Merge branch 'master' into fixWeakObjectRelationCheck

# Conflicts:
#	tests/baselines/reference/infiniteConstraints.errors.txt

Gulpfile.js

@@ -24,10 +24,9 @@ const baselineAccept = require("./scripts/build/baselineAccept");
 const cmdLineOptions = require("./scripts/build/options");
 const exec = require("./scripts/build/exec");
 const browserify = require("./scripts/build/browserify");
-const debounce = require("./scripts/build/debounce");
 const prepend = require("./scripts/build/prepend");
 const { removeSourceMaps } = require("./scripts/build/sourcemaps");
-const { CancelSource, CancelError } = require("./scripts/build/cancellation");
+const { CancellationTokenSource, CancelError, delay, Semaphore } = require("prex"); 
 const { libraryTargets, generateLibs } = require("./scripts/build/lib");
 const { runConsoleTests, cleanTestDirs, writeTestConfigFile, refBaseline, localBaseline, refRwcBaseline, localRwcBaseline } = require("./scripts/build/tests");
 
@@ -534,57 +533,80 @@ gulp.task(
     ["watch-diagnostics", "watch-lib"].concat(useCompilerDeps),
     () => project.watch(tsserverProject, { typescript: useCompiler }));
 
-gulp.task(
-    "watch-local",
-    /*help*/ false,
-    ["watch-lib", "watch-tsc", "watch-services", "watch-server"]);
-
 gulp.task(
     "watch-runner",
     /*help*/ false,
     useCompilerDeps,
     () => project.watch(testRunnerProject, { typescript: useCompiler }));
 
-const watchPatterns = [
-    runJs,
-    typescriptDts,
-    tsserverlibraryDts
-];
+gulp.task(
+    "watch-local",
+    "Watches for changes to projects in src/ (but does not execute tests).",
+    ["watch-lib", "watch-tsc", "watch-services", "watch-server", "watch-runner", "watch-lssl"]);
 
 gulp.task(
     "watch",
-    "Watches for changes to the build inputs for built/local/run.js, then executes runtests-parallel.",
+    "Watches for changes to the build inputs for built/local/run.js, then runs tests.",
     ["build-rules", "watch-runner", "watch-services", "watch-lssl"],
     () => {
-        /** @type {CancelSource | undefined} */
-        let runTestsSource;
+        const sem = new Semaphore(1);
 
-        const fn = debounce(() => {
-            runTests().catch(error => {
-                if (error instanceof CancelError) {
-                    log.warn("Operation was canceled");
-                }
-                else {
-                    log.error(error);
-                }
-            });
-        }, /*timeout*/ 100, { max: 500 });
-
-        gulp.watch(watchPatterns, () => project.wait().then(fn));
+        gulp.watch([runJs, typescriptDts, tsserverlibraryDts], () => {
+            runTests();
+        });
 
         // NOTE: gulp.watch is far too slow when watching tests/cases/**/* as it first enumerates *every* file
         const testFilePattern = /(\.ts|[\\/]tsconfig\.json)$/;
         fs.watch("tests/cases", { recursive: true }, (_, file) => {
-            if (testFilePattern.test(file)) project.wait().then(fn);
+            if (testFilePattern.test(file)) runTests();
         });
 
-        function runTests() {
-            if (runTestsSource) runTestsSource.cancel();
-            runTestsSource = new CancelSource();
-            return cmdLineOptions.tests || cmdLineOptions.failed
-                ? runConsoleTests(runJs, "mocha-fivemat-progress-reporter", /*runInParallel*/ false, /*watchMode*/ true, runTestsSource.token)
-                : runConsoleTests(runJs, "min", /*runInParallel*/ true, /*watchMode*/ true, runTestsSource.token);
-        }
+        async function runTests() {
+            try {
+                // Ensure only one instance of the test runner is running at any given time.
+                if (sem.count > 0) {
+                    await sem.wait();
+                    try {
+                        // Wait for any concurrent recompilations to complete...
+                        try {
+                            await delay(100);
+                            while (project.hasRemainingWork()) {
+                                await project.waitForWorkToComplete();
+                                await delay(500);
+                            }
+                        }
+                        catch (e) {
+                            if (e instanceof CancelError) return;
+                            throw e;
+                        }
+
+                        // cancel any pending or active test run if a new recompilation is triggered
+                        const source = new CancellationTokenSource();
+                        project.waitForWorkToStart().then(() => {
+                            source.cancel();
+                        });
+                    
+                        if (cmdLineOptions.tests || cmdLineOptions.failed) {
+                            await runConsoleTests(runJs, "mocha-fivemat-progress-reporter", /*runInParallel*/ false, /*watchMode*/ true, source.token);
+                        }
+                        else {
+                            await runConsoleTests(runJs, "min", /*runInParallel*/ true, /*watchMode*/ true, source.token);
+                        }
+                    }
+                    finally {
+                        sem.release();
+                    }
+                }
+            }
+            catch (e) {
+                if (e instanceof CancelError) {
+                    log.warn("Operation was canceled");
+                }
+                else {
+                    log.error(e);
+                }
+            }
+        };
     });
 
 gulp.task("clean-built", /*help*/ false, [`clean:${diagnosticInformationMapTs}`], () => del(["built"]));

package.json

@@ -81,6 +81,7 @@
         "mocha": "latest",
         "mocha-fivemat-progress-reporter": "latest",
         "plugin-error": "latest",
+        "prex": "^0.4.3",
         "q": "latest",
         "remove-internal": "^2.9.2",
         "run-sequence": "latest",

scripts/build/cancellation.js

@@ -1,71 +0,0 @@
-// @ts-check
-const symSource = Symbol("CancelToken.source");
-const symToken = Symbol("CancelSource.token");
-const symCancellationRequested = Symbol("CancelSource.cancellationRequested");
-const symCancellationCallbacks = Symbol("CancelSource.cancellationCallbacks");
-
-class CancelSource {
-    constructor() {
-        this[symCancellationRequested] = false;
-        this[symCancellationCallbacks] = [];
-    }
-
-    /** @type {CancelToken} */
-    get token() {
-        return this[symToken] || (this[symToken] = new CancelToken(this));
-    }
-
-    cancel() {
-        if (!this[symCancellationRequested]) {
-            this[symCancellationRequested] = true;
-            for (const callback of this[symCancellationCallbacks]) {
-                callback();
-            }
-        }
-    }
-}
-exports.CancelSource = CancelSource;
-
-class CancelToken {
-    /**
-     * @param {CancelSource} source
-     */
-    constructor(source) {
-        if (source[symToken]) return source[symToken];
-        this[symSource] = source;
-    }
-
-    /** @type {boolean} */
-    get cancellationRequested() {
-        return this[symSource][symCancellationRequested];
-    }
-
-    /**
-     * @param {() => void} callback
-     */
-    subscribe(callback) {
-        const source = this[symSource];
-        if (source[symCancellationRequested]) {
-            callback();
-            return;
-        }
-
-        source[symCancellationCallbacks].push(callback);
-
-        return {
-            unsubscribe() {
-                const index = source[symCancellationCallbacks].indexOf(callback);
-                if (index !== -1) source[symCancellationCallbacks].splice(index, 1);
-            }
-        };
-    }
-}
-exports.CancelToken = CancelToken;
-
-class CancelError extends Error {
-    constructor(message = "Operation was canceled") {
-        super(message);
-        this.name = "CancelError";
-    }
-}
-exports.CancelError = CancelError;

scripts/build/exec.js

@@ -3,7 +3,7 @@ const cp = require("child_process");
 const log = require("fancy-log"); // was `require("gulp-util").log (see https://github.com/gulpjs/gulp-util)
 const isWin = /^win/.test(process.platform);
 const chalk = require("./chalk");
-const { CancelToken, CancelError } = require("./cancellation");
+const { CancellationToken, CancelError } = require("prex");
 
 module.exports = exec;
 
@@ -15,31 +15,36 @@ module.exports = exec;
  *
  * @typedef ExecOptions
  * @property {boolean} [ignoreExitCode]
- * @property {CancelToken} [cancelToken]
+ * @property {import("prex").CancellationToken} [cancelToken]
  */
 function exec(cmd, args, options = {}) {
     return /**@type {Promise<{exitCode: number}>}*/(new Promise((resolve, reject) => {
-        log(`> ${chalk.green(cmd)} ${args.join(" ")}`);
+        const { ignoreExitCode, cancelToken = CancellationToken.none } = options;
+        cancelToken.throwIfCancellationRequested();
+
         // TODO (weswig): Update child_process types to add windowsVerbatimArguments to the type definition
         const subshellFlag = isWin ? "/c" : "-c";
         const command = isWin ? [possiblyQuote(cmd), ...args] : [`${cmd} ${args.join(" ")}`];
-        const ex = cp.spawn(isWin ? "cmd" : "/bin/sh", [subshellFlag, ...command], { stdio: "inherit", windowsVerbatimArguments: true });
-        const subscription = options.cancelToken && options.cancelToken.subscribe(() => {
-            ex.kill("SIGINT");
-            ex.kill("SIGTERM");
+        
+        log(`> ${chalk.green(cmd)} ${args.join(" ")}`);
+        const proc = cp.spawn(isWin ? "cmd" : "/bin/sh", [subshellFlag, ...command], { stdio: "inherit", windowsVerbatimArguments: true });
+        const registration = cancelToken.register(() => {
+            log(`${chalk.red("killing")} '${chalk.green(cmd)} ${args.join(" ")}'...`);
+            proc.kill("SIGINT");
+            proc.kill("SIGTERM");
             reject(new CancelError());
         });
-        ex.on("exit", exitCode => {
-            subscription && subscription.unsubscribe();
-            if (exitCode === 0 || options.ignoreExitCode) {
+        proc.on("exit", exitCode => {
+            registration.unregister();
+            if (exitCode === 0 || ignoreExitCode) {
                 resolve({ exitCode });
             }
             else {
                 reject(new Error(`Process exited with code: ${exitCode}`));
             }
         });
-        ex.on("error", error => {
-            subscription && subscription.unsubscribe();
+        proc.on("error", error => {
+            registration.unregister();
             reject(error);
         });
     }));

scripts/build/project.js

@@ -3,6 +3,8 @@ const path = require("path");
 const fs = require("fs");
 const gulp = require("./gulp");
 const gulpif = require("gulp-if");
+const log = require("fancy-log"); // was `require("gulp-util").log (see https://github.com/gulpjs/gulp-util)
+const chalk = require("./chalk");
 const sourcemaps = require("gulp-sourcemaps");
 const merge2 = require("merge2");
 const tsc = require("gulp-typescript");
@@ -12,7 +14,12 @@ const ts = require("../../lib/typescript");
 const del = require("del");
 const needsUpdate = require("./needsUpdate");
 const mkdirp = require("./mkdirp");
+const prettyTime = require("pretty-hrtime");
 const { reportDiagnostics } = require("./diagnostics");
+const { CountdownEvent, ManualResetEvent } = require("prex");
+
+const workStartedEvent = new ManualResetEvent();
+const countdown = new CountdownEvent(0);
 
 class CompilationGulp extends gulp.Gulp {
     /**
@@ -20,15 +27,39 @@ class CompilationGulp extends gulp.Gulp {
      */
     fork(verbose) {
         const child = new ForkedGulp(this.tasks);
-        if (verbose) {
-            child.on("task_start", e => gulp.emit("task_start", e));
-            child.on("task_stop", e => gulp.emit("task_stop", e));
-            child.on("task_err", e => gulp.emit("task_err", e));
-            child.on("task_not_found", e => gulp.emit("task_not_found", e));
-            child.on("task_recursion", e => gulp.emit("task_recursion", e));
-        }
+        child.on("task_start", e => {
+            if (countdown.remainingCount === 0) {
+                countdown.reset(1);
+                workStartedEvent.set();
+                workStartedEvent.reset();
+            }
+            else {
+                countdown.add();
+            }
+            if (verbose) {
+                log('Starting', `'${chalk.cyan(e.task)}' ${chalk.gray(`(${countdown.remainingCount} remaining)`)}...`);
+            }
+        });
+        child.on("task_stop", e => {
+            countdown.signal();
+            if (verbose) {
+                log('Finished', `'${chalk.cyan(e.task)}' after ${chalk.magenta(prettyTime(/** @type {*}*/(e).hrDuration))} ${chalk.gray(`(${countdown.remainingCount} remaining)`)}`);
+            }
+        });
+        child.on("task_err", e => {
+            countdown.signal();
+            if (verbose) {
+                log(`'${chalk.cyan(e.task)}' ${chalk.red("errored after")} ${chalk.magenta(prettyTime(/** @type {*}*/(e).hrDuration))} ${chalk.gray(`(${countdown.remainingCount} remaining)`)}`);
+                log(e.err ? e.err.stack : e.message);
+            }
+        });
         return child;
     }
+
+    // @ts-ignore
+    start() {
+        throw new Error("Not supported, use fork.");
+    }
 }
 
 class ForkedGulp extends gulp.Gulp {
@@ -211,24 +242,26 @@ exports.flatten = flatten;
 
