Merge branch 'master' into primitive-type-guards-are-order-independent

Jakefile.js

@@ -5,6 +5,7 @@ var os = require("os");
 var path = require("path");
 var child_process = require("child_process");
 var Linter = require("tslint");
+var runTestsInParallel = require("./scripts/mocha-parallel").runTestsInParallel;
 
 // Variables
 var compilerDirectory = "src/compiler/";
@@ -312,10 +313,7 @@ function compileFile(outFile, sources, prereqs, prefixes, useBuiltCompiler, opts
         }
 
         if (useDebugMode) {
-            options += " -sourcemap";
-            if (!opts.noMapRoot) {
-                options += " -mapRoot file:///" + path.resolve(path.dirname(outFile));
-            }
+            options += " --inlineSourceMap --inlineSources";
         } else {
             options += " --newLine LF";
         }
@@ -485,7 +483,6 @@ var tscFile = path.join(builtLocalDirectory, compilerFilename);
 compileFile(tscFile, compilerSources, [builtLocalDirectory, copyright].concat(compilerSources), [copyright], /*useBuiltCompiler:*/ false);
 
 var servicesFile = path.join(builtLocalDirectory, "typescriptServices.js");
-var servicesFileInBrowserTest = path.join(builtLocalDirectory, "typescriptServicesInBrowserTest.js");
 var standaloneDefinitionsFile = path.join(builtLocalDirectory, "typescriptServices.d.ts");
 var nodePackageFile = path.join(builtLocalDirectory, "typescript.js");
 var nodeDefinitionsFile = path.join(builtLocalDirectory, "typescript.d.ts");
@@ -517,16 +514,6 @@ compileFile(servicesFile, servicesSources,[builtLocalDirectory, copyright].conca
                 fs.writeFileSync(nodeStandaloneDefinitionsFile, nodeStandaloneDefinitionsFileContents);
             });
 
-compileFile(servicesFileInBrowserTest, servicesSources,[builtLocalDirectory, copyright].concat(servicesSources),
-            /*prefixes*/ [copyright],
-            /*useBuiltCompiler*/ true,
-            { noOutFile: false, generateDeclarations: true, preserveConstEnums: true, keepComments: true, noResolve: false, stripInternal: true, noMapRoot: true },
-            /*callback*/ function () {
-                var content = fs.readFileSync(servicesFileInBrowserTest).toString();
-                var i = content.lastIndexOf("\n");
-                fs.writeFileSync(servicesFileInBrowserTest, content.substring(0, i) + "\r\n//# sourceURL=../built/local/typeScriptServices.js" + content.substring(i));
-            });
-
 
 var serverFile = path.join(builtLocalDirectory, "tsserver.js");
 compileFile(serverFile, serverSources,[builtLocalDirectory, copyright].concat(serverSources), /*prefixes*/ [copyright], /*useBuiltCompiler*/ true);
@@ -688,7 +675,6 @@ function cleanTestDirs() {
 // used to pass data from jake command line directly to run.js
 function writeTestConfigFile(tests, light, taskConfigsFolder, workerCount) {
     var testConfigContents = JSON.stringify({ test: tests ? [tests] : undefined, light: light, workerCount: workerCount, taskConfigsFolder: taskConfigsFolder });
-    console.log('Running tests with config: ' + testConfigContents);
     fs.writeFileSync('test.config', testConfigContents);
 }
 
@@ -749,42 +735,16 @@ function runConsoleTests(defaultReporter, runInParallel) {
 
     }
     else {
-        // run task to load all tests and partition them between workers
-        var cmd = "mocha " + " -R min " + colors + run;
-        console.log(cmd);
-        exec(cmd, function() {
-            // read all configuration files and spawn a worker for every config
-            var configFiles = fs.readdirSync(taskConfigsFolder);
-            var counter = configFiles.length;
-            var firstErrorStatus;
-            // schedule work for chunks
-            configFiles.forEach(function (f) {
-                var configPath = path.join(taskConfigsFolder, f);
-                var workerCmd = "mocha" + " -t " + testTimeout + " -R " + reporter + " " + colors + " " + run + " --config='" + configPath + "'";
-                console.log(workerCmd);
-                exec(workerCmd,  finishWorker, finishWorker)
-            });
-
-            function finishWorker(e, errorStatus) {
-                counter--;
-                if (firstErrorStatus === undefined && errorStatus !== undefined) {
-                    firstErrorStatus = errorStatus;
-                }
-                if (counter !== 0) {
-                    complete();
-                }
-                else {
-                    // last worker clean everything and runs linter in case if there were no errors
-                    deleteTemporaryProjectOutput();
-                    jake.rmRf(taskConfigsFolder);
-                    if (firstErrorStatus === undefined) {
-                        runLinter();
-                        complete();
-                    }
-                    else {
-                        failWithStatus(firstErrorStatus);
-                    }
-                }
+        runTestsInParallel(taskConfigsFolder, run, { testTimeout: testTimeout, noColors: colors === " --no-colors " }, function (err) {
+            // last worker clean everything and runs linter in case if there were no errors
+            deleteTemporaryProjectOutput();
+            jake.rmRf(taskConfigsFolder);
+            if (err) {
+                fail(err);
+            }
+            else {
+                runLinter();
+                complete();
             }
         });
     }
@@ -839,12 +799,12 @@ compileFile(nodeServerOutFile, [nodeServerInFile], [builtLocalDirectory, tscFile
 
 desc("Runs browserify on run.js to produce a file suitable for running tests in the browser");
 task("browserify", ["tests", builtLocalDirectory, nodeServerOutFile], function() {
-    var cmd = 'browserify built/local/run.js -o built/local/bundle.js';
+    var cmd = 'browserify built/local/run.js -d -o built/local/bundle.js';
     exec(cmd);
 }, {async: true});
 
 desc("Runs the tests using the built run.js file like 'jake runtests'. Syntax is jake runtests-browser. Additional optional parameters tests=[regex], port=, browser=[chrome|IE]");
-task("runtests-browser", ["tests", "browserify", builtLocalDirectory, servicesFileInBrowserTest], function() {
+task("runtests-browser", ["tests", "browserify", builtLocalDirectory, servicesFile], function() {
     cleanTestDirs();
     host = "node";
     port = process.env.port || process.env.p || '8888';

scripts/mocha-none-reporter.js

@@ -0,0 +1,26 @@
+/**
+ * Module dependencies.
+ */
+
+var Base = require('mocha').reporters.Base;
+
+/**
+ * Expose `None`.
+ */
+
+exports = module.exports = None;
+
+/**
+ * Initialize a new `None` test reporter.
+ *
+ * @api public
+ * @param {Runner} runner
+ */
+function None(runner) {
+  Base.call(this);
+}
+
+/**
+ * Inherit from `Base.prototype`.
+ */
+None.prototype.__proto__ = Base.prototype;

scripts/mocha-parallel.js

@@ -0,0 +1,367 @@
+var tty = require("tty")
+  , readline = require("readline")
+  , fs = require("fs")
+  , path = require("path")
+  , child_process = require("child_process")
+  , os = require("os")
+  , mocha = require("mocha")
+  , Base = mocha.reporters.Base
+  , color = Base.color
+  , cursor = Base.cursor
+  , ms = require("mocha/lib/ms");
+
+var isatty = tty.isatty(1) && tty.isatty(2);
+var tapRangePattern = /^(\d+)\.\.(\d+)(?:$|\r\n?|\n)/;
+var tapTestPattern = /^(not\sok|ok)\s+(\d+)\s+(?:-\s+)?(.*)$/;
+var tapCommentPattern = /^#(?: (tests|pass|fail) (\d+)$)?/;
+
+exports.runTestsInParallel = runTestsInParallel;
+exports.ProgressBars = ProgressBars;
+
+function runTestsInParallel(taskConfigsFolder, run, options, cb) {
+    if (options === undefined) options = { };
+
+    return discoverTests(run, options, function (error) {
+        if (error) {
+            return cb(error);
+        }
+
+        return runTests(taskConfigsFolder, run, options, cb);
+    });
+}
+
+function discoverTests(run, options, cb) {
+    console.log("Discovering tests...");
+
+    var cmd = "mocha -R " + require.resolve("./mocha-none-reporter.js") + " " + run;
+    var p = child_process.spawn(
+        process.platform === "win32" ? "cmd" : "/bin/sh",
+        process.platform === "win32" ? ["/c", cmd] : ["-c", cmd], {
+            windowsVerbatimArguments: true,
+            env: { NODE_ENV: "development" }
+        });
+
+    p.on("exit", function (status) {
+        if (status) {
+            cb(new Error("Process exited with code " + status));
+        }
+        else {
+            cb();
+        }
+    });
+}
+
+function runTests(taskConfigsFolder, run, options, cb) {
+    var configFiles = fs.readdirSync(taskConfigsFolder);
+    var numPartitions = configFiles.length;
+    if (numPartitions <= 0) {
+        cb();
+        return;
+    }
+
+    console.log("Running tests on " + numPartitions + " threads...");
+
+    var partitions = Array(numPartitions);
+    var progressBars = new ProgressBars();
+    progressBars.enable();
+
+    var counter = numPartitions;
+    configFiles.forEach(runTestsInPartition);
+
+    function runTestsInPartition(file, index) {
+        var partition = {
+            file: path.join(taskConfigsFolder, file),
+            tests: 0,
+            passed: 0,
+            failed: 0,
+            completed: 0,
+            current: undefined,
+            start: undefined,
+            end: undefined,
+            failures: []
+        };
+        partitions[index] = partition;
+
+        // Set up the progress bar.
+        updateProgress(0);
+
+        // Start the background process.
+        var cmd = "mocha -t " + (options.testTimeout || 20000) + " -R tap --no-colors " + run + " --config='" + partition.file + "'";
+        var p = child_process.spawn(
+            process.platform === "win32" ? "cmd" : "/bin/sh",
+            process.platform === "win32" ? ["/c", cmd] : ["-c", cmd], {
+                windowsVerbatimArguments: true,
+                env: { NODE_ENV: "development" }
+            });
+
+        var rl = readline.createInterface({
+            input: p.stdout,
+            terminal: false
+        });
+
+        rl.on("line", onmessage);
+        p.on("exit", onexit)
+
+        function onmessage(line) {
+            if (partition.start === undefined) {
+                partition.start = Date.now();
+            }
+
+            var rangeMatch = tapRangePattern.exec(line);
+            if (rangeMatch) {
+                partition.tests = parseInt(rangeMatch[2]);
+                return;
+            }
+
+            var testMatch = tapTestPattern.exec(line);
+            if (testMatch) {
+                var test = {
+                    result: testMatch[1],
+                    id: parseInt(testMatch[2]),
+                    name: testMatch[3],
+                    output: []
+                };
+
+                partition.current = test;
+                partition.completed++;
+
+                if (test.result === "ok") {
+                    partition.passed++;
+                }
+                else {
+                    partition.failed++;
+                    partition.failures.push(test);
+                }
+
+                var progress = partition.completed / partition.tests;
+                if (progress < 1) {
+                    updateProgress(progress);
+                }
+
+                return;
+            }
+
+            var commentMatch = tapCommentPattern.exec(line);
+            if (commentMatch) {
+                switch (commentMatch[1]) {
+                    case "tests":
+                        partition.current = undefined;
+                        partition.tests = parseInt(commentMatch[2]);
+                        break;
+
+                    case "pass":
+                        partition.passed = parseInt(commentMatch[2]);
+                        break;
+
+                    case "fail":
+                        partition.failed = parseInt(commentMatch[2]);
+                        break;
+                }
+
+                return;
+            }
+
+            if (partition.current) {
+                partition.current.output.push(line);
+            }
+        }
+
+        function onexit() {
+            if (partition.end === undefined) {
+                partition.end = Date.now();
+            }
+
+            partition.duration = partition.end - partition.start;
+            var summaryColor = partition.failed ? "fail" : "green";
+            var summarySymbol = partition.failed ? Base.symbols.err : Base.symbols.ok;
+            var summaryTests = (partition.passed === partition.tests ? partition.passed : partition.passed + "/" + partition.tests) + " passing";
+            var summaryDuration = "(" + ms(partition.duration) + ")";
+            var savedUseColors = Base.useColors;
+            Base.useColors = !options.noColors;
+
+            var summary = color(summaryColor, summarySymbol + " " + summaryTests) + " " + color("light", summaryDuration);
+            Base.useColors = savedUseColors;
+
+            updateProgress(1, summary);
+
+            signal();
+        }
+
+        function updateProgress(percentComplete, title) {
+            var progressColor = "pending";
+            if (partition.failed) {
+                progressColor = "fail";
+            }
+
+            progressBars.update(
+                index,
+                percentComplete,
+                progressColor,
+                title
+            );
+        }
+    }
+
+    function signal() {
+        counter--;
+
+        if (counter <= 0) {
+            var failed = 0;
+            var reporter = new Base(),
+                stats = reporter.stats,
+                failures = reporter.failures;
+
+            var duration = 0;
+            for (var i = 0; i < numPartitions; i++) {
+                var partition = partitions[i];
+                stats.passes += partition.passed;
+                stats.failures += partition.failed;
+                stats.tests += partition.tests;
+                duration += partition.duration;
+                for (var j = 0; j < partition.failures.length; j++) {
+                    var failure = partition.failures[j];
+                    failures.push(makeMochaTest(failure));
+                }
+            }
+
+            stats.duration = duration;
+            progressBars.disable();
+
+            if (options.noColors) {
+                var savedUseColors = Base.useColors;
+                Base.useColors = false;
+                reporter.epilogue();
+                Base.useColors = savedUseColors;
+            }
+            else {
+                reporter.epilogue();
+            }
+
+            if (failed) {
+                return cb(new Error("Test failures reported: " + failed));
+            }
+            else {
+                return cb();
+            }
+        }
+    }
+
+    function makeMochaTest(test) {
+        return {
+            fullTitle: function() {
+                return test.name;
+            },
+            err: {
+                message: test.output[0],
+                stack: test.output.join(os.EOL)
+            }
+        };
+    }
+}
+
+function ProgressBars(options) {
+    if (!options) options = {};
+    var open = options.open || '[';
+    var close = options.close || ']';
+    var complete = options.complete || '▬';
+    var incomplete = options.incomplete || Base.symbols.dot;
+    var maxWidth = Math.floor(Base.window.width * .30) - open.length - close.length - 2;
+    var width = minMax(options.width || maxWidth, 10, maxWidth);
+    this._options = {
+        open: open,
+        complete: complete,
+        incomplete: incomplete,
+        close: close,
+        width: width
+    };
+
+    this._progressBars = [];
+    this._lineCount = 0;
+    this._enabled = false;
+}
+ProgressBars.prototype = {
+    enable: function () {
+        if (!this._enabled) {
+            process.stdout.write(os.EOL);
+            this._enabled = true;
+        }
+    },
+    disable: function () {
+        if (this._enabled) {
+            process.stdout.write(os.EOL);
+            this._enabled = false;
+        }
+    },
+    update: function (index, percentComplete, color, title) {
+        percentComplete = minMax(percentComplete, 0, 1);
+
+        var progressBar = this._progressBars[index] || (this._progressBars[index] = { });
+        var width = this._options.width;
+        var n = Math.floor(width * percentComplete);
+        var i = width - n;
+        if (n === progressBar.lastN && title === progressBar.title && color === progressBar.progressColor) {
+            return;
+        }
+
+        progressBar.lastN = n;
+        progressBar.title = title;
+        progressBar.progressColor = color;
+
+        var progress = "  ";
+        progress += this._color('progress', this._options.open);
+        progress += this._color(color, fill(this._options.complete, n));
+        progress += this._color('progress', fill(this._options.incomplete, i));
+        progress += this._color('progress', this._options.close);
+
+        if (title) {
+            progress += this._color('progress', ' ' + title);
+        }
+
+        if (progressBar.text !== progress) {
+            progressBar.text = progress;
+            this._render(index);
+        }
+    },
+    _render: function (index) {
+        if (!this._enabled || !isatty) {
+            return;
+        }
+
+        cursor.hide();
+        readline.moveCursor(process.stdout, -process.stdout.columns, -this._lineCount);
+        var lineCount = 0;
+        var numProgressBars = this._progressBars.length;
+        for (var i = 0; i < numProgressBars; i++) {
+            if (i === index) {
+                readline.clearLine(process.stdout, 1);
+                process.stdout.write(this._progressBars[i].text + os.EOL);
+            }
+            else {
+                readline.moveCursor(process.stdout, -process.stdout.columns, +1);
+            }
+
+            lineCount++;
+        }
+
+        this._lineCount = lineCount;
+        cursor.show();
+    },
+    _color: function (type, text) {
+        return type && !this._options.noColors ? color(type, text) : text;
+    }
+};
+
+function fill(ch, size) {
+    var s = "";
+    while (s.length < size) {
+        s += ch;
+    }
+
+    return s.length > size ? s.substr(0, size) : s;
+}
+
+function minMax(value, min, max) {
+    if (value < min) return min;
+    if (value > max) return max;
+    return value;
+}

src/compiler/binder.ts

@@ -1198,9 +1198,9 @@ namespace ts {
             lastContainer = next;
         }
 
-        function declareSymbolAndAddToSymbolTable(node: Declaration, symbolFlags: SymbolFlags, symbolExcludes: SymbolFlags): void {
+        function declareSymbolAndAddToSymbolTable(node: Declaration, symbolFlags: SymbolFlags, symbolExcludes: SymbolFlags): Symbol {
             // Just call this directly so that the return type of this function stays "void".
-            declareSymbolAndAddToSymbolTableWorker(node, symbolFlags, symbolExcludes);
+            return declareSymbolAndAddToSymbolTableWorker(node, symbolFlags, symbolExcludes);
         }
 
         function declareSymbolAndAddToSymbolTableWorker(node: Declaration, symbolFlags: SymbolFlags, symbolExcludes: SymbolFlags): Symbol {
@@ -1304,7 +1304,22 @@ namespace ts {
                     declareSymbolAndAddToSymbolTable(node, SymbolFlags.NamespaceModule, SymbolFlags.NamespaceModuleExcludes);
                 }
                 else {
-                    declareSymbolAndAddToSymbolTable(node, SymbolFlags.ValueModule, SymbolFlags.ValueModuleExcludes);
+                    let pattern: Pattern | undefined;
+                    if (node.name.kind === SyntaxKind.StringLiteral) {
+                        const text = (<StringLiteral>node.name).text;
+                        if (hasZeroOrOneAsteriskCharacter(text)) {
+                            pattern = tryParsePattern(text);
+                        }
+                        else {
+                            errorOnFirstToken(node.name, Diagnostics.Pattern_0_can_have_at_most_one_Asterisk_character, text);
+                        }
+                    }
+
+                    const symbol = declareSymbolAndAddToSymbolTable(node, SymbolFlags.ValueModule, SymbolFlags.ValueModuleExcludes);
+
+                    if (pattern) {
+                        (file.patternAmbientModules || (file.patternAmbientModules = [])).push({ pattern, symbol });
+                    }
                 }
             }
             else {
@@ -2082,10 +2097,10 @@ namespace ts {
             checkStrictModeFunctionName(<FunctionDeclaration>node);
             if (inStrictMode) {
                 checkStrictModeFunctionDeclaration(node);
-                return bindBlockScopedDeclaration(node, SymbolFlags.Function, SymbolFlags.FunctionExcludes);
+                bindBlockScopedDeclaration(node, SymbolFlags.Function, SymbolFlags.FunctionExcludes);
             }
             else {
-                return declareSymbolAndAddToSymbolTable(<Declaration>node, SymbolFlags.Function, SymbolFlags.FunctionExcludes);
+                declareSymbolAndAddToSymbolTable(<Declaration>node, SymbolFlags.Function, SymbolFlags.FunctionExcludes);
             }
         }
 

src/compiler/checker.ts

@@ -140,6 +140,12 @@ namespace ts {
         const enumNumberIndexInfo = createIndexInfo(stringType, /*isReadonly*/ true);
 
         const globals: SymbolTable = {};
+        /**
+         * List of every ambient module with a "*" wildcard.
+         * Unlike other ambient modules, these can't be stored in `globals` because symbol tables only deal with exact matches.
+         * This is only used if there is no exact match.
+        */
+        let patternAmbientModules: PatternAmbientModule[];
 
         let getGlobalESSymbolConstructorSymbol: () => Symbol;
 
@@ -1285,6 +1291,14 @@ namespace ts {
                 }
                 return undefined;
             }
+
+            if (patternAmbientModules) {
+                const pattern = findBestPatternMatch(patternAmbientModules, _ => _.pattern, moduleName);
+                if (pattern) {
+                    return getMergedSymbol(pattern.symbol);
+                }
+            }
+
             if (moduleNotFoundError) {
                 // report errors only if it was requested
                 error(moduleReferenceLiteral, moduleNotFoundError, moduleName);
@@ -2844,7 +2858,7 @@ namespace ts {
             }
             // In strict null checking mode, if a default value of a non-undefined type is specified, remove
             // undefined from the final type.
-            if (strictNullChecks && declaration.initializer && !(getNullableKind(checkExpressionCached(declaration.initializer)) & TypeFlags.Undefined)) {
+            if (strictNullChecks && declaration.initializer && !(getCombinedTypeFlags(checkExpressionCached(declaration.initializer)) & TypeFlags.Undefined)) {
                 type = getTypeWithFacts(type, TypeFacts.NEUndefined);
             }
             return type;
@@ -2887,7 +2901,7 @@ namespace ts {
         }
 
         function addOptionality(type: Type, optional: boolean): Type {
-            return strictNullChecks && optional ? addNullableKind(type, TypeFlags.Undefined) : type;
+            return strictNullChecks && optional ? addTypeKind(type, TypeFlags.Undefined) : type;
         }
 
         // Return the inferred type for a variable, parameter, or property declaration
@@ -3222,7 +3236,7 @@ namespace ts {
             if (!links.type) {
                 const type = createObjectType(TypeFlags.Anonymous, symbol);
                 links.type = strictNullChecks && symbol.flags & SymbolFlags.Optional ?
-                    addNullableKind(type, TypeFlags.Undefined) : type;
+                    addTypeKind(type, TypeFlags.Undefined) : type;
             }
             return links.type;
         }
@@ -6746,7 +6760,7 @@ namespace ts {
                 return getUnionType(types);
             }
             const supertype = forEach(primaryTypes, t => isSupertypeOfEach(t, primaryTypes) ? t : undefined);
-            return supertype && addNullableKind(supertype, getCombinedFlagsOfTypes(types) & TypeFlags.Nullable);
+            return supertype && addTypeKind(supertype, getCombinedFlagsOfTypes(types) & TypeFlags.Nullable);
         }
 
         function reportNoCommonSupertypeError(types: Type[], errorLocation: Node, errorMessageChainHead: DiagnosticMessageChain): void {
@@ -6817,28 +6831,22 @@ namespace ts {
             return !!(type.flags & TypeFlags.Tuple);
         }
 
-        function getNullableKind(type: Type): TypeFlags {
-            let flags = type.flags;
-            if (flags & TypeFlags.Union) {
-                for (const t of (type as UnionType).types) {
-                    flags |= t.flags;
-                }
-            }
-            return flags & TypeFlags.Nullable;
+        function getCombinedTypeFlags(type: Type): TypeFlags {
+            return type.flags & TypeFlags.Union ? getCombinedFlagsOfTypes((<UnionType>type).types) : type.flags;
         }
 
-        function addNullableKind(type: Type, kind: TypeFlags): Type {
-            if ((getNullableKind(type) & kind) !== kind) {
-                const types = [type];
-                if (kind & TypeFlags.Undefined) {
-                    types.push(undefinedType);
-                }
-                if (kind & TypeFlags.Null) {
-                    types.push(nullType);
-                }
-                type = getUnionType(types);
+        function addTypeKind(type: Type, kind: TypeFlags) {
+            if ((getCombinedTypeFlags(type) & kind) === kind) {
+                return type;
             }
-            return type;
+            const types = [type];
+            if (kind & TypeFlags.String) types.push(stringType);
+            if (kind & TypeFlags.Number) types.push(numberType);
+            if (kind & TypeFlags.Boolean) types.push(booleanType);
+            if (kind & TypeFlags.Void) types.push(voidType);
+            if (kind & TypeFlags.Undefined) types.push(undefinedType);
+            if (kind & TypeFlags.Null) types.push(nullType);
+            return getUnionType(types);
         }
 
         function getNonNullableType(type: Type): Type {
@@ -7662,12 +7670,27 @@ namespace ts {
                 getInitialTypeOfBindingElement(<BindingElement>node);
         }
 
