", text, position);
+        export function jsxSelfClosingTagName(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.jsxSelfClosingTagName, text, position);
         }
 
-        export function jsxAttribute(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("jsxAttribute", text, position);
+        export function jsxAttribute(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.jsxAttribute, text, position);
         }
 
-        export function jsxText(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("jsxText", text, position);
+        export function jsxText(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.jsxText, text, position);
         }
 
-        export function jsxAttributeStringLiteralValue(text: string, position?: number): { classificationType: string; text: string; textSpan?: FourSlash.TextSpan } {
-            return getClassification("jsxAttributeStringLiteralValue", text, position);
+        export function jsxAttributeStringLiteralValue(text: string, position?: number): Classification {
+            return getClassification(ts.ClassificationTypeNames.jsxAttributeStringLiteralValue, text, position);
         }
 
-        function getClassification(type: string, text: string, position?: number) {
+        function getClassification(classificationType: ts.ClassificationTypeNames, text: string, position?: number): Classification {
             return {
-                classificationType: type,
+                classificationType,
                 text: text,
                 textSpan: position === undefined ? undefined : { start: position, end: position + text.length }
             };

src/harness/harness.ts

@@ -172,7 +172,7 @@ namespace Utils {
                     assert.isFalse(child.pos < currentPos, "child.pos < currentPos");
                     currentPos = child.end;
                 },
-                (array: ts.NodeArray<ts.Node>) => {
+                array => {
                     assert.isFalse(array.pos < node.pos, "array.pos < node.pos");
                     assert.isFalse(array.end > node.end, "array.end > node.end");
                     assert.isFalse(array.pos < currentPos, "array.pos < currentPos");
@@ -383,7 +383,7 @@ namespace Utils {
 
                 assertStructuralEquals(child1, child2);
             },
-            (array1: ts.NodeArray<ts.Node>) => {
+            array1 => {
                 const childName = findChildName(node1, array1);
                 const array2: ts.NodeArray<ts.Node> = (<any>node2)[childName];
 
@@ -1990,5 +1990,5 @@ namespace Harness {
         return { unitName: libFile, content: io.readFile(libFile) };
     }
 
-    if (Error) (<any>Error).stackTraceLimit = 1;
+    if (Error) (<any>Error).stackTraceLimit = 100;
 }

src/harness/harnessLanguageService.ts

@@ -489,6 +489,15 @@ namespace Harness.LanguageService {
         getCodeFixesAtPosition(): ts.CodeAction[] {
             throw new Error("Not supported on the shim.");
         }
+        getCodeFixDiagnostics(): ts.Diagnostic[] {
+            throw new Error("Not supported on the shim.");
+        }
+        getRefactorCodeActions(): ts.CodeAction[] {
+            throw new Error("Not supported on the shim.");
+        }
+        getApplicableRefactors(): ts.ApplicableRefactorInfo[] {
+            throw new Error("Not supported on the shim.");
+        }
         getEmitOutput(fileName: string): ts.EmitOutput {
             return unwrapJSONCallResult(this.shim.getEmitOutput(fileName));
         }

src/harness/projectsRunner.ts

@@ -373,7 +373,7 @@ class ProjectRunner extends RunnerBase {
             const compilerOptions = compilerResult.program.getCompilerOptions();
 
             ts.forEach(compilerResult.program.getSourceFiles(), sourceFile => {
-                if (ts.isDeclarationFile(sourceFile)) {
+                if (sourceFile.isDeclarationFile) {
                     allInputFiles.unshift({ emittedFileName: sourceFile.fileName, code: sourceFile.text });
                 }
                 else if (!(compilerOptions.outFile || compilerOptions.out)) {

src/harness/unittests/commandLineParsing.ts

@@ -60,7 +60,7 @@ namespace ts {
             assertParseResult(["--lib", "es5,invalidOption", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 
@@ -263,7 +263,7 @@ namespace ts {
             assertParseResult(["--lib", "es5,", "es7", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 
@@ -283,7 +283,7 @@ namespace ts {
             assertParseResult(["--lib", "es5, ", "es7", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 

src/harness/unittests/convertCompilerOptionsFromJson.ts

@@ -266,7 +266,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -297,7 +297,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -328,7 +328,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -359,7 +359,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]

src/harness/unittests/printer.ts

@@ -98,8 +98,43 @@ namespace ts {
                     )
                 ])
             );
+
+            // https://github.com/Microsoft/TypeScript/issues/15971
+            const classWithOptionalMethodAndProperty = createClassDeclaration(
+                undefined,
+                /* modifiers */ createNodeArray([createToken(SyntaxKind.DeclareKeyword)]),
+                /* name      */ createIdentifier("X"),
+                undefined,
+                undefined,
+                createNodeArray([
+                    createMethod(
+                        undefined,
+                        undefined,
+                        undefined,
+                        /* name          */ createIdentifier("method"),
+                        /* questionToken */ createToken(SyntaxKind.QuestionToken),
+                        undefined,
+                        undefined,
+                        /* type          */ createKeywordTypeNode(SyntaxKind.VoidKeyword),
+                        undefined
+                    ),
+                    createProperty(
+                        undefined,
+                        undefined,
+                        /* name          */ createIdentifier("property"),
+                        /* questionToken */ createToken(SyntaxKind.QuestionToken),
+                        /* type          */ createKeywordTypeNode(SyntaxKind.StringKeyword),
+                        undefined
+                    ),
+                ])
+            );
+
             // tslint:enable boolean-trivia
             printsCorrectly("class", {}, printer => printer.printNode(EmitHint.Unspecified, syntheticNode, sourceFile));
+
+            printsCorrectly("namespaceExportDeclaration", {}, printer => printer.printNode(EmitHint.Unspecified, createNamespaceExportDeclaration("B"), sourceFile));
+
+            printsCorrectly("classWithOptionalMethodAndProperty", {}, printer => printer.printNode(EmitHint.Unspecified, classWithOptionalMethodAndProperty, sourceFile));
         });
     });
 }

src/harness/unittests/services/preProcessFile.ts

@@ -37,8 +37,8 @@ describe("PreProcessFile:", function () {
                 /*readImportFile*/ true,
                 /*detectJavaScriptImports*/ false,
                 {
-                    referencedFiles: [{ fileName: "refFile1.ts", pos: 0, end: 37 }, { fileName: "refFile2.ts", pos: 38, end: 73 },
-                        { fileName: "refFile3.ts", pos: 74, end: 109 }, { fileName: "..\\refFile4d.ts", pos: 110, end: 150 }],
+                    referencedFiles: [{ fileName: "refFile1.ts", pos: 22, end: 33 }, { fileName: "refFile2.ts", pos: 59, end: 70 },
+                        { fileName: "refFile3.ts", pos: 94, end: 105 }, { fileName: "..\\refFile4d.ts", pos: 131, end: 146 }],
                     importedFiles: <ts.FileReference[]>[],
                     typeReferenceDirectives: [],
                     ambientExternalModules: undefined,
@@ -104,7 +104,7 @@ describe("PreProcessFile:", function () {
                 /*readImportFile*/ true,
                 /*detectJavaScriptImports*/ false,
                 {
-                    referencedFiles: [{ fileName: "refFile1.ts", pos: 0, end: 35 }, { fileName: "refFile2.ts", pos: 36, end: 71 }],
+                    referencedFiles: [{ fileName: "refFile1.ts", pos: 20, end: 31 }, { fileName: "refFile2.ts", pos: 57, end: 68 }],
                     typeReferenceDirectives: [],
                     importedFiles: [{ fileName: "r1.ts", pos: 92, end: 97 }, { fileName: "r2.ts", pos: 121, end: 126 }],
                     ambientExternalModules: undefined,
@@ -117,7 +117,7 @@ describe("PreProcessFile:", function () {
                 /*readImportFile*/ true,
                 /*detectJavaScriptImports*/ false,
                 {
-                    referencedFiles: [{ fileName: "refFile1.ts", pos: 0, end: 35 }],
+                    referencedFiles: [{ fileName: "refFile1.ts", pos: 20, end: 31 }],
                     typeReferenceDirectives: [],
                     importedFiles: [{ fileName: "r1.ts", pos: 91, end: 96 }, { fileName: "r3.ts", pos: 148, end: 153 }],
                     ambientExternalModules: undefined,
@@ -442,12 +442,12 @@ describe("PreProcessFile:", function () {
             /*detectJavaScriptImports*/ false,
             {
                 referencedFiles: [
-                    { "pos": 13, "end": 38, "fileName": "a" },
-                    { "pos": 91, "end": 117, "fileName": "a2" }
+                    { "pos": 34, "end": 35, "fileName": "a" },
+                    { "pos": 112, "end": 114, "fileName": "a2" }
                 ],
                 typeReferenceDirectives: [
-                    { "pos": 51, "end": 78, "fileName": "a1" },
-                    { "pos": 130, "end": 157, "fileName": "a3" }
+                    { "pos": 73, "end": 75, "fileName": "a1" },
+                    { "pos": 152, "end": 154, "fileName": "a3" }
                 ],
                 importedFiles: [],
                 ambientExternalModules: undefined,

src/harness/unittests/session.ts

@@ -134,7 +134,7 @@ namespace ts.server {
                     type: "request",
                     arguments: {
                         formatOptions: {
-                            indentStyle: "Block"
+                            indentStyle: protocol.IndentStyle.Block,
                         }
                     }
                 };
@@ -149,11 +149,11 @@ namespace ts.server {
                     type: "request",
                     arguments: {
                         options: {
-                            module: "System",
-                            target: "ES5",
-                            jsx: "React",
-                            newLine: "Lf",
-                            moduleResolution: "Node"
+                            module: protocol.ModuleKind.System,
+                            target: protocol.ScriptTarget.ES5,
+                            jsx: protocol.JsxEmit.React,
+                            newLine: protocol.NewLineKind.Lf,
+                            moduleResolution: protocol.ModuleResolutionKind.Node,
                         }
                     }
                 };
@@ -172,12 +172,81 @@ namespace ts.server {
         });
 
         describe("onMessage", () => {
+            const allCommandNames: CommandNames[] = [
+                CommandNames.Brace,
+                CommandNames.BraceFull,
+                CommandNames.BraceCompletion,
+                CommandNames.Change,
+                CommandNames.Close,
+                CommandNames.Completions,
+                CommandNames.CompletionsFull,
+                CommandNames.CompletionDetails,
+                CommandNames.CompileOnSaveAffectedFileList,
+                CommandNames.Configure,
+                CommandNames.Definition,
+                CommandNames.DefinitionFull,
+                CommandNames.Implementation,
+                CommandNames.ImplementationFull,
+                CommandNames.Exit,
+                CommandNames.Format,
+                CommandNames.Formatonkey,
+                CommandNames.FormatFull,
+                CommandNames.FormatonkeyFull,
+                CommandNames.FormatRangeFull,
+                CommandNames.Geterr,
+                CommandNames.GeterrForProject,
+                CommandNames.SemanticDiagnosticsSync,
+                CommandNames.SyntacticDiagnosticsSync,
+                CommandNames.NavBar,
+                CommandNames.NavBarFull,
+                CommandNames.Navto,
+                CommandNames.NavtoFull,
+                CommandNames.NavTree,
+                CommandNames.NavTreeFull,
+                CommandNames.Occurrences,
+                CommandNames.DocumentHighlights,
+                CommandNames.DocumentHighlightsFull,
+                CommandNames.Open,
+                CommandNames.Quickinfo,
+                CommandNames.QuickinfoFull,
+                CommandNames.References,
+                CommandNames.ReferencesFull,
+                CommandNames.Reload,
+                CommandNames.Rename,
+                CommandNames.RenameInfoFull,
+                CommandNames.RenameLocationsFull,
+                CommandNames.Saveto,
+                CommandNames.SignatureHelp,
+                CommandNames.SignatureHelpFull,
+                CommandNames.TypeDefinition,
+                CommandNames.ProjectInfo,
+                CommandNames.ReloadProjects,
+                CommandNames.Unknown,
+                CommandNames.OpenExternalProject,
+                CommandNames.CloseExternalProject,
+                CommandNames.SynchronizeProjectList,
+                CommandNames.ApplyChangedToOpenFiles,
+                CommandNames.EncodedSemanticClassificationsFull,
+                CommandNames.Cleanup,
+                CommandNames.OutliningSpans,
+                CommandNames.TodoComments,
+                CommandNames.Indentation,
+                CommandNames.DocCommentTemplate,
+                CommandNames.CompilerOptionsDiagnosticsFull,
+                CommandNames.NameOrDottedNameSpan,
+                CommandNames.BreakpointStatement,
+                CommandNames.CompilerOptionsForInferredProjects,
+                CommandNames.GetCodeFixes,
+                CommandNames.GetCodeFixesFull,
+                CommandNames.GetSupportedCodeFixes,
+                CommandNames.GetApplicableRefactors,
+                CommandNames.GetRefactorCodeActions,
+                CommandNames.GetRefactorCodeActionsFull,
+            ];
+
             it("should not throw when commands are executed with invalid arguments", () => {
                 let i = 0;
-                for (const name in CommandNames) {
-                    if (!Object.prototype.hasOwnProperty.call(CommandNames, name)) {
-                        continue;
-                    }
+                for (const name of allCommandNames) {
                     const req: protocol.Request = {
                         command: name,
                         seq: i,

src/harness/unittests/tsserverProjectSystem.ts

@@ -337,6 +337,7 @@ namespace ts.projectSystem {
             this.map[timeoutId] = cb.bind(/*this*/ undefined, ...args);
             return timeoutId;
         }
+
         unregister(id: any) {
             if (typeof id === "number") {
                 delete this.map[id];
@@ -352,10 +353,13 @@ namespace ts.projectSystem {
         }
 
         invoke() {
+            // Note: invoking a callback may result in new callbacks been queued,
+            // so do not clear the entire callback list regardless. Only remove the
+            // ones we have invoked.
             for (const key in this.map) {
                 this.map[key]();
+                delete this.map[key];
             }
-            this.map = [];
         }
     }
 
@@ -3743,7 +3747,7 @@ namespace ts.projectSystem {
 
                 // run first step
                 host.runQueuedTimeoutCallbacks();
-                assert.equal(host.getOutput().length, 1, "expect 1 messages");
+                assert.equal(host.getOutput().length, 1, "expect 1 message");
                 const e1 = <protocol.Event>getMessage(0);
                 assert.equal(e1.event, "syntaxDiag");
                 host.clearOutput();
@@ -3765,11 +3769,12 @@ namespace ts.projectSystem {
 
                 // run first step
                 host.runQueuedTimeoutCallbacks();
-                assert.equal(host.getOutput().length, 1, "expect 1 messages");
+                assert.equal(host.getOutput().length, 1, "expect 1 message");
                 const e1 = <protocol.Event>getMessage(0);
                 assert.equal(e1.event, "syntaxDiag");
                 host.clearOutput();
 
+                // the semanticDiag message
                 host.runQueuedImmediateCallbacks();
                 assert.equal(host.getOutput().length, 2, "expect 2 messages");
                 const e2 = <protocol.Event>getMessage(0);
@@ -3787,7 +3792,7 @@ namespace ts.projectSystem {
                 assert.equal(host.getOutput().length, 0, "expect 0 messages");
                 // run first step
                 host.runQueuedTimeoutCallbacks();
-                assert.equal(host.getOutput().length, 1, "expect 1 messages");
+                assert.equal(host.getOutput().length, 1, "expect 1 message");
                 const e1 = <protocol.Event>getMessage(0);
                 assert.equal(e1.event, "syntaxDiag");
                 host.clearOutput();

src/lib/es2017.d.ts

@@ -1,4 +1,5 @@
 /// <reference path="lib.es2016.d.ts" />
 /// <reference path="lib.es2017.object.d.ts" />
 /// <reference path="lib.es2017.sharedmemory.d.ts" />
-/// <reference path="lib.es2017.string.d.ts" />
+/// <reference path="lib.es2017.string.d.ts" />
+/// <reference path="lib.es2017.intl.d.ts" />

src/lib/es2017.intl.d.ts

@@ -0,0 +1,10 @@
+type DateTimeFormatPartTypes = "day" | "dayPeriod" | "era" | "hour" | "literal" | "minute" | "month" | "second" | "timeZoneName" | "weekday" | "year";
+
+interface DateTimeFormatPart {
+    type: DateTimeFormatPartTypes;
+    value: string;
+}
+
+interface DateTimeFormat {
+    formatToParts(date?: Date | number): DateTimeFormatPart[];
+}

src/lib/webworker.generated.d.ts

@@ -1,6 +1,6 @@
 
 /////////////////////////////
-/// IE Worker APIs
+/// Worker APIs
 /////////////////////////////
 
 interface Algorithm {
@@ -8,16 +8,16 @@ interface Algorithm {
 }
 
 interface CacheQueryOptions {
-    ignoreSearch?: boolean;
-    ignoreMethod?: boolean;
-    ignoreVary?: boolean;
     cacheName?: string;
+    ignoreMethod?: boolean;
+    ignoreSearch?: boolean;
+    ignoreVary?: boolean;
 }
 
 interface CloseEventInit extends EventInit {
-    wasClean?: boolean;
     code?: number;
     reason?: string;
+    wasClean?: boolean;
 }
 
 interface EventInit {
@@ -49,16 +49,16 @@ interface MessageEventInit extends EventInit {
     channel?: string;
     data?: any;
     origin?: string;
-    source?: any;
     ports?: MessagePort[];
+    source?: any;
 }
 
 interface NotificationOptions {
-    dir?: NotificationDirection;
-    lang?: string;
     body?: string;
-    tag?: string;
+    dir?: NotificationDirection;
     icon?: string;
+    lang?: string;
+    tag?: string;
 }
 
 interface ObjectURLOptions {
@@ -66,29 +66,29 @@ interface ObjectURLOptions {
 }
 
 interface PushSubscriptionOptionsInit {
-    userVisibleOnly?: boolean;
     applicationServerKey?: any;
+    userVisibleOnly?: boolean;
 }
 
 interface RequestInit {
-    method?: string;
-    headers?: any;
     body?: any;
-    referrer?: string;
-    referrerPolicy?: ReferrerPolicy;
-    mode?: RequestMode;
-    credentials?: RequestCredentials;
     cache?: RequestCache;
-    redirect?: RequestRedirect;
+    credentials?: RequestCredentials;
+    headers?: any;
     integrity?: string;
     keepalive?: boolean;
+    method?: string;
+    mode?: RequestMode;
+    redirect?: RequestRedirect;
+    referrer?: string;
+    referrerPolicy?: ReferrerPolicy;
     window?: any;
 }
 
 interface ResponseInit {
+    headers?: any;
     status?: number;
     statusText?: string;
-    headers?: any;
 }
 
 interface ClientQueryOptions {
@@ -156,7 +156,7 @@ interface AudioBuffer {
 declare var AudioBuffer: {
     prototype: AudioBuffer;
     new(): AudioBuffer;
-}
+};
 
 interface Blob {
     readonly size: number;
@@ -169,7 +169,7 @@ interface Blob {
 declare var Blob: {
     prototype: Blob;
     new (blobParts?: any[], options?: BlobPropertyBag): Blob;
-}
+};
 
 interface Cache {
     add(request: RequestInfo): Promise<void>;
@@ -184,7 +184,7 @@ interface Cache {
 declare var Cache: {
     prototype: Cache;
     new(): Cache;
-}
+};
 
 interface CacheStorage {
     delete(cacheName: string): Promise<boolean>;
@@ -197,7 +197,7 @@ interface CacheStorage {
 declare var CacheStorage: {
     prototype: CacheStorage;
     new(): CacheStorage;
-}
+};
 
 interface CloseEvent extends Event {
     readonly code: number;
@@ -209,7 +209,7 @@ interface CloseEvent extends Event {
 declare var CloseEvent: {
     prototype: CloseEvent;
     new(typeArg: string, eventInitDict?: CloseEventInit): CloseEvent;
-}
+};
 
 interface Console {
     assert(test?: boolean, message?: string, ...optionalParams: any[]): void;
@@ -220,8 +220,8 @@ interface Console {
     dirxml(value: any): void;
     error(message?: any, ...optionalParams: any[]): void;
     exception(message?: string, ...optionalParams: any[]): void;
-    group(groupTitle?: string): void;
-    groupCollapsed(groupTitle?: string): void;
+    group(groupTitle?: string, ...optionalParams: any[]): void;
+    groupCollapsed(groupTitle?: string, ...optionalParams: any[]): void;
     groupEnd(): void;
     info(message?: any, ...optionalParams: any[]): void;
     log(message?: any, ...optionalParams: any[]): void;
@@ -239,7 +239,7 @@ interface Console {
 declare var Console: {
     prototype: Console;
     new(): Console;
-}
+};
 
 interface Coordinates {
     readonly accuracy: number;
@@ -254,7 +254,7 @@ interface Coordinates {
 declare var Coordinates: {
     prototype: Coordinates;
     new(): Coordinates;
-}
+};
 
 interface CryptoKey {
     readonly algorithm: KeyAlgorithm;
@@ -266,7 +266,7 @@ interface CryptoKey {
 declare var CryptoKey: {
     prototype: CryptoKey;
     new(): CryptoKey;
-}
+};
 