 /**
  * Returns a Promise that resolves when all pending build tasks have completed
+ * @param {import("prex").CancellationToken} [token]
  */
-function wait() {
-    return new Promise(resolve => {
-        if (compilationGulp.allDone()) {
-            resolve();
-        }
-        else {
-            const onDone = () => {
-                compilationGulp.removeListener("onDone", onDone);
-                compilationGulp.removeListener("err", onDone);
-                resolve();
-            };
-            compilationGulp.on("stop", onDone);
-            compilationGulp.on("err", onDone);
-        }
-    });
+function waitForWorkToComplete(token) {
+    return countdown.wait(token);
 }
-exports.wait = wait;
+exports.waitForWorkToComplete = waitForWorkToComplete;
+
+/**
+ * Returns a Promise that resolves when all pending build tasks have completed
+ * @param {import("prex").CancellationToken} [token]
+ */
+function waitForWorkToStart(token) {
+    return workStartedEvent.wait(token);
+}
+exports.waitForWorkToStart = waitForWorkToStart;
+
+function getRemainingWork() {
+    return countdown.remainingCount > 0;
+}
+exports.hasRemainingWork = getRemainingWork;
 
 /**
  * Resolve a TypeScript specifier into a fully-qualified module specifier and any requisite dependencies.

scripts/build/tests.js

@@ -8,6 +8,7 @@ const mkdirP = require("./mkdirp");
 const cmdLineOptions = require("./options");
 const exec = require("./exec");
 const log = require("fancy-log"); // was `require("gulp-util").log (see https://github.com/gulpjs/gulp-util)
+const { CancellationToken } = require("prex");
 const mochaJs = require.resolve("mocha/bin/_mocha");
 
 exports.localBaseline = "tests/baselines/local/";
@@ -21,9 +22,9 @@ exports.localTest262Baseline = "internal/baselines/test262/local";
  * @param {string} defaultReporter
  * @param {boolean} runInParallel
  * @param {boolean} watchMode
- * @param {InstanceType<typeof import("./cancellation").CancelToken>} [cancelToken]
+ * @param {import("prex").CancellationToken} [cancelToken]
  */
-async function runConsoleTests(runJs, defaultReporter, runInParallel, watchMode, cancelToken) {
+async function runConsoleTests(runJs, defaultReporter, runInParallel, watchMode, cancelToken = CancellationToken.none) {
     let testTimeout = cmdLineOptions.timeout;
     let tests = cmdLineOptions.tests;
     const lintFlag = cmdLineOptions.lint;
@@ -37,6 +38,7 @@ async function runConsoleTests(runJs, defaultReporter, runInParallel, watchMode,
     const keepFailed = cmdLineOptions.keepFailed;
     if (!cmdLineOptions.dirty) {
         await cleanTestDirs();
+        cancelToken.throwIfCancellationRequested();
     }
 
     if (fs.existsSync(testConfigFile)) {

src/compiler/binder.ts

@@ -236,8 +236,9 @@ namespace ts {
             if (symbolFlags & SymbolFlags.Value) {
                 const { valueDeclaration } = symbol;
                 if (!valueDeclaration ||
+                    (isAssignmentDeclaration(valueDeclaration) && !isAssignmentDeclaration(node)) ||
                     (valueDeclaration.kind !== node.kind && isEffectiveModuleDeclaration(valueDeclaration))) {
-                    // other kinds of value declarations take precedence over modules
+                    // other kinds of value declarations take precedence over modules and assignment declarations
                     symbol.valueDeclaration = node;
                 }
             }
@@ -373,7 +374,8 @@ namespace ts {
                         // prototype symbols like methods.
                         symbolTable.set(name, symbol = createSymbol(SymbolFlags.None, name));
                     }
-                    else {
+                    else if (!(includes & SymbolFlags.Variable && symbol.flags & SymbolFlags.JSContainer)) {
+                        // JSContainers are allowed to merge with variables, no matter what other flags they have.
                         if (isNamedDeclaration(node)) {
                             node.name.parent = node;
                         }
@@ -2537,12 +2539,10 @@ namespace ts {
                 (namespaceSymbol.members || (namespaceSymbol.members = createSymbolTable())) :
                 (namespaceSymbol.exports || (namespaceSymbol.exports = createSymbolTable()));
 
-            // Declare the method/property
-            const jsContainerFlag = isToplevelNamespaceableInitializer ? SymbolFlags.JSContainer : 0;
             const isMethod = isFunctionLikeDeclaration(getAssignedJavascriptInitializer(propertyAccess)!);
-            const symbolFlags = (isMethod ? SymbolFlags.Method : SymbolFlags.Property) | jsContainerFlag;
-            const symbolExcludes = (isMethod ? SymbolFlags.MethodExcludes : SymbolFlags.PropertyExcludes) & ~jsContainerFlag;
-            declareSymbol(symbolTable, namespaceSymbol, propertyAccess, symbolFlags, symbolExcludes);
+            const includes = isMethod ? SymbolFlags.Method : SymbolFlags.Property;
+            const excludes = isMethod ? SymbolFlags.MethodExcludes : SymbolFlags.PropertyExcludes;
+            declareSymbol(symbolTable, namespaceSymbol, propertyAccess, includes | SymbolFlags.JSContainer, excludes & ~SymbolFlags.JSContainer);
         }
 
         /**

src/compiler/checker.ts

@@ -837,8 +837,9 @@ namespace ts {
                 target.flags |= source.flags;
                 if (source.valueDeclaration &&
                     (!target.valueDeclaration ||
+                     isAssignmentDeclaration(target.valueDeclaration) ||
                      isEffectiveModuleDeclaration(target.valueDeclaration) && !isEffectiveModuleDeclaration(source.valueDeclaration))) {
-                    // other kinds of value declarations take precedence over modules
+                    // other kinds of value declarations take precedence over modules and assignment declarations
                     target.valueDeclaration = source.valueDeclaration;
                 }
                 addRange(target.declarations, source.declarations);
@@ -1212,7 +1213,7 @@ namespace ts {
                             }
                             if (meaning & SymbolFlags.Value && result.flags & SymbolFlags.Variable) {
                                 // expression inside parameter will lookup as normal variable scope when targeting es2015+
-                                if (compilerOptions.target && compilerOptions.target >= ScriptTarget.ES2015 && isParameter(lastLocation) && !isParameterPropertyDeclaration(lastLocation) && result.valueDeclaration !== lastLocation) {
+                                if (compilerOptions.target && compilerOptions.target >= ScriptTarget.ES2015 && isParameter(lastLocation) && !isParameterPropertyDeclaration(lastLocation) && result.valueDeclaration.pos > lastLocation.end) {
                                     useResult = false;
                                 }
                                 else if (result.flags & SymbolFlags.FunctionScopedVariable) {
@@ -3933,7 +3934,7 @@ namespace ts {
                     // specifier preference
                     const { moduleResolverHost } = context.tracker;
                     const specifierCompilerOptions = isBundle ? { ...compilerOptions, baseUrl: moduleResolverHost.getCommonSourceDirectory() } : compilerOptions;
-                    specifier = first(first(moduleSpecifiers.getModuleSpecifiers(
+                    specifier = first(moduleSpecifiers.getModuleSpecifiers(
                         symbol,
                         specifierCompilerOptions,
                         contextFile,
@@ -3941,7 +3942,7 @@ namespace ts {
                         host.getSourceFiles(),
                         { importModuleSpecifierPreference: isBundle ? "non-relative" : "relative" },
                         host.redirectTargetsMap,
-                    )));
+                    ));
                     links.specifierCache = links.specifierCache || createMap();
                     links.specifierCache.set(contextFile.path, specifier);
                 }
@@ -10527,9 +10528,13 @@ namespace ts {
          * attempt to issue more specific errors on, for example, specific object literal properties or tuple members.
          */
         function checkTypeAssignableToAndOptionallyElaborate(source: Type, target: Type, errorNode: Node | undefined, expr: Expression | undefined, headMessage?: DiagnosticMessage, containingMessageChain?: () => DiagnosticMessageChain | undefined): boolean {
-            if (isTypeAssignableTo(source, target)) return true;
-            if (!elaborateError(expr, source, target)) {
-                return checkTypeRelatedTo(source, target, assignableRelation, errorNode, headMessage, containingMessageChain);
+            return checkTypeRelatedToAndOptionallyElaborate(source, target, assignableRelation, errorNode, expr, headMessage, containingMessageChain);
+        }
+
+        function checkTypeRelatedToAndOptionallyElaborate(source: Type, target: Type, relation: Map<RelationComparisonResult>, errorNode: Node | undefined, expr: Expression | undefined, headMessage?: DiagnosticMessage, containingMessageChain?: () => DiagnosticMessageChain | undefined): boolean {
+            if (isTypeRelatedTo(source, target, relation)) return true;
+            if (!errorNode || !elaborateError(expr, source, target)) {
+                return checkTypeRelatedTo(source, target, relation, errorNode, headMessage, containingMessageChain);
             }
             return false;
         }
@@ -11320,7 +11325,7 @@ namespace ts {
                         return hasExcessProperties(source, discriminant, /*discriminant*/ undefined, reportErrors);
                     }
                     for (const prop of getPropertiesOfObjectType(source)) {
-                        if (!isKnownProperty(target, prop.escapedName, isComparingJsxAttributes)) {
+                        if (!isPropertyFromSpread(prop, source.symbol) && !isKnownProperty(target, prop.escapedName, isComparingJsxAttributes)) {
                             if (reportErrors) {
                                 // We know *exactly* where things went wrong when comparing the types.
                                 // Use this property as the error node as this will be more helpful in
@@ -11364,6 +11369,10 @@ namespace ts {
                 return false;
             }
 
+            function isPropertyFromSpread(prop: Symbol, container: Symbol) {
+                return prop.valueDeclaration && container.valueDeclaration && prop.valueDeclaration.parent !== container.valueDeclaration;
+            }
+
             function eachTypeRelatedToSomeType(source: UnionOrIntersectionType, target: UnionOrIntersectionType): Ternary {
                 let result = Ternary.True;
                 const sourceTypes = source.types;
@@ -13658,7 +13667,7 @@ namespace ts {
             return inference.priority! & InferencePriority.PriorityImpliesCombination ? getIntersectionType(inference.contraCandidates!) : getCommonSubtype(inference.contraCandidates!);
         }
 