+        function getReferenceFromExpression(node: Expression): Expression {
+            switch (node.kind) {
+                case SyntaxKind.ParenthesizedExpression:
+                    return getReferenceFromExpression((<ParenthesizedExpression>node).expression);
+                case SyntaxKind.BinaryExpression:
+                    switch ((<BinaryExpression>node).operatorToken.kind) {
+                        case SyntaxKind.EqualsToken:
+                            return getReferenceFromExpression((<BinaryExpression>node).left);
+                        case SyntaxKind.CommaToken:
+                            return getReferenceFromExpression((<BinaryExpression>node).right);
+                    }
+            }
+            return node;
+        }
+
         function getFlowTypeOfReference(reference: Node, declaredType: Type, assumeInitialized: boolean, includeOuterFunctions: boolean) {
             let key: string;
             if (!reference.flowNode || assumeInitialized && !(declaredType.flags & TypeFlags.Narrowable)) {
                 return declaredType;
             }
-            const initialType = assumeInitialized ? declaredType : addNullableKind(declaredType, TypeFlags.Undefined);
+            const initialType = assumeInitialized ? declaredType : addTypeKind(declaredType, TypeFlags.Undefined);
             const visitedFlowStart = visitedFlowCount;
             const result = getTypeAtFlowNode(reference.flowNode);
             visitedFlowCount = visitedFlowStart;
@@ -7885,7 +7908,7 @@ namespace ts {
                 if (operator === SyntaxKind.ExclamationEqualsToken || operator === SyntaxKind.ExclamationEqualsEqualsToken) {
                     assumeTrue = !assumeTrue;
                 }
-                if (!strictNullChecks || !isMatchingReference(reference, narrowed)) {
+                if (!strictNullChecks || !isMatchingReference(reference, getReferenceFromExpression(narrowed))) {
                     return type;
                 }
                 const doubleEquals = operator === SyntaxKind.EqualsEqualsToken || operator === SyntaxKind.ExclamationEqualsToken;
@@ -7900,12 +7923,12 @@ namespace ts {
             function narrowTypeByTypeof(type: Type, expr: BinaryExpression, assumeTrue: boolean): Type {
                 // We have '==', '!=', '====', or !==' operator with 'typeof xxx' on the left
                 // and string literal on the right
-                const typeOf = <TypeOfExpression>(expr.left.kind === SyntaxKind.TypeOfExpression ? expr.left : expr.right);
+                const narrowed = getReferenceFromExpression((<TypeOfExpression>(expr.left.kind === SyntaxKind.TypeOfExpression ? expr.left : expr.right)).expression);
                 const literal = <LiteralExpression>(expr.right.kind === SyntaxKind.StringLiteral ? expr.right : expr.left);
-                if (!isMatchingReference(reference, typeOf.expression)) {
+                if (!isMatchingReference(reference, narrowed)) {
                     // For a reference of the form 'x.y', a 'typeof x === ...' type guard resets the
                     // narrowed type of 'y' to its declared type.
-                    if (containsMatchingReference(reference, typeOf.expression)) {
+                    if (containsMatchingReference(reference, narrowed)) {
                         return declaredType;
                     }
                     return type;
@@ -7930,10 +7953,11 @@ namespace ts {
             }
 
             function narrowTypeByInstanceof(type: Type, expr: BinaryExpression, assumeTrue: boolean): Type {
-                if (!isMatchingReference(reference, expr.left)) {
+                const left = getReferenceFromExpression(expr.left);
+                if (!isMatchingReference(reference, left)) {
                     // For a reference of the form 'x.y', an 'x instanceof T' type guard resets the
                     // narrowed type of 'y' to its declared type.
-                    if (containsMatchingReference(reference, expr.left)) {
+                    if (containsMatchingReference(reference, left)) {
                         return declaredType;
                     }
                     return type;
@@ -8000,7 +8024,7 @@ namespace ts {
                 const targetType = type.flags & TypeFlags.TypeParameter ? getApparentType(type) : type;
                 return isTypeAssignableTo(candidate, targetType) ? candidate :
                     isTypeAssignableTo(type, candidate) ? type :
-                    neverType;
+                    getIntersectionType([type, candidate]);
             }
 
             function narrowTypeByTypePredicate(type: Type, callExpression: CallExpression, assumeTrue: boolean): Type {
@@ -8175,7 +8199,7 @@ namespace ts {
                 getRootDeclaration(declaration).kind === SyntaxKind.Parameter || isInAmbientContext(declaration) ||
                 !isDeclarationIncludedInFlow(node, declaration, includeOuterFunctions);
             const flowType = getFlowTypeOfReference(node, type, assumeInitialized, includeOuterFunctions);
-            if (!assumeInitialized && !(getNullableKind(type) & TypeFlags.Undefined) && getNullableKind(flowType) & TypeFlags.Undefined) {
+            if (!assumeInitialized && !(getCombinedTypeFlags(type) & TypeFlags.Undefined) && getCombinedTypeFlags(flowType) & TypeFlags.Undefined) {
                 error(node, Diagnostics.Variable_0_is_used_before_being_assigned, symbolToString(symbol));
                 // Return the declared type to reduce follow-on errors
                 return type;
@@ -8749,6 +8773,16 @@ namespace ts {
 
         function getContextualTypeForReturnExpression(node: Expression): Type {
             const func = getContainingFunction(node);
+
+            if (isAsyncFunctionLike(func)) {
+                const contextualReturnType = getContextualReturnType(func);
+                if (contextualReturnType) {
+                    return getPromisedType(contextualReturnType);
+                }
+
+                return undefined;
+            }
+
             if (func && !func.asteriskToken) {
                 return getContextualReturnType(func);
             }
@@ -9957,7 +9991,7 @@ namespace ts {
         function checkNonNullExpression(node: Expression | QualifiedName) {
             const type = checkExpression(node);
             if (strictNullChecks) {
-                const kind = getNullableKind(type);
+                const kind = getCombinedTypeFlags(type) & TypeFlags.Nullable;
                 if (kind) {
                     error(node, kind & TypeFlags.Undefined ? kind & TypeFlags.Null ?
                         Diagnostics.Object_is_possibly_null_or_undefined :
@@ -11491,7 +11525,7 @@ namespace ts {
             if (strictNullChecks) {
                 const declaration = symbol.valueDeclaration;
                 if (declaration && (<VariableLikeDeclaration>declaration).initializer) {
-                    return addNullableKind(type, TypeFlags.Undefined);
+                    return addTypeKind(type, TypeFlags.Undefined);
                 }
             }
             return type;
@@ -12417,7 +12451,7 @@ namespace ts {
                 case SyntaxKind.InKeyword:
                     return checkInExpression(left, right, leftType, rightType);
                 case SyntaxKind.AmpersandAmpersandToken:
-                    return strictNullChecks ? addNullableKind(rightType, getNullableKind(leftType)) : rightType;
+                    return strictNullChecks ? addTypeKind(rightType, getCombinedTypeFlags(leftType) & TypeFlags.Falsy) : rightType;
                 case SyntaxKind.BarBarToken:
                     return getUnionType([getNonNullableType(leftType), rightType]);
                 case SyntaxKind.EqualsToken:
@@ -16866,10 +16900,7 @@ namespace ts {
                         return getIntrinsicTagSymbol(<JsxOpeningLikeElement>entityName.parent);
                     }
 
-                    // Include aliases in the meaning, this ensures that we do not follow aliases to where they point and instead
-                    // return the alias symbol.
-                    const meaning: SymbolFlags = SymbolFlags.Value | SymbolFlags.Alias;
-                    return resolveEntityName(<Identifier>entityName, meaning);
+                    return resolveEntityName(<Identifier>entityName, SymbolFlags.Value, /*ignoreErrors*/ false, /*dontResolveAlias*/ true);
                 }
                 else if (entityName.kind === SyntaxKind.PropertyAccessExpression) {
                     const symbol = getNodeLinks(entityName).resolvedSymbol;
@@ -16887,11 +16918,8 @@ namespace ts {
                 }
             }
             else if (isTypeReferenceIdentifier(<EntityName>entityName)) {
-                let meaning = (entityName.parent.kind === SyntaxKind.TypeReference || entityName.parent.kind === SyntaxKind.JSDocTypeReference) ? SymbolFlags.Type : SymbolFlags.Namespace;
-                // Include aliases in the meaning, this ensures that we do not follow aliases to where they point and instead
-                // return the alias symbol.
-                meaning |= SymbolFlags.Alias;
-                return resolveEntityName(<EntityName>entityName, meaning);
+                const meaning = (entityName.parent.kind === SyntaxKind.TypeReference || entityName.parent.kind === SyntaxKind.JSDocTypeReference) ? SymbolFlags.Type : SymbolFlags.Namespace;
+                return resolveEntityName(<EntityName>entityName, meaning, /*ignoreErrors*/ false, /*dontResolveAlias*/true);
             }
             else if (entityName.parent.kind === SyntaxKind.JsxAttribute) {
                 return getJsxAttributePropertySymbol(<JsxAttribute>entityName.parent);
@@ -17635,6 +17663,10 @@ namespace ts {
                 if (!isExternalOrCommonJsModule(file)) {
                     mergeSymbolTable(globals, file.locals);
                 }
+                if (file.patternAmbientModules && file.patternAmbientModules.length) {
+                    patternAmbientModules = concatenate(patternAmbientModules, file.patternAmbientModules);
+                }
+
                 if (file.moduleAugmentations.length) {
                     (augmentations || (augmentations = [])).push(file.moduleAugmentations);
                 }
@@ -17765,6 +17797,8 @@ namespace ts {
                 case SyntaxKind.ImportEqualsDeclaration:
                 case SyntaxKind.ExportDeclaration:
                 case SyntaxKind.ExportAssignment:
+                case SyntaxKind.FunctionExpression:
+                case SyntaxKind.ArrowFunction:
                 case SyntaxKind.Parameter:
                     break;
                 case SyntaxKind.FunctionDeclaration:

src/compiler/commandLineParser.ts

@@ -6,7 +6,7 @@
 
 namespace ts {
     /* @internal */
-    export let optionDeclarations: CommandLineOption[] = [
+    export const optionDeclarations: CommandLineOption[] = [
         {
             name: "charset",
             type: "string",

src/compiler/core.ts

@@ -849,13 +849,22 @@ namespace ts {
     const extensionsToRemove = [".d.ts", ".ts", ".js", ".tsx", ".jsx"];
     export function removeFileExtension(path: string): string {
         for (const ext of extensionsToRemove) {
-            if (fileExtensionIs(path, ext)) {
-                return path.substr(0, path.length - ext.length);
+            const extensionless = tryRemoveExtension(path, ext);
+            if (extensionless !== undefined) {
+                return extensionless;
             }
         }
         return path;
     }
 
+    export function tryRemoveExtension(path: string, extension: string): string {
+        return fileExtensionIs(path, extension) ? path.substring(0, path.length - extension.length) : undefined;
+    }
+
+    export function isJsxOrTsxExtension(ext: string): boolean {
+        return ext === ".jsx" || ext === ".tsx";
+    }
+
     export interface ObjectAllocator {
         getNodeConstructor(): new (kind: SyntaxKind, pos?: number, end?: number) => Node;
         getSourceFileConstructor(): new (kind: SyntaxKind, pos?: number, end?: number) => SourceFile;

src/compiler/diagnosticMessages.json

@@ -2260,7 +2260,7 @@
         "category": "Error",
         "code": 5047
     },
-    "Option 'inlineSources' can only be used when either option '--inlineSourceMap' or option '--sourceMap' is provided.": {
+    "Option '{0} can only be used when either option '--inlineSourceMap' or option '--sourceMap' is provided.": {
         "category": "Error",
         "code": 5051
     },
@@ -2772,6 +2772,10 @@
         "category": "Error",
         "code": 6131
     },
+    "File name '{0}' has a '{1}' extension - stripping it": {
+        "category": "Message",
+        "code": 6132
+    },
 
     "Variable '{0}' implicitly has an '{1}' type.": {
         "category": "Error",

src/compiler/program.ts

@@ -95,7 +95,8 @@ namespace ts {
         return compilerOptions.traceResolution && host.trace !== undefined;
     }
 
-    function hasZeroOrOneAsteriskCharacter(str: string): boolean {
+    /* @internal */
+    export function hasZeroOrOneAsteriskCharacter(str: string): boolean {
         let seenAsterisk = false;
         for (let i = 0; i < str.length; i++) {
             if (str.charCodeAt(i) === CharacterCodes.asterisk) {
@@ -496,48 +497,23 @@ namespace ts {
             trace(state.host, Diagnostics.baseUrl_option_is_set_to_0_using_this_value_to_resolve_non_relative_module_name_1, state.compilerOptions.baseUrl, moduleName);
         }
 
-        let longestMatchPrefixLength = -1;
-        let matchedPattern: string;
-        let matchedStar: string;
-
+        // string is for exact match
+        let matchedPattern: Pattern | string | undefined = undefined;
         if (state.compilerOptions.paths) {
             if (state.traceEnabled) {
                 trace(state.host, Diagnostics.paths_option_is_specified_looking_for_a_pattern_to_match_module_name_0, moduleName);
             }
-
-            for (const key in state.compilerOptions.paths) {
-                const pattern: string = key;
-                const indexOfStar = pattern.indexOf("*");
-                if (indexOfStar !== -1) {
-                    const prefix = pattern.substr(0, indexOfStar);
-                    const suffix = pattern.substr(indexOfStar + 1);
-                    if (moduleName.length >= prefix.length + suffix.length &&
-                        startsWith(moduleName, prefix) &&
-                        endsWith(moduleName, suffix)) {
-
-                        // use length of prefix as betterness criteria
-                        if (prefix.length > longestMatchPrefixLength) {
-                            longestMatchPrefixLength = prefix.length;
-                            matchedPattern = pattern;
-                            matchedStar = moduleName.substr(prefix.length, moduleName.length - suffix.length);
-                        }
-                    }
-                }
-                else if (pattern === moduleName) {
-                    // pattern was matched as is - no need to search further
-                    matchedPattern = pattern;
-                    matchedStar = undefined;
-                    break;
-                }
-            }
+            matchedPattern = matchPatternOrExact(getKeys(state.compilerOptions.paths), moduleName);
         }
 
         if (matchedPattern) {
+            const matchedStar = typeof matchedPattern === "string" ? undefined : matchedText(matchedPattern, moduleName);
+            const matchedPatternText = typeof matchedPattern === "string" ? matchedPattern : patternText(matchedPattern);
             if (state.traceEnabled) {
-                trace(state.host, Diagnostics.Module_name_0_matched_pattern_1, moduleName, matchedPattern);
+                trace(state.host, Diagnostics.Module_name_0_matched_pattern_1, moduleName, matchedPatternText);
             }
-            for (const subst of state.compilerOptions.paths[matchedPattern]) {
-                const path = matchedStar ? subst.replace("\*", matchedStar) : subst;
+            for (const subst of state.compilerOptions.paths[matchedPatternText]) {
+                const path = matchedStar ? subst.replace("*", matchedStar) : subst;
                 const candidate = normalizePath(combinePaths(state.compilerOptions.baseUrl, path));
                 if (state.traceEnabled) {
                     trace(state.host, Diagnostics.Trying_substitution_0_candidate_module_location_Colon_1, subst, path);
@@ -560,6 +536,75 @@ namespace ts {
         }
     }
 
+    /**
+     * patternStrings contains both pattern strings (containing "*") and regular strings.
+     * Return an exact match if possible, or a pattern match, or undefined.
+     * (These are verified by verifyCompilerOptions to have 0 or 1 "*" characters.)
+     */
+    function matchPatternOrExact(patternStrings: string[], candidate: string): string | Pattern | undefined {
+        const patterns: Pattern[] = [];
+        for (const patternString of patternStrings) {
+            const pattern = tryParsePattern(patternString);
+            if (pattern) {
+                patterns.push(pattern);
+            }
+            else if (patternString === candidate) {
+                // pattern was matched as is - no need to search further
+                return patternString;
+            }
+        }
+
+        return findBestPatternMatch(patterns, _ => _, candidate);
+    }
+
+    function patternText({prefix, suffix}: Pattern): string {
+        return `${prefix}*${suffix}`;
+    }
+
+    /**
+     * Given that candidate matches pattern, returns the text matching the '*'.
+     * E.g.: matchedText(tryParsePattern("foo*baz"), "foobarbaz") === "bar"
+     */
+    function matchedText(pattern: Pattern, candidate: string): string {
+        Debug.assert(isPatternMatch(pattern, candidate));
+        return candidate.substr(pattern.prefix.length, candidate.length - pattern.suffix.length);
+    }
+
+    /** Return the object corresponding to the best pattern to match `candidate`. */
+    /* @internal */
+    export function findBestPatternMatch<T>(values: T[], getPattern: (value: T) => Pattern, candidate: string): T | undefined {
+        let matchedValue: T | undefined = undefined;
+        // use length of prefix as betterness criteria
+        let longestMatchPrefixLength = -1;
+
+        for (const v of values) {
+            const pattern = getPattern(v);
+            if (isPatternMatch(pattern, candidate) && pattern.prefix.length > longestMatchPrefixLength) {
+                longestMatchPrefixLength = pattern.prefix.length;
+                matchedValue = v;
+            }
+        }
+
+        return matchedValue;
+    }
+
+    function isPatternMatch({prefix, suffix}: Pattern, candidate: string) {
+        return candidate.length >= prefix.length + suffix.length &&
+               startsWith(candidate, prefix) &&
+               endsWith(candidate, suffix);
+    }
+
+    /* @internal */
+    export function tryParsePattern(pattern: string): Pattern | undefined {
+        // This should be verified outside of here and a proper error thrown.
+        Debug.assert(hasZeroOrOneAsteriskCharacter(pattern));
+        const indexOfStar = pattern.indexOf("*");
+        return indexOfStar === -1 ? undefined : {
+            prefix: pattern.substr(0, indexOfStar),
+            suffix: pattern.substr(indexOfStar + 1)
+        };
+    }
+
     export function nodeModuleNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost): ResolvedModuleWithFailedLookupLocations {
         const containingDirectory = getDirectoryPath(containingFile);
         const supportedExtensions = getSupportedExtensions(compilerOptions);
@@ -619,8 +664,25 @@ namespace ts {
      * in cases when we know upfront that all load attempts will fail (because containing folder does not exists) however we still need to record all failed lookup locations.
      */
     function loadModuleFromFile(candidate: string, extensions: string[], failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): string {
+        // First try to keep/add an extension: importing "./foo.ts" can be matched by a file "./foo.ts", and "./foo" by "./foo.d.ts"
+        const resolvedByAddingOrKeepingExtension = loadModuleFromFileWorker(candidate, extensions, failedLookupLocation, onlyRecordFailures, state);
+        if (resolvedByAddingOrKeepingExtension) {
+            return resolvedByAddingOrKeepingExtension;
+        }
+        // Then try stripping a ".js" or ".jsx" extension and replacing it with a TypeScript one, e.g. "./foo.js" can be matched by "./foo.ts" or "./foo.d.ts"
+        if (hasJavaScriptFileExtension(candidate)) {
+            const extensionless = removeFileExtension(candidate);
+            if (state.traceEnabled) {
+                const extension = candidate.substring(extensionless.length);
+                trace(state.host, Diagnostics.File_name_0_has_a_1_extension_stripping_it, candidate, extension);
+            }
+            return loadModuleFromFileWorker(extensionless, extensions, failedLookupLocation, onlyRecordFailures, state);
+        }
+    }
+
+    function loadModuleFromFileWorker(candidate: string, extensions: string[], failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): string {
         if (!onlyRecordFailures) {
-            // check if containig folder exists - if it doesn't then just record failures for all supported extensions without disk probing
+            // check if containing folder exists - if it doesn't then just record failures for all supported extensions without disk probing
             const directory = getDirectoryPath(candidate);
             if (directory) {
                 onlyRecordFailures = !directoryProbablyExists(directory, state.host);
@@ -629,7 +691,7 @@ namespace ts {
         return forEach(extensions, tryLoad);
 
         function tryLoad(ext: string): string {
-            if (ext === ".tsx" && state.skipTsx) {
+            if (state.skipTsx && isJsxOrTsxExtension(ext)) {
                 return undefined;
             }
             const fileName = fileExtensionIs(candidate, ext) ? candidate : candidate + ext;
@@ -2043,12 +2105,12 @@ namespace ts {
                 }
             }
 
-            if (options.inlineSources) {
-                if (!options.sourceMap && !options.inlineSourceMap) {
-                    programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_inlineSources_can_only_be_used_when_either_option_inlineSourceMap_or_option_sourceMap_is_provided));
+            if (!options.sourceMap && !options.inlineSourceMap) {
+                if (options.inlineSources) {
+                    programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_can_only_be_used_when_either_option_inlineSourceMap_or_option_sourceMap_is_provided, "inlineSources"));
                 }
                 if (options.sourceRoot) {
-                    programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_with_option_1, "sourceRoot", "inlineSources"));
+                    programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_can_only_be_used_when_either_option_inlineSourceMap_or_option_sourceMap_is_provided, "sourceRoot"));
                 }
             }
 
@@ -2056,14 +2118,9 @@ namespace ts {
                 programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_with_option_1, "out", "outFile"));
             }
 
-            if (!options.sourceMap && (options.mapRoot || options.sourceRoot)) {
-                // Error to specify --mapRoot or --sourceRoot without mapSourceFiles
-                if (options.mapRoot) {
-                    programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_without_specifying_option_1, "mapRoot", "sourceMap"));
-                }
-                if (options.sourceRoot && !options.inlineSourceMap) {
-                    programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_without_specifying_option_1, "sourceRoot", "sourceMap"));
-                }
+            if (options.mapRoot && !options.sourceMap) {
+                // Error to specify --mapRoot without --sourcemap
+                programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_without_specifying_option_1, "mapRoot", "sourceMap"));
             }
 
             if (options.declarationDir) {

src/compiler/types.ts

@@ -1658,6 +1658,7 @@ namespace ts {
         /* @internal */ resolvedTypeReferenceDirectiveNames: Map<ResolvedTypeReferenceDirective>;
         /* @internal */ imports: LiteralExpression[];
         /* @internal */ moduleAugmentations: LiteralExpression[];
+        /* @internal */ patternAmbientModules?: PatternAmbientModule[];
     }
 
     export interface ScriptReferenceHost {
@@ -2135,6 +2136,20 @@ namespace ts {
         [index: string]: Symbol;
     }
 
+    /** Represents a "prefix*suffix" pattern. */
+    /* @internal */
+    export interface Pattern {
+        prefix: string;
+        suffix: string;
+    }
+
+    /** Used to track a `declare module "foo*"`-like declaration. */
+    /* @internal */
+    export interface PatternAmbientModule {
+        pattern: Pattern;
+        symbol: Symbol;
+    }
+
     /* @internal */
     export const enum NodeCheckFlags {
         TypeChecked                         = 0x00000001,  // Node has been type checked
@@ -2209,6 +2224,7 @@ namespace ts {
 
         /* @internal */
         Nullable = Undefined | Null,
+        Falsy = String | Number | Boolean | Void | Undefined | Null,
         /* @internal */
         Intrinsic = Any | String | Number | Boolean | ESSymbol | Void | Undefined | Null | Never,
         /* @internal */

src/harness/harness.ts

@@ -1692,6 +1692,3 @@ namespace Harness {
 
     if (Error) (<any>Error).stackTraceLimit = 1;
 }
-
-// TODO: not sure why Utils.evalFile isn't working with this, eventually will concat it like old compiler instead of eval
-eval(Harness.tcServicesFile);

src/server/session.ts

@@ -1207,7 +1207,11 @@ namespace ts.server {
                     // Handle cancellation exceptions
                 }
                 this.logError(err, message);
-                this.output(undefined, request ? request.command : CommandNames.Unknown, request ? request.seq : 0, "Error processing request. " + err.message);
+                this.output(
+                    undefined,
+                    request ? request.command : CommandNames.Unknown,
+                    request ? request.seq : 0,
+                    "Error processing request. " + (<StackTraceError>err).message + "\n" + (<StackTraceError>err).stack);
             }
         }
     }

src/services/breakpoints.ts

@@ -722,5 +722,5 @@ namespace ts.BreakpointResolver {
                 return spanInNode(node.parent);
             }
         }
-   }
+    }
 }

src/services/services.ts

@@ -1064,10 +1064,10 @@ namespace ts {
         getCancellationToken?(): HostCancellationToken;
         getCurrentDirectory(): string;
         getDefaultLibFileName(options: CompilerOptions): string;
-        log? (s: string): void;
-        trace? (s: string): void;
-        error? (s: string): void;
-        useCaseSensitiveFileNames? (): boolean;
+        log?(s: string): void;
+        trace?(s: string): void;
+        error?(s: string): void;
+        useCaseSensitiveFileNames?(): boolean;
 
         /*
          * LS host can optionally implement this method if it wants to be completely in charge of module name resolution.
@@ -1939,6 +1939,40 @@ namespace ts {
         sourceMapText?: string;
     }
 
+
+
+    let commandLineOptions_stringToEnum: CommandLineOptionOfCustomType[];
+
+    /** JS users may pass in string values for enum compiler options (such as ModuleKind), so convert. */
+    function fixupCompilerOptions(options: CompilerOptions, diagnostics: Diagnostic[]): CompilerOptions {
+        // Lazily create this value to fix module loading errors.
+        commandLineOptions_stringToEnum = commandLineOptions_stringToEnum || <CommandLineOptionOfCustomType[]>filter(optionDeclarations, o =>
+            typeof o.type === "object" && !forEachValue(<Map<any>> o.type, v => typeof v !== "number"));
+
+        options = clone(options);
+
+        for (const opt of commandLineOptions_stringToEnum) {
+            if (!hasProperty(options, opt.name)) {
+                continue;
+            }
+
+            const value = options[opt.name];
+            // Value should be a key of opt.type
+            if (typeof value === "string") {
+                // If value is not a string, this will fail
+                options[opt.name] = parseCustomTypeOption(opt, value, diagnostics);
+            }
+            else {
+                if (!forEachValue(opt.type, v => v === value)) {
+                    // Supplied value isn't a valid enum value.
+                    diagnostics.push(createCompilerDiagnosticForInvalidCustomType(opt));
+                }
+            }
+        }
+
+        return options;
+    }
+
     /*
      * This function will compile source text from 'input' argument using specified compiler options.
      * If not options are provided - it will use a set of default compiler options.
@@ -1949,7 +1983,9 @@ namespace ts {
      * - noResolve = true
      */
     export function transpileModule(input: string, transpileOptions: TranspileOptions): TranspileOutput {
-        const options = transpileOptions.compilerOptions ? clone(transpileOptions.compilerOptions) : getDefaultCompilerOptions();
+        const diagnostics: Diagnostic[] = [];
+
+        const options: CompilerOptions = transpileOptions.compilerOptions ? fixupCompilerOptions(transpileOptions.compilerOptions, diagnostics) : getDefaultCompilerOptions();
 
         options.isolatedModules = true;
 
@@ -2007,9 +2043,7 @@ namespace ts {
 
         const program = createProgram([inputFileName], options, compilerHost);
 
-        let diagnostics: Diagnostic[];
         if (transpileOptions.reportDiagnostics) {
-            diagnostics = [];
             addRange(/*to*/ diagnostics, /*from*/ program.getSyntacticDiagnostics(sourceFile));
             addRange(/*to*/ diagnostics, /*from*/ program.getOptionsDiagnostics());
         }
@@ -2499,7 +2533,7 @@ namespace ts {
                 }
 
                 // should be start of dependency list
-                if (token !== SyntaxKind.OpenBracketToken)  {
+                if (token !== SyntaxKind.OpenBracketToken) {
                     return true;
                 }
 
@@ -4032,10 +4066,15 @@ namespace ts {
             }
         }
 
-
         function getCompletionsAtPosition(fileName: string, position: number): CompletionInfo {
             synchronizeHostData();
 