 interface DOMError {
     readonly name: string;
@@ -276,7 +276,7 @@ interface DOMError {
 declare var DOMError: {
     prototype: DOMError;
     new(): DOMError;
-}
+};
 
 interface DOMException {
     readonly code: number;
@@ -296,10 +296,10 @@ interface DOMException {
     readonly INVALID_STATE_ERR: number;
     readonly NAMESPACE_ERR: number;
     readonly NETWORK_ERR: number;
-    readonly NOT_FOUND_ERR: number;
-    readonly NOT_SUPPORTED_ERR: number;
     readonly NO_DATA_ALLOWED_ERR: number;
     readonly NO_MODIFICATION_ALLOWED_ERR: number;
+    readonly NOT_FOUND_ERR: number;
+    readonly NOT_SUPPORTED_ERR: number;
     readonly PARSE_ERR: number;
     readonly QUOTA_EXCEEDED_ERR: number;
     readonly SECURITY_ERR: number;
@@ -328,10 +328,10 @@ declare var DOMException: {
     readonly INVALID_STATE_ERR: number;
     readonly NAMESPACE_ERR: number;
     readonly NETWORK_ERR: number;
-    readonly NOT_FOUND_ERR: number;
-    readonly NOT_SUPPORTED_ERR: number;
     readonly NO_DATA_ALLOWED_ERR: number;
     readonly NO_MODIFICATION_ALLOWED_ERR: number;
+    readonly NOT_FOUND_ERR: number;
+    readonly NOT_SUPPORTED_ERR: number;
     readonly PARSE_ERR: number;
     readonly QUOTA_EXCEEDED_ERR: number;
     readonly SECURITY_ERR: number;
@@ -342,7 +342,7 @@ declare var DOMException: {
     readonly URL_MISMATCH_ERR: number;
     readonly VALIDATION_ERR: number;
     readonly WRONG_DOCUMENT_ERR: number;
-}
+};
 
 interface DOMStringList {
     readonly length: number;
@@ -354,7 +354,7 @@ interface DOMStringList {
 declare var DOMStringList: {
     prototype: DOMStringList;
     new(): DOMStringList;
-}
+};
 
 interface ErrorEvent extends Event {
     readonly colno: number;
@@ -368,12 +368,12 @@ interface ErrorEvent extends Event {
 declare var ErrorEvent: {
     prototype: ErrorEvent;
     new(type: string, errorEventInitDict?: ErrorEventInit): ErrorEvent;
-}
+};
 
 interface Event {
     readonly bubbles: boolean;
-    cancelBubble: boolean;
     readonly cancelable: boolean;
+    cancelBubble: boolean;
     readonly currentTarget: EventTarget;
     readonly defaultPrevented: boolean;
     readonly eventPhase: number;
@@ -400,7 +400,7 @@ declare var Event: {
     readonly AT_TARGET: number;
     readonly BUBBLING_PHASE: number;
     readonly CAPTURING_PHASE: number;
-}
+};
 
 interface EventTarget {
     addEventListener(type: string, listener?: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void;
@@ -411,7 +411,7 @@ interface EventTarget {
 declare var EventTarget: {
     prototype: EventTarget;
     new(): EventTarget;
-}
+};
 
 interface File extends Blob {
     readonly lastModifiedDate: any;
@@ -422,7 +422,7 @@ interface File extends Blob {
 declare var File: {
     prototype: File;
     new (parts: (ArrayBuffer | ArrayBufferView | Blob | string)[], filename: string, properties?: FilePropertyBag): File;
-}
+};
 
 interface FileList {
     readonly length: number;
@@ -433,7 +433,7 @@ interface FileList {
 declare var FileList: {
     prototype: FileList;
     new(): FileList;
-}
+};
 
 interface FileReader extends EventTarget, MSBaseReader {
     readonly error: DOMError;
@@ -448,8 +448,17 @@ interface FileReader extends EventTarget, MSBaseReader {
 declare var FileReader: {
     prototype: FileReader;
     new(): FileReader;
+};
+
+interface FormData {
+    append(name: string, value: string | Blob, fileName?: string): void;
 }
 
+declare var FormData: {
+    prototype: FormData;
+    new(): FormData;
+};
+
 interface Headers {
     append(name: string, value: string): void;
     delete(name: string): void;
@@ -462,7 +471,7 @@ interface Headers {
 declare var Headers: {
     prototype: Headers;
     new(init?: any): Headers;
-}
+};
 
 interface IDBCursor {
     readonly direction: IDBCursorDirection;
@@ -486,7 +495,7 @@ declare var IDBCursor: {
     readonly NEXT_NO_DUPLICATE: string;
     readonly PREV: string;
     readonly PREV_NO_DUPLICATE: string;
-}
+};
 
 interface IDBCursorWithValue extends IDBCursor {
     readonly value: any;
@@ -495,7 +504,7 @@ interface IDBCursorWithValue extends IDBCursor {
 declare var IDBCursorWithValue: {
     prototype: IDBCursorWithValue;
     new(): IDBCursorWithValue;
-}
+};
 
 interface IDBDatabaseEventMap {
     "abort": Event;
@@ -512,7 +521,7 @@ interface IDBDatabase extends EventTarget {
     close(): void;
     createObjectStore(name: string, optionalParameters?: IDBObjectStoreParameters): IDBObjectStore;
     deleteObjectStore(name: string): void;
-    transaction(storeNames: string | string[], mode?: string): IDBTransaction;
+    transaction(storeNames: string | string[], mode?: IDBTransactionMode): IDBTransaction;
     addEventListener(type: "versionchange", listener: (ev: IDBVersionChangeEvent) => any, useCapture?: boolean): void;
     addEventListener<K extends keyof IDBDatabaseEventMap>(type: K, listener: (this: IDBDatabase, ev: IDBDatabaseEventMap[K]) => any, useCapture?: boolean): void;
     addEventListener(type: string, listener: EventListenerOrEventListenerObject, useCapture?: boolean): void;
@@ -521,7 +530,7 @@ interface IDBDatabase extends EventTarget {
 declare var IDBDatabase: {
     prototype: IDBDatabase;
     new(): IDBDatabase;
-}
+};
 
 interface IDBFactory {
     cmp(first: any, second: any): number;
@@ -532,7 +541,7 @@ interface IDBFactory {
 declare var IDBFactory: {
     prototype: IDBFactory;
     new(): IDBFactory;
-}
+};
 
 interface IDBIndex {
     keyPath: string | string[];
@@ -543,14 +552,14 @@ interface IDBIndex {
     count(key?: IDBKeyRange | IDBValidKey): IDBRequest;
     get(key: IDBKeyRange | IDBValidKey): IDBRequest;
     getKey(key: IDBKeyRange | IDBValidKey): IDBRequest;
-    openCursor(range?: IDBKeyRange | IDBValidKey, direction?: string): IDBRequest;
-    openKeyCursor(range?: IDBKeyRange | IDBValidKey, direction?: string): IDBRequest;
+    openCursor(range?: IDBKeyRange | IDBValidKey, direction?: IDBCursorDirection): IDBRequest;
+    openKeyCursor(range?: IDBKeyRange | IDBValidKey, direction?: IDBCursorDirection): IDBRequest;
 }
 
 declare var IDBIndex: {
     prototype: IDBIndex;
     new(): IDBIndex;
-}
+};
 
 interface IDBKeyRange {
     readonly lower: any;
@@ -566,7 +575,7 @@ declare var IDBKeyRange: {
     lowerBound(lower: any, open?: boolean): IDBKeyRange;
     only(value: any): IDBKeyRange;
     upperBound(upper: any, open?: boolean): IDBKeyRange;
-}
+};
 
 interface IDBObjectStore {
     readonly indexNames: DOMStringList;
@@ -582,14 +591,14 @@ interface IDBObjectStore {
     deleteIndex(indexName: string): void;
     get(key: any): IDBRequest;
     index(name: string): IDBIndex;
-    openCursor(range?: IDBKeyRange | IDBValidKey, direction?: string): IDBRequest;
+    openCursor(range?: IDBKeyRange | IDBValidKey, direction?: IDBCursorDirection): IDBRequest;
     put(value: any, key?: IDBKeyRange | IDBValidKey): IDBRequest;
 }
 
 declare var IDBObjectStore: {
     prototype: IDBObjectStore;
     new(): IDBObjectStore;
-}
+};
 
 interface IDBOpenDBRequestEventMap extends IDBRequestEventMap {
     "blocked": Event;
@@ -606,7 +615,7 @@ interface IDBOpenDBRequest extends IDBRequest {
 declare var IDBOpenDBRequest: {
     prototype: IDBOpenDBRequest;
     new(): IDBOpenDBRequest;
-}
+};
 
 interface IDBRequestEventMap {
     "error": Event;
@@ -614,7 +623,7 @@ interface IDBRequestEventMap {
 }
 
 interface IDBRequest extends EventTarget {
-    readonly error: DOMError;
+    readonly error: DOMException;
     onerror: (this: IDBRequest, ev: Event) => any;
     onsuccess: (this: IDBRequest, ev: Event) => any;
     readonly readyState: IDBRequestReadyState;
@@ -628,7 +637,7 @@ interface IDBRequest extends EventTarget {
 declare var IDBRequest: {
     prototype: IDBRequest;
     new(): IDBRequest;
-}
+};
 
 interface IDBTransactionEventMap {
     "abort": Event;
@@ -638,7 +647,7 @@ interface IDBTransactionEventMap {
 
 interface IDBTransaction extends EventTarget {
     readonly db: IDBDatabase;
-    readonly error: DOMError;
+    readonly error: DOMException;
     readonly mode: IDBTransactionMode;
     onabort: (this: IDBTransaction, ev: Event) => any;
     oncomplete: (this: IDBTransaction, ev: Event) => any;
@@ -658,7 +667,7 @@ declare var IDBTransaction: {
     readonly READ_ONLY: string;
     readonly READ_WRITE: string;
     readonly VERSION_CHANGE: string;
-}
+};
 
 interface IDBVersionChangeEvent extends Event {
     readonly newVersion: number | null;
@@ -668,7 +677,7 @@ interface IDBVersionChangeEvent extends Event {
 declare var IDBVersionChangeEvent: {
     prototype: IDBVersionChangeEvent;
     new(): IDBVersionChangeEvent;
-}
+};
 
 interface ImageData {
     data: Uint8ClampedArray;
@@ -680,7 +689,7 @@ declare var ImageData: {
     prototype: ImageData;
     new(width: number, height: number): ImageData;
     new(array: Uint8ClampedArray, width: number, height: number): ImageData;
-}
+};
 
 interface MessageChannel {
     readonly port1: MessagePort;
@@ -690,7 +699,7 @@ interface MessageChannel {
 declare var MessageChannel: {
     prototype: MessageChannel;
     new(): MessageChannel;
-}
+};
 
 interface MessageEvent extends Event {
     readonly data: any;
@@ -703,7 +712,7 @@ interface MessageEvent extends Event {
 declare var MessageEvent: {
     prototype: MessageEvent;
     new(type: string, eventInitDict?: MessageEventInit): MessageEvent;
-}
+};
 
 interface MessagePortEventMap {
     "message": MessageEvent;
@@ -721,7 +730,7 @@ interface MessagePort extends EventTarget {
 declare var MessagePort: {
     prototype: MessagePort;
     new(): MessagePort;
-}
+};
 
 interface NotificationEventMap {
     "click": Event;
@@ -751,7 +760,7 @@ declare var Notification: {
     prototype: Notification;
     new(title: string, options?: NotificationOptions): Notification;
     requestPermission(callback?: NotificationPermissionCallback): Promise<NotificationPermission>;
-}
+};
 
 interface Performance {
     readonly navigation: PerformanceNavigation;
@@ -774,7 +783,7 @@ interface Performance {
 declare var Performance: {
     prototype: Performance;
     new(): Performance;
-}
+};
 
 interface PerformanceNavigation {
     readonly redirectCount: number;
@@ -793,18 +802,18 @@ declare var PerformanceNavigation: {
     readonly TYPE_NAVIGATE: number;
     readonly TYPE_RELOAD: number;
     readonly TYPE_RESERVED: number;
-}
+};
 
 interface PerformanceTiming {
     readonly connectEnd: number;
     readonly connectStart: number;
+    readonly domainLookupEnd: number;
+    readonly domainLookupStart: number;
     readonly domComplete: number;
     readonly domContentLoadedEventEnd: number;
     readonly domContentLoadedEventStart: number;
     readonly domInteractive: number;
     readonly domLoading: number;
-    readonly domainLookupEnd: number;
-    readonly domainLookupStart: number;
     readonly fetchStart: number;
     readonly loadEventEnd: number;
     readonly loadEventStart: number;
@@ -824,7 +833,7 @@ interface PerformanceTiming {
 declare var PerformanceTiming: {
     prototype: PerformanceTiming;
     new(): PerformanceTiming;
-}
+};
 
 interface Position {
     readonly coords: Coordinates;
@@ -834,7 +843,7 @@ interface Position {
 declare var Position: {
     prototype: Position;
     new(): Position;
-}
+};
 
 interface PositionError {
     readonly code: number;
@@ -851,7 +860,7 @@ declare var PositionError: {
     readonly PERMISSION_DENIED: number;
     readonly POSITION_UNAVAILABLE: number;
     readonly TIMEOUT: number;
-}
+};
 
 interface ProgressEvent extends Event {
     readonly lengthComputable: boolean;
@@ -863,7 +872,7 @@ interface ProgressEvent extends Event {
 declare var ProgressEvent: {
     prototype: ProgressEvent;
     new(type: string, eventInitDict?: ProgressEventInit): ProgressEvent;
-}
+};
 
 interface PushManager {
     getSubscription(): Promise<PushSubscription>;
@@ -874,7 +883,7 @@ interface PushManager {
 declare var PushManager: {
     prototype: PushManager;
     new(): PushManager;
-}
+};
 
 interface PushSubscription {
     readonly endpoint: USVString;
@@ -887,7 +896,7 @@ interface PushSubscription {
 declare var PushSubscription: {
     prototype: PushSubscription;
     new(): PushSubscription;
-}
+};
 
 interface PushSubscriptionOptions {
     readonly applicationServerKey: ArrayBuffer | null;
@@ -897,7 +906,7 @@ interface PushSubscriptionOptions {
 declare var PushSubscriptionOptions: {
     prototype: PushSubscriptionOptions;
     new(): PushSubscriptionOptions;
-}
+};
 
 interface ReadableStream {
     readonly locked: boolean;
@@ -908,7 +917,7 @@ interface ReadableStream {
 declare var ReadableStream: {
     prototype: ReadableStream;
     new(): ReadableStream;
-}
+};
 
 interface ReadableStreamReader {
     cancel(): Promise<void>;
@@ -919,7 +928,7 @@ interface ReadableStreamReader {
 declare var ReadableStreamReader: {
     prototype: ReadableStreamReader;
     new(): ReadableStreamReader;
-}
+};
 
 interface Request extends Object, Body {
     readonly cache: RequestCache;
@@ -941,7 +950,7 @@ interface Request extends Object, Body {
 declare var Request: {
     prototype: Request;
     new(input: Request | string, init?: RequestInit): Request;
-}
+};
 
 interface Response extends Object, Body {
     readonly body: ReadableStream | null;
@@ -957,7 +966,9 @@ interface Response extends Object, Body {
 declare var Response: {
     prototype: Response;
     new(body?: any, init?: ResponseInit): Response;
-}
+    error: () => Response;
+    redirect: (url: string, status?: number) => Response;
+};
 
 interface ServiceWorkerEventMap extends AbstractWorkerEventMap {
     "statechange": Event;
@@ -975,7 +986,7 @@ interface ServiceWorker extends EventTarget, AbstractWorker {
 declare var ServiceWorker: {
     prototype: ServiceWorker;
     new(): ServiceWorker;
-}
+};
 
 interface ServiceWorkerRegistrationEventMap {
     "updatefound": Event;
@@ -1000,7 +1011,7 @@ interface ServiceWorkerRegistration extends EventTarget {
 declare var ServiceWorkerRegistration: {
     prototype: ServiceWorkerRegistration;
     new(): ServiceWorkerRegistration;
-}
+};
 
 interface SyncManager {
     getTags(): any;
@@ -1010,7 +1021,7 @@ interface SyncManager {
 declare var SyncManager: {
     prototype: SyncManager;
     new(): SyncManager;
-}
+};
 
 interface URL {
     hash: string;
@@ -1033,7 +1044,7 @@ declare var URL: {
     new(url: string, base?: string): URL;
     createObjectURL(object: any, options?: ObjectURLOptions): string;
     revokeObjectURL(url: string): void;
-}
+};
 
 interface WebSocketEventMap {
     "close": CloseEvent;
@@ -1070,7 +1081,7 @@ declare var WebSocket: {
     readonly CLOSING: number;
     readonly CONNECTING: number;
     readonly OPEN: number;
-}
+};
 
 interface WorkerEventMap extends AbstractWorkerEventMap {
     "message": MessageEvent;
@@ -1087,7 +1098,7 @@ interface Worker extends EventTarget, AbstractWorker {
 declare var Worker: {
     prototype: Worker;
     new(stringUrl: string): Worker;
-}
+};
 
 interface XMLHttpRequestEventMap extends XMLHttpRequestEventTargetEventMap {
     "readystatechange": Event;
@@ -1133,7 +1144,7 @@ declare var XMLHttpRequest: {
     readonly LOADING: number;
     readonly OPENED: number;
     readonly UNSENT: number;
-}
+};
 
 interface XMLHttpRequestUpload extends EventTarget, XMLHttpRequestEventTarget {
     addEventListener<K extends keyof XMLHttpRequestEventTargetEventMap>(type: K, listener: (this: XMLHttpRequestUpload, ev: XMLHttpRequestEventTargetEventMap[K]) => any, useCapture?: boolean): void;
@@ -1143,7 +1154,7 @@ interface XMLHttpRequestUpload extends EventTarget, XMLHttpRequestEventTarget {
 declare var XMLHttpRequestUpload: {
     prototype: XMLHttpRequestUpload;
     new(): XMLHttpRequestUpload;
-}
+};
 
 interface AbstractWorkerEventMap {
     "error": ErrorEvent;
@@ -1258,7 +1269,7 @@ interface Client {
 declare var Client: {
     prototype: Client;
     new(): Client;
-}
+};
 
 interface Clients {
     claim(): Promise<void>;
@@ -1270,7 +1281,7 @@ interface Clients {
 declare var Clients: {
     prototype: Clients;
     new(): Clients;
-}
+};
 
 interface DedicatedWorkerGlobalScopeEventMap extends WorkerGlobalScopeEventMap {
     "message": MessageEvent;
@@ -1287,7 +1298,7 @@ interface DedicatedWorkerGlobalScope extends WorkerGlobalScope {
 declare var DedicatedWorkerGlobalScope: {
     prototype: DedicatedWorkerGlobalScope;
     new(): DedicatedWorkerGlobalScope;
-}
+};
 
 interface ExtendableEvent extends Event {
     waitUntil(f: Promise<any>): void;
@@ -1296,7 +1307,7 @@ interface ExtendableEvent extends Event {
 declare var ExtendableEvent: {
     prototype: ExtendableEvent;
     new(type: string, eventInitDict?: ExtendableEventInit): ExtendableEvent;
-}
+};
 
 interface ExtendableMessageEvent extends ExtendableEvent {
     readonly data: any;
@@ -1309,7 +1320,7 @@ interface ExtendableMessageEvent extends ExtendableEvent {
 declare var ExtendableMessageEvent: {
     prototype: ExtendableMessageEvent;
     new(type: string, eventInitDict?: ExtendableMessageEventInit): ExtendableMessageEvent;
-}
+};
 
 interface FetchEvent extends ExtendableEvent {
     readonly clientId: string | null;
@@ -1321,7 +1332,7 @@ interface FetchEvent extends ExtendableEvent {
 declare var FetchEvent: {
     prototype: FetchEvent;
     new(type: string, eventInitDict: FetchEventInit): FetchEvent;
-}
+};
 
 interface FileReaderSync {
     readAsArrayBuffer(blob: Blob): any;
@@ -1333,7 +1344,7 @@ interface FileReaderSync {
 declare var FileReaderSync: {
     prototype: FileReaderSync;
     new(): FileReaderSync;
-}
+};
 
 interface NotificationEvent extends ExtendableEvent {
     readonly action: string;
@@ -1343,7 +1354,7 @@ interface NotificationEvent extends ExtendableEvent {
 declare var NotificationEvent: {
     prototype: NotificationEvent;
     new(type: string, eventInitDict: NotificationEventInit): NotificationEvent;
-}
+};
 
 interface PushEvent extends ExtendableEvent {
     readonly data: PushMessageData | null;
@@ -1352,7 +1363,7 @@ interface PushEvent extends ExtendableEvent {
 declare var PushEvent: {
     prototype: PushEvent;
     new(type: string, eventInitDict?: PushEventInit): PushEvent;
-}
+};
 