-        function getCovariantInference(inference: InferenceInfo, context: InferenceContext, signature: Signature) {
+        function getCovariantInference(inference: InferenceInfo, signature: Signature) {
             // Extract all object literal types and replace them with a single widened and normalized type.
             const candidates = widenObjectLiteralCandidates(inference.candidates!);
             // We widen inferred literal types if
@@ -13671,10 +13680,9 @@ namespace ts {
             const baseCandidates = primitiveConstraint ? sameMap(candidates, getRegularTypeOfLiteralType) :
                 widenLiteralTypes ? sameMap(candidates, getWidenedLiteralType) :
                 candidates;
-            // If all inferences were made from contravariant positions, infer a common subtype. Otherwise, if
-            // union types were requested or if all inferences were made from the return type position, infer a
-            // union type. Otherwise, infer a common supertype.
-            const unwidenedType = context.flags & InferenceFlags.InferUnionTypes || inference.priority! & InferencePriority.PriorityImpliesCombination ?
+            // If all inferences were made from a position that implies a combined result, infer a union type.
+            // Otherwise, infer a common supertype.
+            const unwidenedType = inference.priority! & InferencePriority.PriorityImpliesCombination ?
                 getUnionType(baseCandidates, UnionReduction.Subtype) :
                 getCommonSupertype(baseCandidates);
             return getWidenedType(unwidenedType);
@@ -13694,7 +13702,7 @@ namespace ts {
                         inference.contraCandidates = undefined;
                     }
                     if (inference.candidates) {
-                        inferredType = getCovariantInference(inference, context, signature);
+                        inferredType = getCovariantInference(inference, signature);
                     }
                     else if (context.flags & InferenceFlags.NoDefault) {
                         // We use silentNeverType as the wildcard that signals no inferences.
@@ -16140,6 +16148,16 @@ namespace ts {
                         return true;
                     }
                 case SpecialPropertyAssignmentKind.ThisProperty:
+                    if (!binaryExpression.symbol ||
+                        binaryExpression.symbol.valueDeclaration && !!getJSDocTypeTag(binaryExpression.symbol.valueDeclaration)) {
+                        return true;
+                    }
+                    const thisAccess = binaryExpression.left as PropertyAccessExpression;
+                    if (!isObjectLiteralMethod(getThisContainer(thisAccess.expression, /*includeArrowFunctions*/ false))) {
+                        return false;
+                    }
+                    const thisType = checkThisExpression(thisAccess.expression);
+                    return thisType && !!getPropertyOfType(thisType, thisAccess.name.escapedText);
                 case SpecialPropertyAssignmentKind.ModuleExports:
                     return !binaryExpression.symbol || binaryExpression.symbol.valueDeclaration && !!getJSDocTypeTag(binaryExpression.symbol.valueDeclaration);
                 default:
@@ -18633,7 +18651,7 @@ namespace ts {
 
         // Instantiate a generic signature in the context of a non-generic signature (section 3.8.5 in TypeScript spec)
         function instantiateSignatureInContextOf(signature: Signature, contextualSignature: Signature, contextualMapper?: TypeMapper, compareTypes?: TypeComparer): Signature {
-            const context = createInferenceContext(signature.typeParameters!, signature, InferenceFlags.InferUnionTypes, compareTypes);
+            const context = createInferenceContext(signature.typeParameters!, signature, InferenceFlags.None, compareTypes);
             const sourceSignature = contextualMapper ? instantiateSignature(contextualSignature, contextualMapper) : contextualSignature;
             forEachMatchingParameterType(sourceSignature, signature, (source, target) => {
                 // Type parameters from outer context referenced by source type are fixed by instantiation of the source type
@@ -18859,7 +18877,7 @@ namespace ts {
                     // we obtain the regular type of any object literal arguments because we may not have inferred complete
                     // parameter types yet and therefore excess property checks may yield false positives (see #17041).
                     const checkArgType = excludeArgument ? getRegularTypeOfObjectLiteral(argType) : argType;
-                    if (!checkTypeRelatedTo(checkArgType, paramType, relation, reportErrors ? arg : undefined, headMessage)) {
+                    if (!checkTypeRelatedToAndOptionallyElaborate(checkArgType, paramType, relation, reportErrors ? arg : undefined, arg, headMessage)) {
                         return false;
                     }
                 }
@@ -26347,7 +26365,7 @@ namespace ts {
 
         function checkExportSpecifier(node: ExportSpecifier) {
             checkAliasSymbol(node);
-            if (compilerOptions.declaration) {
+            if (getEmitDeclarations(compilerOptions)) {
                 collectLinkedAliases(node.propertyName || node.name, /*setVisibility*/ true);
             }
             if (!node.parent.parent.moduleSpecifier) {
@@ -26388,7 +26406,7 @@ namespace ts {
             if (node.expression.kind === SyntaxKind.Identifier) {
                 markExportAsReferenced(node);
 
-                if (compilerOptions.declaration) {
+                if (getEmitDeclarations(compilerOptions)) {
                     collectLinkedAliases(node.expression as Identifier, /*setVisibility*/ true);
                 }
             }
@@ -27335,12 +27353,10 @@ namespace ts {
             }
 
             if (isPartOfTypeNode(node)) {
-                let typeFromTypeNode = getTypeFromTypeNode(<TypeNode>node);
+                const typeFromTypeNode = getTypeFromTypeNode(<TypeNode>node);
 
                 if (isExpressionWithTypeArgumentsInClassImplementsClause(node)) {
-                    const containingClass = getContainingClass(node)!;
-                    const classType = getTypeOfNode(containingClass) as InterfaceType;
-                    typeFromTypeNode = getTypeWithThisArgument(typeFromTypeNode, classType.thisType);
+                    return getTypeWithThisArgument(typeFromTypeNode, getTypeOfClassContainingHeritageClause(node).thisType);
                 }
 
                 return typeFromTypeNode;
@@ -27353,8 +27369,7 @@ namespace ts {
             if (isExpressionWithTypeArgumentsInClassExtendsClause(node)) {
                 // A SyntaxKind.ExpressionWithTypeArguments is considered a type node, except when it occurs in the
                 // extends clause of a class. We handle that case here.
-                const classNode = getContainingClass(node)!;
-                const classType = getDeclaredTypeOfSymbol(getSymbolOfNode(classNode)) as InterfaceType;
+                const classType = getTypeOfClassContainingHeritageClause(node);
                 const baseType = firstOrUndefined(getBaseTypes(classType));
                 return baseType ? getTypeWithThisArgument(baseType, classType.thisType) : errorType;
             }
@@ -27396,6 +27411,10 @@ namespace ts {
             return errorType;
         }
 
+        function getTypeOfClassContainingHeritageClause(node: ExpressionWithTypeArguments): InterfaceType {
+            return getDeclaredTypeOfClassOrInterface(getSymbolOfNode(node.parent.parent));
+        }
+
         // Gets the type of object literal or array literal of destructuring assignment.
         // { a } from
         //     for ( { a } of elems) {

src/compiler/commandLineParser.ts

@@ -62,9 +62,7 @@ namespace ts {
     /* @internal */
     export const libMap = createMapFromEntries(libEntries);
 
-    /* @internal */
-    export const optionDeclarations: CommandLineOption[] = [
-        // CommandLine only options
+    const commonOptionsWithBuild: CommandLineOption[] = [
         {
             name: "help",
             shortName: "h",
@@ -78,6 +76,27 @@ namespace ts {
             shortName: "?",
             type: "boolean"
         },
+        {
+            name: "preserveWatchOutput",
+            type: "boolean",
+            showInSimplifiedHelpView: false,
+            category: Diagnostics.Command_line_Options,
+            description: Diagnostics.Whether_to_keep_outdated_console_output_in_watch_mode_instead_of_clearing_the_screen,
+        },
+        {
+            name: "watch",
+            shortName: "w",
+            type: "boolean",
+            showInSimplifiedHelpView: true,
+            category: Diagnostics.Command_line_Options,
+            description: Diagnostics.Watch_input_files,
+        },
+    ];
+
+    /* @internal */
+    export const optionDeclarations: CommandLineOption[] = [
+        // CommandLine only options
+        ...commonOptionsWithBuild,
         {
             name: "all",
             type: "boolean",
@@ -125,21 +144,6 @@ namespace ts {
             category: Diagnostics.Command_line_Options,
             description: Diagnostics.Stylize_errors_and_messages_using_color_and_context_experimental
         },
-        {
-            name: "preserveWatchOutput",
-            type: "boolean",
-            showInSimplifiedHelpView: false,
-            category: Diagnostics.Command_line_Options,
-            description: Diagnostics.Whether_to_keep_outdated_console_output_in_watch_mode_instead_of_clearing_the_screen,
-        },
-        {
-            name: "watch",
-            shortName: "w",
-            type: "boolean",
-            showInSimplifiedHelpView: true,
-            category: Diagnostics.Command_line_Options,
-            description: Diagnostics.Watch_input_files,
-        },
 
         // Basic
         {
@@ -754,6 +758,38 @@ namespace ts {
         }
     ];
 
+    /* @internal */
+    export const buildOpts: CommandLineOption[] = [
+        ...commonOptionsWithBuild,
+        {
+            name: "verbose",
+            shortName: "v",
+            category: Diagnostics.Command_line_Options,
+            description: Diagnostics.Enable_verbose_logging,
+            type: "boolean"
+        },
+        {
+            name: "dry",
+            shortName: "d",
+            category: Diagnostics.Command_line_Options,
+            description: Diagnostics.Show_what_would_be_built_or_deleted_if_specified_with_clean,
+            type: "boolean"
+        },
+        {
+            name: "force",
+            shortName: "f",
+            category: Diagnostics.Command_line_Options,
+            description: Diagnostics.Build_all_projects_including_those_that_appear_to_be_up_to_date,
+            type: "boolean"
+        },
+        {
+            name: "clean",
+            category: Diagnostics.Command_line_Options,
+            description: Diagnostics.Delete_the_outputs_of_all_projects,
+            type: "boolean"
+        }
+    ];
+
     /* @internal */
     export const typeAcquisitionDeclarations: CommandLineOption[] = [
         {
@@ -997,6 +1033,58 @@ namespace ts {
         return optionNameMap.get(optionName);
     }
 
+    /*@internal*/
+    export interface ParsedBuildCommand {
+        buildOptions: BuildOptions;
+        projects: string[];
+        errors: ReadonlyArray<Diagnostic>;
+    }
+
+    /*@internal*/
+    export function parseBuildCommand(args: string[]): ParsedBuildCommand {
+        let buildOptionNameMap: OptionNameMap | undefined;
+        const returnBuildOptionNameMap = () => (buildOptionNameMap || (buildOptionNameMap = createOptionNameMap(buildOpts)));
+
+        const buildOptions: BuildOptions = {};
+        const projects: string[] = [];
+        let errors: Diagnostic[] | undefined;
+        for (const arg of args) {
+            if (arg.charCodeAt(0) === CharacterCodes.minus) {
+                const opt = getOptionDeclarationFromName(returnBuildOptionNameMap, arg.slice(arg.charCodeAt(1) === CharacterCodes.minus ? 2 : 1), /*allowShort*/ true);
+                if (opt) {
+                    buildOptions[opt.name as keyof BuildOptions] = true;
+                }
+                else {
+                    (errors || (errors = [])).push(createCompilerDiagnostic(Diagnostics.Unknown_build_option_0, arg));
+                }
+            }
+            else {
+                // Not a flag, parse as filename
+                projects.push(arg);
+            }
+        }
+
+        if (projects.length === 0) {
+            // tsc -b invoked with no extra arguments; act as if invoked with "tsc -b ."
+            projects.push(".");
+        }
+
+        // Nonsensical combinations
+        if (buildOptions.clean && buildOptions.force) {
+            (errors || (errors = [])).push(createCompilerDiagnostic(Diagnostics.Options_0_and_1_cannot_be_combined, "clean", "force"));
+        }
+        if (buildOptions.clean && buildOptions.verbose) {
+            (errors || (errors = [])).push(createCompilerDiagnostic(Diagnostics.Options_0_and_1_cannot_be_combined, "clean", "verbose"));
+        }
+        if (buildOptions.clean && buildOptions.watch) {
+            (errors || (errors = [])).push(createCompilerDiagnostic(Diagnostics.Options_0_and_1_cannot_be_combined, "clean", "watch"));
+        }
+        if (buildOptions.watch && buildOptions.dry) {
+            (errors || (errors = [])).push(createCompilerDiagnostic(Diagnostics.Options_0_and_1_cannot_be_combined, "watch", "dry"));
+        }
+
+        return { buildOptions, projects, errors: errors || emptyArray };
+    }
 
     function getDiagnosticText(_message: DiagnosticMessage, ..._args: any[]): string {
         const diagnostic = createCompilerDiagnostic.apply(undefined, arguments);

src/compiler/moduleSpecifiers.ts

@@ -75,10 +75,10 @@ namespace ts.moduleSpecifiers {
         const info = getInfo(importingSourceFileName, host);
         const modulePaths = getAllModulePaths(files, importingSourceFileName, toFileName, info.getCanonicalFileName, host, redirectTargetsMap);
         return firstDefined(modulePaths, moduleFileName => tryGetModuleNameAsNodeModule(moduleFileName, info, host, compilerOptions)) ||
-            first(getLocalModuleSpecifiers(toFileName, info, compilerOptions, preferences));
+            getLocalModuleSpecifier(toFileName, info, compilerOptions, preferences);
     }
 