+            const sourceFile = getValidSourceFile(fileName);
+
+            if (isInString(sourceFile, position)) {
+                return getStringLiteralCompletionEntries(sourceFile, position);
+            }
+
             const completionData = getCompletionData(fileName, position);
             if (!completionData) {
                 return undefined;
@@ -4048,12 +4087,10 @@ namespace ts {
                 return { isMemberCompletion: false, isNewIdentifierLocation: false, entries: getAllJsDocCompletionEntries() };
             }
 
-            const sourceFile = getValidSourceFile(fileName);
-
             const entries: CompletionEntry[] = [];
 
             if (isSourceFileJavaScript(sourceFile)) {
-                const uniqueNames = getCompletionEntriesFromSymbols(symbols, entries);
+                const uniqueNames = getCompletionEntriesFromSymbols(symbols, entries, location, /*performCharacterChecks*/ false);
                 addRange(entries, getJavaScriptCompletionEntries(sourceFile, location.pos, uniqueNames));
             }
             else {
@@ -4077,7 +4114,7 @@ namespace ts {
                     }
                 }
 
-                getCompletionEntriesFromSymbols(symbols, entries);
+                getCompletionEntriesFromSymbols(symbols, entries, location, /*performCharacterChecks*/ true);
             }
 
             // Add keywords if this is not a member completion list
@@ -4127,11 +4164,11 @@ namespace ts {
                 }));
             }
 
-            function createCompletionEntry(symbol: Symbol, location: Node): CompletionEntry {
+            function createCompletionEntry(symbol: Symbol, location: Node, performCharacterChecks: boolean): CompletionEntry {
                 // Try to get a valid display name for this symbol, if we could not find one, then ignore it.
                 // We would like to only show things that can be added after a dot, so for instance numeric properties can
                 // not be accessed with a dot (a.1 <- invalid)
-                const displayName = getCompletionEntryDisplayNameForSymbol(symbol, program.getCompilerOptions().target, /*performCharacterChecks*/ true, location);
+                const displayName = getCompletionEntryDisplayNameForSymbol(symbol, program.getCompilerOptions().target, performCharacterChecks, location);
                 if (!displayName) {
                     return undefined;
                 }
@@ -4152,12 +4189,12 @@ namespace ts {
                 };
             }
 
-            function getCompletionEntriesFromSymbols(symbols: Symbol[], entries: CompletionEntry[]): Map<string> {
+            function getCompletionEntriesFromSymbols(symbols: Symbol[], entries: CompletionEntry[], location: Node, performCharacterChecks: boolean): Map<string> {
                 const start = new Date().getTime();
                 const uniqueNames: Map<string> = {};
                 if (symbols) {
                     for (const symbol of symbols) {
-                        const entry = createCompletionEntry(symbol, location);
+                        const entry = createCompletionEntry(symbol, location, performCharacterChecks);
                         if (entry) {
                             const id = escapeIdentifier(entry.name);
                             if (!lookUp(uniqueNames, id)) {
@@ -4171,6 +4208,93 @@ namespace ts {
                 log("getCompletionsAtPosition: getCompletionEntriesFromSymbols: " + (new Date().getTime() - start));
                 return uniqueNames;
             }
+
+            function getStringLiteralCompletionEntries(sourceFile: SourceFile, position: number) {
+                const node = findPrecedingToken(position, sourceFile);
+                if (!node || node.kind !== SyntaxKind.StringLiteral) {
+                    return undefined;
+                }
+
+                const argumentInfo = SignatureHelp.getContainingArgumentInfo(node, position, sourceFile);
+                if (argumentInfo) {
+                    // Get string literal completions from specialized signatures of the target
+                    return getStringLiteralCompletionEntriesFromCallExpression(argumentInfo);
+                }
+                else if (isElementAccessExpression(node.parent) && node.parent.argumentExpression === node) {
+                    // Get all names of properties on the expression
+                    return getStringLiteralCompletionEntriesFromElementAccess(node.parent);
+                }
+                else {
+                    // Otherwise, get the completions from the contextual type if one exists
+                    return getStringLiteralCompletionEntriesFromContextualType(<StringLiteral>node);
+                }
+            }
+
+            function getStringLiteralCompletionEntriesFromCallExpression(argumentInfo: SignatureHelp.ArgumentListInfo) {
+                const typeChecker = program.getTypeChecker();
+                const candidates: Signature[] = [];
+                const entries: CompletionEntry[] = [];
+
+                typeChecker.getResolvedSignature(argumentInfo.invocation, candidates);
+
+                for (const candidate of candidates) {
+                    if (candidate.parameters.length > argumentInfo.argumentIndex) {
+                        const parameter = candidate.parameters[argumentInfo.argumentIndex];
+                        addStringLiteralCompletionsFromType(typeChecker.getTypeAtLocation(parameter.valueDeclaration), entries);
+                    }
+                }
+
+                if (entries.length) {
+                    return { isMemberCompletion: false, isNewIdentifierLocation: true, entries };
+                }
+
+                return undefined;
+            }
+
+            function getStringLiteralCompletionEntriesFromElementAccess(node: ElementAccessExpression) {
+                const typeChecker = program.getTypeChecker();
+                const type = typeChecker.getTypeAtLocation(node.expression);
+                const entries: CompletionEntry[] = [];
+                if (type) {
+                    getCompletionEntriesFromSymbols(type.getApparentProperties(), entries, node, /*performCharacterChecks*/false);
+                    if (entries.length) {
+                        return { isMemberCompletion: true, isNewIdentifierLocation: true, entries };
+                    }
+                }
+                return undefined;
+            }
+
+            function getStringLiteralCompletionEntriesFromContextualType(node: StringLiteral) {
+                const typeChecker = program.getTypeChecker();
+                const type = typeChecker.getContextualType(node);
+                if (type) {
+                    const entries: CompletionEntry[] = [];
+                    addStringLiteralCompletionsFromType(type, entries);
+                    if (entries.length) {
+                        return { isMemberCompletion: false, isNewIdentifierLocation: false, entries };
+                    }
+                }
+                return undefined;
+            }
+
+            function addStringLiteralCompletionsFromType(type: Type, result: CompletionEntry[]): void {
+                if (!type) {
+                    return;
+                }
+                if (type.flags & TypeFlags.Union) {
+                    forEach((<UnionType>type).types, t => addStringLiteralCompletionsFromType(t, result));
+                }
+                else {
+                    if (type.flags & TypeFlags.StringLiteral) {
+                        result.push({
+                            name: (<StringLiteralType>type).text,
+                            kindModifiers: ScriptElementKindModifier.none,
+                            kind: ScriptElementKind.variableElement,
+                            sortText: "0"
+                        });
+                    }
+                }
+            }
         }
 
         function getCompletionEntryDetails(fileName: string, position: number, entryName: string): CompletionEntryDetails {
@@ -4335,7 +4459,7 @@ namespace ts {
                     // try get the call/construct signature from the type if it matches
                     let callExpression: CallExpression;
                     if (location.kind === SyntaxKind.CallExpression || location.kind === SyntaxKind.NewExpression) {
-                        callExpression = <CallExpression> location;
+                        callExpression = <CallExpression>location;
                     }
                     else if (isCallExpressionTarget(location) || isNewExpressionTarget(location)) {
                         callExpression = <CallExpression>location.parent;

src/services/signatureHelp.ts

@@ -162,15 +162,16 @@ namespace ts.SignatureHelp {
     //    // Did not find matching token
     //    return null;
     // }
+
     const emptyArray: any[] = [];
 
-    const enum ArgumentListKind {
+    export const enum ArgumentListKind {
         TypeArguments,
         CallArguments,
         TaggedTemplateArguments
     }
 
-    interface ArgumentListInfo {
+    export interface ArgumentListInfo {
         kind: ArgumentListKind;
         invocation: CallLikeExpression;
         argumentsSpan: TextSpan;
@@ -188,7 +189,8 @@ namespace ts.SignatureHelp {
             return undefined;
         }
 
-        const argumentInfo = getContainingArgumentInfo(startingToken);
+        const argumentInfo = getContainingArgumentInfo(startingToken, position, sourceFile);
+
         cancellationToken.throwIfCancellationRequested();
 
         // Semantic filtering of signature help
@@ -205,431 +207,432 @@ namespace ts.SignatureHelp {
             // We didn't have any sig help items produced by the TS compiler.  If this is a JS
             // file, then see if we can figure out anything better.
             if (isSourceFileJavaScript(sourceFile)) {
-                return createJavaScriptSignatureHelpItems(argumentInfo);
+                return createJavaScriptSignatureHelpItems(argumentInfo, program);
             }
 
             return undefined;
         }
 
-        return createSignatureHelpItems(candidates, resolvedSignature, argumentInfo);
+        return createSignatureHelpItems(candidates, resolvedSignature, argumentInfo, typeChecker);
+    }
 
-        function createJavaScriptSignatureHelpItems(argumentInfo: ArgumentListInfo): SignatureHelpItems {
-            if (argumentInfo.invocation.kind !== SyntaxKind.CallExpression) {
-                return undefined;
-            }
+    function createJavaScriptSignatureHelpItems(argumentInfo: ArgumentListInfo, program: Program): SignatureHelpItems {
+        if (argumentInfo.invocation.kind !== SyntaxKind.CallExpression) {
+            return undefined;
+        }
 
-            // See if we can find some symbol with the call expression name that has call signatures.
-            const callExpression = <CallExpression>argumentInfo.invocation;
-            const expression = callExpression.expression;
-            const name = expression.kind === SyntaxKind.Identifier
-                ? <Identifier> expression
-                : expression.kind === SyntaxKind.PropertyAccessExpression
-                    ? (<PropertyAccessExpression>expression).name
-                    : undefined;
+        // See if we can find some symbol with the call expression name that has call signatures.
+        const callExpression = <CallExpression>argumentInfo.invocation;
+        const expression = callExpression.expression;
+        const name = expression.kind === SyntaxKind.Identifier
+            ? <Identifier>expression
+            : expression.kind === SyntaxKind.PropertyAccessExpression
+                ? (<PropertyAccessExpression>expression).name
+                : undefined;
 
-            if (!name || !name.text) {
-                return undefined;
-            }
+        if (!name || !name.text) {
+            return undefined;
+        }
 
-            const typeChecker = program.getTypeChecker();
-            for (const sourceFile of program.getSourceFiles()) {
-                const nameToDeclarations = sourceFile.getNamedDeclarations();
-                const declarations = getProperty(nameToDeclarations, name.text);
+        const typeChecker = program.getTypeChecker();
+        for (const sourceFile of program.getSourceFiles()) {
+            const nameToDeclarations = sourceFile.getNamedDeclarations();
+            const declarations = getProperty(nameToDeclarations, name.text);
 
-                if (declarations) {
-                    for (const declaration of declarations) {
-                        const symbol = declaration.symbol;
-                        if (symbol) {
-                            const type = typeChecker.getTypeOfSymbolAtLocation(symbol, declaration);
-                            if (type) {
-                                const callSignatures = type.getCallSignatures();
-                                if (callSignatures && callSignatures.length) {
-                                    return createSignatureHelpItems(callSignatures, callSignatures[0], argumentInfo);
-                                }
+            if (declarations) {
+                for (const declaration of declarations) {
+                    const symbol = declaration.symbol;
+                    if (symbol) {
+                        const type = typeChecker.getTypeOfSymbolAtLocation(symbol, declaration);
+                        if (type) {
+                            const callSignatures = type.getCallSignatures();
+                            if (callSignatures && callSignatures.length) {
+                                return createSignatureHelpItems(callSignatures, callSignatures[0], argumentInfo, typeChecker);
                             }
                         }
                     }
                 }
             }
         }
+    }
 
-        /**
-         * Returns relevant information for the argument list and the current argument if we are
-         * in the argument of an invocation; returns undefined otherwise.
-         */
-        function getImmediatelyContainingArgumentInfo(node: Node): ArgumentListInfo {
-            if (node.parent.kind === SyntaxKind.CallExpression || node.parent.kind === SyntaxKind.NewExpression) {
-                const callExpression = <CallExpression>node.parent;
-                // There are 3 cases to handle:
-                //   1. The token introduces a list, and should begin a sig help session
-                //   2. The token is either not associated with a list, or ends a list, so the session should end
-                //   3. The token is buried inside a list, and should give sig help
-                //
-                // The following are examples of each:
-                //
-                //    Case 1:
-                //          foo<#T, U>(#a, b)    -> The token introduces a list, and should begin a sig help session
-                //    Case 2:
-                //          fo#o<T, U>#(a, b)#   -> The token is either not associated with a list, or ends a list, so the session should end
-                //    Case 3:
-                //          foo<T#, U#>(a#, #b#) -> The token is buried inside a list, and should give sig help
-                // Find out if 'node' is an argument, a type argument, or neither
-                if (node.kind === SyntaxKind.LessThanToken ||
-                    node.kind === SyntaxKind.OpenParenToken) {
-                    // Find the list that starts right *after* the < or ( token.
-                    // If the user has just opened a list, consider this item 0.
-                    const list = getChildListThatStartsWithOpenerToken(callExpression, node, sourceFile);
-                    const isTypeArgList = callExpression.typeArguments && callExpression.typeArguments.pos === list.pos;
-                    Debug.assert(list !== undefined);
-                    return {
-                        kind: isTypeArgList ? ArgumentListKind.TypeArguments : ArgumentListKind.CallArguments,
-                        invocation: callExpression,
-                        argumentsSpan: getApplicableSpanForArguments(list),
-                        argumentIndex: 0,
-                        argumentCount: getArgumentCount(list)
-                    };
-                }
-
-                // findListItemInfo can return undefined if we are not in parent's argument list
-                // or type argument list. This includes cases where the cursor is:
-                //   - To the right of the closing paren, non-substitution template, or template tail.
-                //   - Between the type arguments and the arguments (greater than token)
-                //   - On the target of the call (parent.func)
-                //   - On the 'new' keyword in a 'new' expression
-                const listItemInfo = findListItemInfo(node);
-                if (listItemInfo) {
-                    const list = listItemInfo.list;
-                    const isTypeArgList = callExpression.typeArguments && callExpression.typeArguments.pos === list.pos;
-
-                    const argumentIndex = getArgumentIndex(list, node);
-                    const argumentCount = getArgumentCount(list);
-
-                    Debug.assert(argumentIndex === 0 || argumentIndex < argumentCount,
-                        `argumentCount < argumentIndex, ${argumentCount} < ${argumentIndex}`);
-
-                    return {
-                        kind: isTypeArgList ? ArgumentListKind.TypeArguments : ArgumentListKind.CallArguments,
-                        invocation: callExpression,
-                        argumentsSpan: getApplicableSpanForArguments(list),
-                        argumentIndex: argumentIndex,
-                        argumentCount: argumentCount
-                    };
-                }
-            }
-            else if (node.kind === SyntaxKind.NoSubstitutionTemplateLiteral && node.parent.kind === SyntaxKind.TaggedTemplateExpression) {
-                // Check if we're actually inside the template;
-                // otherwise we'll fall out and return undefined.
-                if (isInsideTemplateLiteral(<LiteralExpression>node, position)) {
-                    return getArgumentListInfoForTemplate(<TaggedTemplateExpression>node.parent, /*argumentIndex*/ 0);
-                }
-            }
-            else if (node.kind === SyntaxKind.TemplateHead && node.parent.parent.kind === SyntaxKind.TaggedTemplateExpression) {
-                const templateExpression = <TemplateExpression>node.parent;
-                const tagExpression = <TaggedTemplateExpression>templateExpression.parent;
-                Debug.assert(templateExpression.kind === SyntaxKind.TemplateExpression);
-
-                const argumentIndex = isInsideTemplateLiteral(<LiteralExpression>node, position) ? 0 : 1;
-
-                return getArgumentListInfoForTemplate(tagExpression, argumentIndex);
-            }
-            else if (node.parent.kind === SyntaxKind.TemplateSpan && node.parent.parent.parent.kind === SyntaxKind.TaggedTemplateExpression) {
-                const templateSpan = <TemplateSpan>node.parent;
-                const templateExpression = <TemplateExpression>templateSpan.parent;
-                const tagExpression = <TaggedTemplateExpression>templateExpression.parent;
-                Debug.assert(templateExpression.kind === SyntaxKind.TemplateExpression);
-
-                // If we're just after a template tail, don't show signature help.
-                if (node.kind === SyntaxKind.TemplateTail && !isInsideTemplateLiteral(<LiteralExpression>node, position)) {
-                    return undefined;
-                }
-
-                const spanIndex = templateExpression.templateSpans.indexOf(templateSpan);
-                const argumentIndex = getArgumentIndexForTemplatePiece(spanIndex, node);
-
-                return getArgumentListInfoForTemplate(tagExpression, argumentIndex);
-            }
-
-            return undefined;
-        }
-
-        function getArgumentIndex(argumentsList: Node, node: Node) {
-            // The list we got back can include commas.  In the presence of errors it may
-            // also just have nodes without commas.  For example "Foo(a b c)" will have 3
-            // args without commas.   We want to find what index we're at.  So we count
-            // forward until we hit ourselves, only incrementing the index if it isn't a
-            // comma.
+    /**
+     * Returns relevant information for the argument list and the current argument if we are
+     * in the argument of an invocation; returns undefined otherwise.
+     */
+    function getImmediatelyContainingArgumentInfo(node: Node, position: number, sourceFile: SourceFile): ArgumentListInfo {
+        if (node.parent.kind === SyntaxKind.CallExpression || node.parent.kind === SyntaxKind.NewExpression) {
+            const callExpression = <CallExpression>node.parent;
+            // There are 3 cases to handle:
+            //   1. The token introduces a list, and should begin a sig help session
+            //   2. The token is either not associated with a list, or ends a list, so the session should end
+            //   3. The token is buried inside a list, and should give sig help
             //
-            // Note: the subtlety around trailing commas (in getArgumentCount) does not apply
-            // here.  That's because we're only walking forward until we hit the node we're
-            // on.  In that case, even if we're after the trailing comma, we'll still see
-            // that trailing comma in the list, and we'll have generated the appropriate
-            // arg index.
-            let argumentIndex = 0;
-            const listChildren = argumentsList.getChildren();
-            for (const child of listChildren) {
-                if (child === node) {
-                    break;
-                }
-                if (child.kind !== SyntaxKind.CommaToken) {
-                    argumentIndex++;
-                }
+            // The following are examples of each:
+            //
+            //    Case 1:
+            //          foo<#T, U>(#a, b)    -> The token introduces a list, and should begin a sig help session
+            //    Case 2:
+            //          fo#o<T, U>#(a, b)#   -> The token is either not associated with a list, or ends a list, so the session should end
+            //    Case 3:
+            //          foo<T#, U#>(a#, #b#) -> The token is buried inside a list, and should give sig help
+            // Find out if 'node' is an argument, a type argument, or neither
+            if (node.kind === SyntaxKind.LessThanToken ||
+                node.kind === SyntaxKind.OpenParenToken) {
+                // Find the list that starts right *after* the < or ( token.
+                // If the user has just opened a list, consider this item 0.
+                const list = getChildListThatStartsWithOpenerToken(callExpression, node, sourceFile);
+                const isTypeArgList = callExpression.typeArguments && callExpression.typeArguments.pos === list.pos;
+                Debug.assert(list !== undefined);
+                return {
+                    kind: isTypeArgList ? ArgumentListKind.TypeArguments : ArgumentListKind.CallArguments,
+                    invocation: callExpression,
+                    argumentsSpan: getApplicableSpanForArguments(list, sourceFile),
+                    argumentIndex: 0,
+                    argumentCount: getArgumentCount(list)
+                };
             }
 
-            return argumentIndex;
-        }
+            // findListItemInfo can return undefined if we are not in parent's argument list
+            // or type argument list. This includes cases where the cursor is:
+            //   - To the right of the closing paren, non-substitution template, or template tail.
+            //   - Between the type arguments and the arguments (greater than token)
+            //   - On the target of the call (parent.func)
+            //   - On the 'new' keyword in a 'new' expression
+            const listItemInfo = findListItemInfo(node);
+            if (listItemInfo) {
+                const list = listItemInfo.list;
+                const isTypeArgList = callExpression.typeArguments && callExpression.typeArguments.pos === list.pos;
 
-        function getArgumentCount(argumentsList: Node) {
-            // The argument count for a list is normally the number of non-comma children it has.
-            // For example, if you have "Foo(a,b)" then there will be three children of the arg
-            // list 'a' '<comma>' 'b'.  So, in this case the arg count will be 2.  However, there
-            // is a small subtlety.  If you have  "Foo(a,)", then the child list will just have
-            // 'a' '<comma>'.  So, in the case where the last child is a comma, we increase the
-            // arg count by one to compensate.
-            //
-            // Note: this subtlety only applies to the last comma.  If you had "Foo(a,,"  then
-            // we'll have:  'a' '<comma>' '<missing>'
-            // That will give us 2 non-commas.  We then add one for the last comma, givin us an
-            // arg count of 3.
-            const listChildren = argumentsList.getChildren();
+                const argumentIndex = getArgumentIndex(list, node);
+                const argumentCount = getArgumentCount(list);
 
-            let argumentCount = countWhere(listChildren, arg => arg.kind !== SyntaxKind.CommaToken);
-            if (listChildren.length > 0 && lastOrUndefined(listChildren).kind === SyntaxKind.CommaToken) {
-                argumentCount++;
-            }
+                Debug.assert(argumentIndex === 0 || argumentIndex < argumentCount,
+                    `argumentCount < argumentIndex, ${argumentCount} < ${argumentIndex}`);
 
-            return argumentCount;
-        }
-
-        // spanIndex is either the index for a given template span.
-        // This does not give appropriate results for a NoSubstitutionTemplateLiteral
-        function getArgumentIndexForTemplatePiece(spanIndex: number, node: Node): number {
-            // Because the TemplateStringsArray is the first argument, we have to offset each substitution expression by 1.
-            // There are three cases we can encounter:
-            //      1. We are precisely in the template literal (argIndex = 0).
-            //      2. We are in or to the right of the substitution expression (argIndex = spanIndex + 1).
-            //      3. We are directly to the right of the template literal, but because we look for the token on the left,
-            //          not enough to put us in the substitution expression; we should consider ourselves part of
-            //          the *next* span's expression by offsetting the index (argIndex = (spanIndex + 1) + 1).
-            //
-            // Example: f  `# abcd $#{#  1 + 1#  }# efghi ${ #"#hello"#  }  #  `
-            //              ^       ^ ^       ^   ^          ^ ^      ^     ^
-            // Case:        1       1 3       2   1          3 2      2     1
-            Debug.assert(position >= node.getStart(), "Assumed 'position' could not occur before node.");
-            if (isTemplateLiteralKind(node.kind)) {
-                if (isInsideTemplateLiteral(<LiteralExpression>node, position)) {
-                    return 0;
-                }
-                return spanIndex + 2;
-            }
-            return spanIndex + 1;
-        }
-
-        function getArgumentListInfoForTemplate(tagExpression: TaggedTemplateExpression, argumentIndex: number): ArgumentListInfo {
-            // argumentCount is either 1 or (numSpans + 1) to account for the template strings array argument.
-            const argumentCount = tagExpression.template.kind === SyntaxKind.NoSubstitutionTemplateLiteral
-                ? 1
-                : (<TemplateExpression>tagExpression.template).templateSpans.length + 1;
-
-            Debug.assert(argumentIndex === 0 || argumentIndex < argumentCount, `argumentCount < argumentIndex, ${argumentCount} < ${argumentIndex}`);
-
-            return {
-                kind: ArgumentListKind.TaggedTemplateArguments,
-                invocation: tagExpression,
-                argumentsSpan: getApplicableSpanForTaggedTemplate(tagExpression),
-                argumentIndex: argumentIndex,
-                argumentCount: argumentCount
-            };
-        }
-
-        function getApplicableSpanForArguments(argumentsList: Node): TextSpan {
-            // We use full start and skip trivia on the end because we want to include trivia on
-            // both sides. For example,
-            //
-            //    foo(   /*comment */     a, b, c      /*comment*/     )
-            //        |                                               |
-            //
-            // The applicable span is from the first bar to the second bar (inclusive,
-            // but not including parentheses)
-            const applicableSpanStart = argumentsList.getFullStart();
-            const applicableSpanEnd = skipTrivia(sourceFile.text, argumentsList.getEnd(), /*stopAfterLineBreak*/ false);
-            return createTextSpan(applicableSpanStart, applicableSpanEnd - applicableSpanStart);
-        }
-
-        function getApplicableSpanForTaggedTemplate(taggedTemplate: TaggedTemplateExpression): TextSpan {
-            const template = taggedTemplate.template;
-            const applicableSpanStart = template.getStart();
-            let applicableSpanEnd = template.getEnd();
-
-            // We need to adjust the end position for the case where the template does not have a tail.
-            // Otherwise, we will not show signature help past the expression.
-            // For example,
-            //
-            //      `  ${ 1 + 1        foo(10)
-            //       |        |
-            //
-            // This is because a Missing node has no width. However, what we actually want is to include trivia
-            // leading up to the next token in case the user is about to type in a TemplateMiddle or TemplateTail.
-            if (template.kind === SyntaxKind.TemplateExpression) {
-                const lastSpan = lastOrUndefined((<TemplateExpression>template).templateSpans);
-                if (lastSpan.literal.getFullWidth() === 0) {
-                    applicableSpanEnd = skipTrivia(sourceFile.text, applicableSpanEnd, /*stopAfterLineBreak*/ false);
-                }
-            }
-
-            return createTextSpan(applicableSpanStart, applicableSpanEnd - applicableSpanStart);
-        }
-
-        function getContainingArgumentInfo(node: Node): ArgumentListInfo {
-            for (let n = node; n.kind !== SyntaxKind.SourceFile; n = n.parent) {
-                if (isFunctionBlock(n)) {
-                    return undefined;
-                }
-
-                // If the node is not a subspan of its parent, this is a big problem.
-                // There have been crashes that might be caused by this violation.
-                if (n.pos < n.parent.pos || n.end > n.parent.end) {
-                    Debug.fail("Node of kind " + n.kind + " is not a subspan of its parent of kind " + n.parent.kind);
-                }
-
-                const argumentInfo = getImmediatelyContainingArgumentInfo(n);
-                if (argumentInfo) {
-                    return argumentInfo;
-                }
-
-
-                // TODO: Handle generic call with incomplete syntax
+                return {
+                    kind: isTypeArgList ? ArgumentListKind.TypeArguments : ArgumentListKind.CallArguments,
+                    invocation: callExpression,
+                    argumentsSpan: getApplicableSpanForArguments(list, sourceFile),
+                    argumentIndex: argumentIndex,
+                    argumentCount: argumentCount
+                };
             }
             return undefined;
         }
-
-        function getChildListThatStartsWithOpenerToken(parent: Node, openerToken: Node, sourceFile: SourceFile): Node {
-            const children = parent.getChildren(sourceFile);
-            const indexOfOpenerToken = children.indexOf(openerToken);
-            Debug.assert(indexOfOpenerToken >= 0 && children.length > indexOfOpenerToken + 1);
-            return children[indexOfOpenerToken + 1];
+        else if (node.kind === SyntaxKind.NoSubstitutionTemplateLiteral && node.parent.kind === SyntaxKind.TaggedTemplateExpression) {
+            // Check if we're actually inside the template;
+            // otherwise we'll fall out and return undefined.
+            if (isInsideTemplateLiteral(<LiteralExpression>node, position)) {
+                return getArgumentListInfoForTemplate(<TaggedTemplateExpression>node.parent, /*argumentIndex*/ 0, sourceFile);
+            }
         }
+        else if (node.kind === SyntaxKind.TemplateHead && node.parent.parent.kind === SyntaxKind.TaggedTemplateExpression) {
+            const templateExpression = <TemplateExpression>node.parent;
+            const tagExpression = <TaggedTemplateExpression>templateExpression.parent;
+            Debug.assert(templateExpression.kind === SyntaxKind.TemplateExpression);
 