 interface PushMessageData {
     arrayBuffer(): ArrayBuffer;
@@ -1364,7 +1375,7 @@ interface PushMessageData {
 declare var PushMessageData: {
     prototype: PushMessageData;
     new(): PushMessageData;
-}
+};
 
 interface ServiceWorkerGlobalScopeEventMap extends WorkerGlobalScopeEventMap {
     "activate": ExtendableEvent;
@@ -1398,7 +1409,7 @@ interface ServiceWorkerGlobalScope extends WorkerGlobalScope {
 declare var ServiceWorkerGlobalScope: {
     prototype: ServiceWorkerGlobalScope;
     new(): ServiceWorkerGlobalScope;
-}
+};
 
 interface SyncEvent extends ExtendableEvent {
     readonly lastChance: boolean;
@@ -1408,7 +1419,7 @@ interface SyncEvent extends ExtendableEvent {
 declare var SyncEvent: {
     prototype: SyncEvent;
     new(type: string, init: SyncEventInit): SyncEvent;
-}
+};
 
 interface WindowClient extends Client {
     readonly focused: boolean;
@@ -1420,7 +1431,7 @@ interface WindowClient extends Client {
 declare var WindowClient: {
     prototype: WindowClient;
     new(): WindowClient;
-}
+};
 
 interface WorkerGlobalScopeEventMap {
     "error": ErrorEvent;
@@ -1443,7 +1454,7 @@ interface WorkerGlobalScope extends EventTarget, WorkerUtils, WindowConsole, Glo
 declare var WorkerGlobalScope: {
     prototype: WorkerGlobalScope;
     new(): WorkerGlobalScope;
-}
+};
 
 interface WorkerLocation {
     readonly hash: string;
@@ -1461,7 +1472,7 @@ interface WorkerLocation {
 declare var WorkerLocation: {
     prototype: WorkerLocation;
     new(): WorkerLocation;
-}
+};
 
 interface WorkerNavigator extends Object, NavigatorID, NavigatorOnLine, NavigatorBeacon, NavigatorConcurrentHardware {
     readonly hardwareConcurrency: number;
@@ -1470,7 +1481,7 @@ interface WorkerNavigator extends Object, NavigatorID, NavigatorOnLine, Navigato
 declare var WorkerNavigator: {
     prototype: WorkerNavigator;
     new(): WorkerNavigator;
-}
+};
 
 interface WorkerUtils extends Object, WindowBase64 {
     readonly indexedDB: IDBFactory;
@@ -1513,38 +1524,38 @@ interface ImageBitmap {
 
 interface URLSearchParams {
     /**
-      * Appends a specified key/value pair as a new search parameter.
-      */
+     * Appends a specified key/value pair as a new search parameter.
+     */
     append(name: string, value: string): void;
     /**
-      * Deletes the given search parameter, and its associated value, from the list of all search parameters.
-      */
+     * Deletes the given search parameter, and its associated value, from the list of all search parameters.
+     */
     delete(name: string): void;
     /**
-      * Returns the first value associated to the given search parameter.
-      */
+     * Returns the first value associated to the given search parameter.
+     */
     get(name: string): string | null;
     /**
-      * Returns all the values association with a given search parameter.
-      */
+     * Returns all the values association with a given search parameter.
+     */
     getAll(name: string): string[];
     /**
-      * Returns a Boolean indicating if such a search parameter exists.
-      */
+     * Returns a Boolean indicating if such a search parameter exists.
+     */
     has(name: string): boolean;
     /**
-      * Sets the value associated to a given search parameter to the given value. If there were several values, delete the others.
-      */
+     * Sets the value associated to a given search parameter to the given value. If there were several values, delete the others.
+     */
     set(name: string, value: string): void;
 }
 
 declare var URLSearchParams: {
     prototype: URLSearchParams;
     /**
-      * Constructor returning a URLSearchParams object.
-      */
+     * Constructor returning a URLSearchParams object.
+     */
     new (init?: string | URLSearchParams): URLSearchParams;
-}
+};
 
 interface BlobPropertyBag {
     type?: string;
@@ -1751,8 +1762,23 @@ interface AddEventListenerOptions extends EventListenerOptions {
 
 declare type EventListenerOrEventListenerObject = EventListener | EventListenerObject;
 
+interface DecodeErrorCallback {
+    (error: DOMException): void;
+}
+interface DecodeSuccessCallback {
+    (decodedData: AudioBuffer): void;
+}
 interface ErrorEventHandler {
-    (message: string, filename?: string, lineno?: number, colno?: number, error?:Error): void;
+    (message: string, filename?: string, lineno?: number, colno?: number, error?: Error): void;
+}
+interface ForEachCallback {
+    (keyId: any, status: MediaKeyStatus): void;
+}
+interface FunctionStringCallback {
+    (data: string): void;
+}
+interface NotificationPermissionCallback {
+    (permission: NotificationPermission): void;
 }
 interface PositionCallback {
     (position: Position): void;
@@ -1760,21 +1786,6 @@ interface PositionCallback {
 interface PositionErrorCallback {
     (error: PositionError): void;
 }
-interface DecodeSuccessCallback {
-    (decodedData: AudioBuffer): void;
-}
-interface DecodeErrorCallback {
-    (error: DOMException): void;
-}
-interface FunctionStringCallback {
-    (data: string): void;
-}
-interface ForEachCallback {
-    (keyId: any, status: MediaKeyStatus): void;
-}
-interface NotificationPermissionCallback {
-    (permission: NotificationPermission): void;
-}
 declare var onmessage: (this: DedicatedWorkerGlobalScope, ev: MessageEvent) => any;
 declare function close(): void;
 declare function postMessage(message: any, transfer?: any[]): void;

src/server/client.ts

@@ -224,7 +224,7 @@ namespace ts.server {
                         return { name, kind, kindModifiers, sortText, replacementSpan: convertedSpan };
                     }
 
-                    return entry as { name: string, kind: string, kindModifiers: string, sortText: string };
+                    return entry as { name: string, kind: ScriptElementKind, kindModifiers: string, sortText: string };
                 })
             };
         }
@@ -265,7 +265,7 @@ namespace ts.server {
                 return {
                     name: entry.name,
                     containerName: entry.containerName || "",
-                    containerKind: entry.containerKind || "",
+                    containerKind: entry.containerKind || ScriptElementKind.unknown,
                     kind: entry.kind,
                     kindModifiers: entry.kindModifiers,
                     matchKind: entry.matchKind,
@@ -330,11 +330,11 @@ namespace ts.server {
                 const start = this.lineOffsetToPosition(fileName, entry.start);
                 const end = this.lineOffsetToPosition(fileName, entry.end);
                 return {
-                    containerKind: "",
+                    containerKind: ScriptElementKind.unknown,
                     containerName: "",
                     fileName: fileName,
                     textSpan: ts.createTextSpanFromBounds(start, end),
-                    kind: "",
+                    kind: ScriptElementKind.unknown,
                     name: ""
                 };
             });
@@ -356,11 +356,11 @@ namespace ts.server {
                 const start = this.lineOffsetToPosition(fileName, entry.start);
                 const end = this.lineOffsetToPosition(fileName, entry.end);
                 return {
-                    containerKind: "",
+                    containerKind: ScriptElementKind.unknown,
                     containerName: "",
                     fileName: fileName,
                     textSpan: ts.createTextSpanFromBounds(start, end),
-                    kind: "",
+                    kind: ScriptElementKind.unknown,
                     name: ""
                 };
             });
@@ -695,6 +695,46 @@ namespace ts.server {
             return response.body.map(entry => this.convertCodeActions(entry, fileName));
         }
 
+        private createFileLocationOrRangeRequestArgs(positionOrRange: number | TextRange, fileName: string): protocol.FileLocationOrRangeRequestArgs {
+            if (typeof positionOrRange === "number") {
+                const { line, offset } = this.positionToOneBasedLineOffset(fileName, positionOrRange);
+                return <protocol.FileLocationRequestArgs>{ file: fileName, line, offset };
+            }
+            const { line: startLine, offset: startOffset } = this.positionToOneBasedLineOffset(fileName, positionOrRange.pos);
+            const { line: endLine, offset: endOffset } = this.positionToOneBasedLineOffset(fileName, positionOrRange.end);
+            return <protocol.FileRangeRequestArgs>{
+                file: fileName,
+                startLine,
+                startOffset,
+                endLine,
+                endOffset
+            };
+        }
+
+        getApplicableRefactors(fileName: string, positionOrRange: number | TextRange): ApplicableRefactorInfo[] {
+            const args = this.createFileLocationOrRangeRequestArgs(positionOrRange, fileName);
+
+            const request = this.processRequest<protocol.GetApplicableRefactorsRequest>(CommandNames.GetApplicableRefactors, args);
+            const response = this.processResponse<protocol.GetApplicableRefactorsResponse>(request);
+            return response.body;
+        }
+
+        getRefactorCodeActions(
+            fileName: string,
+            _formatOptions: FormatCodeSettings,
+            positionOrRange: number | TextRange,
+            refactorName: string) {
+
+            const args = this.createFileLocationOrRangeRequestArgs(positionOrRange, fileName) as protocol.GetRefactorCodeActionsRequestArgs;
+            args.refactorName = refactorName;
+
+            const request = this.processRequest<protocol.GetRefactorCodeActionsRequest>(CommandNames.GetRefactorCodeActions, args);
+            const response = this.processResponse<protocol.GetRefactorCodeActionsResponse>(request);
+            const codeActions = response.body.actions;
+
+            return map(codeActions, codeAction => this.convertCodeActions(codeAction, fileName));
+        }
+
         convertCodeActions(entry: protocol.CodeAction, fileName: string): CodeAction {
             return {
                 description: entry.description,

src/server/editorServices.ts

@@ -283,6 +283,7 @@ namespace ts.server {
         throttleWaitMilliseconds?: number;
         globalPlugins?: string[];
         pluginProbeLocations?: string[];
+        allowLocalPluginLoads?: boolean;
     }
 
     export class ProjectService {
@@ -342,6 +343,7 @@ namespace ts.server {
 
         public readonly globalPlugins: ReadonlyArray<string>;
         public readonly pluginProbeLocations: ReadonlyArray<string>;
+        public readonly allowLocalPluginLoads: boolean;
 
         constructor(opts: ProjectServiceOptions) {
             this.host = opts.host;
@@ -353,6 +355,7 @@ namespace ts.server {
             this.eventHandler = opts.eventHandler;
             this.globalPlugins = opts.globalPlugins || emptyArray;
             this.pluginProbeLocations = opts.pluginProbeLocations || emptyArray;
+            this.allowLocalPluginLoads = !!opts.allowLocalPluginLoads;
 
             Debug.assert(!!this.host.createHash, "'ServerHost.createHash' is required for ProjectService");
 

src/server/project.ts

@@ -13,13 +13,6 @@ namespace ts.server {
         External
     }
 
-    function remove<T>(items: T[], item: T) {
-        const index = items.indexOf(item);
-        if (index >= 0) {
-            items.splice(index, 1);
-        }
-    }
-
     function countEachFileTypes(infos: ScriptInfo[]): { js: number, jsx: number, ts: number, tsx: number, dts: number } {
         const result = { js: 0, jsx: 0, ts: 0, tsx: 0, dts: 0 };
         for (const info of infos) {
@@ -769,7 +762,7 @@ namespace ts.server {
 
         // remove a root file from project
         protected removeRoot(info: ScriptInfo): void {
-            remove(this.rootFiles, info);
+            orderedRemoveItem(this.rootFiles, info);
             this.rootFilesMap.remove(info.path);
         }
     }
@@ -910,6 +903,12 @@ namespace ts.server {
             // ../../.. to walk from X/node_modules/typescript/lib/tsserver.js to X/node_modules/
             const searchPaths = [combinePaths(host.getExecutingFilePath(), "../../.."), ...this.projectService.pluginProbeLocations];
 
+            if (this.projectService.allowLocalPluginLoads) {
+                const local = getDirectoryPath(this.canonicalConfigFilePath);
+                this.projectService.logger.info(`Local plugin loading enabled; adding ${local} to search paths`);
+                searchPaths.unshift(local);
+            }
+
             // Enable tsconfig-specified plugins
             if (options.plugins) {
                 for (const pluginConfigEntry of options.plugins) {

src/server/protocol.ts

@@ -2,99 +2,104 @@
  * Declaration module describing the TypeScript Server protocol
  */
 namespace ts.server.protocol {
-    export namespace CommandTypes {
-        export type Brace = "brace";
+    // NOTE: If updating this, be sure to also update `allCommandNames` in `harness/unittests/session.ts`.
+    export const enum CommandTypes {
+        Brace = "brace",
         /* @internal */
-        export type BraceFull = "brace-full";
-        export type BraceCompletion = "braceCompletion";
-        export type Change = "change";
-        export type Close = "close";
-        export type Completions = "completions";
+        BraceFull = "brace-full",
+        BraceCompletion = "braceCompletion",
+        Change = "change",
+        Close = "close",
+        Completions = "completions",
         /* @internal */
-        export type CompletionsFull = "completions-full";
-        export type CompletionDetails = "completionEntryDetails";
-        export type CompileOnSaveAffectedFileList = "compileOnSaveAffectedFileList";
-        export type CompileOnSaveEmitFile = "compileOnSaveEmitFile";
-        export type Configure = "configure";
-        export type Definition = "definition";
+        CompletionsFull = "completions-full",
+        CompletionDetails = "completionEntryDetails",
+        CompileOnSaveAffectedFileList = "compileOnSaveAffectedFileList",
+        CompileOnSaveEmitFile = "compileOnSaveEmitFile",
+        Configure = "configure",
+        Definition = "definition",
         /* @internal */
-        export type DefinitionFull = "definition-full";
-        export type Implementation = "implementation";
+        DefinitionFull = "definition-full",
+        Implementation = "implementation",
         /* @internal */
-        export type ImplementationFull = "implementation-full";
-        export type Exit = "exit";
-        export type Format = "format";
-        export type Formatonkey = "formatonkey";
+        ImplementationFull = "implementation-full",
+        Exit = "exit",
+        Format = "format",
+        Formatonkey = "formatonkey",
         /* @internal */
-        export type FormatFull = "format-full";
+        FormatFull = "format-full",
         /* @internal */
-        export type FormatonkeyFull = "formatonkey-full";
+        FormatonkeyFull = "formatonkey-full",
         /* @internal */
-        export type FormatRangeFull = "formatRange-full";
-        export type Geterr = "geterr";
-        export type GeterrForProject = "geterrForProject";
-        export type SemanticDiagnosticsSync = "semanticDiagnosticsSync";
-        export type SyntacticDiagnosticsSync = "syntacticDiagnosticsSync";
-        export type NavBar = "navbar";
+        FormatRangeFull = "formatRange-full",
+        Geterr = "geterr",
+        GeterrForProject = "geterrForProject",
+        SemanticDiagnosticsSync = "semanticDiagnosticsSync",
+        SyntacticDiagnosticsSync = "syntacticDiagnosticsSync",
+        NavBar = "navbar",
         /* @internal */
-        export type NavBarFull = "navbar-full";
-        export type Navto = "navto";
+        NavBarFull = "navbar-full",
+        Navto = "navto",
         /* @internal */
-        export type NavtoFull = "navto-full";
-        export type NavTree = "navtree";
-        export type NavTreeFull = "navtree-full";
-        export type Occurrences = "occurrences";
-        export type DocumentHighlights = "documentHighlights";
+        NavtoFull = "navto-full",
+        NavTree = "navtree",
+        NavTreeFull = "navtree-full",
+        Occurrences = "occurrences",
+        DocumentHighlights = "documentHighlights",
         /* @internal */
-        export type DocumentHighlightsFull = "documentHighlights-full";
-        export type Open = "open";
-        export type Quickinfo = "quickinfo";
+        DocumentHighlightsFull = "documentHighlights-full",
+        Open = "open",
+        Quickinfo = "quickinfo",
         /* @internal */
-        export type QuickinfoFull = "quickinfo-full";
-        export type References = "references";
+        QuickinfoFull = "quickinfo-full",
+        References = "references",
         /* @internal */
-        export type ReferencesFull = "references-full";
-        export type Reload = "reload";
-        export type Rename = "rename";
+        ReferencesFull = "references-full",
+        Reload = "reload",
+        Rename = "rename",
         /* @internal */
-        export type RenameInfoFull = "rename-full";
+        RenameInfoFull = "rename-full",
         /* @internal */
-        export type RenameLocationsFull = "renameLocations-full";
-        export type Saveto = "saveto";
-        export type SignatureHelp = "signatureHelp";
+        RenameLocationsFull = "renameLocations-full",
+        Saveto = "saveto",
+        SignatureHelp = "signatureHelp",
         /* @internal */
-        export type SignatureHelpFull = "signatureHelp-full";
-        export type TypeDefinition = "typeDefinition";
-        export type ProjectInfo = "projectInfo";
-        export type ReloadProjects = "reloadProjects";
-        export type Unknown = "unknown";
-        export type OpenExternalProject = "openExternalProject";
-        export type OpenExternalProjects = "openExternalProjects";
-        export type CloseExternalProject = "closeExternalProject";
+        SignatureHelpFull = "signatureHelp-full",
+        TypeDefinition = "typeDefinition",
+        ProjectInfo = "projectInfo",
+        ReloadProjects = "reloadProjects",
+        Unknown = "unknown",
+        OpenExternalProject = "openExternalProject",
+        OpenExternalProjects = "openExternalProjects",
+        CloseExternalProject = "closeExternalProject",
         /* @internal */
-        export type SynchronizeProjectList = "synchronizeProjectList";
+        SynchronizeProjectList = "synchronizeProjectList",
         /* @internal */
-        export type ApplyChangedToOpenFiles = "applyChangedToOpenFiles";
+        ApplyChangedToOpenFiles = "applyChangedToOpenFiles",
         /* @internal */
-        export type EncodedSemanticClassificationsFull = "encodedSemanticClassifications-full";
+        EncodedSemanticClassificationsFull = "encodedSemanticClassifications-full",
         /* @internal */
-        export type Cleanup = "cleanup";
+        Cleanup = "cleanup",
         /* @internal */
-        export type OutliningSpans = "outliningSpans";
-        export type TodoComments = "todoComments";
-        export type Indentation = "indentation";
-        export type DocCommentTemplate = "docCommentTemplate";
+        OutliningSpans = "outliningSpans",
+        TodoComments = "todoComments",
+        Indentation = "indentation",
+        DocCommentTemplate = "docCommentTemplate",
         /* @internal */
-        export type CompilerOptionsDiagnosticsFull = "compilerOptionsDiagnostics-full";
+        CompilerOptionsDiagnosticsFull = "compilerOptionsDiagnostics-full",
         /* @internal */
-        export type NameOrDottedNameSpan = "nameOrDottedNameSpan";
+        NameOrDottedNameSpan = "nameOrDottedNameSpan",
         /* @internal */
-        export type BreakpointStatement = "breakpointStatement";
-        export type CompilerOptionsForInferredProjects = "compilerOptionsForInferredProjects";
-        export type GetCodeFixes = "getCodeFixes";
+        BreakpointStatement = "breakpointStatement",
+        CompilerOptionsForInferredProjects = "compilerOptionsForInferredProjects",
+        GetCodeFixes = "getCodeFixes",
         /* @internal */
-        export type GetCodeFixesFull = "getCodeFixes-full";
-        export type GetSupportedCodeFixes = "getSupportedCodeFixes";
+        GetCodeFixesFull = "getCodeFixes-full",
+        GetSupportedCodeFixes = "getSupportedCodeFixes",
+
+        GetApplicableRefactors = "getApplicableRefactors",
+        GetRefactorCodeActions = "getRefactorCodeActions",
+        GetRefactorCodeActionsFull = "getRefactorCodeActions-full",
     }
 
     /**
@@ -394,6 +399,54 @@ namespace ts.server.protocol {
         position?: number;
     }
 
+    export type FileLocationOrRangeRequestArgs = FileLocationRequestArgs | FileRangeRequestArgs;
+
+    export interface GetApplicableRefactorsRequest extends Request {
+        command: CommandTypes.GetApplicableRefactors;
+        arguments: GetApplicableRefactorsRequestArgs;
+    }
+
+    export type GetApplicableRefactorsRequestArgs = FileLocationOrRangeRequestArgs;
+
+    export interface ApplicableRefactorInfo {
+        name: string;
+        description: string;
+    }
+
+    export interface GetApplicableRefactorsResponse extends Response {
+        body?: ApplicableRefactorInfo[];
+    }
+
+    export interface GetRefactorCodeActionsRequest extends Request {
+        command: CommandTypes.GetRefactorCodeActions;
+        arguments: GetRefactorCodeActionsRequestArgs;
+    }
+
+    export type GetRefactorCodeActionsRequestArgs = FileLocationOrRangeRequestArgs & {
+        /* The kind of the applicable refactor */
+        refactorName: string;
+    };
+
+    export type RefactorCodeActions = {
+        actions: protocol.CodeAction[];
+        renameLocation?: number
+    };
+
+    /* @internal */
+    export type RefactorCodeActionsFull = {
+        actions: ts.CodeAction[];
+        renameLocation?: number
+    };
+
+    export interface GetRefactorCodeActionsResponse extends Response {
+        body: RefactorCodeActions;
+    }
+
+    /* @internal */
+    export interface GetRefactorCodeActionsFullResponse extends Response {
+        body: RefactorCodeActionsFull;
+    }
+
     /**
      * Request for the available codefixes at a specific position.
      */
@@ -402,10 +455,7 @@ namespace ts.server.protocol {
         arguments: CodeFixRequestArgs;
     }
 