-    // For each symlink/original for a module, returns a list of ways to import that file.
+    // Returns an import for each symlink and for the realpath.
     export function getModuleSpecifiers(
         moduleSymbol: Symbol,
         compilerOptions: CompilerOptions,
@@ -87,9 +87,9 @@ namespace ts.moduleSpecifiers {
         files: ReadonlyArray<SourceFile>,
         userPreferences: UserPreferences,
         redirectTargetsMap: RedirectTargetsMap,
-    ): ReadonlyArray<ReadonlyArray<string>> {
+    ): ReadonlyArray<string> {
         const ambient = tryGetModuleNameFromAmbientModule(moduleSymbol);
-        if (ambient) return [[ambient]];
+        if (ambient) return [ambient];
 
         const info = getInfo(importingSourceFile.path, host);
         const moduleSourceFile = getSourceFileOfNode(moduleSymbol.valueDeclaration || getNonAugmentationDeclaration(moduleSymbol));
@@ -97,8 +97,7 @@ namespace ts.moduleSpecifiers {
 
         const preferences = getPreferences(userPreferences, compilerOptions, importingSourceFile);
         const global = mapDefined(modulePaths, moduleFileName => tryGetModuleNameAsNodeModule(moduleFileName, info, host, compilerOptions));
-        return global.length ? global.map(g => [g]) : modulePaths.map(moduleFileName =>
-            getLocalModuleSpecifiers(moduleFileName, info, compilerOptions, preferences));
+        return global.length ? global : modulePaths.map(moduleFileName => getLocalModuleSpecifier(moduleFileName, info, compilerOptions, preferences));
     }
 
     interface Info {
@@ -112,68 +111,40 @@ namespace ts.moduleSpecifiers {
         return { getCanonicalFileName, sourceDirectory };
     }
 
-    function getLocalModuleSpecifiers(moduleFileName: string, { getCanonicalFileName, sourceDirectory }: Info, compilerOptions: CompilerOptions, { ending, relativePreference }: Preferences): ReadonlyArray<string> {
+    function getLocalModuleSpecifier(moduleFileName: string, { getCanonicalFileName, sourceDirectory }: Info, compilerOptions: CompilerOptions, { ending, relativePreference }: Preferences): string {
         const { baseUrl, paths, rootDirs } = compilerOptions;
 
         const relativePath = rootDirs && tryGetModuleNameFromRootDirs(rootDirs, moduleFileName, sourceDirectory, getCanonicalFileName) ||
             removeExtensionAndIndexPostFix(ensurePathIsNonModuleName(getRelativePathFromDirectory(sourceDirectory, moduleFileName, getCanonicalFileName)), ending, compilerOptions);
         if (!baseUrl || relativePreference === RelativePreference.Relative) {
-            return [relativePath];
+            return relativePath;
         }
 
         const relativeToBaseUrl = getRelativePathIfInDirectory(moduleFileName, baseUrl, getCanonicalFileName);
         if (!relativeToBaseUrl) {
-            return [relativePath];
+            return relativePath;
         }
 
         const importRelativeToBaseUrl = removeExtensionAndIndexPostFix(relativeToBaseUrl, ending, compilerOptions);
-        if (paths) {
-            const fromPaths = tryGetModuleNameFromPaths(removeFileExtension(relativeToBaseUrl), importRelativeToBaseUrl, paths);
-            if (fromPaths) {
-                return [fromPaths];
-            }
-        }
+        const fromPaths = paths && tryGetModuleNameFromPaths(removeFileExtension(relativeToBaseUrl), importRelativeToBaseUrl, paths);
+        const nonRelative = fromPaths === undefined ? importRelativeToBaseUrl : fromPaths;
 
         if (relativePreference === RelativePreference.NonRelative) {
-            return [importRelativeToBaseUrl];
+            return nonRelative;
         }
 
         if (relativePreference !== RelativePreference.Auto) Debug.assertNever(relativePreference);
 
-        if (isPathRelativeToParent(relativeToBaseUrl)) {
-            return [relativePath];
+        // Prefer a relative import over a baseUrl import if it has fewer components.
+        return isPathRelativeToParent(nonRelative) || countPathComponents(relativePath) < countPathComponents(nonRelative) ? relativePath : nonRelative;
+    }
+
+    function countPathComponents(path: string): number {
+        let count = 0;
+        for (let i = startsWith(path, "./") ? 2 : 0; i < path.length; i++) {
+            if (path.charCodeAt(i) === CharacterCodes.slash) count++;
         }
-
-        /*
-        Prefer a relative import over a baseUrl import if it doesn't traverse up to baseUrl.
-
-        Suppose we have:
-            baseUrl = /base
-            sourceDirectory = /base/a/b
-            moduleFileName = /base/foo/bar
-        Then:
-            relativePath = ../../foo/bar
-            getRelativePathNParents(relativePath) = 2
-            pathFromSourceToBaseUrl = ../../
-            getRelativePathNParents(pathFromSourceToBaseUrl) = 2
-            2 < 2 = false
-        In this case we should prefer using the baseUrl path "/a/b" instead of the relative path "../../foo/bar".
-
-        Suppose we have:
-            baseUrl = /base
-            sourceDirectory = /base/foo/a
-            moduleFileName = /base/foo/bar
-        Then:
-            relativePath = ../a
-            getRelativePathNParents(relativePath) = 1
-            pathFromSourceToBaseUrl = ../../
-            getRelativePathNParents(pathFromSourceToBaseUrl) = 2
-            1 < 2 = true
-        In this case we should prefer using the relative path "../a" instead of the baseUrl path "foo/a".
-        */
-        const pathFromSourceToBaseUrl = ensurePathIsNonModuleName(getRelativePathFromDirectory(sourceDirectory, baseUrl, getCanonicalFileName));
-        const relativeFirst = getRelativePathNParents(relativePath) < getRelativePathNParents(pathFromSourceToBaseUrl);
-        return relativeFirst ? [relativePath, importRelativeToBaseUrl] : [importRelativeToBaseUrl, relativePath];
+        return count;
     }
 
     function usesJsExtensionOnImports({ imports }: SourceFile): boolean {
@@ -245,15 +216,6 @@ namespace ts.moduleSpecifiers {
         return result;
     }
 
-    function getRelativePathNParents(relativePath: string): number {
-        const components = getPathComponents(relativePath);
-        if (components[0] || components.length === 1) return 0;
-        for (let i = 1; i < components.length; i++) {
-            if (components[i] !== "..") return i - 1;
-        }
-        return components.length - 1;
-    }
-
     function tryGetModuleNameFromAmbientModule(moduleSymbol: Symbol): string | undefined {
         const decl = find(moduleSymbol.declarations,
             d => isNonGlobalAmbientModule(d) && (!isExternalModuleAugmentation(d) || !isExternalModuleNameRelative(getTextOfIdentifierOrLiteral(d.name)))

src/compiler/parser.ts

@@ -6856,7 +6856,7 @@ namespace ts {
 
                 function parseTypedefTag(atToken: AtToken, tagName: Identifier, indent: number): JSDocTypedefTag {
                     const typeExpression = tryParseTypeExpression();
-                    skipWhitespace();
+                    skipWhitespaceOrAsterisk();
 
                     const typedefTag = <JSDocTypedefTag>createNode(SyntaxKind.JSDocTypedefTag, atToken.pos);
                     typedefTag.atToken = atToken;

src/compiler/program.ts

@@ -1259,8 +1259,6 @@ namespace ts {
         }
 
         function getProjectReferences() {
-            if (!resolvedProjectReferences) return;
-
             return resolvedProjectReferences;
         }
 

src/compiler/tsbuild.ts

@@ -429,6 +429,7 @@ namespace ts {
                 projectPendingBuild.removeKey(proj);
                 if (!projectPendingBuild.getSize()) {
                     invalidatedProjectQueue.length = 0;
+                    nextIndex = 0;
                 }
                 return proj;
             }

src/compiler/types.ts

@@ -3441,8 +3441,8 @@ namespace ts {
 
         Enum = RegularEnum | ConstEnum,
         Variable = FunctionScopedVariable | BlockScopedVariable,
-        Value = Variable | Property | EnumMember | Function | Class | Enum | ValueModule | Method | GetAccessor | SetAccessor | JSContainer,
-        Type = Class | Interface | Enum | EnumMember | TypeLiteral | ObjectLiteral | TypeParameter | TypeAlias | JSContainer,
+        Value = Variable | Property | EnumMember | ObjectLiteral | Function | Class | Enum | ValueModule | Method | GetAccessor | SetAccessor | JSContainer,
+        Type = Class | Interface | Enum | EnumMember | TypeLiteral | TypeParameter | TypeAlias | JSContainer,
         Namespace = ValueModule | NamespaceModule | Enum,
         Module = ValueModule | NamespaceModule,
         Accessor = GetAccessor | SetAccessor,
@@ -3463,7 +3463,7 @@ namespace ts {
         InterfaceExcludes = Type & ~(Interface | Class),
         RegularEnumExcludes = (Value | Type) & ~(RegularEnum | ValueModule), // regular enums merge only with regular enums and modules
         ConstEnumExcludes = (Value | Type) & ~ConstEnum, // const enums merge only with const enums
-        ValueModuleExcludes = Value & ~(Function | Class | RegularEnum | ValueModule),
+        ValueModuleExcludes = Value & ~(Function | Class | RegularEnum | ValueModule | JSContainer),
         NamespaceModuleExcludes = 0,
         MethodExcludes = Value & ~Method,
         GetAccessorExcludes = Value & ~SetAccessor,
@@ -4175,9 +4175,8 @@ namespace ts {
     /* @internal */
     export const enum InferenceFlags {
         None            =      0,  // No special inference behaviors
-        InferUnionTypes = 1 << 0,  // Infer union types for disjoint candidates (otherwise unknownType)
-        NoDefault       = 1 << 1,  // Infer unknownType for no inferences (otherwise anyType or emptyObjectType)
-        AnyDefault      = 1 << 2,  // Infer anyType for no inferences (otherwise emptyObjectType)
+        NoDefault       = 1 << 0,  // Infer unknownType for no inferences (otherwise anyType or emptyObjectType)
+        AnyDefault      = 1 << 1,  // Infer anyType for no inferences (otherwise emptyObjectType)
     }
 
     /**

src/compiler/utilities.ts

@@ -1762,6 +1762,10 @@ namespace ts {
         return decl;
     }
 
+    export function isAssignmentDeclaration(decl: Declaration) {
+        return isBinaryExpression(decl) || isPropertyAccessExpression(decl) || isIdentifier(decl);
+    }
+
     /** Get the initializer, taking into account defaulted Javascript initializers */
     export function getEffectiveInitializer(node: HasExpressionInitializer) {
         if (isInJavaScriptFile(node) && node.initializer &&
@@ -3743,7 +3747,7 @@ namespace ts {
         return false;
     }
 