-        /**
-         * The selectedItemIndex could be negative for several reasons.
-         *     1. There are too many arguments for all of the overloads
-         *     2. None of the overloads were type compatible
-         * The solution here is to try to pick the best overload by picking
-         * either the first one that has an appropriate number of parameters,
-         * or the one with the most parameters.
-         */
-        function selectBestInvalidOverloadIndex(candidates: Signature[], argumentCount: number): number {
-            let maxParamsSignatureIndex = -1;
-            let maxParams = -1;
-            for (let i = 0; i < candidates.length; i++) {
-                const candidate = candidates[i];
+            const argumentIndex = isInsideTemplateLiteral(<LiteralExpression>node, position) ? 0 : 1;
 
-                if (candidate.hasRestParameter || candidate.parameters.length >= argumentCount) {
-                    return i;
-                }
+            return getArgumentListInfoForTemplate(tagExpression, argumentIndex, sourceFile);
+        }
+        else if (node.parent.kind === SyntaxKind.TemplateSpan && node.parent.parent.parent.kind === SyntaxKind.TaggedTemplateExpression) {
+            const templateSpan = <TemplateSpan>node.parent;
+            const templateExpression = <TemplateExpression>templateSpan.parent;
+            const tagExpression = <TaggedTemplateExpression>templateExpression.parent;
+            Debug.assert(templateExpression.kind === SyntaxKind.TemplateExpression);
 
-                if (candidate.parameters.length > maxParams) {
-                    maxParams = candidate.parameters.length;
-                    maxParamsSignatureIndex = i;
-                }
+            // If we're just after a template tail, don't show signature help.
+            if (node.kind === SyntaxKind.TemplateTail && !isInsideTemplateLiteral(<LiteralExpression>node, position)) {
+                return undefined;
             }
 
-            return maxParamsSignatureIndex;
+            const spanIndex = templateExpression.templateSpans.indexOf(templateSpan);
+            const argumentIndex = getArgumentIndexForTemplatePiece(spanIndex, node, position);
+
+            return getArgumentListInfoForTemplate(tagExpression, argumentIndex, sourceFile);
         }
 
-        function createSignatureHelpItems(candidates: Signature[], bestSignature: Signature, argumentListInfo: ArgumentListInfo): SignatureHelpItems {
-            const applicableSpan = argumentListInfo.argumentsSpan;
-            const isTypeParameterList = argumentListInfo.kind === ArgumentListKind.TypeArguments;
+        return undefined;
+    }
 
-            const invocation = argumentListInfo.invocation;
-            const callTarget = getInvokedExpression(invocation);
-            const callTargetSymbol = typeChecker.getSymbolAtLocation(callTarget);
-            const callTargetDisplayParts = callTargetSymbol && symbolToDisplayParts(typeChecker, callTargetSymbol, /*enclosingDeclaration*/ undefined, /*meaning*/ undefined);
-            const items: SignatureHelpItem[] = map(candidates, candidateSignature => {
-                let signatureHelpParameters: SignatureHelpParameter[];
-                const prefixDisplayParts: SymbolDisplayPart[] = [];
-                const suffixDisplayParts: SymbolDisplayPart[] = [];
+    function getArgumentIndex(argumentsList: Node, node: Node) {
+        // The list we got back can include commas.  In the presence of errors it may 
+        // also just have nodes without commas.  For example "Foo(a b c)" will have 3 
+        // args without commas.   We want to find what index we're at.  So we count
+        // forward until we hit ourselves, only incrementing the index if it isn't a
+        // comma.
+        //
+        // Note: the subtlety around trailing commas (in getArgumentCount) does not apply
+        // here.  That's because we're only walking forward until we hit the node we're
+        // on.  In that case, even if we're after the trailing comma, we'll still see
+        // that trailing comma in the list, and we'll have generated the appropriate
+        // arg index.
+        let argumentIndex = 0;
+        const listChildren = argumentsList.getChildren();
+        for (const child of listChildren) {
+            if (child === node) {
+                break;
+            }
+            if (child.kind !== SyntaxKind.CommaToken) {
+                argumentIndex++;
+            }
+        }
 
-                if (callTargetDisplayParts) {
-                    addRange(prefixDisplayParts, callTargetDisplayParts);
-                }
+        return argumentIndex;
+    }
 
-                if (isTypeParameterList) {
-                    prefixDisplayParts.push(punctuationPart(SyntaxKind.LessThanToken));
-                    const typeParameters = candidateSignature.typeParameters;
-                    signatureHelpParameters = typeParameters && typeParameters.length > 0 ? map(typeParameters, createSignatureHelpParameterForTypeParameter) : emptyArray;
-                    suffixDisplayParts.push(punctuationPart(SyntaxKind.GreaterThanToken));
-                    const parameterParts = mapToDisplayParts(writer =>
-                        typeChecker.getSymbolDisplayBuilder().buildDisplayForParametersAndDelimiters(candidateSignature.thisType, candidateSignature.parameters, writer, invocation));
-                    addRange(suffixDisplayParts, parameterParts);
-                }
-                else {
-                    const typeParameterParts = mapToDisplayParts(writer =>
-                        typeChecker.getSymbolDisplayBuilder().buildDisplayForTypeParametersAndDelimiters(candidateSignature.typeParameters, writer, invocation));
-                    addRange(prefixDisplayParts, typeParameterParts);
-                    prefixDisplayParts.push(punctuationPart(SyntaxKind.OpenParenToken));
+    function getArgumentCount(argumentsList: Node) {
+        // The argument count for a list is normally the number of non-comma children it has.
+        // For example, if you have "Foo(a,b)" then there will be three children of the arg
+        // list 'a' '<comma>' 'b'.  So, in this case the arg count will be 2.  However, there
+        // is a small subtlety.  If you have  "Foo(a,)", then the child list will just have
+        // 'a' '<comma>'.  So, in the case where the last child is a comma, we increase the
+        // arg count by one to compensate.
+        //
+        // Note: this subtlety only applies to the last comma.  If you had "Foo(a,,"  then 
+        // we'll have:  'a' '<comma>' '<missing>' 
+        // That will give us 2 non-commas.  We then add one for the last comma, givin us an
+        // arg count of 3.
+        const listChildren = argumentsList.getChildren();
 
-                    const parameters = candidateSignature.parameters;
-                    signatureHelpParameters = parameters.length > 0 ? map(parameters, createSignatureHelpParameterForParameter) : emptyArray;
-                    suffixDisplayParts.push(punctuationPart(SyntaxKind.CloseParenToken));
-                }
+        let argumentCount = countWhere(listChildren, arg => arg.kind !== SyntaxKind.CommaToken);
+        if (listChildren.length > 0 && lastOrUndefined(listChildren).kind === SyntaxKind.CommaToken) {
+            argumentCount++;
+        }
 
-                const returnTypeParts = mapToDisplayParts(writer =>
-                    typeChecker.getSymbolDisplayBuilder().buildReturnTypeDisplay(candidateSignature, writer, invocation));
-                addRange(suffixDisplayParts, returnTypeParts);
+        return argumentCount;
+    }
 
-                return {
-                    isVariadic: candidateSignature.hasRestParameter,
-                    prefixDisplayParts,
-                    suffixDisplayParts,
-                    separatorDisplayParts: [punctuationPart(SyntaxKind.CommaToken), spacePart()],
-                    parameters: signatureHelpParameters,
-                    documentation: candidateSignature.getDocumentationComment()
-                };
-            });
+    // spanIndex is either the index for a given template span.
+    // This does not give appropriate results for a NoSubstitutionTemplateLiteral
+    function getArgumentIndexForTemplatePiece(spanIndex: number, node: Node, position: number): number {
+        // Because the TemplateStringsArray is the first argument, we have to offset each substitution expression by 1.
+        // There are three cases we can encounter:
+        //      1. We are precisely in the template literal (argIndex = 0).
+        //      2. We are in or to the right of the substitution expression (argIndex = spanIndex + 1).
+        //      3. We are directly to the right of the template literal, but because we look for the token on the left,
+        //          not enough to put us in the substitution expression; we should consider ourselves part of
+        //          the *next* span's expression by offsetting the index (argIndex = (spanIndex + 1) + 1).
+        //
+        // Example: f  `# abcd $#{#  1 + 1#  }# efghi ${ #"#hello"#  }  #  `
+        //              ^       ^ ^       ^   ^          ^ ^      ^     ^
+        // Case:        1       1 3       2   1          3 2      2     1
+        Debug.assert(position >= node.getStart(), "Assumed 'position' could not occur before node.");
+        if (isTemplateLiteralKind(node.kind)) {
+            if (isInsideTemplateLiteral(<LiteralExpression>node, position)) {
+                return 0;
+            }
+            return spanIndex + 2;
+        }
+        return spanIndex + 1;
+    }
 
-            const argumentIndex = argumentListInfo.argumentIndex;
+    function getArgumentListInfoForTemplate(tagExpression: TaggedTemplateExpression, argumentIndex: number, sourceFile: SourceFile): ArgumentListInfo {
+        // argumentCount is either 1 or (numSpans + 1) to account for the template strings array argument.
+        const argumentCount = tagExpression.template.kind === SyntaxKind.NoSubstitutionTemplateLiteral
+            ? 1
+            : (<TemplateExpression>tagExpression.template).templateSpans.length + 1;
 
-            // argumentCount is the *apparent* number of arguments.
-            const argumentCount = argumentListInfo.argumentCount;
+        Debug.assert(argumentIndex === 0 || argumentIndex < argumentCount, `argumentCount < argumentIndex, ${argumentCount} < ${argumentIndex}`);
 
-            let selectedItemIndex = candidates.indexOf(bestSignature);
-            if (selectedItemIndex < 0) {
-                selectedItemIndex = selectBestInvalidOverloadIndex(candidates, argumentCount);
+        return {
+            kind: ArgumentListKind.TaggedTemplateArguments,
+            invocation: tagExpression,
+            argumentsSpan: getApplicableSpanForTaggedTemplate(tagExpression, sourceFile),
+            argumentIndex: argumentIndex,
+            argumentCount: argumentCount
+        };
+    }
+
+    function getApplicableSpanForArguments(argumentsList: Node, sourceFile: SourceFile): TextSpan {
+        // We use full start and skip trivia on the end because we want to include trivia on
+        // both sides. For example,
+        //
+        //    foo(   /*comment */     a, b, c      /*comment*/     )
+        //        |                                               |
+        //
+        // The applicable span is from the first bar to the second bar (inclusive,
+        // but not including parentheses)
+        const applicableSpanStart = argumentsList.getFullStart();
+        const applicableSpanEnd = skipTrivia(sourceFile.text, argumentsList.getEnd(), /*stopAfterLineBreak*/ false);
+        return createTextSpan(applicableSpanStart, applicableSpanEnd - applicableSpanStart);
+    }
+
+    function getApplicableSpanForTaggedTemplate(taggedTemplate: TaggedTemplateExpression, sourceFile: SourceFile): TextSpan {
+        const template = taggedTemplate.template;
+        const applicableSpanStart = template.getStart();
+        let applicableSpanEnd = template.getEnd();
+
+        // We need to adjust the end position for the case where the template does not have a tail.
+        // Otherwise, we will not show signature help past the expression.
+        // For example,
+        //
+        //      `  ${ 1 + 1        foo(10)
+        //       |        |
+        //
+        // This is because a Missing node has no width. However, what we actually want is to include trivia
+        // leading up to the next token in case the user is about to type in a TemplateMiddle or TemplateTail.
+        if (template.kind === SyntaxKind.TemplateExpression) {
+            const lastSpan = lastOrUndefined((<TemplateExpression>template).templateSpans);
+            if (lastSpan.literal.getFullWidth() === 0) {
+                applicableSpanEnd = skipTrivia(sourceFile.text, applicableSpanEnd, /*stopAfterLineBreak*/ false);
+            }
+        }
+
+        return createTextSpan(applicableSpanStart, applicableSpanEnd - applicableSpanStart);
+    }
+
+    export function getContainingArgumentInfo(node: Node, position: number, sourceFile: SourceFile): ArgumentListInfo {
+        for (let n = node; n.kind !== SyntaxKind.SourceFile; n = n.parent) {
+            if (isFunctionBlock(n)) {
+                return undefined;
             }
 
-            Debug.assert(argumentIndex === 0 || argumentIndex < argumentCount, `argumentCount < argumentIndex, ${argumentCount} < ${argumentIndex}`);
+            // If the node is not a subspan of its parent, this is a big problem.
+            // There have been crashes that might be caused by this violation.
+            if (n.pos < n.parent.pos || n.end > n.parent.end) {
+                Debug.fail("Node of kind " + n.kind + " is not a subspan of its parent of kind " + n.parent.kind);
+            }
+
+            const argumentInfo = getImmediatelyContainingArgumentInfo(n, position, sourceFile);
+            if (argumentInfo) {
+                return argumentInfo;
+            }
+
+
+            // TODO: Handle generic call with incomplete syntax
+        }
+        return undefined;
+    }
+
+    function getChildListThatStartsWithOpenerToken(parent: Node, openerToken: Node, sourceFile: SourceFile): Node {
+        const children = parent.getChildren(sourceFile);
+        const indexOfOpenerToken = children.indexOf(openerToken);
+        Debug.assert(indexOfOpenerToken >= 0 && children.length > indexOfOpenerToken + 1);
+        return children[indexOfOpenerToken + 1];
+    }
+
+    /**
+     * The selectedItemIndex could be negative for several reasons.
+     *     1. There are too many arguments for all of the overloads
+     *     2. None of the overloads were type compatible
+     * The solution here is to try to pick the best overload by picking
+     * either the first one that has an appropriate number of parameters,
+     * or the one with the most parameters.
+     */
+    function selectBestInvalidOverloadIndex(candidates: Signature[], argumentCount: number): number {
+        let maxParamsSignatureIndex = -1;
+        let maxParams = -1;
+        for (let i = 0; i < candidates.length; i++) {
+            const candidate = candidates[i];
+
+            if (candidate.hasRestParameter || candidate.parameters.length >= argumentCount) {
+                return i;
+            }
+
+            if (candidate.parameters.length > maxParams) {
+                maxParams = candidate.parameters.length;
+                maxParamsSignatureIndex = i;
+            }
+        }
+
+        return maxParamsSignatureIndex;
+    }
+
+    function createSignatureHelpItems(candidates: Signature[], bestSignature: Signature, argumentListInfo: ArgumentListInfo, typeChecker: TypeChecker): SignatureHelpItems {
+        const applicableSpan = argumentListInfo.argumentsSpan;
+        const isTypeParameterList = argumentListInfo.kind === ArgumentListKind.TypeArguments;
+
+        const invocation = argumentListInfo.invocation;
+        const callTarget = getInvokedExpression(invocation);
+        const callTargetSymbol = typeChecker.getSymbolAtLocation(callTarget);
+        const callTargetDisplayParts = callTargetSymbol && symbolToDisplayParts(typeChecker, callTargetSymbol, /*enclosingDeclaration*/ undefined, /*meaning*/ undefined);
+        const items: SignatureHelpItem[] = map(candidates, candidateSignature => {
+            let signatureHelpParameters: SignatureHelpParameter[];
+            const prefixDisplayParts: SymbolDisplayPart[] = [];
+            const suffixDisplayParts: SymbolDisplayPart[] = [];
+
+            if (callTargetDisplayParts) {
+                addRange(prefixDisplayParts, callTargetDisplayParts);
+            }
+
+            if (isTypeParameterList) {
+                prefixDisplayParts.push(punctuationPart(SyntaxKind.LessThanToken));
+                const typeParameters = candidateSignature.typeParameters;
+                signatureHelpParameters = typeParameters && typeParameters.length > 0 ? map(typeParameters, createSignatureHelpParameterForTypeParameter) : emptyArray;
+                suffixDisplayParts.push(punctuationPart(SyntaxKind.GreaterThanToken));
+                const parameterParts = mapToDisplayParts(writer =>
+                    typeChecker.getSymbolDisplayBuilder().buildDisplayForParametersAndDelimiters(candidateSignature.thisType, candidateSignature.parameters, writer, invocation));
+                addRange(suffixDisplayParts, parameterParts);
+            }
+            else {
+                const typeParameterParts = mapToDisplayParts(writer =>
+                    typeChecker.getSymbolDisplayBuilder().buildDisplayForTypeParametersAndDelimiters(candidateSignature.typeParameters, writer, invocation));
+                addRange(prefixDisplayParts, typeParameterParts);
+                prefixDisplayParts.push(punctuationPart(SyntaxKind.OpenParenToken));
+
+                const parameters = candidateSignature.parameters;
+                signatureHelpParameters = parameters.length > 0 ? map(parameters, createSignatureHelpParameterForParameter) : emptyArray;
+                suffixDisplayParts.push(punctuationPart(SyntaxKind.CloseParenToken));
+            }
+
+            const returnTypeParts = mapToDisplayParts(writer =>
+                typeChecker.getSymbolDisplayBuilder().buildReturnTypeDisplay(candidateSignature, writer, invocation));
+            addRange(suffixDisplayParts, returnTypeParts);
 
             return {
-                items,
-                applicableSpan,
-                selectedItemIndex,
-                argumentIndex,
-                argumentCount
+                isVariadic: candidateSignature.hasRestParameter,
+                prefixDisplayParts,
+                suffixDisplayParts,
+                separatorDisplayParts: [punctuationPart(SyntaxKind.CommaToken), spacePart()],
+                parameters: signatureHelpParameters,
+                documentation: candidateSignature.getDocumentationComment()
             };
+        });
 
-            function createSignatureHelpParameterForParameter(parameter: Symbol): SignatureHelpParameter {
-                const displayParts = mapToDisplayParts(writer =>
-                    typeChecker.getSymbolDisplayBuilder().buildParameterDisplay(parameter, writer, invocation));
+        const argumentIndex = argumentListInfo.argumentIndex;
 
-                return {
-                    name: parameter.name,
-                    documentation: parameter.getDocumentationComment(),
-                    displayParts,
-                    isOptional: typeChecker.isOptionalParameter(<ParameterDeclaration>parameter.valueDeclaration)
-                };
-            }
+        // argumentCount is the *apparent* number of arguments.
+        const argumentCount = argumentListInfo.argumentCount;
 
-            function createSignatureHelpParameterForTypeParameter(typeParameter: TypeParameter): SignatureHelpParameter {
-                const displayParts = mapToDisplayParts(writer =>
-                    typeChecker.getSymbolDisplayBuilder().buildTypeParameterDisplay(typeParameter, writer, invocation));
+        let selectedItemIndex = candidates.indexOf(bestSignature);
+        if (selectedItemIndex < 0) {
+            selectedItemIndex = selectBestInvalidOverloadIndex(candidates, argumentCount);
+        }
 
-                return {
-                    name: typeParameter.symbol.name,
-                    documentation: emptyArray,
-                    displayParts,
-                    isOptional: false
-                };
-            }
+        Debug.assert(argumentIndex === 0 || argumentIndex < argumentCount, `argumentCount < argumentIndex, ${argumentCount} < ${argumentIndex}`);
+
+        return {
+            items,
+            applicableSpan,
+            selectedItemIndex,
+            argumentIndex,
+            argumentCount
+        };
+
+        function createSignatureHelpParameterForParameter(parameter: Symbol): SignatureHelpParameter {
+            const displayParts = mapToDisplayParts(writer =>
+                typeChecker.getSymbolDisplayBuilder().buildParameterDisplay(parameter, writer, invocation));
+
+            return {
+                name: parameter.name,
+                documentation: parameter.getDocumentationComment(),
+                displayParts,
+                isOptional: typeChecker.isOptionalParameter(<ParameterDeclaration>parameter.valueDeclaration)
+            };
+        }
+
+        function createSignatureHelpParameterForTypeParameter(typeParameter: TypeParameter): SignatureHelpParameter {
+            const displayParts = mapToDisplayParts(writer =>
+                typeChecker.getSymbolDisplayBuilder().buildTypeParameterDisplay(typeParameter, writer, invocation));
+
+            return {
+                name: typeParameter.symbol.name,
+                documentation: emptyArray,
+                displayParts,
+                isOptional: false
+            };
         }
     }
 }

src/services/utilities.ts

@@ -426,9 +426,27 @@ namespace ts {
         }
     }
 
-    export function isInString(sourceFile: SourceFile, position: number) {
-        const token = getTokenAtPosition(sourceFile, position);
-        return token && (token.kind === SyntaxKind.StringLiteral || token.kind === SyntaxKind.StringLiteralType) && position > token.getStart(sourceFile);
+    export function isInString(sourceFile: SourceFile, position: number): boolean {
+        const previousToken = findPrecedingToken(position, sourceFile);
+        if (previousToken &&
+            (previousToken.kind === SyntaxKind.StringLiteral || previousToken.kind === SyntaxKind.StringLiteralType)) {
+            const start = previousToken.getStart();
+            const end = previousToken.getEnd();
+
+            // To be "in" one of these literals, the position has to be:
+            //   1. entirely within the token text.
+            //   2. at the end position of an unterminated token.
+            //   3. at the end of a regular expression (due to trailing flags like '/foo/g').
+            if (start < position && position < end) {
+                return true;
+            }
+
+            if (position === end) {
+                return !!(<LiteralExpression>previousToken).isUnterminated;
+            }
+        }
+
+        return false;
     }
 
     export function isInComment(sourceFile: SourceFile, position: number) {

tests/baselines/reference/ambientDeclarationsPatterns.js

@@ -0,0 +1,44 @@
+//// [tests/cases/conformance/ambient/ambientDeclarationsPatterns.ts] ////
+
+//// [declarations.d.ts]
+declare module "foo*baz" {
+    export function foo(s: string): void;
+}
+// Augmentations still work
+declare module "foo*baz" {
+    export const baz: string;
+}
+
+// Longest prefix wins
+declare module "foos*" {
+    export const foos: string;
+}
+
+declare module "*!text" {
+    const x: string;
+    export default x;
+}
+
+//// [user.ts]
+///<reference path="declarations.d.ts" />
+import {foo, baz} from "foobarbaz";
+foo(baz);
+
+import {foos} from "foosball";
+foo(foos);
+
+// Works with relative file name
+import fileText from "./file!text";
+foo(fileText);
+
+
+//// [user.js]
+"use strict";
+///<reference path="declarations.d.ts" />
+var foobarbaz_1 = require("foobarbaz");
+foobarbaz_1.foo(foobarbaz_1.baz);
+var foosball_1 = require("foosball");
+foobarbaz_1.foo(foosball_1.foos);
+// Works with relative file name
+var file_text_1 = require("./file!text");
+foobarbaz_1.foo(file_text_1["default"]);

tests/baselines/reference/ambientDeclarationsPatterns.symbols

@@ -0,0 +1,51 @@
+=== tests/cases/conformance/ambient/user.ts ===
+///<reference path="declarations.d.ts" />
+import {foo, baz} from "foobarbaz";
+>foo : Symbol(foo, Decl(user.ts, 1, 8))
+>baz : Symbol(baz, Decl(user.ts, 1, 12))
+
+foo(baz);
+>foo : Symbol(foo, Decl(user.ts, 1, 8))
+>baz : Symbol(baz, Decl(user.ts, 1, 12))
+
+import {foos} from "foosball";
+>foos : Symbol(foos, Decl(user.ts, 4, 8))
+
+foo(foos);
+>foo : Symbol(foo, Decl(user.ts, 1, 8))
+>foos : Symbol(foos, Decl(user.ts, 4, 8))
+
+// Works with relative file name
+import fileText from "./file!text";
+>fileText : Symbol(fileText, Decl(user.ts, 8, 6))
+
+foo(fileText);
+>foo : Symbol(foo, Decl(user.ts, 1, 8))
+>fileText : Symbol(fileText, Decl(user.ts, 8, 6))
+
+=== tests/cases/conformance/ambient/declarations.d.ts ===
+declare module "foo*baz" {
+    export function foo(s: string): void;
+>foo : Symbol(foo, Decl(declarations.d.ts, 0, 26))
+>s : Symbol(s, Decl(declarations.d.ts, 1, 24))
+}
+// Augmentations still work
+declare module "foo*baz" {
+    export const baz: string;
+>baz : Symbol(baz, Decl(declarations.d.ts, 5, 16))
+}
+
+// Longest prefix wins
+declare module "foos*" {
+    export const foos: string;
+>foos : Symbol(foos, Decl(declarations.d.ts, 10, 16))
+}
+
+declare module "*!text" {
+    const x: string;
+>x : Symbol(x, Decl(declarations.d.ts, 14, 9))
+
+    export default x;
+>x : Symbol(x, Decl(declarations.d.ts, 14, 9))
+}
+

tests/baselines/reference/ambientDeclarationsPatterns.types

@@ -0,0 +1,54 @@
+=== tests/cases/conformance/ambient/user.ts ===
+///<reference path="declarations.d.ts" />
+import {foo, baz} from "foobarbaz";
+>foo : (s: string) => void
+>baz : string
+
+foo(baz);
+>foo(baz) : void
+>foo : (s: string) => void
+>baz : string
+
+import {foos} from "foosball";
+>foos : string
+
+foo(foos);
+>foo(foos) : void
+>foo : (s: string) => void
+>foos : string
+
+// Works with relative file name
+import fileText from "./file!text";
+>fileText : string
+
+foo(fileText);
+>foo(fileText) : void
+>foo : (s: string) => void
+>fileText : string
+
+=== tests/cases/conformance/ambient/declarations.d.ts ===
+declare module "foo*baz" {
+    export function foo(s: string): void;
+>foo : (s: string) => void
+>s : string
+}
+// Augmentations still work
+declare module "foo*baz" {
+    export const baz: string;
+>baz : string
+}
+
+// Longest prefix wins
+declare module "foos*" {
+    export const foos: string;
+>foos : string
+}
+
+declare module "*!text" {
+    const x: string;
+>x : string
+
+    export default x;
+>x : string
+}
+

tests/baselines/reference/ambientDeclarationsPatterns_tooManyAsterisks.errors.txt