-    /**
-     * Instances of this interface specify errorcodes on a specific location in a sourcefile.
-     */
-    export interface CodeFixRequestArgs extends FileRequestArgs {
+    export interface FileRangeRequestArgs extends FileRequestArgs {
         /**
          * The line number for the request (1-based).
          */
@@ -437,7 +487,12 @@ namespace ts.server.protocol {
          */
         /* @internal */
         endPosition?: number;
+    }
 
+    /**
+     * Instances of this interface specify errorcodes on a specific location in a sourcefile.
+     */
+    export interface CodeFixRequestArgs extends FileRangeRequestArgs {
         /**
          * Errorcodes we want to get the fixes for.
          */
@@ -644,10 +699,9 @@ namespace ts.server.protocol {
 
     /**
      * Span augmented with extra information that denotes the kind of the highlighting to be used for span.
-     * Kind is taken from HighlightSpanKind type.
      */
     export interface HighlightSpan extends TextSpan {
-        kind: string;
+        kind: HighlightSpanKind;
     }
 
     /**
@@ -784,7 +838,7 @@ namespace ts.server.protocol {
         /**
          * The items's kind (such as 'className' or 'parameterName' or plain 'text').
          */
-        kind: string;
+        kind: ScriptElementKind;
 
         /**
          * Optional modifiers for the kind (such as 'public').
@@ -1298,7 +1352,7 @@ namespace ts.server.protocol {
         /**
          * The symbol's kind (such as 'className' or 'parameterName' or plain 'text').
          */
-        kind: string;
+        kind: ScriptElementKind;
 
         /**
          * Optional modifiers for the kind (such as 'public').
@@ -1517,7 +1571,7 @@ namespace ts.server.protocol {
         /**
          * The symbol's kind (such as 'className' or 'parameterName').
          */
-        kind: string;
+        kind: ScriptElementKind;
         /**
          * Optional modifiers for the kind (such as 'public').
          */
@@ -1545,7 +1599,7 @@ namespace ts.server.protocol {
         /**
          * The symbol's kind (such as 'className' or 'parameterName').
          */
-        kind: string;
+        kind: ScriptElementKind;
         /**
          * Optional modifiers for the kind (such as 'public').
          */
@@ -2011,7 +2065,7 @@ namespace ts.server.protocol {
         /**
          * The symbol's kind (such as 'className' or 'parameterName').
          */
-        kind: string;
+        kind: ScriptElementKind;
 
         /**
          * exact, substring, or prefix.
@@ -2052,7 +2106,7 @@ namespace ts.server.protocol {
         /**
          * Kind of symbol's container symbol (if any).
          */
-        containerKind?: string;
+        containerKind?: ScriptElementKind;
     }
 
     /**
@@ -2125,7 +2179,7 @@ namespace ts.server.protocol {
         /**
          * The symbol's kind (such as 'className' or 'parameterName').
          */
-        kind: string;
+        kind: ScriptElementKind;
 
         /**
          * Optional modifiers for the kind (such as 'public').
@@ -2151,7 +2205,7 @@ namespace ts.server.protocol {
     /** protocol.NavigationTree is identical to ts.NavigationTree, except using protocol.TextSpan instead of ts.TextSpan */
     export interface NavigationTree {
         text: string;
-        kind: string;
+        kind: ScriptElementKind;
         kindModifiers: string;
         spans: TextSpan[];
         childItems?: NavigationTree[];
@@ -2245,14 +2299,12 @@ namespace ts.server.protocol {
         body?: NavigationTree;
     }
 
-    export namespace IndentStyle {
-        export type None = "None";
-        export type Block = "Block";
-        export type Smart = "Smart";
+    export const enum IndentStyle {
+        None = "None",
+        Block = "Block",
+        Smart = "Smart",
     }
 
-    export type IndentStyle = IndentStyle.None | IndentStyle.Block | IndentStyle.Smart;
-
     export interface EditorSettings {
         baseIndentSize?: number;
         indentSize?: number;
@@ -2349,47 +2401,37 @@ namespace ts.server.protocol {
         [option: string]: CompilerOptionsValue | undefined;
     }
 
-    export namespace JsxEmit {
-        export type None = "None";
-        export type Preserve = "Preserve";
-        export type ReactNative = "ReactNative";
-        export type React = "React";
+    export const enum JsxEmit {
+        None = "None",
+        Preserve = "Preserve",
+        ReactNative = "ReactNative",
+        React = "React",
     }
 
-    export type JsxEmit = JsxEmit.None | JsxEmit.Preserve | JsxEmit.React | JsxEmit.ReactNative;
-
-    export namespace ModuleKind {
-        export type None = "None";
-        export type CommonJS = "CommonJS";
-        export type AMD = "AMD";
-        export type UMD = "UMD";
-        export type System = "System";
-        export type ES6 = "ES6";
-        export type ES2015 = "ES2015";
+    export const enum ModuleKind {
+        None = "None",
+        CommonJS = "CommonJS",
+        AMD = "AMD",
+        UMD = "UMD",
+        System = "System",
+        ES6 = "ES6",
+        ES2015 = "ES2015",
     }
 
-    export type ModuleKind = ModuleKind.None | ModuleKind.CommonJS | ModuleKind.AMD | ModuleKind.UMD | ModuleKind.System | ModuleKind.ES6 | ModuleKind.ES2015;
-
-    export namespace ModuleResolutionKind {
-        export type Classic = "Classic";
-        export type Node = "Node";
+    export const enum ModuleResolutionKind {
+        Classic = "Classic",
+        Node = "Node",
     }
 
-    export type ModuleResolutionKind = ModuleResolutionKind.Classic | ModuleResolutionKind.Node;
-
-    export namespace NewLineKind {
-        export type Crlf = "Crlf";
-        export type Lf = "Lf";
+    export const enum NewLineKind {
+        Crlf = "Crlf",
+        Lf = "Lf",
     }
 
-    export type NewLineKind = NewLineKind.Crlf | NewLineKind.Lf;
-
-    export namespace ScriptTarget {
-        export type ES3 = "ES3";
-        export type ES5 = "ES5";
-        export type ES6 = "ES6";
-        export type ES2015 = "ES2015";
+    export const enum ScriptTarget {
+        ES3 = "ES3",
+        ES5 = "ES5",
+        ES6 = "ES6",
+        ES2015 = "ES2015",
     }
-
-    export type ScriptTarget = ScriptTarget.ES3 | ScriptTarget.ES5 | ScriptTarget.ES6 | ScriptTarget.ES2015;
 }

src/server/server.ts

@@ -16,6 +16,7 @@ namespace ts.server {
         telemetryEnabled: boolean;
         globalPlugins: string[];
         pluginProbeLocations: string[];
+        allowLocalPluginLoads: boolean;
     }
 
     const net: {
@@ -403,7 +404,8 @@ namespace ts.server {
                 logger,
                 canUseEvents,
                 globalPlugins: options.globalPlugins,
-                pluginProbeLocations: options.pluginProbeLocations});
+                pluginProbeLocations: options.pluginProbeLocations,
+                allowLocalPluginLoads: options.allowLocalPluginLoads });
 
             if (telemetryEnabled && typingsInstaller) {
                 typingsInstaller.setTelemetrySender(this);
@@ -743,6 +745,7 @@ namespace ts.server {
 
     const globalPlugins = (findArgument("--globalPlugins") || "").split(",");
     const pluginProbeLocations = (findArgument("--pluginProbeLocations") || "").split(",");
+    const allowLocalPluginLoads = hasArgument("--allowLocalPluginLoads");
 
     const useSingleInferredProject = hasArgument("--useSingleInferredProject");
     const disableAutomaticTypingAcquisition = hasArgument("--disableAutomaticTypingAcquisition");
@@ -760,7 +763,8 @@ namespace ts.server {
         telemetryEnabled,
         logger,
         globalPlugins,
-        pluginProbeLocations
+        pluginProbeLocations,
+        allowLocalPluginLoads
     };
 
     const ioSession = new IOSession(options);

src/server/session.ts

@@ -106,7 +106,7 @@ namespace ts.server {
     }
 
     export interface EventSender {
-        event(payload: any, eventName: string): void;
+        event<T>(payload: T, eventName: string): void;
     }
 
     function allEditsBeforePos(edits: ts.TextChange[], pos: number) {
@@ -118,100 +118,7 @@ namespace ts.server {
         return true;
     }
 
-    export namespace CommandNames {
-        export const Brace: protocol.CommandTypes.Brace = "brace";
-        /* @internal */
-        export const BraceFull: protocol.CommandTypes.BraceFull = "brace-full";
-        export const BraceCompletion: protocol.CommandTypes.BraceCompletion = "braceCompletion";
-        export const Change: protocol.CommandTypes.Change = "change";
-        export const Close: protocol.CommandTypes.Close = "close";
-        export const Completions: protocol.CommandTypes.Completions = "completions";
-        /* @internal */
-        export const CompletionsFull: protocol.CommandTypes.CompletionsFull = "completions-full";
-        export const CompletionDetails: protocol.CommandTypes.CompletionDetails = "completionEntryDetails";
-        export const CompileOnSaveAffectedFileList: protocol.CommandTypes.CompileOnSaveAffectedFileList = "compileOnSaveAffectedFileList";
-        export const CompileOnSaveEmitFile: protocol.CommandTypes.CompileOnSaveEmitFile = "compileOnSaveEmitFile";
-        export const Configure: protocol.CommandTypes.Configure = "configure";
-        export const Definition: protocol.CommandTypes.Definition = "definition";
-        /* @internal */
-        export const DefinitionFull: protocol.CommandTypes.DefinitionFull = "definition-full";
-        export const Exit: protocol.CommandTypes.Exit = "exit";
-        export const Format: protocol.CommandTypes.Format = "format";
-        export const Formatonkey: protocol.CommandTypes.Formatonkey = "formatonkey";
-        /* @internal */
-        export const FormatFull: protocol.CommandTypes.FormatFull = "format-full";
-        /* @internal */
-        export const FormatonkeyFull: protocol.CommandTypes.FormatonkeyFull = "formatonkey-full";
-        /* @internal */
-        export const FormatRangeFull: protocol.CommandTypes.FormatRangeFull = "formatRange-full";
-        export const Geterr: protocol.CommandTypes.Geterr = "geterr";
-        export const GeterrForProject: protocol.CommandTypes.GeterrForProject = "geterrForProject";
-        export const Implementation: protocol.CommandTypes.Implementation = "implementation";
-        /* @internal */
-        export const ImplementationFull: protocol.CommandTypes.ImplementationFull = "implementation-full";
-        export const SemanticDiagnosticsSync: protocol.CommandTypes.SemanticDiagnosticsSync = "semanticDiagnosticsSync";
-        export const SyntacticDiagnosticsSync: protocol.CommandTypes.SyntacticDiagnosticsSync = "syntacticDiagnosticsSync";
-        export const NavBar: protocol.CommandTypes.NavBar = "navbar";
-        /* @internal */
-        export const NavBarFull: protocol.CommandTypes.NavBarFull = "navbar-full";
-        export const NavTree: protocol.CommandTypes.NavTree = "navtree";
-        export const NavTreeFull: protocol.CommandTypes.NavTreeFull = "navtree-full";
-        export const Navto: protocol.CommandTypes.Navto = "navto";
-        /* @internal */
-        export const NavtoFull: protocol.CommandTypes.NavtoFull = "navto-full";
-        export const Occurrences: protocol.CommandTypes.Occurrences = "occurrences";
-        export const DocumentHighlights: protocol.CommandTypes.DocumentHighlights = "documentHighlights";
-        /* @internal */
-        export const DocumentHighlightsFull: protocol.CommandTypes.DocumentHighlightsFull = "documentHighlights-full";
-        export const Open: protocol.CommandTypes.Open = "open";
-        export const Quickinfo: protocol.CommandTypes.Quickinfo = "quickinfo";
-        /* @internal */
-        export const QuickinfoFull: protocol.CommandTypes.QuickinfoFull = "quickinfo-full";
-        export const References: protocol.CommandTypes.References = "references";
-        /* @internal */
-        export const ReferencesFull: protocol.CommandTypes.ReferencesFull = "references-full";
-        export const Reload: protocol.CommandTypes.Reload = "reload";
-        export const Rename: protocol.CommandTypes.Rename = "rename";
-        /* @internal */
-        export const RenameInfoFull: protocol.CommandTypes.RenameInfoFull = "rename-full";
-        /* @internal */
-        export const RenameLocationsFull: protocol.CommandTypes.RenameLocationsFull = "renameLocations-full";
-        export const Saveto: protocol.CommandTypes.Saveto = "saveto";
-        export const SignatureHelp: protocol.CommandTypes.SignatureHelp = "signatureHelp";
-        /* @internal */
-        export const SignatureHelpFull: protocol.CommandTypes.SignatureHelpFull = "signatureHelp-full";
-        export const TypeDefinition: protocol.CommandTypes.TypeDefinition = "typeDefinition";
-        export const ProjectInfo: protocol.CommandTypes.ProjectInfo = "projectInfo";
-        export const ReloadProjects: protocol.CommandTypes.ReloadProjects = "reloadProjects";
-        export const Unknown: protocol.CommandTypes.Unknown = "unknown";
-        export const OpenExternalProject: protocol.CommandTypes.OpenExternalProject = "openExternalProject";
-        export const OpenExternalProjects: protocol.CommandTypes.OpenExternalProjects = "openExternalProjects";
-        export const CloseExternalProject: protocol.CommandTypes.CloseExternalProject = "closeExternalProject";
-        /* @internal */
-        export const SynchronizeProjectList: protocol.CommandTypes.SynchronizeProjectList = "synchronizeProjectList";
-        /* @internal */
-        export const ApplyChangedToOpenFiles: protocol.CommandTypes.ApplyChangedToOpenFiles = "applyChangedToOpenFiles";
-        /* @internal */
-        export const EncodedSemanticClassificationsFull: protocol.CommandTypes.EncodedSemanticClassificationsFull = "encodedSemanticClassifications-full";
-        /* @internal */
-        export const Cleanup: protocol.CommandTypes.Cleanup = "cleanup";
-        /* @internal */
-        export const OutliningSpans: protocol.CommandTypes.OutliningSpans = "outliningSpans";
-        export const TodoComments: protocol.CommandTypes.TodoComments = "todoComments";
-        export const Indentation: protocol.CommandTypes.Indentation = "indentation";
-        export const DocCommentTemplate: protocol.CommandTypes.DocCommentTemplate = "docCommentTemplate";
-        /* @internal */
-        export const CompilerOptionsDiagnosticsFull: protocol.CommandTypes.CompilerOptionsDiagnosticsFull = "compilerOptionsDiagnostics-full";
-        /* @internal */
-        export const NameOrDottedNameSpan: protocol.CommandTypes.NameOrDottedNameSpan = "nameOrDottedNameSpan";
-        /* @internal */
-        export const BreakpointStatement: protocol.CommandTypes.BreakpointStatement = "breakpointStatement";
-        export const CompilerOptionsForInferredProjects: protocol.CommandTypes.CompilerOptionsForInferredProjects = "compilerOptionsForInferredProjects";
-        export const GetCodeFixes: protocol.CommandTypes.GetCodeFixes = "getCodeFixes";
-        /* @internal */
-        export const GetCodeFixesFull: protocol.CommandTypes.GetCodeFixesFull = "getCodeFixes-full";
-        export const GetSupportedCodeFixes: protocol.CommandTypes.GetSupportedCodeFixes = "getSupportedCodeFixes";
-    }
+    export import CommandNames = protocol.CommandTypes;
 
     export function formatMessage<T extends protocol.Message>(msg: T, logger: server.Logger, byteLength: (s: string, encoding: string) => number, newLine: string): string {
         const verboseLogging = logger.hasLevel(LogLevel.verbose);
@@ -368,6 +275,7 @@ namespace ts.server {
 
         globalPlugins?: string[];
         pluginProbeLocations?: string[];
+        allowLocalPluginLoads?: boolean;
     }
 
     export class Session implements EventSender {
@@ -421,7 +329,8 @@ namespace ts.server {
                 throttleWaitMilliseconds,
                 eventHandler: this.eventHandler,
                 globalPlugins: opts.globalPlugins,
-                pluginProbeLocations: opts.pluginProbeLocations
+                pluginProbeLocations: opts.pluginProbeLocations,
+                allowLocalPluginLoads: opts.allowLocalPluginLoads
             };
             this.projectService = new ProjectService(settings);
             this.gcTimer = new GcTimer(this.host, /*delay*/ 7000, this.logger);
@@ -450,7 +359,7 @@ namespace ts.server {
                     break;
                 case ProjectLanguageServiceStateEvent:
                     const eventName: protocol.ProjectLanguageServiceStateEventName = "projectLanguageServiceState";
-                    this.event(<protocol.ProjectLanguageServiceStateEventBody>{
+                    this.event<protocol.ProjectLanguageServiceStateEventBody>({
                         projectName: event.data.project.getProjectName(),
                         languageServiceEnabled: event.data.languageServiceEnabled
                     }, eventName);
@@ -494,7 +403,7 @@ namespace ts.server {
             this.send(ev);
         }
 
-        public event(info: any, eventName: string) {
+        public event<T>(info: T, eventName: string) {
             const ev: protocol.Event = {
                 seq: 0,
                 type: "event",
@@ -529,7 +438,7 @@ namespace ts.server {
                 }
 
                 const bakedDiags = diags.map((diag) => formatDiag(file, project, diag));
-                this.event({ file: file, diagnostics: bakedDiags }, "semanticDiag");
+                this.event<protocol.DiagnosticEventBody>({ file: file, diagnostics: bakedDiags }, "semanticDiag");
             }
             catch (err) {
                 this.logError(err, "semantic check");
@@ -541,7 +450,7 @@ namespace ts.server {
                 const diags = project.getLanguageService().getSyntacticDiagnostics(file);
                 if (diags) {
                     const bakedDiags = diags.map((diag) => formatDiag(file, project, diag));
-                    this.event({ file: file, diagnostics: bakedDiags }, "syntaxDiag");
+                    this.event<protocol.DiagnosticEventBody>({ file: file, diagnostics: bakedDiags }, "syntaxDiag");
                 }
             }
             catch (err) {
@@ -1440,8 +1349,8 @@ namespace ts.server {
             return !items
                 ? undefined
                 : simplifiedResult
-                ? this.decorateNavigationBarItems(items, project.getScriptInfoForNormalizedPath(file))
-                : items;
+                    ? this.decorateNavigationBarItems(items, project.getScriptInfoForNormalizedPath(file))
+                    : items;
         }
 
         private decorateNavigationTree(tree: ts.NavigationTree, scriptInfo: ScriptInfo): protocol.NavigationTree {
@@ -1467,8 +1376,8 @@ namespace ts.server {
             return !tree
                 ? undefined
                 : simplifiedResult
-                ? this.decorateNavigationTree(tree, project.getScriptInfoForNormalizedPath(file))
-                : tree;
+                    ? this.decorateNavigationTree(tree, project.getScriptInfoForNormalizedPath(file))
+                    : tree;
         }
 
         private getNavigateToItems(args: protocol.NavtoRequestArgs, simplifiedResult: boolean): protocol.NavtoItem[] | NavigateToItem[] {
@@ -1555,6 +1464,60 @@ namespace ts.server {
             return ts.getSupportedCodeFixes();
         }
 