-    export function isExpressionWithTypeArgumentsInClassExtendsClause(node: Node): boolean {
+    export function isExpressionWithTypeArgumentsInClassExtendsClause(node: Node): node is ExpressionWithTypeArguments {
         return tryGetClassExtendingExpressionWithTypeArguments(node) !== undefined;
     }
 

src/loc/lcl/ptb/diagnosticMessages/diagnosticMessages.generated.json.lcl

@@ -588,7 +588,7 @@
         <Str Cat="Text">
           <Val><![CDATA[A rest element cannot have a property name.]]></Val>
           <Tgt Cat="Text" Stat="Loc" Orig="New">
-            <Val><![CDATA[Um elemento restante não pode ter um nome de propriedade.]]></Val>
+            <Val><![CDATA[Um elemento rest não pode ter um nome de propriedade.]]></Val>
           </Tgt>
         </Str>
         <Disp Icon="Str" />

src/services/codefixes/importFixes.ts

@@ -283,14 +283,13 @@ namespace ts.codefix {
         preferences: UserPreferences,
     ): ReadonlyArray<FixAddNewImport | FixUseImportType> {
         const isJs = isSourceFileJavaScript(sourceFile);
-        const choicesForEachExportingModule = flatMap<SymbolExportInfo, ReadonlyArray<FixAddNewImport | FixUseImportType>>(moduleSymbols, ({ moduleSymbol, importKind, exportedSymbolIsTypeOnly }) => {
-            const modulePathsGroups = moduleSpecifiers.getModuleSpecifiers(moduleSymbol, program.getCompilerOptions(), sourceFile, host, program.getSourceFiles(), preferences, program.redirectTargetsMap);
-            return modulePathsGroups.map(group => group.map((moduleSpecifier): FixAddNewImport | FixUseImportType =>
+        const choicesForEachExportingModule = flatMap(moduleSymbols, ({ moduleSymbol, importKind, exportedSymbolIsTypeOnly }) =>
+            moduleSpecifiers.getModuleSpecifiers(moduleSymbol, program.getCompilerOptions(), sourceFile, host, program.getSourceFiles(), preferences, program.redirectTargetsMap)
+            .map((moduleSpecifier): FixAddNewImport | FixUseImportType =>
                 // `position` should only be undefined at a missing jsx namespace, in which case we shouldn't be looking for pure types.
                 exportedSymbolIsTypeOnly && isJs ? { kind: ImportFixKind.ImportType, moduleSpecifier, position: Debug.assertDefined(position) } : { kind: ImportFixKind.AddNew, moduleSpecifier, importKind }));
-        });
-        // Sort to keep the shortest paths first, but keep [relativePath, importRelativeToBaseUrl] groups together
-        return flatten<FixAddNewImport | FixUseImportType>(choicesForEachExportingModule.sort((a, b) => first(a).moduleSpecifier.length - first(b).moduleSpecifier.length));
+        // Sort to keep the shortest paths first
+        return choicesForEachExportingModule.sort((a, b) => a.moduleSpecifier.length - b.moduleSpecifier.length);
     }
 
     function getFixesForAddImport(

src/services/completions.ts

@@ -264,6 +264,9 @@ namespace ts.Completions {
     }
 
     function quote(text: string, preferences: UserPreferences): string {
+        if (/^\d+$/.test(text)) {
+            return text;
+        }
         const quoted = JSON.stringify(text);
         switch (preferences.quotePreference) {
             case undefined:

src/testRunner/unittests/commandLineParsing.ts

@@ -366,4 +366,120 @@ namespace ts {
                 });
         });
     });
+
+    describe("parseBuildOptions", () => {
+        function assertParseResult(commandLine: string[], expectedParsedBuildCommand: ParsedBuildCommand) {
+            const parsed = parseBuildCommand(commandLine);
+            const parsedBuildOptions = JSON.stringify(parsed.buildOptions);
+            const expectedBuildOptions = JSON.stringify(expectedParsedBuildCommand.buildOptions);
+            assert.equal(parsedBuildOptions, expectedBuildOptions);
+
+            const parsedErrors = parsed.errors;
+            const expectedErrors = expectedParsedBuildCommand.errors;
+            assert.isTrue(parsedErrors.length === expectedErrors.length, `Expected error: ${JSON.stringify(expectedErrors)}. Actual error: ${JSON.stringify(parsedErrors)}.`);
+            for (let i = 0; i < parsedErrors.length; i++) {
+                const parsedError = parsedErrors[i];
+                const expectedError = expectedErrors[i];
+                assert.equal(parsedError.code, expectedError.code);
+                assert.equal(parsedError.category, expectedError.category);
+                assert.equal(parsedError.messageText, expectedError.messageText);
+            }
+
+            const parsedProjects = parsed.projects;
+            const expectedProjects = expectedParsedBuildCommand.projects;
+            assert.deepEqual(parsedProjects, expectedProjects, `Expected projects: [${JSON.stringify(expectedProjects)}]. Actual projects: [${JSON.stringify(parsedProjects)}].`);
+        }
+        it("parse build without any options ", () => {
+            // --lib es6 0.ts
+            assertParseResult([],
+                {
+                    errors: [],
+                    projects: ["."],
+                    buildOptions: {}
+                });
+        });
+
+        it("Parse multiple options", () => {
+            // --lib es5,es2015.symbol.wellknown 0.ts
+            assertParseResult(["--verbose", "--force", "tests"],
+                {
+                    errors: [],
+                    projects: ["tests"],
+                    buildOptions: { verbose: true, force: true }
+                });
+        });
+
+        it("Parse option with invalid option ", () => {
+            // --lib es5,invalidOption 0.ts
+            assertParseResult(["--verbose", "--invalidOption"],
+                {
+                    errors: [{
+                        messageText: "Unknown build option '--invalidOption'.",
+                        category: Diagnostics.Unknown_build_option_0.category,
+                        code: Diagnostics.Unknown_build_option_0.code,
+                        file: undefined,
+                        start: undefined,
+                        length: undefined,
+                    }],
+                    projects: ["."],
+                    buildOptions: { verbose: true }
+                });
+        });
+
+        it("Parse multiple flags with input projects at the end", () => {
+            // --lib es5,es2015.symbol.wellknown --target es5 0.ts
+            assertParseResult(["--force", "--verbose", "src", "tests"],
+                {
+                    errors: [],
+                    projects: ["src", "tests"],
+                    buildOptions: { force: true, verbose: true }
+                });
+        });
+
+        it("Parse multiple flags with input projects in the middle", () => {
+            // --module commonjs --target es5 0.ts --lib es5,es2015.symbol.wellknown
+            assertParseResult(["--force", "src", "tests", "--verbose"],
+                {
+                    errors: [],
+                    projects: ["src", "tests"],
+                    buildOptions: { force: true, verbose: true }
+                });
+        });
+
+        it("Parse multiple flags with input projects in the beginning", () => {
+            // --module commonjs --target es5 0.ts --lib es5,es2015.symbol.wellknown
+            assertParseResult(["src", "tests", "--force", "--verbose"],
+                {
+                    errors: [],
+                    projects: ["src", "tests"],
+                    buildOptions: { force: true, verbose: true }
+                });
+        });
+
+        describe("Combining options that make no sense together", () => {
+            function verifyInvalidCombination(flag1: keyof BuildOptions, flag2: keyof BuildOptions) {
+                it(`--${flag1} and --${flag2} together is invalid`, () => {
+                    // --module commonjs --target es5 0.ts --lib es5,es2015.symbol.wellknown
+                    assertParseResult([`--${flag1}`, `--${flag2}`],
+                        {
+                            errors: [{
+                                messageText: `Options '${flag1}' and '${flag2}' cannot be combined.`,
+                                category: Diagnostics.Options_0_and_1_cannot_be_combined.category,
+                                code: Diagnostics.Options_0_and_1_cannot_be_combined.code,
+                                file: undefined,
+                                start: undefined,
+                                length: undefined,
+                            }],
+                            projects: ["."],
+                            buildOptions: { [flag1]: true, [flag2]: true }
+                        });
+                });
+            }
+
+            verifyInvalidCombination("clean", "force");
+            verifyInvalidCombination("clean", "verbose");
+            verifyInvalidCombination("clean", "watch");
+            verifyInvalidCombination("watch", "dry");
+        });
+    });
 }

src/testRunner/unittests/tsbuildWatchMode.ts

@@ -98,34 +98,42 @@ namespace ts.tscWatch {
             for (const stamp of outputFileStamps) {
                 assert.isDefined(stamp[1], `${stamp[0]} expected to be present`);
             }
-            return { host, outputFileStamps };
+            return host;
         }
         it("creates solution in watch mode", () => {
             createSolutionInWatchMode();
         });
 
         it("change builds changes and reports found errors message", () => {
-            const { host, outputFileStamps } = createSolutionInWatchMode();
-            host.writeFile(core[1].path, `${core[1].content}
+            const host = createSolutionInWatchMode();
+            verifyChange(`${core[1].content}
 export class someClass { }`);
-            host.checkTimeoutQueueLengthAndRun(1); // Builds core
-            const changedCore = getOutputFileStamps(host);
-            verifyChangedFiles(changedCore, outputFileStamps, [
-                ...getOutputFileNames(SubProject.core, "anotherModule"), // This should not be written really
-                ...getOutputFileNames(SubProject.core, "index")
-            ]);
-            host.checkTimeoutQueueLengthAndRun(1); // Builds tests
-            const changedTests = getOutputFileStamps(host);
-            verifyChangedFiles(changedTests, changedCore, [
-                ...getOutputFileNames(SubProject.tests, "index") // Again these need not be written
-            ]);
-            host.checkTimeoutQueueLengthAndRun(1); // Builds logic
-            const changedLogic = getOutputFileStamps(host);
-            verifyChangedFiles(changedLogic, changedTests, [
-                ...getOutputFileNames(SubProject.logic, "index") // Again these need not be written
-            ]);
-            host.checkTimeoutQueueLength(0);
-            checkOutputErrorsIncremental(host, emptyArray);
+
+            // Another change requeues and builds it
+            verifyChange(core[1].content);
+
+            function verifyChange(coreContent: string) {
+                const outputFileStamps = getOutputFileStamps(host);
+                host.writeFile(core[1].path, coreContent);
+                host.checkTimeoutQueueLengthAndRun(1); // Builds core
+                const changedCore = getOutputFileStamps(host);
+                verifyChangedFiles(changedCore, outputFileStamps, [
+                    ...getOutputFileNames(SubProject.core, "anotherModule"), // This should not be written really
+                    ...getOutputFileNames(SubProject.core, "index")
+                ]);
+                host.checkTimeoutQueueLengthAndRun(1); // Builds tests
+                const changedTests = getOutputFileStamps(host);
+                verifyChangedFiles(changedTests, changedCore, [
+                    ...getOutputFileNames(SubProject.tests, "index") // Again these need not be written
+                ]);
+                host.checkTimeoutQueueLengthAndRun(1); // Builds logic
+                const changedLogic = getOutputFileStamps(host);
+                verifyChangedFiles(changedLogic, changedTests, [
+                    ...getOutputFileNames(SubProject.logic, "index") // Again these need not be written
+                ]);
+                host.checkTimeoutQueueLength(0);
+                checkOutputErrorsIncremental(host, emptyArray);
+            }
         });
 