@@ -0,0 +1,8 @@
+tests/cases/conformance/ambient/ambientDeclarationsPatterns_tooManyAsterisks.ts(1,16): error TS5061: Pattern 'too*many*asterisks' can have at most one '*' character
+
+
+==== tests/cases/conformance/ambient/ambientDeclarationsPatterns_tooManyAsterisks.ts (1 errors) ====
+    declare module "too*many*asterisks" { }
+                   ~~~~~~~~~~~~~~~~~~~~
+!!! error TS5061: Pattern 'too*many*asterisks' can have at most one '*' character
+    

tests/baselines/reference/ambientDeclarationsPatterns_tooManyAsterisks.js

@@ -0,0 +1,5 @@
+//// [ambientDeclarationsPatterns_tooManyAsterisks.ts]
+declare module "too*many*asterisks" { }
+
+
+//// [ambientDeclarationsPatterns_tooManyAsterisks.js]

tests/baselines/reference/asyncFunctionReturnType.js

@@ -0,0 +1,33 @@
+//// [asyncFunctionReturnType.ts]
+async function fAsync() {
+    // Without explicit type annotation, this is just an array.
+    return [1, true];
+}
+
+async function fAsyncExplicit(): Promise<[number, boolean]> {
+    // This is contextually typed as a tuple.
+    return [1, true];
+}
+
+
+//// [asyncFunctionReturnType.js]
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator.throw(value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments)).next());
+    });
+};
+function fAsync() {
+    return __awaiter(this, void 0, void 0, function* () {
+        // Without explicit type annotation, this is just an array.
+        return [1, true];
+    });
+}
+function fAsyncExplicit() {
+    return __awaiter(this, void 0, void 0, function* () {
+        // This is contextually typed as a tuple.
+        return [1, true];
+    });
+}

tests/baselines/reference/asyncFunctionReturnType.symbols

@@ -0,0 +1,16 @@
+=== tests/cases/compiler/asyncFunctionReturnType.ts ===
+async function fAsync() {
+>fAsync : Symbol(fAsync, Decl(asyncFunctionReturnType.ts, 0, 0))
+
+    // Without explicit type annotation, this is just an array.
+    return [1, true];
+}
+
+async function fAsyncExplicit(): Promise<[number, boolean]> {
+>fAsyncExplicit : Symbol(fAsyncExplicit, Decl(asyncFunctionReturnType.ts, 3, 1))
+>Promise : Symbol(Promise, Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --))
+
+    // This is contextually typed as a tuple.
+    return [1, true];
+}
+

tests/baselines/reference/asyncFunctionReturnType.types

@@ -0,0 +1,22 @@
+=== tests/cases/compiler/asyncFunctionReturnType.ts ===
+async function fAsync() {
+>fAsync : () => Promise<(number | boolean)[]>
+
+    // Without explicit type annotation, this is just an array.
+    return [1, true];
+>[1, true] : (number | boolean)[]
+>1 : number
+>true : boolean
+}
+
+async function fAsyncExplicit(): Promise<[number, boolean]> {
+>fAsyncExplicit : () => Promise<[number, boolean]>
+>Promise : Promise<T>
+
+    // This is contextually typed as a tuple.
+    return [1, true];
+>[1, true] : [number, boolean]
+>1 : number
+>true : boolean
+}
+

tests/baselines/reference/disallowAsyncModifierInES5.errors.txt

@@ -0,0 +1,27 @@
+error TS2318: Cannot find global type 'Promise'.
+tests/cases/compiler/disallowAsyncModifierInES5.ts(2,1): error TS1311: Async functions are only available when targeting ECMAScript 6 and higher.
+tests/cases/compiler/disallowAsyncModifierInES5.ts(2,16): error TS1057: An async function or method must have a valid awaitable return type.
+tests/cases/compiler/disallowAsyncModifierInES5.ts(3,11): error TS1057: An async function or method must have a valid awaitable return type.
+tests/cases/compiler/disallowAsyncModifierInES5.ts(3,11): error TS1311: Async functions are only available when targeting ECMAScript 6 and higher.
+tests/cases/compiler/disallowAsyncModifierInES5.ts(4,11): error TS1311: Async functions are only available when targeting ECMAScript 6 and higher.
+tests/cases/compiler/disallowAsyncModifierInES5.ts(4,11): error TS1057: An async function or method must have a valid awaitable return type.
+
+
+!!! error TS2318: Cannot find global type 'Promise'.
+==== tests/cases/compiler/disallowAsyncModifierInES5.ts (6 errors) ====
+    
+    async function foo() { return 42; } // ERROR: Async functions are only available in ES6+
+    ~~~~~
+!!! error TS1311: Async functions are only available when targeting ECMAScript 6 and higher.
+                   ~~~
+!!! error TS1057: An async function or method must have a valid awaitable return type.
+    let bar = async function () { return 42; } // OK, but should be an error
+              ~~~~~
+!!! error TS1057: An async function or method must have a valid awaitable return type.
+              ~~~~~
+!!! error TS1311: Async functions are only available when targeting ECMAScript 6 and higher.
+    let baz = async () => 42; // OK, but should be an error
+              ~~~~~
+!!! error TS1311: Async functions are only available when targeting ECMAScript 6 and higher.
+              ~~~~~~~~~~~~~~
+!!! error TS1057: An async function or method must have a valid awaitable return type.

tests/baselines/reference/disallowAsyncModifierInES5.js

@@ -0,0 +1,22 @@
+//// [disallowAsyncModifierInES5.ts]
+
+async function foo() { return 42; } // ERROR: Async functions are only available in ES6+
+let bar = async function () { return 42; } // OK, but should be an error
+let baz = async () => 42; // OK, but should be an error
+
+//// [disallowAsyncModifierInES5.js]
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator.throw(value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments)).next());
+    });
+};
+function foo() {
+    return __awaiter(this, void 0, void 0, function* () { return 42; });
+} // ERROR: Async functions are only available in ES6+
+var bar = function () {
+    return __awaiter(this, void 0, void 0, function* () { return 42; });
+}; // OK, but should be an error
+var baz = function () __awaiter(this, void 0, void 0, function* () { return 42; }); // OK, but should be an error

tests/baselines/reference/instanceOfAssignability.types

@@ -133,8 +133,8 @@ function fn5(x: Derived1) {
 		// 1.5: y: Derived1
 		// Want: ???
 		let y = x;
->y : never
->x : never
+>y : Derived1 & Derived2
+>x : Derived1 & Derived2
 	}
 }
 

tests/baselines/reference/logicalAndOperatorStrictMode.js

@@ -0,0 +1,156 @@
+//// [logicalAndOperatorStrictMode.ts]
+
+const a = [0];
+const s = "";
+const x = 0;
+const b = false;
+const v: void = undefined;
+const u = undefined;
+const n = null;
+const z = s || x || u;
+
+const a1 = a && a;
+const a2 = a && s;
+const a3 = a && x;
+const a4 = a && b;
+const a5 = a && v;
+const a6 = a && u;
+const a7 = a && n;
+const a8 = a && z;
+
+const s1 = s && a;
+const s2 = s && s;
+const s3 = s && x;
+const s4 = s && b;
+const s5 = s && v;
+const s6 = s && u;
+const s7 = s && n;
+const s8 = s && z;
+
+const x1 = x && a;
+const x2 = x && s;
+const x3 = x && x;
+const x4 = x && b;
+const x5 = x && v;
+const x6 = x && u;
+const x7 = x && n;
+const x8 = x && z;
+
+const b1 = b && a;
+const b2 = b && s;
+const b3 = b && x;
+const b4 = b && b;
+const b5 = b && v;
+const b6 = b && u;
+const b7 = b && n;
+const b8 = b && z;
+
+const v1 = v && a;
+const v2 = v && s;
+const v3 = v && x;
+const v4 = v && b;
+const v5 = v && v;
+const v6 = v && u;
+const v7 = v && n;
+const v8 = v && z;
+
+const u1 = u && a;
+const u2 = u && s;
+const u3 = u && x;
+const u4 = u && b;
+const u5 = u && v;
+const u6 = u && u;
+const u7 = u && n;
+const u8 = u && z;
+
+const n1 = n && a;
+const n2 = n && s;
+const n3 = n && x;
+const n4 = n && b;
+const n5 = n && v;
+const n6 = n && u;
+const n7 = n && n;
+const n8 = n && z;
+
+const z1 = z && a;
+const z2 = z && s;
+const z3 = z && x;
+const z4 = z && b;
+const z5 = z && v;
+const z6 = z && u;
+const z7 = z && n;
+const z8 = z && z;
+
+//// [logicalAndOperatorStrictMode.js]
+var a = [0];
+var s = "";
+var x = 0;
+var b = false;
+var v = undefined;
+var u = undefined;
+var n = null;
+var z = s || x || u;
+var a1 = a && a;
+var a2 = a && s;
+var a3 = a && x;
+var a4 = a && b;
+var a5 = a && v;
+var a6 = a && u;
+var a7 = a && n;
+var a8 = a && z;
+var s1 = s && a;
+var s2 = s && s;
+var s3 = s && x;
+var s4 = s && b;
+var s5 = s && v;
+var s6 = s && u;
+var s7 = s && n;
+var s8 = s && z;
+var x1 = x && a;
+var x2 = x && s;
+var x3 = x && x;
+var x4 = x && b;
+var x5 = x && v;
+var x6 = x && u;
+var x7 = x && n;
+var x8 = x && z;
+var b1 = b && a;
+var b2 = b && s;
+var b3 = b && x;
+var b4 = b && b;
+var b5 = b && v;
+var b6 = b && u;
+var b7 = b && n;
+var b8 = b && z;
+var v1 = v && a;
+var v2 = v && s;
+var v3 = v && x;
+var v4 = v && b;
+var v5 = v && v;
+var v6 = v && u;
+var v7 = v && n;
+var v8 = v && z;
+var u1 = u && a;
+var u2 = u && s;
+var u3 = u && x;
+var u4 = u && b;
+var u5 = u && v;
+var u6 = u && u;
+var u7 = u && n;
+var u8 = u && z;
+var n1 = n && a;
+var n2 = n && s;
+var n3 = n && x;
+var n4 = n && b;
+var n5 = n && v;
+var n6 = n && u;
+var n7 = n && n;
+var n8 = n && z;
+var z1 = z && a;
+var z2 = z && s;
+var z3 = z && x;
+var z4 = z && b;
+var z5 = z && v;
+var z6 = z && u;
+var z7 = z && n;
+var z8 = z && z;

tests/baselines/reference/logicalAndOperatorStrictMode.symbols

@@ -0,0 +1,351 @@
+=== tests/cases/conformance/expressions/binaryOperators/logicalAndOperator/logicalAndOperatorStrictMode.ts ===
+
+const a = [0];
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+
+const s = "";
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+
+const x = 0;
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+
+const b = false;
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+
+const v: void = undefined;
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+>undefined : Symbol(undefined)
+
+const u = undefined;
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+>undefined : Symbol(undefined)
+
+const n = null;
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+
+const z = s || x || u;
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+
+const a1 = a && a;
+>a1 : Symbol(a1, Decl(logicalAndOperatorStrictMode.ts, 10, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+
+const a2 = a && s;
+>a2 : Symbol(a2, Decl(logicalAndOperatorStrictMode.ts, 11, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+
+const a3 = a && x;
+>a3 : Symbol(a3, Decl(logicalAndOperatorStrictMode.ts, 12, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+
+const a4 = a && b;
+>a4 : Symbol(a4, Decl(logicalAndOperatorStrictMode.ts, 13, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+
+const a5 = a && v;
+>a5 : Symbol(a5, Decl(logicalAndOperatorStrictMode.ts, 14, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+
+const a6 = a && u;
+>a6 : Symbol(a6, Decl(logicalAndOperatorStrictMode.ts, 15, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+
+const a7 = a && n;
+>a7 : Symbol(a7, Decl(logicalAndOperatorStrictMode.ts, 16, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+
+const a8 = a && z;
+>a8 : Symbol(a8, Decl(logicalAndOperatorStrictMode.ts, 17, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+
+const s1 = s && a;
+>s1 : Symbol(s1, Decl(logicalAndOperatorStrictMode.ts, 19, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+
+const s2 = s && s;
+>s2 : Symbol(s2, Decl(logicalAndOperatorStrictMode.ts, 20, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+
+const s3 = s && x;
+>s3 : Symbol(s3, Decl(logicalAndOperatorStrictMode.ts, 21, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+
+const s4 = s && b;
+>s4 : Symbol(s4, Decl(logicalAndOperatorStrictMode.ts, 22, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+
+const s5 = s && v;
+>s5 : Symbol(s5, Decl(logicalAndOperatorStrictMode.ts, 23, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+
+const s6 = s && u;
+>s6 : Symbol(s6, Decl(logicalAndOperatorStrictMode.ts, 24, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+
+const s7 = s && n;
+>s7 : Symbol(s7, Decl(logicalAndOperatorStrictMode.ts, 25, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+
+const s8 = s && z;
+>s8 : Symbol(s8, Decl(logicalAndOperatorStrictMode.ts, 26, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+
+const x1 = x && a;
+>x1 : Symbol(x1, Decl(logicalAndOperatorStrictMode.ts, 28, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+
+const x2 = x && s;
+>x2 : Symbol(x2, Decl(logicalAndOperatorStrictMode.ts, 29, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+
+const x3 = x && x;
+>x3 : Symbol(x3, Decl(logicalAndOperatorStrictMode.ts, 30, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+
+const x4 = x && b;
+>x4 : Symbol(x4, Decl(logicalAndOperatorStrictMode.ts, 31, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+
+const x5 = x && v;
+>x5 : Symbol(x5, Decl(logicalAndOperatorStrictMode.ts, 32, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+
+const x6 = x && u;
+>x6 : Symbol(x6, Decl(logicalAndOperatorStrictMode.ts, 33, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+
+const x7 = x && n;
+>x7 : Symbol(x7, Decl(logicalAndOperatorStrictMode.ts, 34, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+
+const x8 = x && z;
+>x8 : Symbol(x8, Decl(logicalAndOperatorStrictMode.ts, 35, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+
+const b1 = b && a;
+>b1 : Symbol(b1, Decl(logicalAndOperatorStrictMode.ts, 37, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+
+const b2 = b && s;
+>b2 : Symbol(b2, Decl(logicalAndOperatorStrictMode.ts, 38, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+
+const b3 = b && x;
+>b3 : Symbol(b3, Decl(logicalAndOperatorStrictMode.ts, 39, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+
+const b4 = b && b;
+>b4 : Symbol(b4, Decl(logicalAndOperatorStrictMode.ts, 40, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+
+const b5 = b && v;
+>b5 : Symbol(b5, Decl(logicalAndOperatorStrictMode.ts, 41, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+
+const b6 = b && u;
+>b6 : Symbol(b6, Decl(logicalAndOperatorStrictMode.ts, 42, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+
+const b7 = b && n;
+>b7 : Symbol(b7, Decl(logicalAndOperatorStrictMode.ts, 43, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+
+const b8 = b && z;
+>b8 : Symbol(b8, Decl(logicalAndOperatorStrictMode.ts, 44, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+
+const v1 = v && a;
+>v1 : Symbol(v1, Decl(logicalAndOperatorStrictMode.ts, 46, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+
+const v2 = v && s;
+>v2 : Symbol(v2, Decl(logicalAndOperatorStrictMode.ts, 47, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+
+const v3 = v && x;
+>v3 : Symbol(v3, Decl(logicalAndOperatorStrictMode.ts, 48, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+
+const v4 = v && b;
+>v4 : Symbol(v4, Decl(logicalAndOperatorStrictMode.ts, 49, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+
+const v5 = v && v;
+>v5 : Symbol(v5, Decl(logicalAndOperatorStrictMode.ts, 50, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+
+const v6 = v && u;
+>v6 : Symbol(v6, Decl(logicalAndOperatorStrictMode.ts, 51, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+
+const v7 = v && n;
+>v7 : Symbol(v7, Decl(logicalAndOperatorStrictMode.ts, 52, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+
+const v8 = v && z;
+>v8 : Symbol(v8, Decl(logicalAndOperatorStrictMode.ts, 53, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+
+const u1 = u && a;
+>u1 : Symbol(u1, Decl(logicalAndOperatorStrictMode.ts, 55, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+
+const u2 = u && s;
+>u2 : Symbol(u2, Decl(logicalAndOperatorStrictMode.ts, 56, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+
+const u3 = u && x;
+>u3 : Symbol(u3, Decl(logicalAndOperatorStrictMode.ts, 57, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+
+const u4 = u && b;
+>u4 : Symbol(u4, Decl(logicalAndOperatorStrictMode.ts, 58, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+
+const u5 = u && v;
+>u5 : Symbol(u5, Decl(logicalAndOperatorStrictMode.ts, 59, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+
+const u6 = u && u;
+>u6 : Symbol(u6, Decl(logicalAndOperatorStrictMode.ts, 60, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+
+const u7 = u && n;
+>u7 : Symbol(u7, Decl(logicalAndOperatorStrictMode.ts, 61, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+
+const u8 = u && z;
+>u8 : Symbol(u8, Decl(logicalAndOperatorStrictMode.ts, 62, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+
+const n1 = n && a;
+>n1 : Symbol(n1, Decl(logicalAndOperatorStrictMode.ts, 64, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+
+const n2 = n && s;
+>n2 : Symbol(n2, Decl(logicalAndOperatorStrictMode.ts, 65, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+
+const n3 = n && x;
+>n3 : Symbol(n3, Decl(logicalAndOperatorStrictMode.ts, 66, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+
+const n4 = n && b;
+>n4 : Symbol(n4, Decl(logicalAndOperatorStrictMode.ts, 67, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+
+const n5 = n && v;
+>n5 : Symbol(n5, Decl(logicalAndOperatorStrictMode.ts, 68, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+
+const n6 = n && u;
+>n6 : Symbol(n6, Decl(logicalAndOperatorStrictMode.ts, 69, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+
+const n7 = n && n;
+>n7 : Symbol(n7, Decl(logicalAndOperatorStrictMode.ts, 70, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+
+const n8 = n && z;
+>n8 : Symbol(n8, Decl(logicalAndOperatorStrictMode.ts, 71, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+
+const z1 = z && a;
+>z1 : Symbol(z1, Decl(logicalAndOperatorStrictMode.ts, 73, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+>a : Symbol(a, Decl(logicalAndOperatorStrictMode.ts, 1, 5))
+
+const z2 = z && s;
+>z2 : Symbol(z2, Decl(logicalAndOperatorStrictMode.ts, 74, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+>s : Symbol(s, Decl(logicalAndOperatorStrictMode.ts, 2, 5))
+
+const z3 = z && x;
+>z3 : Symbol(z3, Decl(logicalAndOperatorStrictMode.ts, 75, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+>x : Symbol(x, Decl(logicalAndOperatorStrictMode.ts, 3, 5))
+
+const z4 = z && b;
+>z4 : Symbol(z4, Decl(logicalAndOperatorStrictMode.ts, 76, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+>b : Symbol(b, Decl(logicalAndOperatorStrictMode.ts, 4, 5))
+
+const z5 = z && v;
+>z5 : Symbol(z5, Decl(logicalAndOperatorStrictMode.ts, 77, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+>v : Symbol(v, Decl(logicalAndOperatorStrictMode.ts, 5, 5))
+
+const z6 = z && u;
+>z6 : Symbol(z6, Decl(logicalAndOperatorStrictMode.ts, 78, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+>u : Symbol(u, Decl(logicalAndOperatorStrictMode.ts, 6, 5))
+
+const z7 = z && n;
+>z7 : Symbol(z7, Decl(logicalAndOperatorStrictMode.ts, 79, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+>n : Symbol(n, Decl(logicalAndOperatorStrictMode.ts, 7, 5))
+
+const z8 = z && z;
+>z8 : Symbol(z8, Decl(logicalAndOperatorStrictMode.ts, 80, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+>z : Symbol(z, Decl(logicalAndOperatorStrictMode.ts, 8, 5))
+

tests/baselines/reference/logicalAndOperatorStrictMode.types

@@ -0,0 +1,423 @@
+=== tests/cases/conformance/expressions/binaryOperators/logicalAndOperator/logicalAndOperatorStrictMode.ts ===
+
+const a = [0];
+>a : number[]
+>[0] : number[]
+>0 : number
+
+const s = "";
+>s : string
+>"" : string
+
+const x = 0;
+>x : number
+>0 : number
+
+const b = false;
+>b : boolean
+>false : boolean
+
+const v: void = undefined;
+>v : void
+>undefined : undefined
+
+const u = undefined;
+>u : undefined
+>undefined : undefined
+
+const n = null;
+>n : null
+>null : null
+
+const z = s || x || u;
+>z : string | number | undefined
+>s || x || u : string | number | undefined
+>s || x : string | number
+>s : string
+>x : number
+>u : undefined
+
+const a1 = a && a;
+>a1 : number[]
+>a && a : number[]
+>a : number[]
+>a : number[]
+
+const a2 = a && s;
+>a2 : string
+>a && s : string
+>a : number[]
+>s : string
+
+const a3 = a && x;
+>a3 : number
+>a && x : number
+>a : number[]
+>x : number
+
+const a4 = a && b;
+>a4 : boolean
+>a && b : boolean
+>a : number[]
+>b : boolean
+
+const a5 = a && v;
+>a5 : void
+>a && v : void
+>a : number[]
+>v : void
+
+const a6 = a && u;
+>a6 : undefined
+>a && u : undefined
+>a : number[]
+>u : undefined
+
+const a7 = a && n;
+>a7 : null
+>a && n : null
+>a : number[]
+>n : null
+
+const a8 = a && z;
+>a8 : string | number | undefined
+>a && z : string | number | undefined
+>a : number[]
+>z : string | number | undefined
+
+const s1 = s && a;
+>s1 : number[] | string
+>s && a : number[] | string
+>s : string
+>a : number[]
+
+const s2 = s && s;
+>s2 : string
+>s && s : string
+>s : string
+>s : string
+
+const s3 = s && x;
+>s3 : number | string
+>s && x : number | string
+>s : string
+>x : number
+
+const s4 = s && b;
+>s4 : boolean | string
+>s && b : boolean | string
+>s : string
+>b : boolean
+
+const s5 = s && v;
+>s5 : void | string
+>s && v : void | string
+>s : string
+>v : void
+
+const s6 = s && u;
+>s6 : string | undefined
+>s && u : string | undefined
+>s : string
+>u : undefined
+
+const s7 = s && n;
+>s7 : string | null
+>s && n : string | null
+>s : string
+>n : null
+
+const s8 = s && z;
+>s8 : string | number | undefined
+>s && z : string | number | undefined
+>s : string
+>z : string | number | undefined
+
+const x1 = x && a;
+>x1 : number[] | number
+>x && a : number[] | number
+>x : number
+>a : number[]
+
+const x2 = x && s;
+>x2 : string | number
+>x && s : string | number
+>x : number
+>s : string
+
+const x3 = x && x;
+>x3 : number
+>x && x : number
+>x : number
+>x : number
+
+const x4 = x && b;
+>x4 : boolean | number
+>x && b : boolean | number
+>x : number
+>b : boolean
+
+const x5 = x && v;
+>x5 : void | number
+>x && v : void | number
+>x : number
+>v : void
+
+const x6 = x && u;
+>x6 : number | undefined
+>x && u : number | undefined
+>x : number
+>u : undefined
+
+const x7 = x && n;
+>x7 : number | null
+>x && n : number | null
+>x : number
+>n : null
+
+const x8 = x && z;
+>x8 : string | number | undefined
+>x && z : string | number | undefined
+>x : number
+>z : string | number | undefined
+
+const b1 = b && a;
+>b1 : number[] | boolean
+>b && a : number[] | boolean
+>b : boolean
+>a : number[]
+
+const b2 = b && s;
+>b2 : string | boolean
+>b && s : string | boolean
+>b : boolean
+>s : string
+
+const b3 = b && x;
+>b3 : number | boolean
+>b && x : number | boolean
+>b : boolean
+>x : number
+
+const b4 = b && b;
+>b4 : boolean
+>b && b : boolean
+>b : boolean
+>b : boolean
+
+const b5 = b && v;
+>b5 : void | boolean
+>b && v : void | boolean
+>b : boolean
+>v : void
+
+const b6 = b && u;
+>b6 : boolean | undefined
+>b && u : boolean | undefined
+>b : boolean
+>u : undefined
+
+const b7 = b && n;
+>b7 : boolean | null
+>b && n : boolean | null
+>b : boolean
+>n : null
+
+const b8 = b && z;
+>b8 : string | number | boolean | undefined
+>b && z : string | number | boolean | undefined
+>b : boolean
+>z : string | number | undefined
+
+const v1 = v && a;
+>v1 : number[] | void
+>v && a : number[] | void
+>v : void
+>a : number[]
+
+const v2 = v && s;
+>v2 : string | void
+>v && s : string | void
+>v : void
+>s : string
+
+const v3 = v && x;
+>v3 : number | void
+>v && x : number | void
+>v : void
+>x : number
+
+const v4 = v && b;
+>v4 : boolean | void
+>v && b : boolean | void
+>v : void
+>b : boolean
+
+const v5 = v && v;
+>v5 : void
+>v && v : void
+>v : void
+>v : never
+
+const v6 = v && u;
+>v6 : void
+>v && u : void
+>v : void
+>u : undefined
+
+const v7 = v && n;
+>v7 : void | null
+>v && n : void | null
+>v : void
+>n : null
+
+const v8 = v && z;
+>v8 : string | number | void
+>v && z : string | number | void
+>v : void
+>z : string | number | undefined
+
+const u1 = u && a;
+>u1 : number[] | undefined
+>u && a : number[] | undefined
+>u : undefined
+>a : number[]
+
+const u2 = u && s;
+>u2 : string | undefined
+>u && s : string | undefined
+>u : undefined
+>s : string
+
+const u3 = u && x;
+>u3 : number | undefined
+>u && x : number | undefined
+>u : undefined
+>x : number
+
+const u4 = u && b;
+>u4 : boolean | undefined
+>u && b : boolean | undefined
+>u : undefined
+>b : boolean
+
+const u5 = u && v;
+>u5 : void
+>u && v : void
+>u : undefined
+>v : void
+
+const u6 = u && u;
+>u6 : undefined
+>u && u : undefined
+>u : undefined
+>u : never
+
+const u7 = u && n;
+>u7 : null | undefined
+>u && n : null | undefined
+>u : undefined
+>n : null
+
+const u8 = u && z;
+>u8 : string | number | undefined
+>u && z : string | number | undefined
+>u : undefined
+>z : string | number | undefined
+
+const n1 = n && a;
+>n1 : number[] | null
+>n && a : number[] | null
+>n : null
+>a : number[]
+
+const n2 = n && s;
+>n2 : string | null
+>n && s : string | null
+>n : null
+>s : string
+
+const n3 = n && x;
+>n3 : number | null
+>n && x : number | null
+>n : null
+>x : number
+
+const n4 = n && b;
+>n4 : boolean | null
+>n && b : boolean | null
+>n : null
+>b : boolean
+
+const n5 = n && v;
+>n5 : void | null
+>n && v : void | null
+>n : null
+>v : void
+
+const n6 = n && u;
+>n6 : null | undefined
+>n && u : null | undefined
+>n : null
+>u : undefined
+
+const n7 = n && n;
+>n7 : null
+>n && n : null
+>n : null
+>n : never
+
+const n8 = n && z;
+>n8 : string | number | null | undefined
+>n && z : string | number | null | undefined
+>n : null
+>z : string | number | undefined
+
+const z1 = z && a;
+>z1 : number[] | string | number | undefined
+>z && a : number[] | string | number | undefined
+>z : string | number | undefined
+>a : number[]
+
+const z2 = z && s;
+>z2 : string | number | undefined
+>z && s : string | number | undefined
+>z : string | number | undefined
+>s : string
+
+const z3 = z && x;
+>z3 : number | string | undefined
+>z && x : number | string | undefined
+>z : string | number | undefined
+>x : number
+
+const z4 = z && b;
+>z4 : boolean | string | number | undefined
+>z && b : boolean | string | number | undefined
+>z : string | number | undefined
+>b : boolean
+
+const z5 = z && v;
+>z5 : void | string | number
+>z && v : void | string | number
+>z : string | number | undefined
+>v : void
+
+const z6 = z && u;
+>z6 : string | number | undefined
+>z && u : string | number | undefined
+>z : string | number | undefined
+>u : undefined
+
+const z7 = z && n;
+>z7 : string | number | null | undefined
+>z && n : string | number | null | undefined
+>z : string | number | undefined
+>n : null
+
+const z8 = z && z;
+>z8 : string | number | undefined
+>z && z : string | number | undefined
+>z : string | number | undefined
+>z : string | number
+

tests/baselines/reference/moduleResolutionWithExtensions.js

@@ -0,0 +1,46 @@
+//// [tests/cases/conformance/externalModules/moduleResolutionWithExtensions.ts] ////
+
+//// [a.ts]
+
+export default 0;
+
+// No extension: '.ts' added
+//// [b.ts]
+import a from './a';
+
+// Matching extension
+//// [c.ts]
+import a from './a.ts';
+
+// '.js' extension: stripped and replaced with '.ts'
+//// [d.ts]
+import a from './a.js';
+
+//// [jquery.d.ts]
+declare var x: number;
+export default x;
+
+// No extension: '.d.ts' added
+//// [jquery_user_1.ts]
+import j from "./jquery";
+
+// '.js' extension: stripped and replaced with '.d.ts'
+//// [jquery_user_1.ts]
+import j from "./jquery.js"
+
+
+//// [a.js]
+"use strict";
+exports.__esModule = true;
+exports["default"] = 0;
+// No extension: '.ts' added 
+//// [b.js]
+"use strict";
+// Matching extension 
+//// [c.js]
+"use strict";
+// '.js' extension: stripped and replaced with '.ts' 
+//// [d.js]
+"use strict";
+//// [jquery_user_1.js]
+"use strict";

tests/baselines/reference/moduleResolutionWithExtensions.symbols

@@ -0,0 +1,37 @@
+=== /src/a.ts ===
+
+No type information for this code.export default 0;
+No type information for this code.
+No type information for this code.// No extension: '.ts' added
+No type information for this code.=== /src/b.ts ===
+import a from './a';
+>a : Symbol(a, Decl(b.ts, 0, 6))
+
+// Matching extension
+=== /src/c.ts ===
+import a from './a.ts';
+>a : Symbol(a, Decl(c.ts, 0, 6))
+
+// '.js' extension: stripped and replaced with '.ts'
+=== /src/d.ts ===
+import a from './a.js';
+>a : Symbol(a, Decl(d.ts, 0, 6))
+
+=== /src/jquery.d.ts ===
+declare var x: number;
+>x : Symbol(x, Decl(jquery.d.ts, 0, 11))
+
+export default x;
+>x : Symbol(x, Decl(jquery.d.ts, 0, 11))
+
+// No extension: '.d.ts' added
+=== /src/jquery_user_1.ts ===
+import j from "./jquery";
+>j : Symbol(j, Decl(jquery_user_1.ts, 0, 6))
+
+// '.js' extension: stripped and replaced with '.d.ts'
+=== /src/jquery_user_1.ts ===
+import j from "./jquery.js"
+>j : Symbol(j, Decl(jquery_user_1.ts, 0, 6))
+>j : Symbol(j, Decl(jquery_user_1.ts, 0, 6))
+

tests/baselines/reference/moduleResolutionWithExtensions.trace.json

@@ -0,0 +1,32 @@
+[
+    "======== Resolving module './a' from '/src/b.ts'. ========",
+    "Module resolution kind is not specified, using 'NodeJs'.",
+    "Loading module as file / folder, candidate module location '/src/a'.",
+    "File '/src/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a' was successfully resolved to '/src/a.ts'. ========",
+    "======== Resolving module './a.ts' from '/src/c.ts'. ========",
+    "Module resolution kind is not specified, using 'NodeJs'.",
+    "Loading module as file / folder, candidate module location '/src/a.ts'.",
+    "File '/src/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a.ts' was successfully resolved to '/src/a.ts'. ========",
+    "======== Resolving module './a.js' from '/src/d.ts'. ========",
+    "Module resolution kind is not specified, using 'NodeJs'.",
+    "Loading module as file / folder, candidate module location '/src/a.js'.",
+    "File '/src/a.js.ts' does not exist.",
+    "File '/src/a.js.tsx' does not exist.",
+    "File '/src/a.js.d.ts' does not exist.",
+    "File name '/src/a.js' has a '.js' extension - stripping it",
+    "File '/src/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a.js' was successfully resolved to '/src/a.ts'. ========",
+    "======== Resolving module './jquery.js' from '/src/jquery_user_1.ts'. ========",
+    "Module resolution kind is not specified, using 'NodeJs'.",
+    "Loading module as file / folder, candidate module location '/src/jquery.js'.",
+    "File '/src/jquery.js.ts' does not exist.",
+    "File '/src/jquery.js.tsx' does not exist.",
+    "File '/src/jquery.js.d.ts' does not exist.",
+    "File name '/src/jquery.js' has a '.js' extension - stripping it",
+    "File '/src/jquery.ts' does not exist.",
+    "File '/src/jquery.tsx' does not exist.",
+    "File '/src/jquery.d.ts' exist - use it as a name resolution result.",
+    "======== Module name './jquery.js' was successfully resolved to '/src/jquery.d.ts'. ========"
+]

tests/baselines/reference/moduleResolutionWithExtensions.types

@@ -0,0 +1,37 @@
+=== /src/a.ts ===
+
+No type information for this code.export default 0;
+No type information for this code.
+No type information for this code.// No extension: '.ts' added
+No type information for this code.=== /src/b.ts ===
+import a from './a';
+>a : number
+
+// Matching extension
+=== /src/c.ts ===
+import a from './a.ts';
+>a : number
+
+// '.js' extension: stripped and replaced with '.ts'
+=== /src/d.ts ===
+import a from './a.js';
+>a : number
+
+=== /src/jquery.d.ts ===
+declare var x: number;
+>x : number
+
+export default x;
+>x : number
+
+// No extension: '.d.ts' added
+=== /src/jquery_user_1.ts ===
+import j from "./jquery";
+>j : number
+
+// '.js' extension: stripped and replaced with '.d.ts'
+=== /src/jquery_user_1.ts ===
+import j from "./jquery.js"
+>j : number
+>j : number
+

tests/baselines/reference/nameWithFileExtension.errors.txt

@@ -1,12 +0,0 @@
-tests/cases/conformance/externalModules/foo_1.ts(1,22): error TS2307: Cannot find module './foo_0.js'.
-
-
-==== tests/cases/conformance/externalModules/foo_1.ts (1 errors) ====
-    import foo = require('./foo_0.js');
-                         ~~~~~~~~~~~~
-!!! error TS2307: Cannot find module './foo_0.js'.
-    var x = foo.foo + 42;
-    
-==== tests/cases/conformance/externalModules/foo_0.ts (0 errors) ====
-    export var foo = 42;
-    