+        private isLocation(locationOrSpan: protocol.FileLocationOrRangeRequestArgs): locationOrSpan is protocol.FileLocationRequestArgs {
+            return (<protocol.FileLocationRequestArgs>locationOrSpan).line !== undefined;
+        }
+
+        private extractPositionAndRange(args: protocol.FileLocationOrRangeRequestArgs, scriptInfo: ScriptInfo): { position: number, textRange: TextRange } {
+            let position: number = undefined;
+            let textRange: TextRange;
+            if (this.isLocation(args)) {
+                position = getPosition(args);
+            }
+            else {
+                const { startPosition, endPosition } = this.getStartAndEndPosition(args, scriptInfo);
+                textRange = { pos: startPosition, end: endPosition };
+            }
+            return { position, textRange };
+
+            function getPosition(loc: protocol.FileLocationRequestArgs) {
+                return loc.position !== undefined ? loc.position : scriptInfo.lineOffsetToPosition(loc.line, loc.offset);
+            }
+        }
+
+        private getApplicableRefactors(args: protocol.GetApplicableRefactorsRequestArgs): protocol.ApplicableRefactorInfo[] {
+            const { file, project } = this.getFileAndProjectWithoutRefreshingInferredProjects(args);
+            const scriptInfo = project.getScriptInfoForNormalizedPath(file);
+            const { position, textRange } = this.extractPositionAndRange(args, scriptInfo);
+            return project.getLanguageService().getApplicableRefactors(file, position || textRange);
+        }
+
+        private getRefactorCodeActions(args: protocol.GetRefactorCodeActionsRequestArgs, simplifiedResult: boolean): protocol.RefactorCodeActions | protocol.RefactorCodeActionsFull {
+            const { file, project } = this.getFileAndProjectWithoutRefreshingInferredProjects(args);
+            const scriptInfo = project.getScriptInfoForNormalizedPath(file);
+            const { position, textRange } = this.extractPositionAndRange(args, scriptInfo);
+
+            const result: ts.CodeAction[] = project.getLanguageService().getRefactorCodeActions(
+                file,
+                this.projectService.getFormatCodeOptions(),
+                position || textRange,
+                args.refactorName
+            );
+
+            if (simplifiedResult) {
+                // Not full
+                return {
+                    actions: result.map(action => this.mapCodeAction(action, scriptInfo))
+                };
+            }
+            else {
+                // Full
+                return {
+                    actions: result
+                };
+            }
+        }
+
         private getCodeFixes(args: protocol.CodeFixRequestArgs, simplifiedResult: boolean): protocol.CodeAction[] | CodeAction[] {
             if (args.errorCodes.length === 0) {
                 return undefined;
@@ -1562,8 +1525,7 @@ namespace ts.server {
             const { file, project } = this.getFileAndProjectWithoutRefreshingInferredProjects(args);
 
             const scriptInfo = project.getScriptInfoForNormalizedPath(file);
-            const startPosition = getStartPosition();
-            const endPosition = getEndPosition();
+            const { startPosition, endPosition } = this.getStartAndEndPosition(args, scriptInfo);
             const formatOptions = this.projectService.getFormatCodeOptions(file);
 
             const codeActions = project.getLanguageService().getCodeFixesAtPosition(file, startPosition, endPosition, args.errorCodes, formatOptions);
@@ -1576,14 +1538,28 @@ namespace ts.server {
             else {
                 return codeActions;
             }
+        }
 
-            function getStartPosition() {
-                return args.startPosition !== undefined ? args.startPosition : scriptInfo.lineOffsetToPosition(args.startLine, args.startOffset);
+        private getStartAndEndPosition(args: protocol.FileRangeRequestArgs, scriptInfo: ScriptInfo) {
+            let startPosition: number = undefined, endPosition: number = undefined;
+            if (args.startPosition !== undefined) {
+                startPosition = args.startPosition;
+            }
+            else {
+                startPosition = scriptInfo.lineOffsetToPosition(args.startLine, args.startOffset);
+                // save the result so we don't always recompute
+                args.startPosition = startPosition;
             }
 
-            function getEndPosition() {
-                return args.endPosition !== undefined ? args.endPosition : scriptInfo.lineOffsetToPosition(args.endLine, args.endOffset);
+            if (args.endPosition !== undefined) {
+                endPosition = args.endPosition;
             }
+            else {
+                endPosition = scriptInfo.lineOffsetToPosition(args.endLine, args.endOffset);
+                args.endPosition = endPosition;
+            }
+
+            return { startPosition, endPosition };
         }
 
         private mapCodeAction(codeAction: CodeAction, scriptInfo: ScriptInfo): protocol.CodeAction {
@@ -1614,8 +1590,8 @@ namespace ts.server {
             return !spans
                 ? undefined
                 : simplifiedResult
-                ? spans.map(span => this.decorateSpan(span, scriptInfo))
-                : spans;
+                    ? spans.map(span => this.decorateSpan(span, scriptInfo))
+                    : spans;
         }
 
         private getDiagnosticsForProject(next: NextStep, delay: number, fileName: string): void {
@@ -1940,6 +1916,15 @@ namespace ts.server {
             },
             [CommandNames.GetSupportedCodeFixes]: () => {
                 return this.requiredResponse(this.getSupportedCodeFixes());
+            },
+            [CommandNames.GetApplicableRefactors]: (request: protocol.GetApplicableRefactorsRequest) => {
+                return this.requiredResponse(this.getApplicableRefactors(request.arguments));
+            },
+            [CommandNames.GetRefactorCodeActions]: (request: protocol.GetRefactorCodeActionsRequest) => {
+                return this.requiredResponse(this.getRefactorCodeActions(request.arguments, /*simplifiedResult*/ true));
+            },
+            [CommandNames.GetRefactorCodeActionsFull]: (request: protocol.GetRefactorCodeActionsRequest) => {
+                return this.requiredResponse(this.getRefactorCodeActions(request.arguments, /*simplifiedResult*/ false));
             }
         });
 
@@ -1997,7 +1982,7 @@ namespace ts.server {
             let request: protocol.Request;
             try {
                 request = <protocol.Request>JSON.parse(message);
-                const {response, responseRequired} = this.executeCommand(request);
+                const { response, responseRequired } = this.executeCommand(request);
 
                 if (this.logger.hasLevel(LogLevel.requestTime)) {
                     const elapsedTime = hrTimeToMilliseconds(this.hrtime(start)).toFixed(4);

src/services/breakpoints.ts

@@ -14,7 +14,7 @@ namespace ts.BreakpointResolver {
             return undefined;
         }
 
-        let tokenAtLocation = getTokenAtPosition(sourceFile, position);
+        let tokenAtLocation = getTokenAtPosition(sourceFile, position, /*includeJsDocComment*/ false);
         const lineOfPosition = sourceFile.getLineAndCharacterOfPosition(position).line;
         if (sourceFile.getLineAndCharacterOfPosition(tokenAtLocation.getStart(sourceFile)).line > lineOfPosition) {
             // Get previous token if the token is returned starts on new line

src/services/classifier.ts

@@ -573,7 +573,7 @@ namespace ts {
         }
     }
 
-    function getClassificationTypeName(type: ClassificationType) {
+    function getClassificationTypeName(type: ClassificationType): ClassificationTypeNames {
         switch (type) {
             case ClassificationType.comment: return ClassificationTypeNames.comment;
             case ClassificationType.identifier: return ClassificationTypeNames.identifier;

src/services/codeFixProvider.ts

@@ -19,14 +19,14 @@ namespace ts {
     export namespace codefix {
         const codeFixes: CodeFix[][] = [];
 
-        export function registerCodeFix(action: CodeFix) {
-            forEach(action.errorCodes, error => {
+        export function registerCodeFix(codeFix: CodeFix) {
+            forEach(codeFix.errorCodes, error => {
                 let fixes = codeFixes[error];
                 if (!fixes) {
                     fixes = [];
                     codeFixes[error] = fixes;
                 }
-                fixes.push(action);
+                fixes.push(codeFix);
             });
         }
 

src/services/codefixes/disableJsDiagnostics.ts

@@ -22,7 +22,7 @@ namespace ts.codefix {
         // We also want to check if the previous line holds a comment for a node on the next line
         // if so, we do not want to separate the node from its comment if we can.
         if (!isInComment(sourceFile, startPosition) && !isInString(sourceFile, startPosition) && !isInTemplateString(sourceFile, startPosition)) {
-            const token = getTouchingToken(sourceFile, startPosition);
+            const token = getTouchingToken(sourceFile, startPosition, /*includeJsDocComment*/ false);
             const tokenLeadingCommnets = getLeadingCommentRangesOfNode(token, sourceFile);
             if (!tokenLeadingCommnets || !tokenLeadingCommnets.length || tokenLeadingCommnets[0].pos >= startPosition) {
                 return {

src/services/codefixes/fixAddMissingMember.ts

@@ -13,7 +13,7 @@ namespace ts.codefix {
         // This is the identifier of the missing property. eg:
         // this.missing = 1;
         //      ^^^^^^^
-        const token = getTokenAtPosition(sourceFile, start);
+        const token = getTokenAtPosition(sourceFile, start, /*includeJsDocComment*/ false);
 
         if (token.kind !== SyntaxKind.Identifier) {
             return undefined;

src/services/codefixes/fixClassDoesntImplementInheritedAbstractMember.ts

@@ -15,7 +15,7 @@ namespace ts.codefix {
         const start = context.span.start;
         // This is the identifier in the case of a class declaration
         // or the class keyword token in the case of a class expression.
-        const token = getTokenAtPosition(sourceFile, start);
+        const token = getTokenAtPosition(sourceFile, start, /*includeJsDocComment*/ false);
         const checker = context.program.getTypeChecker();
 
         if (isClassLike(token.parent)) {

src/services/codefixes/fixClassIncorrectlyImplementsInterface.ts

@@ -8,7 +8,7 @@ namespace ts.codefix {
     function getActionForClassLikeIncorrectImplementsInterface(context: CodeFixContext): CodeAction[] | undefined {
         const sourceFile = context.sourceFile;
         const start = context.span.start;
-        const token = getTokenAtPosition(sourceFile, start);
+        const token = getTokenAtPosition(sourceFile, start, /*includeJsDocComment*/ false);
         const checker = context.program.getTypeChecker();
 
         const classDeclaration = getContainingClass(token);

src/services/codefixes/fixClassSuperMustPrecedeThisAccess.ts

@@ -5,7 +5,7 @@ namespace ts.codefix {
         getCodeActions: (context: CodeFixContext) => {
             const sourceFile = context.sourceFile;
 
-            const token = getTokenAtPosition(sourceFile, context.span.start);
+            const token = getTokenAtPosition(sourceFile, context.span.start, /*includeJsDocComment*/ false);
             if (token.kind !== SyntaxKind.ThisKeyword) {
                 return undefined;
             }

src/services/codefixes/fixConstructorForDerivedNeedSuperCall.ts

@@ -4,7 +4,7 @@ namespace ts.codefix {
         errorCodes: [Diagnostics.Constructors_for_derived_classes_must_contain_a_super_call.code],
         getCodeActions: (context: CodeFixContext) => {
             const sourceFile = context.sourceFile;
-            const token = getTokenAtPosition(sourceFile, context.span.start);
+            const token = getTokenAtPosition(sourceFile, context.span.start, /*includeJsDocComment*/ false);
 
             if (token.kind !== SyntaxKind.ConstructorKeyword) {
                 return undefined;

src/services/codefixes/fixExtendsInterfaceBecomesImplements.ts

@@ -5,7 +5,7 @@ namespace ts.codefix {
         getCodeActions: (context: CodeFixContext) => {
             const sourceFile = context.sourceFile;
             const start = context.span.start;
-            const token = getTokenAtPosition(sourceFile, start);
+            const token = getTokenAtPosition(sourceFile, start, /*includeJsDocComment*/ false);
             const classDeclNode = getContainingClass(token);
             if (!(token.kind === SyntaxKind.Identifier && isClassLike(classDeclNode))) {
                 return undefined;

src/services/codefixes/fixForgottenThisPropertyAccess.ts

@@ -4,7 +4,7 @@ namespace ts.codefix {
         errorCodes: [Diagnostics.Cannot_find_name_0_Did_you_mean_the_instance_member_this_0.code],
         getCodeActions: (context: CodeFixContext) => {
             const sourceFile = context.sourceFile;
-            const token = getTokenAtPosition(sourceFile, context.span.start);
+            const token = getTokenAtPosition(sourceFile, context.span.start, /*includeJsDocComment*/ false);
             if (token.kind !== SyntaxKind.Identifier) {
                 return undefined;
             }

src/services/codefixes/fixSpelling.ts

@@ -12,7 +12,7 @@ namespace ts.codefix {
         // This is the identifier of the misspelled word. eg:
         // this.speling = 1;
         //      ^^^^^^^
-        const node = getTokenAtPosition(sourceFile, context.span.start);
+        const node = getTokenAtPosition(sourceFile, context.span.start, /*includeJsDocComment*/ false); // TODO: GH#15852
         const checker = context.program.getTypeChecker();
         let suggestion: string;
         if (node.kind === SyntaxKind.Identifier && isPropertyAccessExpression(node.parent)) {

src/services/codefixes/helpers.ts

@@ -130,7 +130,7 @@ namespace ts.codefix {
         }
 
         function signatureToMethodDeclaration(signature: Signature, enclosingDeclaration: Node, body?: Block) {
-            const signatureDeclaration = <MethodDeclaration>checker.signatureToSignatureDeclaration(signature, SyntaxKind.MethodDeclaration, enclosingDeclaration);
+            const signatureDeclaration = <MethodDeclaration>checker.signatureToSignatureDeclaration(signature, SyntaxKind.MethodDeclaration, enclosingDeclaration, NodeBuilderFlags.SuppressAnyReturnType);
             if (signatureDeclaration) {
                 signatureDeclaration.decorators = undefined;
                 signatureDeclaration.modifiers = modifiers;

src/services/codefixes/importFixes.ts

@@ -128,7 +128,7 @@ namespace ts.codefix {
         const allSourceFiles = context.program.getSourceFiles();
         const useCaseSensitiveFileNames = context.host.useCaseSensitiveFileNames ? context.host.useCaseSensitiveFileNames() : false;
 
-        const token = getTokenAtPosition(sourceFile, context.span.start);
+        const token = getTokenAtPosition(sourceFile, context.span.start, /*includeJsDocComment*/ false);
         const name = token.getText();
         const symbolIdActionMap = new ImportCodeActionMap();
 
@@ -523,7 +523,7 @@ namespace ts.codefix {
                             catch (e) { }
                         }
 
-                        return relativeFileName;
+                        return getPackageNameFromAtTypesDirectory(relativeFileName);
                     }
                 }
 

src/services/codefixes/unusedIdentifierFixes.ts

@@ -9,11 +9,11 @@ namespace ts.codefix {
             const sourceFile = context.sourceFile;
             const start = context.span.start;
 
-            let token = getTokenAtPosition(sourceFile, start);
+            let token = getTokenAtPosition(sourceFile, start, /*includeJsDocComment*/ false);
 
             // this handles var ["computed"] = 12;
             if (token.kind === SyntaxKind.OpenBracketToken) {
-                token = getTokenAtPosition(sourceFile, start + 1);
+                token = getTokenAtPosition(sourceFile, start + 1, /*includeJsDocComment*/ false);
             }
 
             switch (token.kind) {
@@ -48,11 +48,11 @@ namespace ts.codefix {
                     case SyntaxKind.TypeParameter:
                         const typeParameters = (<DeclarationWithTypeParameters>token.parent.parent).typeParameters;
                         if (typeParameters.length === 1) {
-                            const previousToken = getTokenAtPosition(sourceFile, typeParameters.pos - 1);
+                            const previousToken = getTokenAtPosition(sourceFile, typeParameters.pos - 1, /*includeJsDocComment*/ false);
                             if (!previousToken || previousToken.kind !== SyntaxKind.LessThanToken) {
                                 return deleteRange(typeParameters);
                             }
-                            const nextToken = getTokenAtPosition(sourceFile, typeParameters.end);
+                            const nextToken = getTokenAtPosition(sourceFile, typeParameters.end, /*includeJsDocComment*/ false);
                             if (!nextToken || nextToken.kind !== SyntaxKind.GreaterThanToken) {
                                 return deleteRange(typeParameters);
                             }
@@ -99,7 +99,7 @@ namespace ts.codefix {
                         else {
                             // import |d,| * as ns from './file'
                             const start = importClause.name.getStart(sourceFile);
-                            const nextToken = getTokenAtPosition(sourceFile, importClause.name.end);
+                            const nextToken = getTokenAtPosition(sourceFile, importClause.name.end, /*includeJsDocComment*/ false);
                             if (nextToken && nextToken.kind === SyntaxKind.CommaToken) {
                                 // shift first non-whitespace position after comma to the start position of the node
                                 return deleteRange({ pos: start, end: skipTrivia(sourceFile.text, nextToken.end, /*stopAfterLineBreaks*/ false, /*stopAtComments*/ true) });
@@ -116,7 +116,7 @@ namespace ts.codefix {
                             return deleteNode(importDecl);
                         }
                         else {
-                            const previousToken = getTokenAtPosition(sourceFile, namespaceImport.pos - 1);
+                            const previousToken = getTokenAtPosition(sourceFile, namespaceImport.pos - 1, /*includeJsDocComment*/ false);
                             if (previousToken && previousToken.kind === SyntaxKind.CommaToken) {
                                 const startPosition = textChanges.getAdjustedStartPosition(sourceFile, previousToken, {}, textChanges.Position.FullStart);
                                 return deleteRange({ pos: startPosition, end: namespaceImport.end });

src/services/completions.ts

@@ -275,7 +275,7 @@ namespace ts.Completions {
             }
         }
         else if (type.flags & TypeFlags.StringLiteral) {
-            const name = (<LiteralType>type).text;
+            const name = (<StringLiteralType>type).value;
             if (!uniques.has(name)) {
                 uniques.set(name, true);
                 result.push({
@@ -354,12 +354,12 @@ namespace ts.Completions {
         let requestJsDocTag = false;
 
         let start = timestamp();
-        const currentToken = getTokenAtPosition(sourceFile, position);
+        const currentToken = getTokenAtPosition(sourceFile, position, /*includeJsDocComment*/ false); // TODO: GH#15853
         log("getCompletionData: Get current token: " + (timestamp() - start));
 
         start = timestamp();
         // Completion not allowed inside comments, bail out if this is the case
-        const insideComment = isInsideComment(sourceFile, currentToken, position);
+        const insideComment = isInComment(sourceFile, position, currentToken);
         log("getCompletionData: Is inside comment: " + (timestamp() - start));
 
         if (insideComment) {
@@ -449,7 +449,7 @@ namespace ts.Completions {
         let isRightOfOpenTag = false;
         let isStartingCloseTag = false;
 
-        let location = getTouchingPropertyName(sourceFile, position);
+        let location = getTouchingPropertyName(sourceFile, position, /*includeJsDocComment*/ false); // TODO: GH#15853
         if (contextToken) {
             // Bail out if this is a known invalid completion location
             if (isCompletionListBlocker(contextToken)) {

src/services/documentHighlights.ts

@@ -1,8 +1,8 @@
 /* @internal */
 namespace ts.DocumentHighlights {
-    export function getDocumentHighlights(typeChecker: TypeChecker, cancellationToken: CancellationToken, sourceFile: SourceFile, position: number, sourceFilesToSearch: SourceFile[]): DocumentHighlights[] {
-        const node = getTouchingWord(sourceFile, position);
-        return node && (getSemanticDocumentHighlights(node, typeChecker, cancellationToken, sourceFilesToSearch) || getSyntacticDocumentHighlights(node, sourceFile));
+    export function getDocumentHighlights(program: Program, cancellationToken: CancellationToken, sourceFile: SourceFile, position: number, sourceFilesToSearch: SourceFile[]): DocumentHighlights[] {
+        const node = getTouchingWord(sourceFile, position, /*includeJsDocComment*/ true);
+        return node && (getSemanticDocumentHighlights(node, program, cancellationToken, sourceFilesToSearch) || getSyntacticDocumentHighlights(node, sourceFile));
     }
 
     function getHighlightSpanForNode(node: Node, sourceFile: SourceFile): HighlightSpan {
@@ -16,8 +16,8 @@ namespace ts.DocumentHighlights {
         };
     }
 
-    function getSemanticDocumentHighlights(node: Node, typeChecker: TypeChecker, cancellationToken: CancellationToken, sourceFilesToSearch: SourceFile[]): DocumentHighlights[] {
-        const referenceEntries = FindAllReferences.getReferenceEntriesForNode(node, sourceFilesToSearch, typeChecker, cancellationToken);
+    function getSemanticDocumentHighlights(node: Node, program: Program, cancellationToken: CancellationToken, sourceFilesToSearch: SourceFile[]): DocumentHighlights[] {
+        const referenceEntries = FindAllReferences.getReferenceEntriesForNode(node, program, sourceFilesToSearch, cancellationToken);
         return referenceEntries && convertReferencedSymbols(referenceEntries);
     }
 

src/services/findAllReferences.ts

@@ -41,14 +41,15 @@ namespace ts.FindAllReferences {
         readonly implementations?: boolean;
     }
 
-    export function findReferencedSymbols(checker: TypeChecker, cancellationToken: CancellationToken, sourceFiles: SourceFile[], sourceFile: SourceFile, position: number): ReferencedSymbol[] | undefined {
-        const referencedSymbols = findAllReferencedSymbols(checker, cancellationToken, sourceFiles, sourceFile, position);
+    export function findReferencedSymbols(program: Program, cancellationToken: CancellationToken, sourceFiles: SourceFile[], sourceFile: SourceFile, position: number): ReferencedSymbol[] | undefined {
+        const referencedSymbols = findAllReferencedSymbols(program, cancellationToken, sourceFiles, sourceFile, position);
 
         if (!referencedSymbols || !referencedSymbols.length) {
             return undefined;
         }
 
         const out: ReferencedSymbol[] = [];
+        const checker = program.getTypeChecker();
         for (const { definition, references } of referencedSymbols) {
             // Only include referenced symbols that have a valid definition.
             if (definition) {
@@ -59,44 +60,51 @@ namespace ts.FindAllReferences {
         return out;
     }
 