         // TODO: write tests reporting errors but that will have more involved work since file

src/tsc/tsc.ts

@@ -165,79 +165,10 @@ namespace ts {
     }
 
     function performBuild(args: string[]): number | undefined {
-        const buildOpts: CommandLineOption[] = [
-            {
-                name: "help",
-                shortName: "h",
-                type: "boolean",
-                showInSimplifiedHelpView: true,
-                category: Diagnostics.Command_line_Options,
-                description: Diagnostics.Print_this_message,
-            },
-            {
-                name: "help",
-                shortName: "?",
-                type: "boolean"
-            },
-            {
-                name: "verbose",
-                shortName: "v",
-                category: Diagnostics.Command_line_Options,
-                description: Diagnostics.Enable_verbose_logging,
-                type: "boolean"
-            },
-            {
-                name: "dry",
-                shortName: "d",
-                category: Diagnostics.Command_line_Options,
-                description: Diagnostics.Show_what_would_be_built_or_deleted_if_specified_with_clean,
-                type: "boolean"
-            },
-            {
-                name: "force",
-                shortName: "f",
-                category: Diagnostics.Command_line_Options,
-                description: Diagnostics.Build_all_projects_including_those_that_appear_to_be_up_to_date,
-                type: "boolean"
-            },
-            {
-                name: "clean",
-                category: Diagnostics.Command_line_Options,
-                description: Diagnostics.Delete_the_outputs_of_all_projects,
-                type: "boolean"
-            },
-            {
-                name: "watch",
-                category: Diagnostics.Command_line_Options,
-                description: Diagnostics.Watch_input_files,
-                type: "boolean"
-            },
-            {
-                name: "preserveWatchOutput",
-                type: "boolean",
-                category: Diagnostics.Command_line_Options,
-                description: Diagnostics.Whether_to_keep_outdated_console_output_in_watch_mode_instead_of_clearing_the_screen,
-            },
-        ];
-        let buildOptionNameMap: OptionNameMap | undefined;
-        const returnBuildOptionNameMap = () => (buildOptionNameMap || (buildOptionNameMap = createOptionNameMap(buildOpts)));
-
-        const buildOptions: BuildOptions = {};
-        const projects: string[] = [];
-        for (const arg of args) {
-            if (arg.charCodeAt(0) === CharacterCodes.minus) {
-                const opt = getOptionDeclarationFromName(returnBuildOptionNameMap, arg.slice(arg.charCodeAt(1) === CharacterCodes.minus ? 2 : 1), /*allowShort*/ true);
-                if (opt) {
-                    buildOptions[opt.name as keyof BuildOptions] = true;
-                }
-                else {
-                    reportDiagnostic(createCompilerDiagnostic(Diagnostics.Unknown_build_option_0, arg));
-                }
-            }
-            else {
-                // Not a flag, parse as filename
-                addProject(arg);
-            }
+        const { buildOptions, projects: buildProjects, errors } = parseBuildCommand(args);
+        if (errors.length > 0) {
+            errors.forEach(reportDiagnostic);
+            return ExitStatus.DiagnosticsPresent_OutputsSkipped;
         }
 
         if (buildOptions.help) {
@@ -248,6 +179,21 @@ namespace ts {
 
         // Update to pretty if host supports it
         updateReportDiagnostic();
+        const projects = mapDefined(buildProjects, project => {
+            const fileName = resolvePath(sys.getCurrentDirectory(), project);
+            const refPath = resolveProjectReferencePath(sys, { path: fileName });
+            if (!sys.fileExists(refPath)) {
+                reportDiagnostic(createCompilerDiagnostic(Diagnostics.File_0_does_not_exist, fileName));
+                return undefined;
+            }
+            return refPath;
+        });
+
+        if (projects.length === 0) {
+            printVersion();
+            printHelp(buildOpts, "--build ");
+            return ExitStatus.Success;
+        }
 
         if (!sys.getModifiedTime || !sys.setModifiedTime || (buildOptions.clean && !sys.deleteFile)) {
             reportDiagnostic(createCompilerDiagnostic(Diagnostics.The_current_host_does_not_support_the_0_option, "--build"));
@@ -257,29 +203,6 @@ namespace ts {
             reportWatchModeWithoutSysSupport();
         }
 
-        // Nonsensical combinations
-        if (buildOptions.clean && buildOptions.force) {
-            reportDiagnostic(createCompilerDiagnostic(Diagnostics.Options_0_and_1_cannot_be_combined, "clean", "force"));
-            return ExitStatus.DiagnosticsPresent_OutputsSkipped;
-        }
-        if (buildOptions.clean && buildOptions.verbose) {
-            reportDiagnostic(createCompilerDiagnostic(Diagnostics.Options_0_and_1_cannot_be_combined, "clean", "verbose"));
-            return ExitStatus.DiagnosticsPresent_OutputsSkipped;
-        }
-        if (buildOptions.clean && buildOptions.watch) {
-            reportDiagnostic(createCompilerDiagnostic(Diagnostics.Options_0_and_1_cannot_be_combined, "clean", "watch"));
-            return ExitStatus.DiagnosticsPresent_OutputsSkipped;
-        }
-        if (buildOptions.watch && buildOptions.dry) {
-            reportDiagnostic(createCompilerDiagnostic(Diagnostics.Options_0_and_1_cannot_be_combined, "watch", "dry"));
-            return ExitStatus.DiagnosticsPresent_OutputsSkipped;
-        }
-
-        if (projects.length === 0) {
-            // tsc -b invoked with no extra arguments; act as if invoked with "tsc -b ."
-            addProject(".");
-        }
-
         // TODO: change this to host if watch => watchHost otherwiue without wathc
         const builder = createSolutionBuilder(createSolutionBuilderWithWatchHost(sys, reportDiagnostic, createBuilderStatusReporter(sys, shouldBePretty()), createWatchStatusReporter()), projects, buildOptions);
         if (buildOptions.clean) {
@@ -293,15 +216,6 @@ namespace ts {
         }
 
         return builder.buildAllProjects();
-
-        function addProject(projectSpecification: string) {
-            const fileName = resolvePath(sys.getCurrentDirectory(), projectSpecification);
-            const refPath = resolveProjectReferencePath(sys, { path: fileName });
-            if (!sys.fileExists(refPath)) {
-                return reportDiagnostic(createCompilerDiagnostic(Diagnostics.File_0_does_not_exist, fileName));
-            }
-            projects.push(refPath);
-        }
     }
 
     function performCompilation(rootNames: string[], projectReferences: ReadonlyArray<ProjectReference> | undefined, options: CompilerOptions, configFileParsingDiagnostics?: ReadonlyArray<Diagnostic>) {

tests/baselines/reference/api/tsserverlibrary.d.ts

@@ -2060,28 +2060,28 @@ declare namespace ts {
         ModuleExports = 134217728,
         Enum = 384,
         Variable = 3,
-        Value = 67216319,
-        Type = 67901928,
+        Value = 67220415,
+        Type = 67897832,
         Namespace = 1920,
         Module = 1536,
         Accessor = 98304,
-        FunctionScopedVariableExcludes = 67216318,
-        BlockScopedVariableExcludes = 67216319,
-        ParameterExcludes = 67216319,
+        FunctionScopedVariableExcludes = 67220414,
+        BlockScopedVariableExcludes = 67220415,
+        ParameterExcludes = 67220415,
         PropertyExcludes = 0,
         EnumMemberExcludes = 68008959,
-        FunctionExcludes = 67215791,
+        FunctionExcludes = 67219887,
         ClassExcludes = 68008383,
-        InterfaceExcludes = 67901832,
+        InterfaceExcludes = 67897736,
         RegularEnumExcludes = 68008191,
         ConstEnumExcludes = 68008831,
-        ValueModuleExcludes = 67215503,
+        ValueModuleExcludes = 110735,
         NamespaceModuleExcludes = 0,
-        MethodExcludes = 67208127,
-        GetAccessorExcludes = 67150783,
-        SetAccessorExcludes = 67183551,
-        TypeParameterExcludes = 67639784,
-        TypeAliasExcludes = 67901928,
+        MethodExcludes = 67212223,
+        GetAccessorExcludes = 67154879,
+        SetAccessorExcludes = 67187647,
+        TypeParameterExcludes = 67635688,
+        TypeAliasExcludes = 67897832,
         AliasExcludes = 2097152,
         ModuleMember = 2623475,
         ExportHasLocal = 944,

tests/baselines/reference/api/typescript.d.ts

@@ -2060,28 +2060,28 @@ declare namespace ts {
         ModuleExports = 134217728,
         Enum = 384,
         Variable = 3,
-        Value = 67216319,
-        Type = 67901928,
+        Value = 67220415,
+        Type = 67897832,
         Namespace = 1920,
         Module = 1536,
         Accessor = 98304,
-        FunctionScopedVariableExcludes = 67216318,
-        BlockScopedVariableExcludes = 67216319,
-        ParameterExcludes = 67216319,
+        FunctionScopedVariableExcludes = 67220414,
+        BlockScopedVariableExcludes = 67220415,
+        ParameterExcludes = 67220415,
         PropertyExcludes = 0,
         EnumMemberExcludes = 68008959,
-        FunctionExcludes = 67215791,
+        FunctionExcludes = 67219887,
         ClassExcludes = 68008383,
-        InterfaceExcludes = 67901832,
+        InterfaceExcludes = 67897736,
         RegularEnumExcludes = 68008191,
         ConstEnumExcludes = 68008831,
-        ValueModuleExcludes = 67215503,
+        ValueModuleExcludes = 110735,
         NamespaceModuleExcludes = 0,
-        MethodExcludes = 67208127,
-        GetAccessorExcludes = 67150783,
-        SetAccessorExcludes = 67183551,
-        TypeParameterExcludes = 67639784,
-        TypeAliasExcludes = 67901928,
+        MethodExcludes = 67212223,
+        GetAccessorExcludes = 67154879,
+        SetAccessorExcludes = 67187647,
+        TypeParameterExcludes = 67635688,
+        TypeAliasExcludes = 67897832,
         AliasExcludes = 2097152,
         ModuleMember = 2623475,
         ExportHasLocal = 944,

tests/baselines/reference/assignmentCompatFunctionsWithOptionalArgs.errors.txt

@@ -1,7 +1,5 @@
 tests/cases/compiler/assignmentCompatFunctionsWithOptionalArgs.ts(1,10): error TS2391: Function implementation is missing or not immediately following the declaration.
-tests/cases/compiler/assignmentCompatFunctionsWithOptionalArgs.ts(4,5): error TS2345: Argument of type '{ id: number; name: boolean; }' is not assignable to parameter of type '{ id: number; name?: string; }'.
-  Types of property 'name' are incompatible.
-    Type 'boolean' is not assignable to type 'string'.
+tests/cases/compiler/assignmentCompatFunctionsWithOptionalArgs.ts(4,17): error TS2322: Type 'false' is not assignable to type 'string'.
 tests/cases/compiler/assignmentCompatFunctionsWithOptionalArgs.ts(5,5): error TS2345: Argument of type '{ name: string; }' is not assignable to parameter of type '{ id: number; name?: string; }'.
   Property 'id' is missing in type '{ name: string; }'.
 
@@ -13,10 +11,9 @@ tests/cases/compiler/assignmentCompatFunctionsWithOptionalArgs.ts(5,5): error TS
     foo({ id: 1234 });                 // Ok
     foo({ id: 1234, name: "hello" });  // Ok
     foo({ id: 1234, name: false });    // Error, name of wrong type
-        ~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ id: number; name: boolean; }' is not assignable to parameter of type '{ id: number; name?: string; }'.
-!!! error TS2345:   Types of property 'name' are incompatible.
-!!! error TS2345:     Type 'boolean' is not assignable to type 'string'.
+                    ~~~~
+!!! error TS2322: Type 'false' is not assignable to type 'string'.
+!!! related TS6500 tests/cases/compiler/assignmentCompatFunctionsWithOptionalArgs.ts:1:31: The expected type comes from property 'name' which is declared here on type '{ id: number; name?: string; }'
     foo({ name: "hello" });            // Error, id required but missing
         ~~~~~~~~~~~~~~~~~
 !!! error TS2345: Argument of type '{ name: string; }' is not assignable to parameter of type '{ id: number; name?: string; }'.

tests/baselines/reference/assignmentCompatWithCallSignatures3.errors.txt

@@ -45,6 +45,11 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
           Property 'baz' is missing in type 'Base'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures3.ts(83,1): error TS2322: Type '(x: Base[], y: Derived[]) => Derived[]' is not assignable to type '<T extends Derived[]>(x: Base[], y: T) => T'.
   Type 'Derived[]' is not assignable to type 'T'.
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures3.ts(85,1): error TS2322: Type '<T>(x: { a: T; b: T; }) => T' is not assignable to type '(x: { a: string; b: number; }) => Object'.
+  Types of parameters 'x' and 'x' are incompatible.
+    Type '{ a: string; b: number; }' is not assignable to type '{ a: string; b: string; }'.
+      Types of property 'b' are incompatible.
+        Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures3.ts(86,1): error TS2322: Type '(x: { a: string; b: number; }) => Object' is not assignable to type '<T>(x: { a: T; b: T; }) => T'.
   Types of parameters 'x' and 'x' are incompatible.
     Type '{ a: T; b: T; }' is not assignable to type '{ a: string; b: number; }'.
@@ -52,7 +57,7 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
         Type 'T' is not assignable to type 'string'.
 
 
-==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures3.ts (14 errors) ====
+==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures3.ts (15 errors) ====
     // these are all permitted with the current rules, since we do not do contextual signature instantiation
     
     class Base { foo: string; }
@@ -198,6 +203,12 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
 !!! error TS2322:   Type 'Derived[]' is not assignable to type 'T'.
     var b14: <T>(x: { a: T; b: T }) => T; 
     a14 = b14; // ok
+    ~~~
+!!! error TS2322: Type '<T>(x: { a: T; b: T; }) => T' is not assignable to type '(x: { a: string; b: number; }) => Object'.
+!!! error TS2322:   Types of parameters 'x' and 'x' are incompatible.
+!!! error TS2322:     Type '{ a: string; b: number; }' is not assignable to type '{ a: string; b: string; }'.
+!!! error TS2322:       Types of property 'b' are incompatible.
+!!! error TS2322:         Type 'number' is not assignable to type 'string'.
     b14 = a14; // ok
     ~~~
 !!! error TS2322: Type '(x: { a: string; b: number; }) => Object' is not assignable to type '<T>(x: { a: T; b: T; }) => T'.