tests/baselines/reference/nameWithFileExtension.js

@@ -8,6 +8,9 @@ import foo = require('./foo_0.js');
 var x = foo.foo + 42;
 
 
+//// [foo_0.js]
+"use strict";
+exports.foo = 42;
 //// [foo_1.js]
 "use strict";
 var foo = require('./foo_0.js');

tests/baselines/reference/nameWithFileExtension.symbols

@@ -0,0 +1,14 @@
+=== tests/cases/conformance/externalModules/foo_1.ts ===
+import foo = require('./foo_0.js');
+>foo : Symbol(foo, Decl(foo_1.ts, 0, 0))
+
+var x = foo.foo + 42;
+>x : Symbol(x, Decl(foo_1.ts, 1, 3))
+>foo.foo : Symbol(foo.foo, Decl(foo_0.ts, 0, 10))
+>foo : Symbol(foo, Decl(foo_1.ts, 0, 0))
+>foo : Symbol(foo.foo, Decl(foo_0.ts, 0, 10))
+
+=== tests/cases/conformance/externalModules/foo_0.ts ===
+export var foo = 42;
+>foo : Symbol(foo, Decl(foo_0.ts, 0, 10))
+

tests/baselines/reference/nameWithFileExtension.types

@@ -0,0 +1,17 @@
+=== tests/cases/conformance/externalModules/foo_1.ts ===
+import foo = require('./foo_0.js');
+>foo : typeof foo
+
+var x = foo.foo + 42;
+>x : number
+>foo.foo + 42 : number
+>foo.foo : number
+>foo : typeof foo
+>foo : number
+>42 : number
+
+=== tests/cases/conformance/externalModules/foo_0.ts ===
+export var foo = 42;
+>foo : number
+>42 : number
+

tests/baselines/reference/optionsSourcemapInlineSourcesSourceRoot.errors.txt

@@ -1,7 +0,0 @@
-error TS5053: Option 'sourceRoot' cannot be specified with option 'inlineSources'.
-
-
-!!! error TS5053: Option 'sourceRoot' cannot be specified with option 'inlineSources'.
-==== tests/cases/compiler/optionsSourcemapInlineSourcesSourceRoot.ts (0 errors) ====
-    
-    var a = 10;

tests/baselines/reference/optionsSourcemapInlineSourcesSourceRoot.symbols

@@ -0,0 +1,5 @@
+=== tests/cases/compiler/optionsSourcemapInlineSourcesSourceRoot.ts ===
+
+var a = 10;
+>a : Symbol(a, Decl(optionsSourcemapInlineSourcesSourceRoot.ts, 1, 3))
+

tests/baselines/reference/optionsSourcemapInlineSourcesSourceRoot.types

@@ -0,0 +1,6 @@
+=== tests/cases/compiler/optionsSourcemapInlineSourcesSourceRoot.ts ===
+
+var a = 10;
+>a : number
+>10 : number
+

tests/baselines/reference/project/cantFindTheModule/amd/cantFindTheModule.errors.txt

@@ -1,12 +1,12 @@
-decl.ts(1,26): error TS2307: Cannot find module './foo/bar.js'.
+decl.ts(1,26): error TS2307: Cannot find module './foo/bar.tx'.
 decl.ts(2,26): error TS2307: Cannot find module 'baz'.
 decl.ts(3,26): error TS2307: Cannot find module './baz'.
 
 
 ==== decl.ts (3 errors) ====
-    import modErr  = require("./foo/bar.js");
+    import modErr  = require("./foo/bar.tx");
                              ~~~~~~~~~~~~~~
-!!! error TS2307: Cannot find module './foo/bar.js'.
+!!! error TS2307: Cannot find module './foo/bar.tx'.
     import modErr1 = require("baz");
                              ~~~~~
 !!! error TS2307: Cannot find module 'baz'.

tests/baselines/reference/project/cantFindTheModule/node/cantFindTheModule.errors.txt

@@ -1,12 +1,12 @@
-decl.ts(1,26): error TS2307: Cannot find module './foo/bar.js'.
+decl.ts(1,26): error TS2307: Cannot find module './foo/bar.tx'.
 decl.ts(2,26): error TS2307: Cannot find module 'baz'.
 decl.ts(3,26): error TS2307: Cannot find module './baz'.
 
 
 ==== decl.ts (3 errors) ====
-    import modErr  = require("./foo/bar.js");
+    import modErr  = require("./foo/bar.tx");
                              ~~~~~~~~~~~~~~
-!!! error TS2307: Cannot find module './foo/bar.js'.
+!!! error TS2307: Cannot find module './foo/bar.tx'.
     import modErr1 = require("baz");
                              ~~~~~
 !!! error TS2307: Cannot find module 'baz'.

tests/baselines/reference/project/mapRootSourceRootWithNoSourceMapOption/amd/mapRootSourceRootWithNoSourceMapOption.errors.txt

@@ -1,9 +1,9 @@
+error TS5051: Option 'sourceRoot can only be used when either option '--inlineSourceMap' or option '--sourceMap' is provided.
 error TS5052: Option 'mapRoot' cannot be specified without specifying option 'sourceMap'.
-error TS5052: Option 'sourceRoot' cannot be specified without specifying option 'sourceMap'.
 
 
+!!! error TS5051: Option 'sourceRoot can only be used when either option '--inlineSourceMap' or option '--sourceMap' is provided.
 !!! error TS5052: Option 'mapRoot' cannot be specified without specifying option 'sourceMap'.
-!!! error TS5052: Option 'sourceRoot' cannot be specified without specifying option 'sourceMap'.
 ==== m1.ts (0 errors) ====
     var m1_a1 = 10;
     class m1_c1 {

tests/baselines/reference/project/mapRootSourceRootWithNoSourceMapOption/node/mapRootSourceRootWithNoSourceMapOption.errors.txt

@@ -1,9 +1,9 @@
+error TS5051: Option 'sourceRoot can only be used when either option '--inlineSourceMap' or option '--sourceMap' is provided.
 error TS5052: Option 'mapRoot' cannot be specified without specifying option 'sourceMap'.
-error TS5052: Option 'sourceRoot' cannot be specified without specifying option 'sourceMap'.
 
 
+!!! error TS5051: Option 'sourceRoot can only be used when either option '--inlineSourceMap' or option '--sourceMap' is provided.
 !!! error TS5052: Option 'mapRoot' cannot be specified without specifying option 'sourceMap'.
-!!! error TS5052: Option 'sourceRoot' cannot be specified without specifying option 'sourceMap'.
 ==== m1.ts (0 errors) ====
     var m1_a1 = 10;
     class m1_c1 {

tests/baselines/reference/project/sourceRootWithNoSourceMapOption/amd/sourceRootWithNoSourceMapOption.errors.txt

@@ -1,7 +1,7 @@
-error TS5052: Option 'sourceRoot' cannot be specified without specifying option 'sourceMap'.
+error TS5051: Option 'sourceRoot can only be used when either option '--inlineSourceMap' or option '--sourceMap' is provided.
 
 
-!!! error TS5052: Option 'sourceRoot' cannot be specified without specifying option 'sourceMap'.
+!!! error TS5051: Option 'sourceRoot can only be used when either option '--inlineSourceMap' or option '--sourceMap' is provided.
 ==== m1.ts (0 errors) ====
     var m1_a1 = 10;
     class m1_c1 {

tests/baselines/reference/project/sourceRootWithNoSourceMapOption/node/sourceRootWithNoSourceMapOption.errors.txt

@@ -1,7 +1,7 @@
-error TS5052: Option 'sourceRoot' cannot be specified without specifying option 'sourceMap'.
+error TS5051: Option 'sourceRoot can only be used when either option '--inlineSourceMap' or option '--sourceMap' is provided.
 
 
-!!! error TS5052: Option 'sourceRoot' cannot be specified without specifying option 'sourceMap'.
+!!! error TS5051: Option 'sourceRoot can only be used when either option '--inlineSourceMap' or option '--sourceMap' is provided.
 ==== m1.ts (0 errors) ====
     var m1_a1 = 10;
     class m1_c1 {

tests/baselines/reference/stringLiteralTypesAsTags01.types

@@ -116,6 +116,6 @@ if (!hasKind(x, "B")) {
 }
 else {
     let d = x;
->d : never
->x : never
+>d : A & B
+>x : A & B
 }

tests/baselines/reference/stringLiteralTypesAsTags02.types

@@ -110,6 +110,6 @@ if (!hasKind(x, "B")) {
 }
 else {
     let d = x;
->d : never
->x : never
+>d : A & B
+>x : A & B
 }

tests/baselines/reference/stringLiteralTypesAsTags03.types

@@ -113,6 +113,6 @@ if (!hasKind(x, "B")) {
 }
 else {
     let d = x;
->d : never
->x : never
+>d : A & B
+>x : A & B
 }

tests/baselines/reference/typeGuardIntersectionTypes.js

@@ -0,0 +1,179 @@
+//// [typeGuardIntersectionTypes.ts]
+
+interface X {
+    x: string;
+}
+
+interface Y {
+    y: string;
+}
+
+interface Z {
+    z: string;
+}
+
+declare function isX(obj: any): obj is X;
+declare function isY(obj: any): obj is Y;
+declare function isZ(obj: any): obj is Z;
+
+function f1(obj: Object) {
+    if (isX(obj) || isY(obj) || isZ(obj)) {
+        obj;
+    }
+    if (isX(obj) && isY(obj) && isZ(obj)) {
+        obj;
+    }
+}
+
+// Repro from #8911
+
+// two interfaces
+interface A {
+  a: string;
+}
+
+interface B {
+  b: string;
+}
+
+// a type guard for B
+function isB(toTest: any): toTest is B {
+  return toTest && toTest.b;
+}
+
+// a function that turns an A into an A & B
+function union(a: A): A & B | null {
+  if (isB(a)) {
+    return a;
+  } else {
+    return null;
+  }
+}
+
+// Repro from #9016
+
+declare function log(s: string): void;
+
+// Supported beast features
+interface Beast     { wings?: boolean; legs?: number }
+interface Legged    { legs: number; }
+interface Winged    { wings: boolean; }
+
+// Beast feature detection via user-defined type guards
+function hasLegs(x: Beast): x is Legged { return x && typeof x.legs === 'number'; }
+function hasWings(x: Beast): x is Winged { return x && !!x.wings; }
+
+// Function to identify a given beast by detecting its features
+function identifyBeast(beast: Beast) {
+
+    // All beasts with legs
+    if (hasLegs(beast)) {
+
+        // All winged beasts with legs
+        if (hasWings(beast)) {
+            if (beast.legs === 4) {
+                log(`pegasus - 4 legs, wings`);
+            }
+            else if (beast.legs === 2) {
+                log(`bird - 2 legs, wings`);
+            }
+            else {
+                log(`unknown - ${beast.legs} legs, wings`);
+            }
+        }
+
+        // All non-winged beasts with legs
+        else {
+            log(`manbearpig - ${beast.legs} legs, no wings`);
+        }
+    }
+
+    // All beasts without legs    
+    else {
+        if (hasWings(beast)) {
+            log(`quetzalcoatl - no legs, wings`)
+        }
+        else {
+            log(`snake - no legs, no wings`)
+        }
+    }
+}
+
+function beastFoo(beast: Object) {
+    if (hasWings(beast) && hasLegs(beast)) {
+        beast;  // Winged & Legged
+    }
+    else {
+        beast;
+    }
+
+    if (hasLegs(beast) && hasWings(beast)) {
+        beast;  // Legged & Winged
+    }
+}
+
+//// [typeGuardIntersectionTypes.js]
+function f1(obj) {
+    if (isX(obj) || isY(obj) || isZ(obj)) {
+        obj;
+    }
+    if (isX(obj) && isY(obj) && isZ(obj)) {
+        obj;
+    }
+}
+// a type guard for B
+function isB(toTest) {
+    return toTest && toTest.b;
+}
+// a function that turns an A into an A & B
+function union(a) {
+    if (isB(a)) {
+        return a;
+    }
+    else {
+        return null;
+    }
+}
+// Beast feature detection via user-defined type guards
+function hasLegs(x) { return x && typeof x.legs === 'number'; }
+function hasWings(x) { return x && !!x.wings; }
+// Function to identify a given beast by detecting its features
+function identifyBeast(beast) {
+    // All beasts with legs
+    if (hasLegs(beast)) {
+        // All winged beasts with legs
+        if (hasWings(beast)) {
+            if (beast.legs === 4) {
+                log("pegasus - 4 legs, wings");
+            }
+            else if (beast.legs === 2) {
+                log("bird - 2 legs, wings");
+            }
+            else {
+                log("unknown - " + beast.legs + " legs, wings");
+            }
+        }
+        else {
+            log("manbearpig - " + beast.legs + " legs, no wings");
+        }
+    }
+    else {
+        if (hasWings(beast)) {
+            log("quetzalcoatl - no legs, wings");
+        }
+        else {
+            log("snake - no legs, no wings");
+        }
+    }
+}
+function beastFoo(beast) {
+    if (hasWings(beast) && hasLegs(beast)) {
+        beast; // Winged & Legged
+    }
+    else {
+        beast;
+    }
+    if (hasLegs(beast) && hasWings(beast)) {
+        beast; // Legged & Winged
+    }
+}