-    export function getImplementationsAtPosition(checker: TypeChecker, cancellationToken: CancellationToken, sourceFiles: SourceFile[], sourceFile: SourceFile, position: number): ImplementationLocation[] {
-        const node = getTouchingPropertyName(sourceFile, position);
-        const referenceEntries = getImplementationReferenceEntries(checker, cancellationToken, sourceFiles, node);
+    export function getImplementationsAtPosition(program: Program, cancellationToken: CancellationToken, sourceFiles: SourceFile[], sourceFile: SourceFile, position: number): ImplementationLocation[] {
+        // A node in a JSDoc comment can't have an implementation anyway.
+        const node = getTouchingPropertyName(sourceFile, position, /*includeJsDocComment*/ false);
+        const referenceEntries = getImplementationReferenceEntries(program, cancellationToken, sourceFiles, node);
+        const checker = program.getTypeChecker();
         return map(referenceEntries, entry => toImplementationLocation(entry, checker));
     }
 
-    function getImplementationReferenceEntries(typeChecker: TypeChecker, cancellationToken: CancellationToken, sourceFiles: SourceFile[], node: Node): Entry[] | undefined {
+    function getImplementationReferenceEntries(program: Program, cancellationToken: CancellationToken, sourceFiles: SourceFile[], node: Node): Entry[] | undefined {
+        if (node.kind === SyntaxKind.SourceFile) {
+            return undefined;
+        }
+
+        const checker = program.getTypeChecker();
         // If invoked directly on a shorthand property assignment, then return
         // the declaration of the symbol being assigned (not the symbol being assigned to).
         if (node.parent.kind === SyntaxKind.ShorthandPropertyAssignment) {
             const result: NodeEntry[] = [];
-            Core.getReferenceEntriesForShorthandPropertyAssignment(node, typeChecker, node => result.push(nodeEntry(node)));
+            Core.getReferenceEntriesForShorthandPropertyAssignment(node, checker, node => result.push(nodeEntry(node)));
             return result;
         }
         else if (node.kind === SyntaxKind.SuperKeyword || isSuperProperty(node.parent)) {
             // References to and accesses on the super keyword only have one possible implementation, so no
             // need to "Find all References"
-            const symbol = typeChecker.getSymbolAtLocation(node);
+            const symbol = checker.getSymbolAtLocation(node);
             return symbol.valueDeclaration && [nodeEntry(symbol.valueDeclaration)];
         }
         else {
             // Perform "Find all References" and retrieve only those that are implementations
-            return getReferenceEntriesForNode(node, sourceFiles, typeChecker, cancellationToken, { implementations: true });
+            return getReferenceEntriesForNode(node, program, sourceFiles, cancellationToken, { implementations: true });
         }
     }
 
-    export function findReferencedEntries(checker: TypeChecker, cancellationToken: CancellationToken, sourceFiles: SourceFile[], sourceFile: SourceFile, position: number, options?: Options): ReferenceEntry[] | undefined {
-        const x = flattenEntries(findAllReferencedSymbols(checker, cancellationToken, sourceFiles, sourceFile, position, options));
+    export function findReferencedEntries(program: Program, cancellationToken: CancellationToken, sourceFiles: SourceFile[], sourceFile: SourceFile, position: number, options?: Options): ReferenceEntry[] | undefined {
+        const x = flattenEntries(findAllReferencedSymbols(program, cancellationToken, sourceFiles, sourceFile, position, options));
         return map(x, toReferenceEntry);
     }
 
-    export function getReferenceEntriesForNode(node: Node, sourceFiles: SourceFile[], checker: TypeChecker, cancellationToken: CancellationToken, options: Options = {}): Entry[] | undefined {
-        return flattenEntries(Core.getReferencedSymbolsForNode(node, sourceFiles, checker, cancellationToken, options));
+    export function getReferenceEntriesForNode(node: Node, program: Program, sourceFiles: SourceFile[], cancellationToken: CancellationToken, options: Options = {}): Entry[] | undefined {
+        return flattenEntries(Core.getReferencedSymbolsForNode(node, program, sourceFiles, cancellationToken, options));
     }
 
-    function findAllReferencedSymbols(checker: TypeChecker, cancellationToken: CancellationToken, sourceFiles: SourceFile[], sourceFile: SourceFile, position: number, options?: Options): SymbolAndEntries[] | undefined {
+    function findAllReferencedSymbols(program: Program, cancellationToken: CancellationToken, sourceFiles: SourceFile[], sourceFile: SourceFile, position: number, options?: Options): SymbolAndEntries[] | undefined {
         const node = getTouchingPropertyName(sourceFile, position, /*includeJsDocComment*/ true);
-        return Core.getReferencedSymbolsForNode(node, sourceFiles, checker, cancellationToken, options);
+        return Core.getReferencedSymbolsForNode(node, program, sourceFiles, cancellationToken, options);
     }
 
     function flattenEntries(referenceSymbols: SymbolAndEntries[]): Entry[] {
@@ -142,7 +150,7 @@ namespace ts.FindAllReferences {
         const { node, name, kind, displayParts } = info;
         const sourceFile = node.getSourceFile();
         return {
-            containerKind: "",
+            containerKind: ScriptElementKind.unknown,
             containerName: "",
             fileName: sourceFile.fileName,
             kind,
@@ -152,7 +160,7 @@ namespace ts.FindAllReferences {
         };
     }
 
-    function getDefinitionKindAndDisplayParts(symbol: Symbol, node: Node, checker: TypeChecker): { displayParts: SymbolDisplayPart[], kind: string } {
+    function getDefinitionKindAndDisplayParts(symbol: Symbol, node: Node, checker: TypeChecker): { displayParts: SymbolDisplayPart[], kind: ScriptElementKind } {
         const { displayParts, symbolKind } =
             SymbolDisplay.getSymbolDisplayPartsDocumentationAndSymbolKind(checker, symbol, node.getSourceFile(), getContainerNode(node), node);
         return { displayParts, kind: symbolKind };
@@ -168,7 +176,7 @@ namespace ts.FindAllReferences {
             fileName: node.getSourceFile().fileName,
             textSpan: getTextSpan(node),
             isWriteAccess: isWriteAccess(node),
-            isDefinition: isDeclarationName(node) || isLiteralComputedPropertyDeclarationName(node),
+            isDefinition: isAnyDeclarationName(node) || isLiteralComputedPropertyDeclarationName(node),
             isInString
         };
     }
@@ -183,7 +191,7 @@ namespace ts.FindAllReferences {
         }
     }
 
-    function implementationKindDisplayParts(node: ts.Node, checker: ts.TypeChecker): { kind: string, displayParts: SymbolDisplayPart[] } {
+    function implementationKindDisplayParts(node: ts.Node, checker: ts.TypeChecker): { kind: ScriptElementKind, displayParts: SymbolDisplayPart[] } {
         const symbol = checker.getSymbolAtLocation(isDeclaration(node) && node.name ? node.name : node);
         if (symbol) {
             return getDefinitionKindAndDisplayParts(symbol, node, checker);
@@ -234,22 +242,20 @@ namespace ts.FindAllReferences {
 
     /** A node is considered a writeAccess iff it is a name of a declaration or a target of an assignment */
     function isWriteAccess(node: Node): boolean {
-        if (node.kind === SyntaxKind.Identifier && isDeclarationName(node)) {
+        if (isAnyDeclarationName(node)) {
             return true;
         }
 
-        const parent = node.parent;
-        if (parent) {
-            if (parent.kind === SyntaxKind.PostfixUnaryExpression || parent.kind === SyntaxKind.PrefixUnaryExpression) {
+        const { parent } = node;
+        switch (parent && parent.kind) {
+            case SyntaxKind.PostfixUnaryExpression:
+            case SyntaxKind.PrefixUnaryExpression:
                 return true;
-            }
-            else if (parent.kind === SyntaxKind.BinaryExpression && (<BinaryExpression>parent).left === node) {
-                const operator = (<BinaryExpression>parent).operatorToken.kind;
-                return SyntaxKind.FirstAssignment <= operator && operator <= SyntaxKind.LastAssignment;
-            }
+            case SyntaxKind.BinaryExpression:
+                return (<BinaryExpression>parent).left === node && isAssignmentOperator((<BinaryExpression>parent).operatorToken.kind);
+            default:
+                return false;
         }
-
-        return false;
     }
 }
 
@@ -257,7 +263,7 @@ namespace ts.FindAllReferences {
 /* @internal */
 namespace ts.FindAllReferences.Core {
     /** Core find-all-references algorithm. Handles special cases before delegating to `getReferencedSymbolsForSymbol`. */
-    export function getReferencedSymbolsForNode(node: Node, sourceFiles: SourceFile[], checker: TypeChecker, cancellationToken: CancellationToken, options: Options = {}): SymbolAndEntries[] | undefined {
+    export function getReferencedSymbolsForNode(node: Node, program: Program, sourceFiles: SourceFile[], cancellationToken: CancellationToken, options: Options = {}): SymbolAndEntries[] | undefined {
         if (node.kind === ts.SyntaxKind.SourceFile) {
             return undefined;
         }
@@ -269,6 +275,7 @@ namespace ts.FindAllReferences.Core {
             }
         }
 
+        const checker = program.getTypeChecker();
         const symbol = checker.getSymbolAtLocation(node);
 
         // Could not find a symbol e.g. unknown identifier
@@ -281,9 +288,65 @@ namespace ts.FindAllReferences.Core {
             return undefined;
         }
 
+        if (symbol.flags & SymbolFlags.Module && isModuleReferenceLocation(node)) {
+            return getReferencedSymbolsForModule(program, symbol, sourceFiles);
+        }
+
         return getReferencedSymbolsForSymbol(symbol, node, sourceFiles, checker, cancellationToken, options);
     }
 
+    function isModuleReferenceLocation(node: ts.Node): boolean {
+        if (node.kind !== SyntaxKind.StringLiteral) {
+            return false;
+        }
+        switch (node.parent.kind) {
+            case SyntaxKind.ModuleDeclaration:
+            case SyntaxKind.ExternalModuleReference:
+            case SyntaxKind.ImportDeclaration:
+            case SyntaxKind.ExportDeclaration:
+                return true;
+            case SyntaxKind.CallExpression:
+                return isRequireCall(node.parent as CallExpression, /*checkArgumentIsStringLiteral*/ false);
+            default:
+                return false;
+        }
+    }
+
+    function getReferencedSymbolsForModule(program: Program, symbol: Symbol, sourceFiles: SourceFile[]): SymbolAndEntries[] {
+        Debug.assert(!!symbol.valueDeclaration);
+
+        const references = findModuleReferences(program, sourceFiles, symbol).map<Entry>(reference => {
+            if (reference.kind === "import") {
+                return { type: "node", node: reference.literal };
+            }
+            else {
+                return {
+                    type: "span",
+                    fileName: reference.referencingFile.fileName,
+                    textSpan: createTextSpanFromRange(reference.ref),
+                };
+            }
+        });
+
+        for (const decl of symbol.declarations) {
+            switch (decl.kind) {
+                case ts.SyntaxKind.SourceFile:
+                    // Don't include the source file itself. (This may not be ideal behavior, but awkward to include an entire file as a reference.)
+                    break;
+                case ts.SyntaxKind.ModuleDeclaration:
+                    references.push({ type: "node", node: (decl as ts.ModuleDeclaration).name });
+                    break;
+                default:
+                    Debug.fail("Expected a module symbol to be declared by a SourceFile or ModuleDeclaration.");
+            }
+        }
+
+        return [{
+            definition: { type: "symbol", symbol, node: symbol.valueDeclaration },
+            references
+        }];
+    }
+
     /** getReferencedSymbols for special node kinds. */
     function getReferencedSymbolsSpecial(node: Node, sourceFiles: SourceFile[], cancellationToken: CancellationToken): SymbolAndEntries[] | undefined {
         if (isTypeKeyword(node.kind)) {
@@ -550,7 +613,7 @@ namespace ts.FindAllReferences.Core {
     }
 
     function isObjectBindingPatternElementWithoutPropertyName(symbol: Symbol): boolean {
-        const bindingElement = <BindingElement>getDeclarationOfKind(symbol, SyntaxKind.BindingElement);
+        const bindingElement = getDeclarationOfKind<BindingElement>(symbol, SyntaxKind.BindingElement);
         return bindingElement &&
             bindingElement.parent.kind === SyntaxKind.ObjectBindingPattern &&
             !bindingElement.propertyName;
@@ -558,7 +621,7 @@ namespace ts.FindAllReferences.Core {
 
     function getPropertySymbolOfObjectBindingPatternWithoutPropertyName(symbol: Symbol, checker: TypeChecker): Symbol | undefined {
         if (isObjectBindingPatternElementWithoutPropertyName(symbol)) {
-            const bindingElement = <BindingElement>getDeclarationOfKind(symbol, SyntaxKind.BindingElement);
+            const bindingElement = getDeclarationOfKind<BindingElement>(symbol, SyntaxKind.BindingElement);
             const typeOfPattern = checker.getTypeAtLocation(bindingElement.parent);
             return typeOfPattern && checker.getPropertyOfType(typeOfPattern, (<Identifier>bindingElement.name).text);
         }
@@ -680,7 +743,7 @@ namespace ts.FindAllReferences.Core {
         const labelName = targetLabel.text;
         const possiblePositions = getPossibleSymbolReferencePositions(sourceFile, labelName, container);
         for (const position of possiblePositions) {
-            const node = getTouchingWord(sourceFile, position);
+            const node = getTouchingWord(sourceFile, position, /*includeJsDocComment*/ false);
             // Only pick labels that are either the target label, or have a target that is the target label
             if (node && (node === targetLabel || (isJumpStatementTarget(node) && getTargetLabel(node, labelName) === targetLabel))) {
                 references.push(nodeEntry(node));
@@ -718,9 +781,10 @@ namespace ts.FindAllReferences.Core {
     }
 
     function addReferencesForKeywordInFile(sourceFile: SourceFile, kind: SyntaxKind, searchText: string, references: Push<NodeEntry>): void {
-        const possiblePositions = getPossibleSymbolReferencePositions(sourceFile, searchText);
+        // Want fullStart so we can find the symbol in JSDoc comments
+        const possiblePositions = getPossibleSymbolReferencePositions(sourceFile, searchText, sourceFile, /*fullStart*/ true);
         for (const position of possiblePositions) {
-            const referenceLocation = getTouchingPropertyName(sourceFile, position);
+            const referenceLocation = getTouchingPropertyName(sourceFile, position, /*includeJsDocComment*/ true);
             if (referenceLocation.kind === kind) {
                 references.push(nodeEntry(referenceLocation));
             }
@@ -742,13 +806,13 @@ namespace ts.FindAllReferences.Core {
             return;
         }
 
-        for (const position of getPossibleSymbolReferencePositions(sourceFile, search.text, container, /*fullStart*/ state.findInComments)) {
+        for (const position of getPossibleSymbolReferencePositions(sourceFile, search.text, container, /*fullStart*/ state.findInComments || container.jsDoc !== undefined)) {
             getReferencesAtLocation(sourceFile, position, search, state);
         }
     }
 
     function getReferencesAtLocation(sourceFile: SourceFile, position: number, search: Search, state: State): void {
-        const referenceLocation = getTouchingPropertyName(sourceFile, position);
+        const referenceLocation = getTouchingPropertyName(sourceFile, position, /*includeJsDocComment*/ true);
 
         if (!isValidReferencePosition(referenceLocation, search.text)) {
             // This wasn't the start of a token.  Check to see if it might be a
@@ -1188,7 +1252,7 @@ namespace ts.FindAllReferences.Core {
         const sourceFile = searchSpaceNode.getSourceFile();
         const possiblePositions = getPossibleSymbolReferencePositions(sourceFile, "super", searchSpaceNode);
         for (const position of possiblePositions) {
-            const node = getTouchingWord(sourceFile, position);
+            const node = getTouchingWord(sourceFile, position, /*includeJsDocComment*/ false);
 
             if (!node || node.kind !== SyntaxKind.SuperKeyword) {
                 continue;
@@ -1265,7 +1329,7 @@ namespace ts.FindAllReferences.Core {
 
         function getThisReferencesInFile(sourceFile: SourceFile, searchSpaceNode: Node, possiblePositions: number[], result: Entry[]): void {
             forEach(possiblePositions, position => {
-                const node = getTouchingWord(sourceFile, position);
+                const node = getTouchingWord(sourceFile, position, /*includeJsDocComment*/ false);
                 if (!node || !isThis(node)) {
                     return;
                 }
@@ -1319,7 +1383,7 @@ namespace ts.FindAllReferences.Core {
 
         function getReferencesForStringLiteralInFile(sourceFile: SourceFile, searchText: string, possiblePositions: number[], references: Push<NodeEntry>): void {
             for (const position of possiblePositions) {
-                const node = getTouchingWord(sourceFile, position);
+                const node = getTouchingWord(sourceFile, position, /*includeJsDocComment*/ false);
                 if (node && node.kind === SyntaxKind.StringLiteral && (node as StringLiteral).text === searchText) {
                     references.push(nodeEntry(node, /*isInString*/ true));
                 }

src/services/formatting/formatting.ts

@@ -599,7 +599,7 @@ namespace ts.formatting {
                 child => {
                     processChildNode(child, /*inheritedIndentation*/ Constants.Unknown, node, nodeDynamicIndentation, nodeStartLine, undecoratedNodeStartLine, /*isListItem*/ false);
                 },
-                (nodes: NodeArray<Node>) => {
+                nodes => {
                     processChildNodes(nodes, node, nodeStartLine, nodeDynamicIndentation);
                 });
 

src/services/goToDefinition.ts

@@ -19,7 +19,7 @@ namespace ts.GoToDefinition {
                 [getDefinitionInfoForFileReference(typeReferenceDirective.fileName, referenceFile.resolvedFileName)];
         }
 
-        const node = getTouchingPropertyName(sourceFile, position);
+        const node = getTouchingPropertyName(sourceFile, position, /*includeJsDocComment*/ true);
         if (node === sourceFile) {
             return undefined;
         }
@@ -95,7 +95,7 @@ namespace ts.GoToDefinition {
 
     /// Goto type
     export function getTypeDefinitionAtPosition(typeChecker: TypeChecker, sourceFile: SourceFile, position: number): DefinitionInfo[] {
-        const node = getTouchingPropertyName(sourceFile, position);
+        const node = getTouchingPropertyName(sourceFile, position, /*includeJsDocComment*/ true);
         if (node === sourceFile) {
             return undefined;
         }
@@ -165,7 +165,7 @@ namespace ts.GoToDefinition {
 
         return result;
 
-        function tryAddConstructSignature(symbol: Symbol, location: Node, symbolKind: string, symbolName: string, containerName: string, result: DefinitionInfo[]) {
+        function tryAddConstructSignature(symbol: Symbol, location: Node, symbolKind: ScriptElementKind, symbolName: string, containerName: string, result: DefinitionInfo[]) {
             // Applicable only if we are in a new expression, or we are on a constructor declaration
             // and in either case the symbol has a construct signature definition, i.e. class
             if (isNewExpressionTarget(location) || location.kind === SyntaxKind.ConstructorKeyword) {
@@ -173,12 +173,8 @@ namespace ts.GoToDefinition {
                     // Find the first class-like declaration and try to get the construct signature.
                     for (const declaration of symbol.getDeclarations()) {
                         if (isClassLike(declaration)) {
-                            return tryAddSignature(declaration.members,
-                                                    /*selectConstructors*/ true,
-                                                    symbolKind,
-                                                    symbolName,
-                                                    containerName,
-                                                    result);
+                            return tryAddSignature(
+                                declaration.members, /*selectConstructors*/ true, symbolKind, symbolName, containerName, result);
                         }
                     }
 
@@ -188,14 +184,14 @@ namespace ts.GoToDefinition {
             return false;
         }
 
-        function tryAddCallSignature(symbol: Symbol, location: Node, symbolKind: string, symbolName: string, containerName: string, result: DefinitionInfo[]) {
+        function tryAddCallSignature(symbol: Symbol, location: Node, symbolKind: ScriptElementKind, symbolName: string, containerName: string, result: DefinitionInfo[]) {
             if (isCallExpressionTarget(location) || isNewExpressionTarget(location) || isNameOfFunctionDeclaration(location)) {
                 return tryAddSignature(symbol.declarations, /*selectConstructors*/ false, symbolKind, symbolName, containerName, result);
             }
             return false;
         }
 
-        function tryAddSignature(signatureDeclarations: Declaration[] | undefined, selectConstructors: boolean, symbolKind: string, symbolName: string, containerName: string, result: DefinitionInfo[]) {
+        function tryAddSignature(signatureDeclarations: Declaration[] | undefined, selectConstructors: boolean, symbolKind: ScriptElementKind, symbolName: string, containerName: string, result: DefinitionInfo[]) {
             if (!signatureDeclarations) {
                 return false;
             }
@@ -231,12 +227,12 @@ namespace ts.GoToDefinition {
     }
 
     /** Creates a DefinitionInfo from a Declaration, using the declaration's name if possible. */
-    function createDefinitionInfo(node: Declaration, symbolKind: string, symbolName: string, containerName: string): DefinitionInfo {
+    function createDefinitionInfo(node: Declaration, symbolKind: ScriptElementKind, symbolName: string, containerName: string): DefinitionInfo {
         return createDefinitionInfoFromName(getNameOfDeclaration(node) || node, symbolKind, symbolName, containerName);
     }
 