tests/baselines/reference/assignmentCompatWithCallSignatures4.errors.txt

@@ -22,8 +22,10 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures4.ts(66,9): error TS2322: Type '(x: Base[], y: Derived2[]) => Derived[]' is not assignable to type '<T extends Derived2[]>(x: Base[], y: Base[]) => T'.
   Type 'Derived[]' is not assignable to type 'T'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures4.ts(69,9): error TS2322: Type '<T>(x: { a: T; b: T; }) => T' is not assignable to type '(x: { a: string; b: number; }) => number'.
-  Type 'string | number' is not assignable to type 'number'.
-    Type 'string' is not assignable to type 'number'.
+  Types of parameters 'x' and 'x' are incompatible.
+    Type '{ a: string; b: number; }' is not assignable to type '{ a: string; b: string; }'.
+      Types of property 'b' are incompatible.
+        Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures4.ts(70,9): error TS2322: Type '(x: { a: string; b: number; }) => number' is not assignable to type '<T>(x: { a: T; b: T; }) => T'.
   Types of parameters 'x' and 'x' are incompatible.
     Type '{ a: T; b: T; }' is not assignable to type '{ a: string; b: number; }'.
@@ -156,8 +158,10 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
             a15 = b15;
             ~~~
 !!! error TS2322: Type '<T>(x: { a: T; b: T; }) => T' is not assignable to type '(x: { a: string; b: number; }) => number'.
-!!! error TS2322:   Type 'string | number' is not assignable to type 'number'.
-!!! error TS2322:     Type 'string' is not assignable to type 'number'.
+!!! error TS2322:   Types of parameters 'x' and 'x' are incompatible.
+!!! error TS2322:     Type '{ a: string; b: number; }' is not assignable to type '{ a: string; b: string; }'.
+!!! error TS2322:       Types of property 'b' are incompatible.
+!!! error TS2322:         Type 'number' is not assignable to type 'string'.
             b15 = a15;
             ~~~
 !!! error TS2322: Type '(x: { a: string; b: number; }) => number' is not assignable to type '<T>(x: { a: T; b: T; }) => T'.

tests/baselines/reference/assignmentCompatWithCallSignatures5.errors.txt

@@ -1,9 +1,15 @@
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures5.ts(40,1): error TS2322: Type '<T>(x: T) => void' is not assignable to type '<T>(x: T) => T'.
   Type 'void' is not assignable to type 'T'.
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures5.ts(52,1): error TS2322: Type '<T>(x: { foo: T; }, y: { foo: T; bar: T; }) => Base' is not assignable to type '<T, U>(x: { foo: T; }, y: { foo: U; bar: U; }) => Base'.
+  Types of parameters 'y' and 'y' are incompatible.
+    Type '{ foo: U; bar: U; }' is not assignable to type '{ foo: T; bar: T; }'.
+      Types of property 'foo' are incompatible.
+        Type 'U' is not assignable to type 'T'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures5.ts(55,1): error TS2322: Type '<T>(x: { a: T; b: T; }) => T[]' is not assignable to type '<U, V>(x: { a: U; b: V; }) => U[]'.
-  Type '(U | V)[]' is not assignable to type 'U[]'.
-    Type 'U | V' is not assignable to type 'U'.
-      Type 'V' is not assignable to type 'U'.
+  Types of parameters 'x' and 'x' are incompatible.
+    Type '{ a: U; b: V; }' is not assignable to type '{ a: U; b: U; }'.
+      Types of property 'b' are incompatible.
+        Type 'V' is not assignable to type 'U'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures5.ts(58,1): error TS2322: Type '<T extends Base>(x: { a: T; b: T; }) => T[]' is not assignable to type '<U, V>(x: { a: U; b: V; }) => U[]'.
   Types of parameters 'x' and 'x' are incompatible.
     Type '{ a: U; b: V; }' is not assignable to type '{ a: Base; b: Base; }'.
@@ -11,7 +17,7 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
         Type 'U' is not assignable to type 'Base'.
 
 
-==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures5.ts (3 errors) ====
+==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures5.ts (4 errors) ====
     // checking assignment compat for function types. No errors in this file
     
     class Base { foo: string; }
@@ -67,14 +73,21 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
     var b11: <T, U>(x: { foo: T }, y: { foo: U; bar: U }) => Base; 
     a11 = b11; // ok
     b11 = a11; // ok
+    ~~~
+!!! error TS2322: Type '<T>(x: { foo: T; }, y: { foo: T; bar: T; }) => Base' is not assignable to type '<T, U>(x: { foo: T; }, y: { foo: U; bar: U; }) => Base'.
+!!! error TS2322:   Types of parameters 'y' and 'y' are incompatible.
+!!! error TS2322:     Type '{ foo: U; bar: U; }' is not assignable to type '{ foo: T; bar: T; }'.
+!!! error TS2322:       Types of property 'foo' are incompatible.
+!!! error TS2322:         Type 'U' is not assignable to type 'T'.
     var b15: <U, V>(x: { a: U; b: V; }) => U[]; 
     a15 = b15; // ok, T = U, T = V
     b15 = a15; // ok
     ~~~
 !!! error TS2322: Type '<T>(x: { a: T; b: T; }) => T[]' is not assignable to type '<U, V>(x: { a: U; b: V; }) => U[]'.
-!!! error TS2322:   Type '(U | V)[]' is not assignable to type 'U[]'.
-!!! error TS2322:     Type 'U | V' is not assignable to type 'U'.
-!!! error TS2322:       Type 'V' is not assignable to type 'U'.
+!!! error TS2322:   Types of parameters 'x' and 'x' are incompatible.
+!!! error TS2322:     Type '{ a: U; b: V; }' is not assignable to type '{ a: U; b: U; }'.
+!!! error TS2322:       Types of property 'b' are incompatible.
+!!! error TS2322:         Type 'V' is not assignable to type 'U'.
     var b16: <T>(x: { a: T; b: T }) => T[]; 
     a15 = b16; // ok
     b15 = a16; // ok

tests/baselines/reference/assignmentCompatWithCallSignatures6.errors.txt

@@ -1,5 +1,10 @@
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures6.ts(30,1): error TS2322: Type '<T>(x: T) => void' is not assignable to type '<T>(x: T) => T'.
   Type 'void' is not assignable to type 'T'.
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures6.ts(39,1): error TS2322: Type '<T>(x: { foo: T; }, y: { foo: T; bar: T; }) => Base' is not assignable to type '<T, U>(x: { foo: T; }, y: { foo: U; bar: U; }) => Base'.
+  Types of parameters 'y' and 'y' are incompatible.
+    Type '{ foo: U; bar: U; }' is not assignable to type '{ foo: T; bar: T; }'.
+      Types of property 'foo' are incompatible.
+        Type 'U' is not assignable to type 'T'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures6.ts(42,1): error TS2322: Type '<T extends Base>(x: { a: T; b: T; }) => T[]' is not assignable to type '<T>(x: { a: T; b: T; }) => T[]'.
   Types of parameters 'x' and 'x' are incompatible.
     Type '{ a: T; b: T; }' is not assignable to type '{ a: Base; b: Base; }'.
@@ -7,7 +12,7 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
         Type 'T' is not assignable to type 'Base'.
 
 
-==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures6.ts (2 errors) ====
+==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithCallSignatures6.ts (3 errors) ====
     // checking assignment compatibility relations for function types. All valid
     
     class Base { foo: string; }
@@ -50,6 +55,12 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
     var b11: <T, U>(x: { foo: T }, y: { foo: U; bar: U }) => Base; 
     x.a11 = b11;
     b11 = x.a11;
+    ~~~
+!!! error TS2322: Type '<T>(x: { foo: T; }, y: { foo: T; bar: T; }) => Base' is not assignable to type '<T, U>(x: { foo: T; }, y: { foo: U; bar: U; }) => Base'.
+!!! error TS2322:   Types of parameters 'y' and 'y' are incompatible.
+!!! error TS2322:     Type '{ foo: U; bar: U; }' is not assignable to type '{ foo: T; bar: T; }'.
+!!! error TS2322:       Types of property 'foo' are incompatible.
+!!! error TS2322:         Type 'U' is not assignable to type 'T'.
     var b16: <T>(x: { a: T; b: T }) => T[]; 
     x.a16 = b16;
     b16 = x.a16;

tests/baselines/reference/assignmentCompatWithConstructSignatures3.errors.txt

@@ -45,6 +45,11 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
           Property 'baz' is missing in type 'Base'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures3.ts(83,1): error TS2322: Type 'new (x: Base[], y: Derived[]) => Derived[]' is not assignable to type 'new <T extends Derived[]>(x: Base[], y: T) => T'.
   Type 'Derived[]' is not assignable to type 'T'.
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures3.ts(85,1): error TS2322: Type 'new <T>(x: { a: T; b: T; }) => T' is not assignable to type 'new (x: { a: string; b: number; }) => Object'.
+  Types of parameters 'x' and 'x' are incompatible.
+    Type '{ a: string; b: number; }' is not assignable to type '{ a: string; b: string; }'.
+      Types of property 'b' are incompatible.
+        Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures3.ts(86,1): error TS2322: Type 'new (x: { a: string; b: number; }) => Object' is not assignable to type 'new <T>(x: { a: T; b: T; }) => T'.
   Types of parameters 'x' and 'x' are incompatible.
     Type '{ a: T; b: T; }' is not assignable to type '{ a: string; b: number; }'.
@@ -52,7 +57,7 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
         Type 'T' is not assignable to type 'string'.
 