tests/baselines/reference/typeGuardIntersectionTypes.symbols

@@ -0,0 +1,258 @@
+=== tests/cases/conformance/expressions/typeGuards/typeGuardIntersectionTypes.ts ===
+
+interface X {
+>X : Symbol(X, Decl(typeGuardIntersectionTypes.ts, 0, 0))
+
+    x: string;
+>x : Symbol(X.x, Decl(typeGuardIntersectionTypes.ts, 1, 13))
+}
+
+interface Y {
+>Y : Symbol(Y, Decl(typeGuardIntersectionTypes.ts, 3, 1))
+
+    y: string;
+>y : Symbol(Y.y, Decl(typeGuardIntersectionTypes.ts, 5, 13))
+}
+
+interface Z {
+>Z : Symbol(Z, Decl(typeGuardIntersectionTypes.ts, 7, 1))
+
+    z: string;
+>z : Symbol(Z.z, Decl(typeGuardIntersectionTypes.ts, 9, 13))
+}
+
+declare function isX(obj: any): obj is X;
+>isX : Symbol(isX, Decl(typeGuardIntersectionTypes.ts, 11, 1))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 13, 21))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 13, 21))
+>X : Symbol(X, Decl(typeGuardIntersectionTypes.ts, 0, 0))
+
+declare function isY(obj: any): obj is Y;
+>isY : Symbol(isY, Decl(typeGuardIntersectionTypes.ts, 13, 41))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 14, 21))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 14, 21))
+>Y : Symbol(Y, Decl(typeGuardIntersectionTypes.ts, 3, 1))
+
+declare function isZ(obj: any): obj is Z;
+>isZ : Symbol(isZ, Decl(typeGuardIntersectionTypes.ts, 14, 41))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 15, 21))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 15, 21))
+>Z : Symbol(Z, Decl(typeGuardIntersectionTypes.ts, 7, 1))
+
+function f1(obj: Object) {
+>f1 : Symbol(f1, Decl(typeGuardIntersectionTypes.ts, 15, 41))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 17, 12))
+>Object : Symbol(Object, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+
+    if (isX(obj) || isY(obj) || isZ(obj)) {
+>isX : Symbol(isX, Decl(typeGuardIntersectionTypes.ts, 11, 1))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 17, 12))
+>isY : Symbol(isY, Decl(typeGuardIntersectionTypes.ts, 13, 41))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 17, 12))
+>isZ : Symbol(isZ, Decl(typeGuardIntersectionTypes.ts, 14, 41))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 17, 12))
+
+        obj;
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 17, 12))
+    }
+    if (isX(obj) && isY(obj) && isZ(obj)) {
+>isX : Symbol(isX, Decl(typeGuardIntersectionTypes.ts, 11, 1))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 17, 12))
+>isY : Symbol(isY, Decl(typeGuardIntersectionTypes.ts, 13, 41))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 17, 12))
+>isZ : Symbol(isZ, Decl(typeGuardIntersectionTypes.ts, 14, 41))
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 17, 12))
+
+        obj;
+>obj : Symbol(obj, Decl(typeGuardIntersectionTypes.ts, 17, 12))
+    }
+}
+
+// Repro from #8911
+
+// two interfaces
+interface A {
+>A : Symbol(A, Decl(typeGuardIntersectionTypes.ts, 24, 1))
+
+  a: string;
+>a : Symbol(A.a, Decl(typeGuardIntersectionTypes.ts, 29, 13))
+}
+
+interface B {
+>B : Symbol(B, Decl(typeGuardIntersectionTypes.ts, 31, 1))
+
+  b: string;
+>b : Symbol(B.b, Decl(typeGuardIntersectionTypes.ts, 33, 13))
+}
+
+// a type guard for B
+function isB(toTest: any): toTest is B {
+>isB : Symbol(isB, Decl(typeGuardIntersectionTypes.ts, 35, 1))
+>toTest : Symbol(toTest, Decl(typeGuardIntersectionTypes.ts, 38, 13))
+>toTest : Symbol(toTest, Decl(typeGuardIntersectionTypes.ts, 38, 13))
+>B : Symbol(B, Decl(typeGuardIntersectionTypes.ts, 31, 1))
+
+  return toTest && toTest.b;
+>toTest : Symbol(toTest, Decl(typeGuardIntersectionTypes.ts, 38, 13))
+>toTest : Symbol(toTest, Decl(typeGuardIntersectionTypes.ts, 38, 13))
+}
+
+// a function that turns an A into an A & B
+function union(a: A): A & B | null {
+>union : Symbol(union, Decl(typeGuardIntersectionTypes.ts, 40, 1))
+>a : Symbol(a, Decl(typeGuardIntersectionTypes.ts, 43, 15))
+>A : Symbol(A, Decl(typeGuardIntersectionTypes.ts, 24, 1))
+>A : Symbol(A, Decl(typeGuardIntersectionTypes.ts, 24, 1))
+>B : Symbol(B, Decl(typeGuardIntersectionTypes.ts, 31, 1))
+
+  if (isB(a)) {
+>isB : Symbol(isB, Decl(typeGuardIntersectionTypes.ts, 35, 1))
+>a : Symbol(a, Decl(typeGuardIntersectionTypes.ts, 43, 15))
+
+    return a;
+>a : Symbol(a, Decl(typeGuardIntersectionTypes.ts, 43, 15))
+
+  } else {
+    return null;
+  }
+}
+
+// Repro from #9016
+
+declare function log(s: string): void;
+>log : Symbol(log, Decl(typeGuardIntersectionTypes.ts, 49, 1))
+>s : Symbol(s, Decl(typeGuardIntersectionTypes.ts, 53, 21))
+
+// Supported beast features
+interface Beast     { wings?: boolean; legs?: number }
+>Beast : Symbol(Beast, Decl(typeGuardIntersectionTypes.ts, 53, 38))
+>wings : Symbol(Beast.wings, Decl(typeGuardIntersectionTypes.ts, 56, 21))
+>legs : Symbol(Beast.legs, Decl(typeGuardIntersectionTypes.ts, 56, 38))
+
+interface Legged    { legs: number; }
+>Legged : Symbol(Legged, Decl(typeGuardIntersectionTypes.ts, 56, 54))
+>legs : Symbol(Legged.legs, Decl(typeGuardIntersectionTypes.ts, 57, 21))
+
+interface Winged    { wings: boolean; }
+>Winged : Symbol(Winged, Decl(typeGuardIntersectionTypes.ts, 57, 37))
+>wings : Symbol(Winged.wings, Decl(typeGuardIntersectionTypes.ts, 58, 21))
+
+// Beast feature detection via user-defined type guards
+function hasLegs(x: Beast): x is Legged { return x && typeof x.legs === 'number'; }
+>hasLegs : Symbol(hasLegs, Decl(typeGuardIntersectionTypes.ts, 58, 39))
+>x : Symbol(x, Decl(typeGuardIntersectionTypes.ts, 61, 17))
+>Beast : Symbol(Beast, Decl(typeGuardIntersectionTypes.ts, 53, 38))
+>x : Symbol(x, Decl(typeGuardIntersectionTypes.ts, 61, 17))
+>Legged : Symbol(Legged, Decl(typeGuardIntersectionTypes.ts, 56, 54))
+>x : Symbol(x, Decl(typeGuardIntersectionTypes.ts, 61, 17))
+>x.legs : Symbol(Beast.legs, Decl(typeGuardIntersectionTypes.ts, 56, 38))
+>x : Symbol(x, Decl(typeGuardIntersectionTypes.ts, 61, 17))
+>legs : Symbol(Beast.legs, Decl(typeGuardIntersectionTypes.ts, 56, 38))
+
+function hasWings(x: Beast): x is Winged { return x && !!x.wings; }
+>hasWings : Symbol(hasWings, Decl(typeGuardIntersectionTypes.ts, 61, 83))
+>x : Symbol(x, Decl(typeGuardIntersectionTypes.ts, 62, 18))
+>Beast : Symbol(Beast, Decl(typeGuardIntersectionTypes.ts, 53, 38))
+>x : Symbol(x, Decl(typeGuardIntersectionTypes.ts, 62, 18))
+>Winged : Symbol(Winged, Decl(typeGuardIntersectionTypes.ts, 57, 37))
+>x : Symbol(x, Decl(typeGuardIntersectionTypes.ts, 62, 18))
+>x.wings : Symbol(Beast.wings, Decl(typeGuardIntersectionTypes.ts, 56, 21))
+>x : Symbol(x, Decl(typeGuardIntersectionTypes.ts, 62, 18))
+>wings : Symbol(Beast.wings, Decl(typeGuardIntersectionTypes.ts, 56, 21))
+
+// Function to identify a given beast by detecting its features
+function identifyBeast(beast: Beast) {
+>identifyBeast : Symbol(identifyBeast, Decl(typeGuardIntersectionTypes.ts, 62, 67))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 65, 23))
+>Beast : Symbol(Beast, Decl(typeGuardIntersectionTypes.ts, 53, 38))
+
+    // All beasts with legs
+    if (hasLegs(beast)) {
+>hasLegs : Symbol(hasLegs, Decl(typeGuardIntersectionTypes.ts, 58, 39))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 65, 23))
+
+        // All winged beasts with legs
+        if (hasWings(beast)) {
+>hasWings : Symbol(hasWings, Decl(typeGuardIntersectionTypes.ts, 61, 83))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 65, 23))
+
+            if (beast.legs === 4) {
+>beast.legs : Symbol(Legged.legs, Decl(typeGuardIntersectionTypes.ts, 57, 21))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 65, 23))
+>legs : Symbol(Legged.legs, Decl(typeGuardIntersectionTypes.ts, 57, 21))
+
+                log(`pegasus - 4 legs, wings`);
+>log : Symbol(log, Decl(typeGuardIntersectionTypes.ts, 49, 1))
+            }
+            else if (beast.legs === 2) {
+>beast.legs : Symbol(Legged.legs, Decl(typeGuardIntersectionTypes.ts, 57, 21))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 65, 23))
+>legs : Symbol(Legged.legs, Decl(typeGuardIntersectionTypes.ts, 57, 21))
+
+                log(`bird - 2 legs, wings`);
+>log : Symbol(log, Decl(typeGuardIntersectionTypes.ts, 49, 1))
+            }
+            else {
+                log(`unknown - ${beast.legs} legs, wings`);
+>log : Symbol(log, Decl(typeGuardIntersectionTypes.ts, 49, 1))
+>beast.legs : Symbol(Legged.legs, Decl(typeGuardIntersectionTypes.ts, 57, 21))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 65, 23))
+>legs : Symbol(Legged.legs, Decl(typeGuardIntersectionTypes.ts, 57, 21))
+            }
+        }
+
+        // All non-winged beasts with legs
+        else {
+            log(`manbearpig - ${beast.legs} legs, no wings`);
+>log : Symbol(log, Decl(typeGuardIntersectionTypes.ts, 49, 1))
+>beast.legs : Symbol(Legged.legs, Decl(typeGuardIntersectionTypes.ts, 57, 21))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 65, 23))
+>legs : Symbol(Legged.legs, Decl(typeGuardIntersectionTypes.ts, 57, 21))
+        }
+    }
+
+    // All beasts without legs    
+    else {
+        if (hasWings(beast)) {
+>hasWings : Symbol(hasWings, Decl(typeGuardIntersectionTypes.ts, 61, 83))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 65, 23))
+
+            log(`quetzalcoatl - no legs, wings`)
+>log : Symbol(log, Decl(typeGuardIntersectionTypes.ts, 49, 1))
+        }
+        else {
+            log(`snake - no legs, no wings`)
+>log : Symbol(log, Decl(typeGuardIntersectionTypes.ts, 49, 1))
+        }
+    }
+}
+
+function beastFoo(beast: Object) {
+>beastFoo : Symbol(beastFoo, Decl(typeGuardIntersectionTypes.ts, 98, 1))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 100, 18))
+>Object : Symbol(Object, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+
+    if (hasWings(beast) && hasLegs(beast)) {
+>hasWings : Symbol(hasWings, Decl(typeGuardIntersectionTypes.ts, 61, 83))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 100, 18))
+>hasLegs : Symbol(hasLegs, Decl(typeGuardIntersectionTypes.ts, 58, 39))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 100, 18))
+
+        beast;  // Winged & Legged
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 100, 18))
+    }
+    else {
+        beast;
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 100, 18))
+    }
+
+    if (hasLegs(beast) && hasWings(beast)) {
+>hasLegs : Symbol(hasLegs, Decl(typeGuardIntersectionTypes.ts, 58, 39))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 100, 18))
+>hasWings : Symbol(hasWings, Decl(typeGuardIntersectionTypes.ts, 61, 83))
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 100, 18))
+
+        beast;  // Legged & Winged
+>beast : Symbol(beast, Decl(typeGuardIntersectionTypes.ts, 100, 18))
+    }
+}

tests/baselines/reference/typeGuardIntersectionTypes.types

@@ -0,0 +1,306 @@
+=== tests/cases/conformance/expressions/typeGuards/typeGuardIntersectionTypes.ts ===
+
+interface X {
+>X : X
+
+    x: string;
+>x : string
+}
+
+interface Y {
+>Y : Y
+
+    y: string;
+>y : string
+}
+
+interface Z {
+>Z : Z
+
+    z: string;
+>z : string
+}
+
+declare function isX(obj: any): obj is X;
+>isX : (obj: any) => obj is X
+>obj : any
+>obj : any
+>X : X
+
+declare function isY(obj: any): obj is Y;
+>isY : (obj: any) => obj is Y
+>obj : any
+>obj : any
+>Y : Y
+
+declare function isZ(obj: any): obj is Z;
+>isZ : (obj: any) => obj is Z
+>obj : any
+>obj : any
+>Z : Z
+
+function f1(obj: Object) {
+>f1 : (obj: Object) => void
+>obj : Object
+>Object : Object
+
+    if (isX(obj) || isY(obj) || isZ(obj)) {
+>isX(obj) || isY(obj) || isZ(obj) : boolean
+>isX(obj) || isY(obj) : boolean
+>isX(obj) : boolean
+>isX : (obj: any) => obj is X
+>obj : Object
+>isY(obj) : boolean
+>isY : (obj: any) => obj is Y
+>obj : Object
+>isZ(obj) : boolean
+>isZ : (obj: any) => obj is Z
+>obj : Object
+
+        obj;
+>obj : X | Y | Z
+    }
+    if (isX(obj) && isY(obj) && isZ(obj)) {
+>isX(obj) && isY(obj) && isZ(obj) : boolean
+>isX(obj) && isY(obj) : boolean
+>isX(obj) : boolean
+>isX : (obj: any) => obj is X
+>obj : Object
+>isY(obj) : boolean
+>isY : (obj: any) => obj is Y
+>obj : X
+>isZ(obj) : boolean
+>isZ : (obj: any) => obj is Z
+>obj : X & Y
+
+        obj;
+>obj : X & Y & Z
+    }
+}
+
+// Repro from #8911
+
+// two interfaces
+interface A {
+>A : A
+
+  a: string;
+>a : string
+}
+
+interface B {
+>B : B
+
+  b: string;
+>b : string
+}
+
+// a type guard for B
+function isB(toTest: any): toTest is B {
+>isB : (toTest: any) => toTest is B
+>toTest : any
+>toTest : any
+>B : B
+
+  return toTest && toTest.b;
+>toTest && toTest.b : any
+>toTest : any
+>toTest.b : any
+>toTest : any
+>b : any
+}
+
+// a function that turns an A into an A & B
+function union(a: A): A & B | null {
+>union : (a: A) => (A & B) | null
+>a : A
+>A : A
+>A : A
+>B : B
+>null : null
+
+  if (isB(a)) {
+>isB(a) : boolean
+>isB : (toTest: any) => toTest is B
+>a : A
+
+    return a;
+>a : A & B
+
+  } else {
+    return null;
+>null : null
+  }
+}
+
+// Repro from #9016
+
+declare function log(s: string): void;
+>log : (s: string) => void
+>s : string
+
+// Supported beast features
+interface Beast     { wings?: boolean; legs?: number }
+>Beast : Beast
+>wings : boolean | undefined
+>legs : number | undefined
+
+interface Legged    { legs: number; }
+>Legged : Legged
+>legs : number
+
+interface Winged    { wings: boolean; }
+>Winged : Winged
+>wings : boolean
+
+// Beast feature detection via user-defined type guards
+function hasLegs(x: Beast): x is Legged { return x && typeof x.legs === 'number'; }
+>hasLegs : (x: Beast) => x is Legged
+>x : Beast
+>Beast : Beast
+>x : any
+>Legged : Legged
+>x && typeof x.legs === 'number' : boolean
+>x : Beast
+>typeof x.legs === 'number' : boolean
+>typeof x.legs : string
+>x.legs : number | undefined
+>x : Beast
+>legs : number | undefined
+>'number' : string
+
+function hasWings(x: Beast): x is Winged { return x && !!x.wings; }
+>hasWings : (x: Beast) => x is Winged
+>x : Beast
+>Beast : Beast
+>x : any
+>Winged : Winged
+>x && !!x.wings : boolean
+>x : Beast
+>!!x.wings : boolean
+>!x.wings : boolean
+>x.wings : boolean | undefined
+>x : Beast
+>wings : boolean | undefined
+
+// Function to identify a given beast by detecting its features
+function identifyBeast(beast: Beast) {
+>identifyBeast : (beast: Beast) => void
+>beast : Beast
+>Beast : Beast
+
+    // All beasts with legs
+    if (hasLegs(beast)) {
+>hasLegs(beast) : boolean
+>hasLegs : (x: Beast) => x is Legged
+>beast : Beast
+
+        // All winged beasts with legs
+        if (hasWings(beast)) {
+>hasWings(beast) : boolean
+>hasWings : (x: Beast) => x is Winged
+>beast : Legged
+
+            if (beast.legs === 4) {
+>beast.legs === 4 : boolean
+>beast.legs : number
+>beast : Legged & Winged
+>legs : number
+>4 : number
+
+                log(`pegasus - 4 legs, wings`);
+>log(`pegasus - 4 legs, wings`) : void
+>log : (s: string) => void
+>`pegasus - 4 legs, wings` : string
+            }
+            else if (beast.legs === 2) {
+>beast.legs === 2 : boolean
+>beast.legs : number
+>beast : Legged & Winged
+>legs : number
+>2 : number
+
+                log(`bird - 2 legs, wings`);
+>log(`bird - 2 legs, wings`) : void
+>log : (s: string) => void
+>`bird - 2 legs, wings` : string
+            }
+            else {
+                log(`unknown - ${beast.legs} legs, wings`);
+>log(`unknown - ${beast.legs} legs, wings`) : void
+>log : (s: string) => void
+>`unknown - ${beast.legs} legs, wings` : string
+>beast.legs : number
+>beast : Legged & Winged
+>legs : number
+            }
+        }
+
+        // All non-winged beasts with legs
+        else {
+            log(`manbearpig - ${beast.legs} legs, no wings`);
+>log(`manbearpig - ${beast.legs} legs, no wings`) : void
+>log : (s: string) => void
+>`manbearpig - ${beast.legs} legs, no wings` : string
+>beast.legs : number
+>beast : Legged
+>legs : number
+        }
+    }
+
+    // All beasts without legs    
+    else {
+        if (hasWings(beast)) {
+>hasWings(beast) : boolean
+>hasWings : (x: Beast) => x is Winged
+>beast : Beast
+
+            log(`quetzalcoatl - no legs, wings`)
+>log(`quetzalcoatl - no legs, wings`) : void
+>log : (s: string) => void
+>`quetzalcoatl - no legs, wings` : string
+        }
+        else {
+            log(`snake - no legs, no wings`)
+>log(`snake - no legs, no wings`) : void
+>log : (s: string) => void
+>`snake - no legs, no wings` : string
+        }
+    }
+}
+
+function beastFoo(beast: Object) {
+>beastFoo : (beast: Object) => void
+>beast : Object
+>Object : Object
+
+    if (hasWings(beast) && hasLegs(beast)) {
+>hasWings(beast) && hasLegs(beast) : boolean
+>hasWings(beast) : boolean
+>hasWings : (x: Beast) => x is Winged
+>beast : Object
+>hasLegs(beast) : boolean
+>hasLegs : (x: Beast) => x is Legged
+>beast : Winged
+
+        beast;  // Winged & Legged
+>beast : Winged & Legged
+    }
+    else {
+        beast;
+>beast : Object
+    }
+
+    if (hasLegs(beast) && hasWings(beast)) {
+>hasLegs(beast) && hasWings(beast) : boolean
+>hasLegs(beast) : boolean
+>hasLegs : (x: Beast) => x is Legged
+>beast : Object
+>hasWings(beast) : boolean
+>hasWings : (x: Beast) => x is Winged
+>beast : Legged
+
+        beast;  // Legged & Winged
+>beast : Legged & Winged
+    }
+}

tests/baselines/reference/typeGuardsNestedAssignments.js

@@ -0,0 +1,86 @@
+//// [typeGuardsNestedAssignments.ts]
+
+class Foo {
+    x: string;
+}
+
+declare function getFooOrNull(): Foo | null;
+declare function getStringOrNumberOrNull(): string | number | null;
+
+function f1() {
+    let foo: Foo | null;
+    if ((foo = getFooOrNull()) !== null) {
+        foo;  // Foo
+    }
+}
+
+function f2() {
+    let foo1: Foo | null;
+    let foo2: Foo | null;
+    if ((foo1 = getFooOrNull(), foo2 = foo1) !== null) {
+        foo1;  // Foo | null
+        foo2;  // Foo
+    }
+}
+
+function f3() {
+    let obj: Object | null;
+    if ((obj = getFooOrNull()) instanceof Foo) {
+        obj;
+    }
+}
+
+function f4() {
+    let x: string | number | null;
+    if (typeof (x = getStringOrNumberOrNull()) === "number") {
+        x;
+    }
+}
+
+// Repro from #8851
+
+const re = /./g
+let match: RegExpExecArray | null
+
+while ((match = re.exec("xxx")) != null) {
+    const length = match[1].length + match[2].length
+}
+
+//// [typeGuardsNestedAssignments.js]
+var Foo = (function () {
+    function Foo() {
+    }
+    return Foo;
+}());
+function f1() {
+    var foo;
+    if ((foo = getFooOrNull()) !== null) {
+        foo; // Foo
+    }
+}
+function f2() {
+    var foo1;
+    var foo2;
+    if ((foo1 = getFooOrNull(), foo2 = foo1) !== null) {
+        foo1; // Foo | null
+        foo2; // Foo
+    }
+}
+function f3() {
+    var obj;
+    if ((obj = getFooOrNull()) instanceof Foo) {
+        obj;
+    }
+}
+function f4() {
+    var x;
+    if (typeof (x = getStringOrNumberOrNull()) === "number") {
+        x;
+    }
+}
+// Repro from #8851
+var re = /./g;
+var match;
+while ((match = re.exec("xxx")) != null) {
+    var length = match[1].length + match[2].length;
+}

tests/baselines/reference/typeGuardsNestedAssignments.symbols

@@ -0,0 +1,113 @@
+=== tests/cases/conformance/controlFlow/typeGuardsNestedAssignments.ts ===
+
+class Foo {
+>Foo : Symbol(Foo, Decl(typeGuardsNestedAssignments.ts, 0, 0))
+
+    x: string;
+>x : Symbol(Foo.x, Decl(typeGuardsNestedAssignments.ts, 1, 11))
+}
+
+declare function getFooOrNull(): Foo | null;
+>getFooOrNull : Symbol(getFooOrNull, Decl(typeGuardsNestedAssignments.ts, 3, 1))
+>Foo : Symbol(Foo, Decl(typeGuardsNestedAssignments.ts, 0, 0))
+
+declare function getStringOrNumberOrNull(): string | number | null;
+>getStringOrNumberOrNull : Symbol(getStringOrNumberOrNull, Decl(typeGuardsNestedAssignments.ts, 5, 44))
+
+function f1() {
+>f1 : Symbol(f1, Decl(typeGuardsNestedAssignments.ts, 6, 67))
+
+    let foo: Foo | null;
+>foo : Symbol(foo, Decl(typeGuardsNestedAssignments.ts, 9, 7))
+>Foo : Symbol(Foo, Decl(typeGuardsNestedAssignments.ts, 0, 0))
+
+    if ((foo = getFooOrNull()) !== null) {
+>foo : Symbol(foo, Decl(typeGuardsNestedAssignments.ts, 9, 7))
+>getFooOrNull : Symbol(getFooOrNull, Decl(typeGuardsNestedAssignments.ts, 3, 1))
+
+        foo;  // Foo
+>foo : Symbol(foo, Decl(typeGuardsNestedAssignments.ts, 9, 7))
+    }
+}
+
+function f2() {
+>f2 : Symbol(f2, Decl(typeGuardsNestedAssignments.ts, 13, 1))
+
+    let foo1: Foo | null;
+>foo1 : Symbol(foo1, Decl(typeGuardsNestedAssignments.ts, 16, 7))
+>Foo : Symbol(Foo, Decl(typeGuardsNestedAssignments.ts, 0, 0))
+
+    let foo2: Foo | null;
+>foo2 : Symbol(foo2, Decl(typeGuardsNestedAssignments.ts, 17, 7))
+>Foo : Symbol(Foo, Decl(typeGuardsNestedAssignments.ts, 0, 0))
+
+    if ((foo1 = getFooOrNull(), foo2 = foo1) !== null) {
+>foo1 : Symbol(foo1, Decl(typeGuardsNestedAssignments.ts, 16, 7))
+>getFooOrNull : Symbol(getFooOrNull, Decl(typeGuardsNestedAssignments.ts, 3, 1))
+>foo2 : Symbol(foo2, Decl(typeGuardsNestedAssignments.ts, 17, 7))
+>foo1 : Symbol(foo1, Decl(typeGuardsNestedAssignments.ts, 16, 7))
+
+        foo1;  // Foo | null
+>foo1 : Symbol(foo1, Decl(typeGuardsNestedAssignments.ts, 16, 7))
+
+        foo2;  // Foo
+>foo2 : Symbol(foo2, Decl(typeGuardsNestedAssignments.ts, 17, 7))
+    }
+}
+
+function f3() {
+>f3 : Symbol(f3, Decl(typeGuardsNestedAssignments.ts, 22, 1))
+
+    let obj: Object | null;
+>obj : Symbol(obj, Decl(typeGuardsNestedAssignments.ts, 25, 7))
+>Object : Symbol(Object, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+
+    if ((obj = getFooOrNull()) instanceof Foo) {
+>obj : Symbol(obj, Decl(typeGuardsNestedAssignments.ts, 25, 7))
+>getFooOrNull : Symbol(getFooOrNull, Decl(typeGuardsNestedAssignments.ts, 3, 1))
+>Foo : Symbol(Foo, Decl(typeGuardsNestedAssignments.ts, 0, 0))
+
+        obj;
+>obj : Symbol(obj, Decl(typeGuardsNestedAssignments.ts, 25, 7))
+    }
+}
+
+function f4() {
+>f4 : Symbol(f4, Decl(typeGuardsNestedAssignments.ts, 29, 1))
+
+    let x: string | number | null;
+>x : Symbol(x, Decl(typeGuardsNestedAssignments.ts, 32, 7))
+
+    if (typeof (x = getStringOrNumberOrNull()) === "number") {
+>x : Symbol(x, Decl(typeGuardsNestedAssignments.ts, 32, 7))
+>getStringOrNumberOrNull : Symbol(getStringOrNumberOrNull, Decl(typeGuardsNestedAssignments.ts, 5, 44))
+
+        x;
+>x : Symbol(x, Decl(typeGuardsNestedAssignments.ts, 32, 7))
+    }
+}
+
+// Repro from #8851
+
+const re = /./g
+>re : Symbol(re, Decl(typeGuardsNestedAssignments.ts, 40, 5))
+
+let match: RegExpExecArray | null
+>match : Symbol(match, Decl(typeGuardsNestedAssignments.ts, 41, 3))
+>RegExpExecArray : Symbol(RegExpExecArray, Decl(lib.d.ts, --, --))
+
+while ((match = re.exec("xxx")) != null) {
+>match : Symbol(match, Decl(typeGuardsNestedAssignments.ts, 41, 3))
+>re.exec : Symbol(RegExp.exec, Decl(lib.d.ts, --, --))
+>re : Symbol(re, Decl(typeGuardsNestedAssignments.ts, 40, 5))
+>exec : Symbol(RegExp.exec, Decl(lib.d.ts, --, --))
+
+    const length = match[1].length + match[2].length
+>length : Symbol(length, Decl(typeGuardsNestedAssignments.ts, 44, 9))
+>match[1].length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>match : Symbol(match, Decl(typeGuardsNestedAssignments.ts, 41, 3))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>match[2].length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>match : Symbol(match, Decl(typeGuardsNestedAssignments.ts, 41, 3))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+}