     /** Creates a DefinitionInfo directly from the name of a declaration. */
-    function createDefinitionInfoFromName(name: Node, symbolKind: string, symbolName: string, containerName: string): DefinitionInfo {
+    function createDefinitionInfoFromName(name: Node, symbolKind: ScriptElementKind, symbolName: string, containerName: string): DefinitionInfo {
         const sourceFile = name.getSourceFile();
         return {
             fileName: sourceFile.fileName,
@@ -263,7 +259,7 @@ namespace ts.GoToDefinition {
 
     function findReferenceInPosition(refs: FileReference[], pos: number): FileReference {
         for (const ref of refs) {
-            if (ref.pos <= pos && pos < ref.end) {
+            if (ref.pos <= pos && pos <= ref.end) {
                 return ref;
             }
         }

src/services/importTracker.ts

@@ -300,6 +300,40 @@ namespace ts.FindAllReferences {
         });
     }
 
+    export type ModuleReference =
+        /** "import" also includes require() calls. */
+        | { kind: "import", literal: StringLiteral }
+        /** <reference path> or <reference types> */
+        | { kind: "reference", referencingFile: SourceFile, ref: FileReference };
+    export function findModuleReferences(program: Program, sourceFiles: SourceFile[], searchModuleSymbol: Symbol): ModuleReference[] {
+        const refs: ModuleReference[] = [];
+        const checker = program.getTypeChecker();
+        for (const referencingFile of sourceFiles) {
+            const searchSourceFile = searchModuleSymbol.valueDeclaration;
+            if (searchSourceFile.kind === ts.SyntaxKind.SourceFile) {
+                for (const ref of referencingFile.referencedFiles) {
+                    if (program.getSourceFileFromReference(referencingFile, ref) === searchSourceFile) {
+                        refs.push({ kind: "reference", referencingFile, ref });
+                    }
+                }
+                for (const ref of referencingFile.typeReferenceDirectives) {
+                    const referenced = program.getResolvedTypeReferenceDirectives().get(ref.fileName);
+                    if (referenced !== undefined && referenced.resolvedFileName === (searchSourceFile as ts.SourceFile).fileName) {
+                        refs.push({ kind: "reference", referencingFile, ref });
+                    }
+                }
+            }
+
+            forEachImport(referencingFile, (_importDecl, moduleSpecifier) => {
+                const moduleSymbol = checker.getSymbolAtLocation(moduleSpecifier);
+                if (moduleSymbol === searchModuleSymbol) {
+                    refs.push({ kind: "import", literal: moduleSpecifier });
+                }
+            });
+        }
+        return refs;
+    }
+
     /** Returns a map from a module symbol Id to all import statements that directly reference the module. */
     function getDirectImportsMap(sourceFiles: SourceFile[], checker: TypeChecker, cancellationToken: CancellationToken): Map<ImporterOrCallExpression[]> {
         const map = createMap<ImporterOrCallExpression[]>();
@@ -371,7 +405,7 @@ namespace ts.FindAllReferences {
             case SyntaxKind.ExternalModuleReference:
                 return (decl as ExternalModuleReference).parent;
             default:
-                Debug.assert(false);
+                Debug.fail(`Unexpected module specifier parent: ${decl.kind}`);
         }
     }
 

src/services/jsDoc.ts

@@ -44,7 +44,7 @@ namespace ts.JsDoc {
     let jsDocTagNameCompletionEntries: CompletionEntry[];
     let jsDocTagCompletionEntries: CompletionEntry[];
 
-    export function getJsDocCommentsFromDeclarations(declarations: Declaration[]) {
+    export function getJsDocCommentsFromDeclarations(declarations?: Declaration[]) {
         // Only collect doc comments from duplicate declarations once:
         // In case of a union property there might be same declaration multiple times
         // which only varies in type parameter
@@ -69,7 +69,7 @@ namespace ts.JsDoc {
         return documentationComment;
     }
 
-    export function getJsDocTagsFromDeclarations(declarations: Declaration[]) {
+    export function getJsDocTagsFromDeclarations(declarations?: Declaration[]) {
         // Only collect doc comments from duplicate declarations once.
         const tags: JSDocTagInfo[] = [];
         forEachUnique(declarations, declaration => {
@@ -158,7 +158,7 @@ namespace ts.JsDoc {
             return undefined;
         }
 
-        const tokenAtPos = getTokenAtPosition(sourceFile, position);
+        const tokenAtPos = getTokenAtPosition(sourceFile, position, /*includeJsDocComment*/ false);
         const tokenStart = tokenAtPos.getStart();
         if (!tokenAtPos || tokenStart < position) {
             return undefined;

src/services/navigateTo.ts

@@ -205,7 +205,7 @@ namespace ts.NavigateTo {
                 textSpan: createTextSpanFromNode(declaration),
                 // TODO(jfreeman): What should be the containerName when the container has a computed name?
                 containerName: containerName ? (<Identifier>containerName).text : "",
-                containerKind: containerName ? getNodeKind(container) : ""
+                containerKind: containerName ? getNodeKind(container) : ScriptElementKind.unknown
             };
         }
     }

src/services/pathCompletions.ts

@@ -245,18 +245,15 @@ namespace ts.Completions.PathCompletions {
 
         // Get modules that the type checker picked up
         const ambientModules = map(typeChecker.getAmbientModules(), sym => stripQuotes(sym.name));
-        let nonRelativeModules = filter(ambientModules, moduleName => startsWith(moduleName, fragment));
+        let nonRelativeModuleNames = filter(ambientModules, moduleName => startsWith(moduleName, fragment));
 
         // Nested modules of the form "module-name/sub" need to be adjusted to only return the string
         // after the last '/' that appears in the fragment because that's where the replacement span
         // starts
         if (isNestedModule) {
             const moduleNameWithSeperator = ensureTrailingDirectorySeparator(moduleNameFragment);
-            nonRelativeModules = map(nonRelativeModules, moduleName => {
-                if (startsWith(fragment, moduleNameWithSeperator)) {
-                    return moduleName.substr(moduleNameWithSeperator.length);
-                }
-                return moduleName;
+            nonRelativeModuleNames = map(nonRelativeModuleNames, nonRelativeModuleName => {
+                return removePrefix(nonRelativeModuleName, moduleNameWithSeperator);
             });
         }
 
@@ -264,7 +261,7 @@ namespace ts.Completions.PathCompletions {
         if (!options.moduleResolution || options.moduleResolution === ModuleResolutionKind.NodeJs) {
             for (const visibleModule of enumerateNodeModulesVisibleToScript(host, scriptPath)) {
                 if (!isNestedModule) {
-                    nonRelativeModules.push(visibleModule.moduleName);
+                    nonRelativeModuleNames.push(visibleModule.moduleName);
                 }
                 else if (startsWith(visibleModule.moduleName, moduleNameFragment)) {
                     const nestedFiles = tryReadDirectory(host, visibleModule.moduleDir, supportedTypeScriptExtensions, /*exclude*/ undefined, /*include*/ ["./*"]);
@@ -272,18 +269,18 @@ namespace ts.Completions.PathCompletions {
                         for (let f of nestedFiles) {
                             f = normalizePath(f);
                             const nestedModule = removeFileExtension(getBaseFileName(f));
-                            nonRelativeModules.push(nestedModule);
+                            nonRelativeModuleNames.push(nestedModule);
                         }
                     }
                 }
             }
         }
 
-        return deduplicate(nonRelativeModules);
+        return deduplicate(nonRelativeModuleNames);
     }
 
     export function getTripleSlashReferenceCompletion(sourceFile: SourceFile, position: number, compilerOptions: CompilerOptions, host: LanguageServiceHost): CompletionInfo {
-        const token = getTokenAtPosition(sourceFile, position);
+        const token = getTokenAtPosition(sourceFile, position, /*includeJsDocComment*/ false);
         if (!token) {
             return undefined;
         }
@@ -458,7 +455,7 @@ namespace ts.Completions.PathCompletions {
         }
     }
 
-    function createCompletionEntryForModule(name: string, kind: string, replacementSpan: TextSpan): CompletionEntry {
+    function createCompletionEntryForModule(name: string, kind: ScriptElementKind, replacementSpan: TextSpan): CompletionEntry {
         return { name, kind, kindModifiers: ScriptElementKindModifier.none, sortText: name, replacementSpan };
     }
 

src/services/refactorProvider.ts

@@ -0,0 +1,69 @@
+/* @internal */
+namespace ts {
+    export interface Refactor {
+        /** An unique code associated with each refactor */
+        name: string;
+
+        /** Description of the refactor to display in the UI of the editor */
+        description: string;
+
+        /** Compute the associated code actions */
+        getCodeActions(context: RefactorContext): CodeAction[];
+
+        /** A fast syntactic check to see if the refactor is applicable at given position. */
+        isApplicable(context: RefactorContext): boolean;
+    }
+
+    export interface RefactorContext {
+        file: SourceFile;
+        startPosition: number;
+        endPosition?: number;
+        program: Program;
+        newLineCharacter: string;
+        rulesProvider?: formatting.RulesProvider;
+        cancellationToken?: CancellationToken;
+    }
+
+    export namespace refactor {
+        // A map with the refactor code as key, the refactor itself as value
+        // e.g.  nonSuggestableRefactors[refactorCode] -> the refactor you want
+        const refactors: Map<Refactor> = createMap<Refactor>();
+
+        export function registerRefactor(refactor: Refactor) {
+            refactors.set(refactor.name, refactor);
+        }
+
+        export function getApplicableRefactors(context: RefactorContext): ApplicableRefactorInfo[] | undefined {
+
+            let results: ApplicableRefactorInfo[];
+            const refactorList: Refactor[] = [];
+            refactors.forEach(refactor => {
+                refactorList.push(refactor);
+            });
+            for (const refactor of refactorList) {
+                if (context.cancellationToken && context.cancellationToken.isCancellationRequested()) {
+                    return results;
+                }
+                if (refactor.isApplicable(context)) {
+                    (results || (results = [])).push({ name: refactor.name, description: refactor.description });
+                }
+            }
+            return results;
+        }
+
+        export function getRefactorCodeActions(context: RefactorContext, refactorName: string): CodeAction[] | undefined {
+
+            let result: CodeAction[];
+            const refactor = refactors.get(refactorName);
+            if (!refactor) {
+                return undefined;
+            }
+
+            const codeActions = refactor.getCodeActions(context);
+            if (codeActions) {
+                addRange((result || (result = [])), codeActions);
+            }
+            return result;
+        }
+    }
+}

src/services/refactors/convertFunctionToEs6Class.ts

@@ -0,0 +1,209 @@
+/* @internal */
+
+namespace ts.refactor {
+    const convertFunctionToES6Class: Refactor = {
+        name: "Convert to ES2015 class",
+        description: Diagnostics.Convert_function_to_an_ES2015_class.message,
+        getCodeActions,
+        isApplicable
+    };
+
+    registerRefactor(convertFunctionToES6Class);
+
+    function isApplicable(context: RefactorContext): boolean {
+        const start = context.startPosition;
+        const node = getTokenAtPosition(context.file, start, /*includeJsDocComment*/ false);
+        const checker = context.program.getTypeChecker();
+        let symbol = checker.getSymbolAtLocation(node);
+
+        if (symbol && isDeclarationOfFunctionOrClassExpression(symbol)) {
+            symbol = (symbol.valueDeclaration as VariableDeclaration).initializer.symbol;
+        }
+
+        return symbol && symbol.flags & SymbolFlags.Function && symbol.members && symbol.members.size > 0;
+    }
+
+    function getCodeActions(context: RefactorContext): CodeAction[] | undefined {
+        const start = context.startPosition;
+        const sourceFile = context.file;
+        const checker = context.program.getTypeChecker();
+        const token = getTokenAtPosition(sourceFile, start, /*includeJsDocComment*/ false);
+        const ctorSymbol = checker.getSymbolAtLocation(token);
+        const newLine = context.rulesProvider.getFormatOptions().newLineCharacter;
+
+        const deletedNodes: Node[] = [];
+        const deletes: (() => any)[] = [];
+
+        if (!(ctorSymbol.flags & (SymbolFlags.Function | SymbolFlags.Variable))) {
+            return [];
+        }
+
+        const ctorDeclaration = ctorSymbol.valueDeclaration;
+        const changeTracker = textChanges.ChangeTracker.fromCodeFixContext(context as { newLineCharacter: string, rulesProvider: formatting.RulesProvider });
+
+        let precedingNode: Node;
+        let newClassDeclaration: ClassDeclaration;
+        switch (ctorDeclaration.kind) {
+            case SyntaxKind.FunctionDeclaration:
+                precedingNode = ctorDeclaration;
+                deleteNode(ctorDeclaration);
+                newClassDeclaration = createClassFromFunctionDeclaration(ctorDeclaration as FunctionDeclaration);
+                break;
+
+            case SyntaxKind.VariableDeclaration:
+                precedingNode = ctorDeclaration.parent.parent;
+                if ((<VariableDeclarationList>ctorDeclaration.parent).declarations.length === 1) {
+                    deleteNode(precedingNode);
+                }
+                else {
+                    deleteNode(ctorDeclaration, /*inList*/ true);
+                }
+                newClassDeclaration = createClassFromVariableDeclaration(ctorDeclaration as VariableDeclaration);
+                break;
+        }
+
+        if (!newClassDeclaration) {
+            return [];
+        }
+
+        // Because the preceding node could be touched, we need to insert nodes before delete nodes.
+        changeTracker.insertNodeAfter(sourceFile, precedingNode, newClassDeclaration, { suffix: newLine });
+        for (const deleteCallback of deletes) {
+            deleteCallback();
+        }
+
+        return [{
+            description: formatStringFromArgs(Diagnostics.Convert_function_0_to_class.message, [ctorSymbol.name]),
+            changes: changeTracker.getChanges()
+        }];
+
+        function deleteNode(node: Node, inList = false) {
+            if (deletedNodes.some(n => isNodeDescendantOf(node, n))) {
+                // Parent node has already been deleted; do nothing
+                return;
+            }
+            deletedNodes.push(node);
+            if (inList) {
+                deletes.push(() => changeTracker.deleteNodeInList(sourceFile, node));
+            }
+            else {
+                deletes.push(() => changeTracker.deleteNode(sourceFile, node));
+            }
+        }
+
+        function createClassElementsFromSymbol(symbol: Symbol) {
+            const memberElements: ClassElement[] = [];
+            // all instance members are stored in the "member" array of symbol
+            if (symbol.members) {
+                symbol.members.forEach(member => {
+                    const memberElement = createClassElement(member, /*modifiers*/ undefined);
+                    if (memberElement) {
+                        memberElements.push(memberElement);
+                    }
+                });
+            }
+
+            // all static members are stored in the "exports" array of symbol
+            if (symbol.exports) {
+                symbol.exports.forEach(member => {
+                    const memberElement = createClassElement(member, [createToken(SyntaxKind.StaticKeyword)]);
+                    if (memberElement) {
+                        memberElements.push(memberElement);
+                    }
+                });
+            }
+
+            return memberElements;
+
+            function shouldConvertDeclaration(_target: PropertyAccessExpression, source: Expression) {
+                // Right now the only thing we can convert are function expressions - other values shouldn't get
+                // transformed. We can update this once ES public class properties are available.
+                return isFunctionLike(source);
+            }
+
+            function createClassElement(symbol: Symbol, modifiers: Modifier[]): ClassElement {
+                // both properties and methods are bound as property symbols
+                if (!(symbol.flags & SymbolFlags.Property)) {
+                    return;
+                }
+
+                const memberDeclaration = symbol.valueDeclaration as PropertyAccessExpression;
+                const assignmentBinaryExpression = memberDeclaration.parent as BinaryExpression;
+
+                if (!shouldConvertDeclaration(memberDeclaration, assignmentBinaryExpression.right)) {
+                    return;
+                }
+
+                // delete the entire statement if this expression is the sole expression to take care of the semicolon at the end
+                const nodeToDelete = assignmentBinaryExpression.parent && assignmentBinaryExpression.parent.kind === SyntaxKind.ExpressionStatement
+                    ? assignmentBinaryExpression.parent : assignmentBinaryExpression;
+                deleteNode(nodeToDelete);
+
+                if (!assignmentBinaryExpression.right) {
+                    return createProperty([], modifiers, symbol.name, /*questionToken*/ undefined,
+                        /*type*/ undefined, /*initializer*/ undefined);
+                }
+
+                switch (assignmentBinaryExpression.right.kind) {
+                    case SyntaxKind.FunctionExpression:
+                        const functionExpression = assignmentBinaryExpression.right as FunctionExpression;
+                        return createMethod(/*decorators*/ undefined, modifiers, /*asteriskToken*/ undefined, memberDeclaration.name, /*questionToken*/ undefined,
+                            /*typeParameters*/ undefined, functionExpression.parameters, /*type*/ undefined, functionExpression.body);
+
+                    case SyntaxKind.ArrowFunction:
+                        const arrowFunction = assignmentBinaryExpression.right as ArrowFunction;
+                        const arrowFunctionBody = arrowFunction.body;
+                        let bodyBlock: Block;
+
+                        // case 1: () => { return [1,2,3] }
+                        if (arrowFunctionBody.kind === SyntaxKind.Block) {
+                            bodyBlock = arrowFunctionBody as Block;
+                        }
+                        // case 2: () => [1,2,3]
+                        else {
+                            const expression = arrowFunctionBody as Expression;
+                            bodyBlock = createBlock([createReturn(expression)]);
+                        }
+                        return createMethod(/*decorators*/ undefined, modifiers, /*asteriskToken*/ undefined, memberDeclaration.name, /*questionToken*/ undefined,
+                            /*typeParameters*/ undefined, arrowFunction.parameters, /*type*/ undefined, bodyBlock);
+
+                    default:
+                        // Don't try to declare members in JavaScript files
+                        if (isSourceFileJavaScript(sourceFile)) {
+                            return;
+                        }
+                        return createProperty(/*decorators*/ undefined, modifiers, memberDeclaration.name, /*questionToken*/ undefined,
+                            /*type*/ undefined, assignmentBinaryExpression.right);
+                }
+            }
+        }
+
+        function createClassFromVariableDeclaration(node: VariableDeclaration): ClassDeclaration {
+            const initializer = node.initializer as FunctionExpression;
+            if (!initializer || initializer.kind !== SyntaxKind.FunctionExpression) {
+                return undefined;
+            }
+
+            if (node.name.kind !== SyntaxKind.Identifier) {
+                return undefined;
+            }
+
+            const memberElements = createClassElementsFromSymbol(initializer.symbol);
+            if (initializer.body) {
+                memberElements.unshift(createConstructor(/*decorators*/ undefined, /*modifiers*/ undefined, initializer.parameters, initializer.body));
+            }
+
+            return createClassDeclaration(/*decorators*/ undefined, /*modifiers*/ undefined, node.name,
+                /*typeParameters*/ undefined, /*heritageClauses*/ undefined, memberElements);
+        }
+
+        function createClassFromFunctionDeclaration(node: FunctionDeclaration): ClassDeclaration {
+            const memberElements = createClassElementsFromSymbol(ctorSymbol);
+            if (node.body) {
+                memberElements.unshift(createConstructor(/*decorators*/ undefined, /*modifiers*/ undefined, node.parameters, node.body));
+            }
+            return createClassDeclaration(/*decorators*/ undefined, /*modifiers*/ undefined, node.name,
+                /*typeParameters*/ undefined, /*heritageClauses*/ undefined, memberElements);
+        }
+    }
+}

src/services/refactors/refactors.ts

@@ -0,0 +1 @@
+/// <reference path="convertFunctionToEs6Class.ts" />

src/services/rename.ts

@@ -53,7 +53,7 @@ namespace ts.Rename {
         }
     }
 
-    function getRenameInfoSuccess(displayName: string, fullDisplayName: string, kind: string, kindModifiers: string, node: Node, sourceFile: SourceFile): RenameInfo {
+    function getRenameInfoSuccess(displayName: string, fullDisplayName: string, kind: ScriptElementKind, kindModifiers: string, node: Node, sourceFile: SourceFile): RenameInfo {
         return {
             canRename: true,
             kind,

src/services/services.ts

@@ -25,7 +25,9 @@
 /// <reference path='formatting\smartIndenter.ts' />
 /// <reference path='textChanges.ts' />
 /// <reference path='codeFixProvider.ts' />
+/// <reference path='refactorProvider.ts' />
 /// <reference path='codefixes\fixes.ts' />
+/// <reference path='refactors\refactors.ts' />
 
 namespace ts {
     /** The version of the language service API */
@@ -105,6 +107,7 @@ namespace ts {
             scanner.setTextPos(pos);
             while (pos < end) {
                 const token = useJSDocScanner ? scanner.scanJSDocToken() : scanner.scan();
+                Debug.assert(token !== SyntaxKind.EndOfFileToken); // Else it would infinitely loop
                 const textPos = scanner.getTextPos();
                 if (textPos <= end) {
                     nodes.push(createNode(token, pos, textPos, this));
@@ -133,10 +136,15 @@ namespace ts {
         }
 
         private createChildren(sourceFile?: SourceFileLike) {
-            let children: Node[];
-            if (this.kind >= SyntaxKind.FirstNode) {
+            if (isJSDocTag(this)) {
+                /** Don't add trivia for "tokens" since this is in a comment. */
+                const children: Node[] = [];
+                this.forEachChild(child => { children.push(child); });
+                this._children = children;
+            }
+            else if (this.kind >= SyntaxKind.FirstNode) {
+                const children: Node[] = [];
                 scanner.setText((sourceFile || this.getSourceFile()).text);
-                children = [];
                 let pos = this.pos;
                 const useJSDocScanner = this.kind >= SyntaxKind.FirstJSDocTagNode && this.kind <= SyntaxKind.LastJSDocTagNode;
                 const processNode = (node: Node) => {
@@ -153,7 +161,7 @@ namespace ts {
                     if (pos < nodes.pos) {
                         pos = this.addSyntheticNodes(children, pos, nodes.pos, useJSDocScanner);
                     }
-                    children.push(this.createSyntaxList(<NodeArray<Node>>nodes));
+                    children.push(this.createSyntaxList(nodes));
                     pos = nodes.end;
                 };
                 // jsDocComments need to be the first children
@@ -171,8 +179,11 @@ namespace ts {
                     this.addSyntheticNodes(children, pos, this.end);
                 }
                 scanner.setText(undefined);
+                this._children = children;
+            }
+            else {
+                this._children = emptyArray;
             }
-            this._children = children || emptyArray;
         }
 
         public getChildCount(sourceFile?: SourceFile): number {
@@ -213,7 +224,7 @@ namespace ts {
             return child.kind < SyntaxKind.FirstNode ? child : child.getLastToken(sourceFile);
         }
 