tests/baselines/reference/typeGuardsNestedAssignments.types

@@ -0,0 +1,155 @@
+=== tests/cases/conformance/controlFlow/typeGuardsNestedAssignments.ts ===
+
+class Foo {
+>Foo : Foo
+
+    x: string;
+>x : string
+}
+
+declare function getFooOrNull(): Foo | null;
+>getFooOrNull : () => Foo | null
+>Foo : Foo
+>null : null
+
+declare function getStringOrNumberOrNull(): string | number | null;
+>getStringOrNumberOrNull : () => string | number | null
+>null : null
+
+function f1() {
+>f1 : () => void
+
+    let foo: Foo | null;
+>foo : Foo | null
+>Foo : Foo
+>null : null
+
+    if ((foo = getFooOrNull()) !== null) {
+>(foo = getFooOrNull()) !== null : boolean
+>(foo = getFooOrNull()) : Foo | null
+>foo = getFooOrNull() : Foo | null
+>foo : Foo | null
+>getFooOrNull() : Foo | null
+>getFooOrNull : () => Foo | null
+>null : null
+
+        foo;  // Foo
+>foo : Foo
+    }
+}
+
+function f2() {
+>f2 : () => void
+
+    let foo1: Foo | null;
+>foo1 : Foo | null
+>Foo : Foo
+>null : null
+
+    let foo2: Foo | null;
+>foo2 : Foo | null
+>Foo : Foo
+>null : null
+
+    if ((foo1 = getFooOrNull(), foo2 = foo1) !== null) {
+>(foo1 = getFooOrNull(), foo2 = foo1) !== null : boolean
+>(foo1 = getFooOrNull(), foo2 = foo1) : Foo | null
+>foo1 = getFooOrNull(), foo2 = foo1 : Foo | null
+>foo1 = getFooOrNull() : Foo | null
+>foo1 : Foo | null
+>getFooOrNull() : Foo | null
+>getFooOrNull : () => Foo | null
+>foo2 = foo1 : Foo | null
+>foo2 : Foo | null
+>foo1 : Foo | null
+>null : null
+
+        foo1;  // Foo | null
+>foo1 : Foo | null
+
+        foo2;  // Foo
+>foo2 : Foo
+    }
+}
+
+function f3() {
+>f3 : () => void
+
+    let obj: Object | null;
+>obj : Object | null
+>Object : Object
+>null : null
+
+    if ((obj = getFooOrNull()) instanceof Foo) {
+>(obj = getFooOrNull()) instanceof Foo : boolean
+>(obj = getFooOrNull()) : Foo | null
+>obj = getFooOrNull() : Foo | null
+>obj : Object | null
+>getFooOrNull() : Foo | null
+>getFooOrNull : () => Foo | null
+>Foo : typeof Foo
+
+        obj;
+>obj : Foo
+    }
+}
+
+function f4() {
+>f4 : () => void
+
+    let x: string | number | null;
+>x : string | number | null
+>null : null
+
+    if (typeof (x = getStringOrNumberOrNull()) === "number") {
+>typeof (x = getStringOrNumberOrNull()) === "number" : boolean
+>typeof (x = getStringOrNumberOrNull()) : string
+>(x = getStringOrNumberOrNull()) : string | number | null
+>x = getStringOrNumberOrNull() : string | number | null
+>x : string | number | null
+>getStringOrNumberOrNull() : string | number | null
+>getStringOrNumberOrNull : () => string | number | null
+>"number" : string
+
+        x;
+>x : number
+    }
+}
+
+// Repro from #8851
+
+const re = /./g
+>re : RegExp
+>/./g : RegExp
+
+let match: RegExpExecArray | null
+>match : RegExpExecArray | null
+>RegExpExecArray : RegExpExecArray
+>null : null
+
+while ((match = re.exec("xxx")) != null) {
+>(match = re.exec("xxx")) != null : boolean
+>(match = re.exec("xxx")) : RegExpExecArray | null
+>match = re.exec("xxx") : RegExpExecArray | null
+>match : RegExpExecArray | null
+>re.exec("xxx") : RegExpExecArray | null
+>re.exec : (string: string) => RegExpExecArray | null
+>re : RegExp
+>exec : (string: string) => RegExpExecArray | null
+>"xxx" : string
+>null : null
+
+    const length = match[1].length + match[2].length
+>length : number
+>match[1].length + match[2].length : number
+>match[1].length : number
+>match[1] : string
+>match : RegExpExecArray
+>1 : number
+>length : number
+>match[2].length : number
+>match[2] : string
+>match : RegExpExecArray
+>2 : number
+>length : number
+}

tests/baselines/reference/typeGuardsWithInstanceOf.errors.txt

@@ -1,14 +0,0 @@
-tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOf.ts(7,20): error TS2339: Property 'global' does not exist on type 'never'.
-
-
-==== tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOf.ts (1 errors) ====
-    interface I { global: string; }
-    var result: I;
-    var result2: I;
-    
-    if (!(result instanceof RegExp)) {
-        result = result2;
-    } else if (!result.global) {
-                       ~~~~~~
-!!! error TS2339: Property 'global' does not exist on type 'never'.
-    }

tests/baselines/reference/typeGuardsWithInstanceOf.symbols

@@ -0,0 +1,26 @@
+=== tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOf.ts ===
+interface I { global: string; }
+>I : Symbol(I, Decl(typeGuardsWithInstanceOf.ts, 0, 0))
+>global : Symbol(I.global, Decl(typeGuardsWithInstanceOf.ts, 0, 13))
+
+var result: I;
+>result : Symbol(result, Decl(typeGuardsWithInstanceOf.ts, 1, 3))
+>I : Symbol(I, Decl(typeGuardsWithInstanceOf.ts, 0, 0))
+
+var result2: I;
+>result2 : Symbol(result2, Decl(typeGuardsWithInstanceOf.ts, 2, 3))
+>I : Symbol(I, Decl(typeGuardsWithInstanceOf.ts, 0, 0))
+
+if (!(result instanceof RegExp)) {
+>result : Symbol(result, Decl(typeGuardsWithInstanceOf.ts, 1, 3))
+>RegExp : Symbol(RegExp, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+
+    result = result2;
+>result : Symbol(result, Decl(typeGuardsWithInstanceOf.ts, 1, 3))
+>result2 : Symbol(result2, Decl(typeGuardsWithInstanceOf.ts, 2, 3))
+
+} else if (!result.global) {
+>result.global : Symbol(global, Decl(typeGuardsWithInstanceOf.ts, 0, 13), Decl(lib.d.ts, --, --))
+>result : Symbol(result, Decl(typeGuardsWithInstanceOf.ts, 1, 3))
+>global : Symbol(global, Decl(typeGuardsWithInstanceOf.ts, 0, 13), Decl(lib.d.ts, --, --))
+}

tests/baselines/reference/typeGuardsWithInstanceOf.types

@@ -0,0 +1,31 @@
+=== tests/cases/conformance/expressions/typeGuards/typeGuardsWithInstanceOf.ts ===
+interface I { global: string; }
+>I : I
+>global : string
+
+var result: I;
+>result : I
+>I : I
+
+var result2: I;
+>result2 : I
+>I : I
+
+if (!(result instanceof RegExp)) {
+>!(result instanceof RegExp) : boolean
+>(result instanceof RegExp) : boolean
+>result instanceof RegExp : boolean
+>result : I
+>RegExp : RegExpConstructor
+
+    result = result2;
+>result = result2 : I
+>result : I
+>result2 : I
+
+} else if (!result.global) {
+>!result.global : boolean
+>result.global : string & boolean
+>result : I & RegExp
+>global : string & boolean
+}

tests/baselines/reference/typeReferenceDirectives13.symbols

@@ -8,7 +8,7 @@ export interface A {
 
     x: () => typeof $
 >x : Symbol(A.x, Decl(app.ts, 2, 20))
->$ : Symbol($, Decl(app.ts, 1, 8))
+>$ : Symbol($, Decl(index.d.ts, 0, 11))
 }
 
 === /ref.d.ts ===

tests/baselines/reference/typeReferenceDirectives5.symbols

@@ -8,7 +8,7 @@ export interface A {
 
     x: typeof $;
 >x : Symbol(A.x, Decl(app.ts, 2, 20))
->$ : Symbol($, Decl(app.ts, 1, 8))
+>$ : Symbol($, Decl(index.d.ts, 0, 11))
 }
 === /ref.d.ts ===
 

tests/cases/compiler/asyncFunctionReturnType.ts

@@ -0,0 +1,10 @@
+// @target: ES6
+async function fAsync() {
+    // Without explicit type annotation, this is just an array.
+    return [1, true];
+}
+
+async function fAsyncExplicit(): Promise<[number, boolean]> {
+    // This is contextually typed as a tuple.
+    return [1, true];
+}

tests/cases/compiler/disallowAsyncModifierInES5.ts

@@ -0,0 +1,5 @@
+// @target: es5
+
+async function foo() { return 42; } // ERROR: Async functions are only available in ES6+
+let bar = async function () { return 42; } // OK, but should be an error
+let baz = async () => 42; // OK, but should be an error

tests/cases/conformance/ambient/ambientDeclarationsPatterns.ts

@@ -0,0 +1,30 @@
+// @Filename: declarations.d.ts
+declare module "foo*baz" {
+    export function foo(s: string): void;
+}
+// Augmentations still work
+declare module "foo*baz" {
+    export const baz: string;
+}
+
+// Longest prefix wins
+declare module "foos*" {
+    export const foos: string;
+}
+
+declare module "*!text" {
+    const x: string;
+    export default x;
+}
+
+// @Filename: user.ts
+///<reference path="declarations.d.ts" />
+import {foo, baz} from "foobarbaz";
+foo(baz);
+
+import {foos} from "foosball";
+foo(foos);
+
+// Works with relative file name
+import fileText from "./file!text";
+foo(fileText);

tests/cases/conformance/ambient/ambientDeclarationsPatterns_tooManyAsterisks.ts

@@ -0,0 +1 @@
+declare module "too*many*asterisks" { }

tests/cases/conformance/controlFlow/typeGuardsNestedAssignments.ts

@@ -0,0 +1,47 @@
+// @strictNullChecks: true
+
+class Foo {
+    x: string;
+}
+
+declare function getFooOrNull(): Foo | null;
+declare function getStringOrNumberOrNull(): string | number | null;
+
+function f1() {
+    let foo: Foo | null;
+    if ((foo = getFooOrNull()) !== null) {
+        foo;  // Foo
+    }
+}
+
+function f2() {
+    let foo1: Foo | null;
+    let foo2: Foo | null;
+    if ((foo1 = getFooOrNull(), foo2 = foo1) !== null) {
+        foo1;  // Foo | null
+        foo2;  // Foo
+    }
+}
+
+function f3() {
+    let obj: Object | null;
+    if ((obj = getFooOrNull()) instanceof Foo) {
+        obj;
+    }
+}
+
+function f4() {
+    let x: string | number | null;
+    if (typeof (x = getStringOrNumberOrNull()) === "number") {
+        x;
+    }
+}
+
+// Repro from #8851
+
+const re = /./g
+let match: RegExpExecArray | null
+
+while ((match = re.exec("xxx")) != null) {
+    const length = match[1].length + match[2].length
+}

tests/cases/conformance/expressions/binaryOperators/logicalAndOperator/logicalAndOperatorStrictMode.ts

@@ -0,0 +1,82 @@
+// @strictNullChecks: true
+
+const a = [0];
+const s = "";
+const x = 0;
+const b = false;
+const v: void = undefined;
+const u = undefined;
+const n = null;
+const z = s || x || u;
+
+const a1 = a && a;
+const a2 = a && s;
+const a3 = a && x;
+const a4 = a && b;
+const a5 = a && v;
+const a6 = a && u;
+const a7 = a && n;
+const a8 = a && z;
+
+const s1 = s && a;
+const s2 = s && s;
+const s3 = s && x;
+const s4 = s && b;
+const s5 = s && v;
+const s6 = s && u;
+const s7 = s && n;
+const s8 = s && z;
+
+const x1 = x && a;
+const x2 = x && s;
+const x3 = x && x;
+const x4 = x && b;
+const x5 = x && v;
+const x6 = x && u;
+const x7 = x && n;
+const x8 = x && z;
+
+const b1 = b && a;
+const b2 = b && s;
+const b3 = b && x;
+const b4 = b && b;
+const b5 = b && v;
+const b6 = b && u;
+const b7 = b && n;
+const b8 = b && z;
+
+const v1 = v && a;
+const v2 = v && s;
+const v3 = v && x;
+const v4 = v && b;
+const v5 = v && v;
+const v6 = v && u;
+const v7 = v && n;
+const v8 = v && z;
+
+const u1 = u && a;
+const u2 = u && s;
+const u3 = u && x;
+const u4 = u && b;
+const u5 = u && v;
+const u6 = u && u;
+const u7 = u && n;
+const u8 = u && z;
+
+const n1 = n && a;
+const n2 = n && s;
+const n3 = n && x;
+const n4 = n && b;
+const n5 = n && v;
+const n6 = n && u;
+const n7 = n && n;
+const n8 = n && z;
+
+const z1 = z && a;
+const z2 = z && s;
+const z3 = z && x;
+const z4 = z && b;
+const z5 = z && v;
+const z6 = z && u;
+const z7 = z && n;
+const z8 = z && z;

tests/cases/conformance/expressions/typeGuards/typeGuardIntersectionTypes.ts

@@ -0,0 +1,113 @@
+// @strictNullChecks: true
+
+interface X {
+    x: string;
+}
+
+interface Y {
+    y: string;
+}
+
+interface Z {
+    z: string;
+}
+
+declare function isX(obj: any): obj is X;
+declare function isY(obj: any): obj is Y;
+declare function isZ(obj: any): obj is Z;
+
+function f1(obj: Object) {
+    if (isX(obj) || isY(obj) || isZ(obj)) {
+        obj;
+    }
+    if (isX(obj) && isY(obj) && isZ(obj)) {
+        obj;
+    }
+}
+
+// Repro from #8911
+
+// two interfaces
+interface A {
+  a: string;
+}
+
+interface B {
+  b: string;
+}
+
+// a type guard for B
+function isB(toTest: any): toTest is B {
+  return toTest && toTest.b;
+}
+
+// a function that turns an A into an A & B
+function union(a: A): A & B | null {
+  if (isB(a)) {
+    return a;
+  } else {
+    return null;
+  }
+}
+
+// Repro from #9016
+
+declare function log(s: string): void;
+
+// Supported beast features
+interface Beast     { wings?: boolean; legs?: number }
+interface Legged    { legs: number; }
+interface Winged    { wings: boolean; }
+
+// Beast feature detection via user-defined type guards
+function hasLegs(x: Beast): x is Legged { return x && typeof x.legs === 'number'; }
+function hasWings(x: Beast): x is Winged { return x && !!x.wings; }
+
+// Function to identify a given beast by detecting its features
+function identifyBeast(beast: Beast) {
+
+    // All beasts with legs
+    if (hasLegs(beast)) {
+
+        // All winged beasts with legs
+        if (hasWings(beast)) {
+            if (beast.legs === 4) {
+                log(`pegasus - 4 legs, wings`);
+            }
+            else if (beast.legs === 2) {
+                log(`bird - 2 legs, wings`);
+            }
+            else {
+                log(`unknown - ${beast.legs} legs, wings`);
+            }
+        }
+
+        // All non-winged beasts with legs
+        else {
+            log(`manbearpig - ${beast.legs} legs, no wings`);
+        }
+    }
+
+    // All beasts without legs    
+    else {
+        if (hasWings(beast)) {
+            log(`quetzalcoatl - no legs, wings`)
+        }
+        else {
+            log(`snake - no legs, no wings`)
+        }
+    }
+}
+
+function beastFoo(beast: Object) {
+    if (hasWings(beast) && hasLegs(beast)) {
+        beast;  // Winged & Legged
+    }
+    else {
+        beast;
+    }
+
+    if (hasLegs(beast) && hasWings(beast)) {
+        beast;  // Legged & Winged
+    }
+}

tests/cases/conformance/externalModules/moduleResolutionWithExtensions.ts

@@ -0,0 +1,28 @@
+// @traceResolution: true
+
+// @Filename: /src/a.ts
+export default 0;
+
+// No extension: '.ts' added
+// @Filename: /src/b.ts
+import a from './a';
+
+// Matching extension
+// @Filename: /src/c.ts
+import a from './a.ts';
+
+// '.js' extension: stripped and replaced with '.ts'
+// @Filename: /src/d.ts
+import a from './a.js';
+
+// @Filename: /src/jquery.d.ts
+declare var x: number;
+export default x;
+
+// No extension: '.d.ts' added
+// @Filename: /src/jquery_user_1.ts
+import j from "./jquery";
+
+// '.js' extension: stripped and replaced with '.d.ts'
+// @Filename: /src/jquery_user_1.ts
+import j from "./jquery.js"

tests/cases/fourslash/completionForStringLiteral.ts

@@ -0,0 +1,15 @@
+/// <reference path='fourslash.ts'/>
+
+////type Options = "Option 1" | "Option 2" | "Option 3";
+////var x: Options = "/*1*/Option 3";
+////
+////function f(a: Options) { };
+////f("/*2*/
+
+goTo.marker('1');
+verify.completionListContains("Option 1");
+verify.memberListCount(3);
+
+goTo.marker('2');
+verify.completionListContains("Option 2");
+verify.memberListCount(3);

tests/cases/fourslash/completionForStringLiteral2.ts

@@ -0,0 +1,20 @@
+/// <reference path='fourslash.ts'/>
+
+////var o = {
+////    foo() { },
+////    bar: 0,
+////    "some other name": 1
+////};
+////
+////o["/*1*/bar"];
+////o["/*2*/
+
+goTo.marker('1');
+verify.completionListContains("foo");
+verify.completionListAllowsNewIdentifier();
+verify.memberListCount(3);
+
+goTo.marker('2');
+verify.completionListContains("some other name");
+verify.completionListAllowsNewIdentifier();
+verify.memberListCount(3);

tests/cases/fourslash/completionForStringLiteral3.ts

@@ -0,0 +1,20 @@
+/// <reference path='fourslash.ts'/>
+
+////declare function f(a: "A", b: number): void;
+////declare function f(a: "B", b: number): void;
+////declare function f(a: "C", b: number): void;
+////declare function f(a: string, b: number): void;
+////
+////f("/*1*/C", 2);
+////
+////f("/*2*/
+
+goTo.marker('1');
+verify.completionListContains("A");
+verify.completionListAllowsNewIdentifier();
+verify.memberListCount(3);
+
+goTo.marker('2');
+verify.completionListContains("A");
+verify.completionListAllowsNewIdentifier();
+verify.memberListCount(3);

tests/cases/fourslash/fourslash.ts

@@ -52,13 +52,13 @@ declare module ts {
         None = 0,
         Block = 1,
         Smart = 2,
-    }  
+    }
 
     interface OutputFile {
         name: string;
         writeByteOrderMark: boolean;
         text: string;
-    }  
+    }
 }
 
 declare namespace FourSlashInterface {
@@ -139,7 +139,7 @@ declare namespace FourSlashInterface {
         isValidBraceCompletionAtPostion(openingBrace?: string): void;
     }
     class verify extends verifyNegatable {
-        assertHasRanges(ranges: FourSlash.Range[]): void;
+        assertHasRanges(ranges: Range[]): void;
         caretAtMarker(markerName?: string): void;
         indentationIs(numberOfSpaces: number): void;
         indentationAtPositionIs(fileName: string, position: number, numberOfSpaces: number, indentStyle?: ts.IndentStyle): void;

tests/cases/fourslash/quickInfoMeaning.ts

@@ -0,0 +1,67 @@
+///<reference path="fourslash.ts" />
+
+// Testing that quickInfo gets information with a corresponding meaning: values to values, types to types.
+// For quick info purposes, we don't resolve past aliases.
+// However, when we have an alias for a type, the quickInfo for a value with the same should skip the alias, and vice versa.
+// goToDefinition should work the same way.
+
+// @Filename: foo.d.ts
+////declare const /*foo_value_declaration*/foo: number;
+////declare module "foo_module" {
+////    interface I { x: number; y: number }
+////    export = I;
+////}
+
+// @Filename: foo_user.ts
+///////<reference path="foo.d.ts" />
+/////*foo_type_declaration*/import foo = require("foo_module");
+////const x = foo/*foo_value*/;
+////const i: foo/*foo_type*/ = { x: 1, y: 2 };
+
+verify.numberOfErrorsInCurrentFile(0);
+
+verify.navigationItemsListCount(2, "foo", "exact");
+verify.navigationItemsListContains("foo", "alias", "foo", "exact");
+verify.navigationItemsListContains("foo", "const", "foo", "exact");
+
+goTo.marker("foo_value");
+verify.quickInfoIs("const foo: number");
+goTo.definition();
+verify.caretAtMarker("foo_value_declaration");
+
+goTo.marker("foo_type");
+verify.quickInfoIs("import foo = require(\"foo_module\")");
+goTo.definition();
+verify.caretAtMarker("foo_type_declaration");
+
+
+// Above tested for global const and imported interface. Now test with global interface and imported const.
+
+
+// @Filename: bar.d.ts
+/////*bar_type_declaration*/declare interface bar { x: number; y: number }
+////declare module "bar_module" {
+////    const x: number;
+////    export = x;
+////}
+
+// @Filename: bar_user.ts
+///////<reference path="bar.d.ts" />
+/////*bar_value_declaration*/import bar = require("bar_module");
+////const x = bar/*bar_value*/;
+////const i: bar/*bar_type*/ = { x: 1, y: 2 };
+
+verify.numberOfErrorsInCurrentFile(0);
+verify.navigationItemsListCount(2, "bar", "exact");
+verify.navigationItemsListContains("bar", "alias", "bar", "exact");
+verify.navigationItemsListContains("bar", "interface", "bar", "exact");
+
+goTo.marker("bar_value");
+verify.quickInfoIs("import bar = require(\"bar_module\")");
+goTo.definition();
+verify.caretAtMarker("bar_value_declaration");
+
+goTo.marker("bar_type");
+verify.quickInfoIs("interface bar");
+goTo.definition();
+verify.caretAtMarker("bar_type_declaration");

tests/cases/projects/NoModule/decl.ts

@@ -1,4 +1,4 @@
-import modErr  = require("./foo/bar.js");
+import modErr  = require("./foo/bar.tx");
 import modErr1 = require("baz");
 import modErr2 = require("./baz");
 

tests/cases/unittests/transpile.ts

@@ -7,17 +7,21 @@ namespace ts {
             options?: TranspileOptions;
             expectedOutput?: string;
             expectedDiagnosticCodes?: number[];
+            expectedDiagnosticTexts?: string[];
         }
 
-        function checkDiagnostics(diagnostics: Diagnostic[], expectedDiagnosticCodes?: number[]) {
-            if (!expectedDiagnosticCodes) {
-                return;
+        function checkDiagnostics(diagnostics: Diagnostic[], expectedDiagnosticCodes: number[] = [], expectedDiagnosticTexts?: string[]) {
+            const n = expectedDiagnosticCodes.length;
+            if (expectedDiagnosticTexts) {
+                assert.equal(n, expectedDiagnosticTexts.length);
             }
-
-            for (let i = 0; i < expectedDiagnosticCodes.length; i++) {
-                assert.equal(expectedDiagnosticCodes[i], diagnostics[i] && diagnostics[i].code, `Could not find expeced diagnostic.`);
-            }
-            assert.equal(diagnostics.length, expectedDiagnosticCodes.length, "Resuting diagnostics count does not match expected");
+            for (let i = 0; i < n; i++) {
+                assert.equal(expectedDiagnosticCodes[i], diagnostics[i] && diagnostics[i].code, `Could not find expected diagnostic.`);
+                if (expectedDiagnosticTexts) {
+                    assert.equal(expectedDiagnosticTexts[i], diagnostics[i] && diagnostics[i].messageText);
+                }
+            };
+            assert.equal(diagnostics.length, n, "Resuting diagnostics count does not match expected");
         }
 
         function test(input: string, testSettings: TranspileTestSettings): void {
@@ -26,7 +30,7 @@ namespace ts {
             if (!transpileOptions.compilerOptions) {
                 transpileOptions.compilerOptions = {};
             }
-            if (transpileOptions.compilerOptions.newLine === undefined) { // 
+            if (transpileOptions.compilerOptions.newLine === undefined) {
                 // use \r\n as default new line
                 transpileOptions.compilerOptions.newLine = ts.NewLineKind.CarriageReturnLineFeed;
             }
@@ -36,7 +40,7 @@ namespace ts {
             transpileOptions.reportDiagnostics = true;
             const transpileModuleResult = transpileModule(input, transpileOptions);
 
-            checkDiagnostics(transpileModuleResult.diagnostics, testSettings.expectedDiagnosticCodes);
+            checkDiagnostics(transpileModuleResult.diagnostics, testSettings.expectedDiagnosticCodes, testSettings.expectedDiagnosticTexts);
 
             if (testSettings.expectedOutput !== undefined) {
                 assert.equal(transpileModuleResult.outputText, testSettings.expectedOutput);
@@ -45,7 +49,7 @@ namespace ts {
             if (canUseOldTranspile) {
                 const diagnostics: Diagnostic[] = [];
                 const transpileResult = transpile(input, transpileOptions.compilerOptions, transpileOptions.fileName, diagnostics, transpileOptions.moduleName);
-                checkDiagnostics(diagnostics, testSettings.expectedDiagnosticCodes);
+                checkDiagnostics(diagnostics, testSettings.expectedDiagnosticCodes, testSettings.expectedDiagnosticTexts);
                 if (testSettings.expectedOutput) {
                     assert.equal(transpileResult, testSettings.expectedOutput);
                 }
@@ -292,13 +296,37 @@ var x = 0;`,
             const output = `"use strict";\nvar a = 10;\n`;
             test(input, {
                 expectedOutput: output,
-                options: { compilerOptions: { newLine: NewLineKind.LineFeed, module: ModuleKind.CommonJS }, fileName: "input.js", reportDiagnostics: true },
-                expectedDiagnosticCodes: []
+                options: { compilerOptions: { newLine: NewLineKind.LineFeed, module: ModuleKind.CommonJS }, fileName: "input.js", reportDiagnostics: true }
             });
         });
 
         it("Supports urls in file name", () => {
             test("var x", { expectedOutput: `"use strict";\r\nvar x;\r\n`, options: { fileName: "http://somewhere/directory//directory2/file.ts" } });
         });
+
+        describe("String values for enums", () => {
+            it("Accepts strings instead of enum values", () => {
+                test(`export const x = 0`, {
+                    options: {
+                        compilerOptions: {
+                            module: <ModuleKind><any>"es6",
+                            // Capitalization and spaces ignored
+                            target: <ScriptTarget><any>" Es6 "
+                        }
+                    },
+                    expectedOutput: "export const x = 0;\r\n"
+                });
+            });
+
+            it("Fails on bad value", () => {
+                for (const value in [123, {}, ""]) {
+                    test(``, {
+                        options: { compilerOptions: { module: <ModuleKind><any>value } },
+                        expectedDiagnosticCodes: [6046],
+                        expectedDiagnosticTexts: ["Argument for '--module' option must be:  'none', 'commonjs', 'amd', 'system', 'umd', 'es6', 'es2015'"]
+                    });
+                }
+            });
+        });
     });
 }