-        public forEachChild<T>(cbNode: (node: Node) => T, cbNodeArray?: (nodes: Node[]) => T): T {
+        public forEachChild<T>(cbNode: (node: Node) => T, cbNodeArray?: (nodes: NodeArray<Node>) => T): T {
             return forEachChild(this, cbNode, cbNodeArray);
         }
     }
@@ -298,15 +309,15 @@ namespace ts {
     class SymbolObject implements Symbol {
         flags: SymbolFlags;
         name: string;
-        declarations: Declaration[];
+        declarations?: Declaration[];
 
         // Undefined is used to indicate the value has not been computed. If, after computing, the
-        // symbol has no doc comment, then the empty string will be returned.
-        documentationComment: SymbolDisplayPart[];
+        // symbol has no doc comment, then the empty array will be returned.
+        documentationComment?: SymbolDisplayPart[];
 
         // Undefined is used to indicate the value has not been computed. If, after computing, the
         // symbol has no JSDoc tags, then the empty array will be returned.
-        tags: JSDocTagInfo[];
+        tags?: JSDocTagInfo[];
 
         constructor(flags: SymbolFlags, name: string) {
             this.flags = flags;
@@ -321,7 +332,7 @@ namespace ts {
             return this.name;
         }
 
-        getDeclarations(): Declaration[] {
+        getDeclarations(): Declaration[] | undefined {
             return this.declarations;
         }
 
@@ -360,6 +371,7 @@ namespace ts {
         _incrementExpressionBrand: any;
         _unaryExpressionBrand: any;
         _expressionBrand: any;
+        /*@internal*/typeArguments: NodeArray<TypeNode>;
         constructor(_kind: SyntaxKind.Identifier, pos: number, end: number) {
             super(pos, end);
         }
@@ -371,7 +383,7 @@ namespace ts {
         flags: TypeFlags;
         objectFlags?: ObjectFlags;
         id: number;
-        symbol: Symbol;
+        symbol?: Symbol;
         constructor(checker: TypeChecker, flags: TypeFlags) {
             this.checker = checker;
             this.flags = flags;
@@ -379,13 +391,13 @@ namespace ts {
         getFlags(): TypeFlags {
             return this.flags;
         }
-        getSymbol(): Symbol {
+        getSymbol(): Symbol | undefined {
             return this.symbol;
         }
         getProperties(): Symbol[] {
             return this.checker.getPropertiesOfType(this);
         }
-        getProperty(propertyName: string): Symbol {
+        getProperty(propertyName: string): Symbol | undefined {
             return this.checker.getPropertyOfType(this, propertyName);
         }
         getApparentProperties(): Symbol[] {
@@ -397,13 +409,13 @@ namespace ts {
         getConstructSignatures(): Signature[] {
             return this.checker.getSignaturesOfType(this, SignatureKind.Construct);
         }
-        getStringIndexType(): Type {
+        getStringIndexType(): Type | undefined {
             return this.checker.getIndexTypeOfType(this, IndexKind.String);
         }
-        getNumberIndexType(): Type {
+        getNumberIndexType(): Type | undefined {
             return this.checker.getIndexTypeOfType(this, IndexKind.Number);
         }
-        getBaseTypes(): BaseType[] {
+        getBaseTypes(): BaseType[] | undefined {
             return this.flags & TypeFlags.Object && this.objectFlags & (ObjectFlags.Class | ObjectFlags.Interface)
                 ? this.checker.getBaseTypes(<InterfaceType><Type>this)
                 : undefined;
@@ -416,7 +428,7 @@ namespace ts {
     class SignatureObject implements Signature {
         checker: TypeChecker;
         declaration: SignatureDeclaration;
-        typeParameters: TypeParameter[];
+        typeParameters?: TypeParameter[];
         parameters: Symbol[];
         thisParameter: Symbol;
         resolvedReturnType: Type;
@@ -426,12 +438,12 @@ namespace ts {
         hasLiteralTypes: boolean;
 
         // Undefined is used to indicate the value has not been computed. If, after computing, the
-        // symbol has no doc comment, then the empty string will be returned.
-        documentationComment: SymbolDisplayPart[];
+        // symbol has no doc comment, then the empty array will be returned.
+        documentationComment?: SymbolDisplayPart[];
 
         // Undefined is used to indicate the value has not been computed. If, after computing, the
         // symbol has no doc comment, then the empty array will be returned.
-        jsDocTags: JSDocTagInfo[];
+        jsDocTags?: JSDocTagInfo[];
 
         constructor(checker: TypeChecker) {
             this.checker = checker;
@@ -439,7 +451,7 @@ namespace ts {
         getDeclaration(): SignatureDeclaration {
             return this.declaration;
         }
-        getTypeParameters(): TypeParameter[] {
+        getTypeParameters(): TypeParameter[] | undefined {
             return this.typeParameters;
         }
         getParameters(): Symbol[] {
@@ -1365,7 +1377,7 @@ namespace ts {
             synchronizeHostData();
 
             const sourceFile = getValidSourceFile(fileName);
-            const node = getTouchingPropertyName(sourceFile, position);
+            const node = getTouchingPropertyName(sourceFile, position, /*includeJsDocComment*/ true);
             if (node === sourceFile) {
                 return undefined;
             }
@@ -1428,7 +1440,7 @@ namespace ts {
         /// Goto implementation
         function getImplementationAtPosition(fileName: string, position: number): ImplementationLocation[] {
             synchronizeHostData();
-            return FindAllReferences.getImplementationsAtPosition(program.getTypeChecker(), cancellationToken, program.getSourceFiles(), getValidSourceFile(fileName), position);
+            return FindAllReferences.getImplementationsAtPosition(program, cancellationToken, program.getSourceFiles(), getValidSourceFile(fileName), position);
         }
 
         /// References and Occurrences
@@ -1450,7 +1462,7 @@ namespace ts {
             synchronizeHostData();
             const sourceFilesToSearch = map(filesToSearch, f => program.getSourceFile(f));
             const sourceFile = getValidSourceFile(fileName);
-            return DocumentHighlights.getDocumentHighlights(program.getTypeChecker(), cancellationToken, sourceFile, position, sourceFilesToSearch);
+            return DocumentHighlights.getDocumentHighlights(program, cancellationToken, sourceFile, position, sourceFilesToSearch);
         }
 
         function getOccurrencesAtPositionCore(fileName: string, position: number): ReferenceEntry[] {
@@ -1488,12 +1500,12 @@ namespace ts {
 
         function getReferences(fileName: string, position: number, options?: FindAllReferences.Options) {
             synchronizeHostData();
-            return FindAllReferences.findReferencedEntries(program.getTypeChecker(), cancellationToken, program.getSourceFiles(), getValidSourceFile(fileName), position, options);
+            return FindAllReferences.findReferencedEntries(program, cancellationToken, program.getSourceFiles(), getValidSourceFile(fileName), position, options);
         }
 
         function findReferences(fileName: string, position: number): ReferencedSymbol[] {
             synchronizeHostData();
-            return FindAllReferences.findReferencedSymbols(program.getTypeChecker(), cancellationToken, program.getSourceFiles(), getValidSourceFile(fileName), position);
+            return FindAllReferences.findReferencedSymbols(program, cancellationToken, program.getSourceFiles(), getValidSourceFile(fileName), position);
         }
 
         /// NavigateTo
@@ -1552,7 +1564,7 @@ namespace ts {
             const sourceFile = syntaxTreeCache.getCurrentSourceFile(fileName);
 
             // Get node at the location
-            const node = getTouchingPropertyName(sourceFile, startPos);
+            const node = getTouchingPropertyName(sourceFile, startPos, /*includeJsDocComment*/ false);
 
             if (node === sourceFile) {
                 return;
@@ -1663,7 +1675,7 @@ namespace ts {
             const sourceFile = syntaxTreeCache.getCurrentSourceFile(fileName);
             const result: TextSpan[] = [];
 
-            const token = getTouchingToken(sourceFile, position);
+            const token = getTouchingToken(sourceFile, position, /*includeJsDocComment*/ false);
 
             if (token.getStart(sourceFile) === position) {
                 const matchKind = getMatchingTokenKind(token);
@@ -1865,8 +1877,7 @@ namespace ts {
 
                     // OK, we have found a match in the file.  This is only an acceptable match if
                     // it is contained within a comment.
-                    const token = getTokenAtPosition(sourceFile, matchPosition);
-                    if (!isInsideComment(sourceFile, token, matchPosition)) {
+                    if (!isInComment(sourceFile, matchPosition)) {
                         continue;
                     }
 
@@ -1970,11 +1981,43 @@ namespace ts {
             return Rename.getRenameInfo(program.getTypeChecker(), defaultLibFileName, getCanonicalFileName, getValidSourceFile(fileName), position);
         }
 
+        function getRefactorContext(file: SourceFile, positionOrRange: number | TextRange, formatOptions?: FormatCodeSettings): RefactorContext {
+            const [startPosition, endPosition] = typeof positionOrRange === "number" ? [positionOrRange, undefined] : [positionOrRange.pos, positionOrRange.end];
+            return {
+                file,
+                startPosition,
+                endPosition,
+                program: getProgram(),
+                newLineCharacter: host.getNewLine(),
+                rulesProvider: getRuleProvider(formatOptions),
+                cancellationToken
+            };
+        }
+
+        function getApplicableRefactors(fileName: string, positionOrRange: number | TextRange): ApplicableRefactorInfo[] {
+            synchronizeHostData();
+            const file = getValidSourceFile(fileName);
+            return refactor.getApplicableRefactors(getRefactorContext(file, positionOrRange));
+        }
+
+        function getRefactorCodeActions(
+            fileName: string,
+            formatOptions: FormatCodeSettings,
+            positionOrRange: number | TextRange,
+            refactorName: string): CodeAction[] | undefined {
+
+            synchronizeHostData();
+            const file = getValidSourceFile(fileName);
+            return refactor.getRefactorCodeActions(getRefactorContext(file, positionOrRange, formatOptions), refactorName);
+        }
+
         return {
             dispose,
             cleanupSemanticCache,
             getSyntacticDiagnostics,
             getSemanticDiagnostics,
+            getApplicableRefactors,
+            getRefactorCodeActions,
             getCompilerOptionsDiagnostics,
             getSyntacticClassifications,
             getSemanticClassifications,

src/services/symbolDisplay.ts

@@ -1,7 +1,7 @@
 /* @internal */
 namespace ts.SymbolDisplay {
     // TODO(drosen): use contextual SemanticMeaning.
-    export function getSymbolKind(typeChecker: TypeChecker, symbol: Symbol, location: Node): string {
+    export function getSymbolKind(typeChecker: TypeChecker, symbol: Symbol, location: Node): ScriptElementKind {
         const { flags } = symbol;
 
         if (flags & SymbolFlags.Class) return getDeclarationOfKind(symbol, SyntaxKind.ClassExpression) ?
@@ -22,7 +22,7 @@ namespace ts.SymbolDisplay {
         return result;
     }
 
-    function getSymbolKindOfConstructorPropertyMethodAccessorFunctionOrVar(typeChecker: TypeChecker, symbol: Symbol, location: Node) {
+    function getSymbolKindOfConstructorPropertyMethodAccessorFunctionOrVar(typeChecker: TypeChecker, symbol: Symbol, location: Node): ScriptElementKind {
         if (typeChecker.isUndefinedSymbol(symbol)) {
             return ScriptElementKind.variableElement;
         }
@@ -275,7 +275,7 @@ namespace ts.SymbolDisplay {
         }
         if (symbolFlags & SymbolFlags.Module) {
             addNewLineIfDisplayPartsExist();
-            const declaration = <ModuleDeclaration>getDeclarationOfKind(symbol, SyntaxKind.ModuleDeclaration);
+            const declaration = getDeclarationOfKind<ModuleDeclaration>(symbol, SyntaxKind.ModuleDeclaration);
             const isNamespace = declaration && declaration.name && declaration.name.kind === SyntaxKind.Identifier;
             displayParts.push(keywordPart(isNamespace ? SyntaxKind.NamespaceKeyword : SyntaxKind.ModuleKeyword));
             displayParts.push(spacePart());
@@ -296,9 +296,9 @@ namespace ts.SymbolDisplay {
             }
             else {
                 // Method/function type parameter
-                let declaration = <Node>getDeclarationOfKind(symbol, SyntaxKind.TypeParameter);
-                Debug.assert(declaration !== undefined);
-                declaration = declaration.parent;
+                const decl = getDeclarationOfKind(symbol, SyntaxKind.TypeParameter);
+                Debug.assert(decl !== undefined);
+                const declaration = decl.parent;
 
                 if (declaration) {
                     if (isFunctionLikeKind(declaration.kind)) {
@@ -336,7 +336,8 @@ namespace ts.SymbolDisplay {
                     displayParts.push(spacePart());
                     displayParts.push(operatorPart(SyntaxKind.EqualsToken));
                     displayParts.push(spacePart());
-                    displayParts.push(displayPart(constantValue.toString(), SymbolDisplayPartKind.numericLiteral));
+                    displayParts.push(displayPart(getTextOfConstantValue(constantValue),
+                        typeof constantValue === "number" ? SymbolDisplayPartKind.numericLiteral : SymbolDisplayPartKind.stringLiteral));
                 }
             }
         }

src/services/textChanges.ts

@@ -157,7 +157,7 @@ namespace ts.textChanges {
         private changes: Change[] = [];
         private readonly newLineCharacter: string;
 
-        public static fromCodeFixContext(context: CodeFixContext) {
+        public static fromCodeFixContext(context: { newLineCharacter: string, rulesProvider: formatting.RulesProvider }) {
             return new ChangeTracker(context.newLineCharacter === "\n" ? NewLineKind.LineFeed : NewLineKind.CarriageReturnLineFeed, context.rulesProvider);
         }
 
@@ -202,7 +202,7 @@ namespace ts.textChanges {
                 return this;
             }
             if (index !== containingList.length - 1) {
-                const nextToken = getTokenAtPosition(sourceFile, node.end);
+                const nextToken = getTokenAtPosition(sourceFile, node.end, /*includeJsDocComment*/ false);
                 if (nextToken && isSeparator(node, nextToken)) {
                     // find first non-whitespace position in the leading trivia of the node
                     const startPosition = skipTrivia(sourceFile.text, getAdjustedStartPosition(sourceFile, node, {}, Position.FullStart), /*stopAfterLineBreak*/ false, /*stopAtComments*/ true);
@@ -214,7 +214,7 @@ namespace ts.textChanges {
                 }
             }
             else {
-                const previousToken = getTokenAtPosition(sourceFile, containingList[index - 1].end);
+                const previousToken = getTokenAtPosition(sourceFile, containingList[index - 1].end, /*includeJsDocComment*/ false);
                 if (previousToken && isSeparator(node, previousToken)) {
                     this.deleteNodeRange(sourceFile, previousToken, node);
                 }
@@ -254,9 +254,9 @@ namespace ts.textChanges {
 
         public insertNodeAfter(sourceFile: SourceFile, after: Node, newNode: Node, options: InsertNodeOptions & ConfigurableEnd = {}) {
             if ((isStatementButNotDeclaration(after)) ||
-                 after.kind === SyntaxKind.PropertyDeclaration ||
-                 after.kind === SyntaxKind.PropertySignature ||
-                 after.kind === SyntaxKind.MethodSignature) {
+                after.kind === SyntaxKind.PropertyDeclaration ||
+                after.kind === SyntaxKind.PropertySignature ||
+                after.kind === SyntaxKind.MethodSignature) {
                 // check if previous statement ends with semicolon
                 // if not - insert semicolon to preserve the code from changing the meaning due to ASI
                 if (sourceFile.text.charCodeAt(after.end - 1) !== CharacterCodes.semicolon) {
@@ -292,7 +292,7 @@ namespace ts.textChanges {
             if (index !== containingList.length - 1) {
                 // any element except the last one
                 // use next sibling as an anchor
-                const nextToken = getTokenAtPosition(sourceFile, after.end);
+                const nextToken = getTokenAtPosition(sourceFile, after.end, /*includeJsDocComment*/ false);
                 if (nextToken && isSeparator(after, nextToken)) {
                     // for list
                     // a, b, c
@@ -481,7 +481,7 @@ namespace ts.textChanges {
             return (options.prefix || "") + text + (options.suffix || "");
         }
 
-        private static normalize(changes: Change[]) {
+        private static normalize(changes: Change[]): Change[] {
             // order changes by start position
             const normalized = stableSort(changes, (a, b) => a.range.pos - b.range.pos);
             // verify that change intervals do not overlap, except possibly at end points.
@@ -497,8 +497,8 @@ namespace ts.textChanges {
         readonly node: Node;
     }
 
-    export function getNonformattedText(node: Node, sourceFile: SourceFile, newLine: NewLineKind): NonFormattedText {
-        const options = { newLine, target: sourceFile.languageVersion };
+    export function getNonformattedText(node: Node, sourceFile: SourceFile | undefined, newLine: NewLineKind): NonFormattedText {
+        const options = { newLine, target: sourceFile && sourceFile.languageVersion };
         const writer = new Writer(getNewLineCharacter(options));
         const printer = createPrinter(options, writer);
         printer.writeNode(EmitHint.Unspecified, node, sourceFile, writer);
@@ -528,26 +528,6 @@ namespace ts.textChanges {
         return skipTrivia(s, 0) === s.length;
     }
 
-    const nullTransformationContext: TransformationContext = {
-        enableEmitNotification: noop,
-        enableSubstitution: noop,
-        endLexicalEnvironment: () => undefined,
-        getCompilerOptions: notImplemented,
-        getEmitHost: notImplemented,
-        getEmitResolver: notImplemented,
-        hoistFunctionDeclaration: noop,
-        hoistVariableDeclaration: noop,
-        isEmitNotificationEnabled: notImplemented,
-        isSubstitutionEnabled: notImplemented,
-        onEmitNode: noop,
-        onSubstituteNode: notImplemented,
-        readEmitHelpers: notImplemented,
-        requestEmitHelper: noop,
-        resumeLexicalEnvironment: noop,
-        startLexicalEnvironment: noop,
-        suspendLexicalEnvironment: noop
-    };
-
     function assignPositionsToNode(node: Node): Node {
         const visited = visitEachChild(node, assignPositionsToNode, nullTransformationContext, assignPositionsToNodeArray, assignPositionsToNode);
         // create proxy node for non synthesized nodes
@@ -580,6 +560,8 @@ namespace ts.textChanges {
         public readonly onEmitNode: PrintHandlers["onEmitNode"];
         public readonly onBeforeEmitNodeArray: PrintHandlers["onBeforeEmitNodeArray"];
         public readonly onAfterEmitNodeArray: PrintHandlers["onAfterEmitNodeArray"];
+        public readonly onBeforeEmitToken: PrintHandlers["onBeforeEmitToken"];
+        public readonly onAfterEmitToken: PrintHandlers["onAfterEmitToken"];
 
         constructor(newLine: string) {
             this.writer = createTextWriter(newLine);
@@ -602,6 +584,16 @@ namespace ts.textChanges {
                     setEnd(nodes, this.lastNonTriviaPosition);
                 }
             };
+            this.onBeforeEmitToken = node => {
+                if (node) {
+                    setPos(node, this.lastNonTriviaPosition);
+                }
+            };
+            this.onAfterEmitToken = node => {
+                if (node) {
+                    setEnd(node, this.lastNonTriviaPosition);
+                }
+            };
         }
 
         private setLastNonTriviaPosition(s: string, force: boolean) {