 
-==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures3.ts (14 errors) ====
+==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures3.ts (15 errors) ====
     // checking assignment compatibility relations for function types. All of these are valid.
     
     class Base { foo: string; }
@@ -198,6 +203,12 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
 !!! error TS2322:   Type 'Derived[]' is not assignable to type 'T'.
     var b14: new <T>(x: { a: T; b: T }) => T; 
     a14 = b14; // ok
+    ~~~
+!!! error TS2322: Type 'new <T>(x: { a: T; b: T; }) => T' is not assignable to type 'new (x: { a: string; b: number; }) => Object'.
+!!! error TS2322:   Types of parameters 'x' and 'x' are incompatible.
+!!! error TS2322:     Type '{ a: string; b: number; }' is not assignable to type '{ a: string; b: string; }'.
+!!! error TS2322:       Types of property 'b' are incompatible.
+!!! error TS2322:         Type 'number' is not assignable to type 'string'.
     b14 = a14; // ok
     ~~~
 !!! error TS2322: Type 'new (x: { a: string; b: number; }) => Object' is not assignable to type 'new <T>(x: { a: T; b: T; }) => T'.

tests/baselines/reference/assignmentCompatWithConstructSignatures4.errors.txt

@@ -22,8 +22,10 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures4.ts(66,9): error TS2322: Type 'new (x: Base[], y: Derived2[]) => Derived[]' is not assignable to type 'new <T extends Derived2[]>(x: Base[], y: Base[]) => T'.
   Type 'Derived[]' is not assignable to type 'T'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures4.ts(69,9): error TS2322: Type 'new <T>(x: { a: T; b: T; }) => T' is not assignable to type 'new (x: { a: string; b: number; }) => number'.
-  Type 'string | number' is not assignable to type 'number'.
-    Type 'string' is not assignable to type 'number'.
+  Types of parameters 'x' and 'x' are incompatible.
+    Type '{ a: string; b: number; }' is not assignable to type '{ a: string; b: string; }'.
+      Types of property 'b' are incompatible.
+        Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures4.ts(70,9): error TS2322: Type 'new (x: { a: string; b: number; }) => number' is not assignable to type 'new <T>(x: { a: T; b: T; }) => T'.
   Types of parameters 'x' and 'x' are incompatible.
     Type '{ a: T; b: T; }' is not assignable to type '{ a: string; b: number; }'.
@@ -172,8 +174,10 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
             a15 = b15; // ok
             ~~~
 !!! error TS2322: Type 'new <T>(x: { a: T; b: T; }) => T' is not assignable to type 'new (x: { a: string; b: number; }) => number'.
-!!! error TS2322:   Type 'string | number' is not assignable to type 'number'.
-!!! error TS2322:     Type 'string' is not assignable to type 'number'.
+!!! error TS2322:   Types of parameters 'x' and 'x' are incompatible.
+!!! error TS2322:     Type '{ a: string; b: number; }' is not assignable to type '{ a: string; b: string; }'.
+!!! error TS2322:       Types of property 'b' are incompatible.
+!!! error TS2322:         Type 'number' is not assignable to type 'string'.
             b15 = a15; // ok
             ~~~
 !!! error TS2322: Type 'new (x: { a: string; b: number; }) => number' is not assignable to type 'new <T>(x: { a: T; b: T; }) => T'.

tests/baselines/reference/assignmentCompatWithConstructSignatures5.errors.txt

@@ -1,9 +1,15 @@
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures5.ts(40,1): error TS2322: Type 'new <T>(x: T) => void' is not assignable to type 'new <T>(x: T) => T'.
   Type 'void' is not assignable to type 'T'.
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures5.ts(52,1): error TS2322: Type 'new <T>(x: { foo: T; }, y: { foo: T; bar: T; }) => Base' is not assignable to type 'new <T, U>(x: { foo: T; }, y: { foo: U; bar: U; }) => Base'.
+  Types of parameters 'y' and 'y' are incompatible.
+    Type '{ foo: U; bar: U; }' is not assignable to type '{ foo: T; bar: T; }'.
+      Types of property 'foo' are incompatible.
+        Type 'U' is not assignable to type 'T'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures5.ts(55,1): error TS2322: Type 'new <T>(x: { a: T; b: T; }) => T[]' is not assignable to type 'new <U, V>(x: { a: U; b: V; }) => U[]'.
-  Type '(U | V)[]' is not assignable to type 'U[]'.
-    Type 'U | V' is not assignable to type 'U'.
-      Type 'V' is not assignable to type 'U'.
+  Types of parameters 'x' and 'x' are incompatible.
+    Type '{ a: U; b: V; }' is not assignable to type '{ a: U; b: U; }'.
+      Types of property 'b' are incompatible.
+        Type 'V' is not assignable to type 'U'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures5.ts(58,1): error TS2322: Type 'new <T extends Base>(x: { a: T; b: T; }) => T[]' is not assignable to type 'new <U, V>(x: { a: U; b: V; }) => U[]'.
   Types of parameters 'x' and 'x' are incompatible.
     Type '{ a: U; b: V; }' is not assignable to type '{ a: Base; b: Base; }'.
@@ -11,7 +17,7 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
         Type 'U' is not assignable to type 'Base'.
 
 
-==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures5.ts (3 errors) ====
+==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures5.ts (4 errors) ====
     // checking assignment compat for function types. All valid
     
     class Base { foo: string; }
@@ -67,14 +73,21 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
     var b11: new <T, U>(x: { foo: T }, y: { foo: U; bar: U }) => Base; 
     a11 = b11; // ok
     b11 = a11; // ok
+    ~~~
+!!! error TS2322: Type 'new <T>(x: { foo: T; }, y: { foo: T; bar: T; }) => Base' is not assignable to type 'new <T, U>(x: { foo: T; }, y: { foo: U; bar: U; }) => Base'.
+!!! error TS2322:   Types of parameters 'y' and 'y' are incompatible.
+!!! error TS2322:     Type '{ foo: U; bar: U; }' is not assignable to type '{ foo: T; bar: T; }'.
+!!! error TS2322:       Types of property 'foo' are incompatible.
+!!! error TS2322:         Type 'U' is not assignable to type 'T'.
     var b15: new <U, V>(x: { a: U; b: V; }) => U[]; 
     a15 = b15; // ok
     b15 = a15; // ok
     ~~~
 !!! error TS2322: Type 'new <T>(x: { a: T; b: T; }) => T[]' is not assignable to type 'new <U, V>(x: { a: U; b: V; }) => U[]'.
-!!! error TS2322:   Type '(U | V)[]' is not assignable to type 'U[]'.
-!!! error TS2322:     Type 'U | V' is not assignable to type 'U'.
-!!! error TS2322:       Type 'V' is not assignable to type 'U'.
+!!! error TS2322:   Types of parameters 'x' and 'x' are incompatible.
+!!! error TS2322:     Type '{ a: U; b: V; }' is not assignable to type '{ a: U; b: U; }'.
+!!! error TS2322:       Types of property 'b' are incompatible.
+!!! error TS2322:         Type 'V' is not assignable to type 'U'.
     var b16: new <T>(x: { a: T; b: T }) => T[]; 
     a15 = b16; // ok
     b15 = a16; // ok

tests/baselines/reference/assignmentCompatWithConstructSignatures6.errors.txt

@@ -1,5 +1,10 @@
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures6.ts(30,1): error TS2322: Type 'new <T>(x: T) => void' is not assignable to type 'new <T>(x: T) => T'.
   Type 'void' is not assignable to type 'T'.
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures6.ts(39,1): error TS2322: Type 'new <T>(x: { foo: T; }, y: { foo: T; bar: T; }) => Base' is not assignable to type 'new <T, U>(x: { foo: T; }, y: { foo: U; bar: U; }) => Base'.
+  Types of parameters 'y' and 'y' are incompatible.
+    Type '{ foo: U; bar: U; }' is not assignable to type '{ foo: T; bar: T; }'.
+      Types of property 'foo' are incompatible.
+        Type 'U' is not assignable to type 'T'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures6.ts(42,1): error TS2322: Type 'new <T extends Base>(x: { a: T; b: T; }) => T[]' is not assignable to type 'new <T>(x: { a: T; b: T; }) => T[]'.
   Types of parameters 'x' and 'x' are incompatible.
     Type '{ a: T; b: T; }' is not assignable to type '{ a: Base; b: Base; }'.
@@ -7,7 +12,7 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
         Type 'T' is not assignable to type 'Base'.
 
 
-==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures6.ts (2 errors) ====
+==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithConstructSignatures6.ts (3 errors) ====
     // checking assignment compatibility relations for function types. All valid.
     
     class Base { foo: string; }
@@ -50,6 +55,12 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
     var b11: new <T, U>(x: { foo: T }, y: { foo: U; bar: U }) => Base; 
     x.a11 = b11;
     b11 = x.a11;
+    ~~~
+!!! error TS2322: Type 'new <T>(x: { foo: T; }, y: { foo: T; bar: T; }) => Base' is not assignable to type 'new <T, U>(x: { foo: T; }, y: { foo: U; bar: U; }) => Base'.
+!!! error TS2322:   Types of parameters 'y' and 'y' are incompatible.
+!!! error TS2322:     Type '{ foo: U; bar: U; }' is not assignable to type '{ foo: T; bar: T; }'.
+!!! error TS2322:       Types of property 'foo' are incompatible.
+!!! error TS2322:         Type 'U' is not assignable to type 'T'.
     var b16: new <T>(x: { a: T; b: T }) => T[]; 
     x.a16 = b16;
     b16 = x.a16;

tests/baselines/reference/assignmentCompatWithGenericCallSignatures2.errors.txt

@@ -1,9 +1,12 @@
+tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithGenericCallSignatures2.ts(15,1): error TS2322: Type 'B' is not assignable to type 'A'.
+  Types of parameters 'y' and 'y' are incompatible.
+    Type 'T[]' is not assignable to type 'T'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithGenericCallSignatures2.ts(16,1): error TS2322: Type 'A' is not assignable to type 'B'.
   Types of parameters 'y' and 'y' are incompatible.
     Type 'S' is not assignable to type 'S[]'.
 
 
-==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithGenericCallSignatures2.ts (1 errors) ====
+==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithGenericCallSignatures2.ts (2 errors) ====
     // some complex cases of assignment compat of generic signatures. No contextual signature instantiation
     
     interface A {
@@ -17,8 +20,12 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignme
     var a: A;
     var b: B;
     
-    // Both ok
+    // Both errors
     a = b;
+    ~
+!!! error TS2322: Type 'B' is not assignable to type 'A'.
+!!! error TS2322:   Types of parameters 'y' and 'y' are incompatible.
+!!! error TS2322:     Type 'T[]' is not assignable to type 'T'.
     b = a;
     ~
 !!! error TS2322: Type 'A' is not assignable to type 'B'.

tests/baselines/reference/assignmentCompatWithGenericCallSignatures2.js

@@ -12,7 +12,7 @@ interface B {
 var a: A;
 var b: B;
 
-// Both ok
+// Both errors
 a = b;
 b = a;
 
@@ -21,6 +21,6 @@ b = a;
 // some complex cases of assignment compat of generic signatures. No contextual signature instantiation
 var a;
 var b;
-// Both ok
+// Both errors
 a = b;
 b = a;

tests/baselines/reference/assignmentCompatWithGenericCallSignatures2.symbols

@@ -31,7 +31,7 @@ var b: B;
 >b : Symbol(b, Decl(assignmentCompatWithGenericCallSignatures2.ts, 11, 3))
 >B : Symbol(B, Decl(assignmentCompatWithGenericCallSignatures2.ts, 4, 1))
 
-// Both ok
+// Both errors
 a = b;
 >a : Symbol(a, Decl(assignmentCompatWithGenericCallSignatures2.ts, 10, 3))
 >b : Symbol(b, Decl(assignmentCompatWithGenericCallSignatures2.ts, 11, 3))

tests/baselines/reference/assignmentCompatWithGenericCallSignatures2.types

@@ -19,7 +19,7 @@ var a: A;
 var b: B;
 >b : B
 
-// Both ok
+// Both errors
 a = b;
 >a = b : B
 >a : A

tests/baselines/reference/callSignatureAssignabilityInInheritance2.js

@@ -62,7 +62,7 @@ interface I extends A {
     a11: <T extends Base>(x: T, y: T) => T; // ok
     a12: <T extends Array<Base>>(x: Array<Base>, y: T) => Array<Derived>; // ok, less specific parameter type
     a13: <T extends Array<Derived>>(x: Array<Base>, y: T) => T; // ok, T = Array<Derived>, satisfies constraint, contextual signature instantiation succeeds
-    a14: <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: <T, U>(x: { a: T; b: U }) => T; // ok
     a15: <T>(x: T) => T[]; // ok
     a16: <T extends Base>(x: T) => number[]; // ok
     a17: <T>(x: (a: T) => T) => T[]; // ok

tests/baselines/reference/callSignatureAssignabilityInInheritance2.symbols

@@ -354,18 +354,19 @@ interface I extends A {
 >T : Symbol(T, Decl(callSignatureAssignabilityInInheritance2.ts, 62, 10))
 >T : Symbol(T, Decl(callSignatureAssignabilityInInheritance2.ts, 62, 10))
 
-    a14: <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: <T, U>(x: { a: T; b: U }) => T; // ok
 >a14 : Symbol(I.a14, Decl(callSignatureAssignabilityInInheritance2.ts, 62, 63))
 >T : Symbol(T, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 10))
->x : Symbol(x, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 13))
->a : Symbol(a, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 17))
->T : Symbol(T, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 10))
->b : Symbol(b, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 23))
+>U : Symbol(U, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 12))
+>x : Symbol(x, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 16))
+>a : Symbol(a, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 20))
 >T : Symbol(T, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 10))
+>b : Symbol(b, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 26))
+>U : Symbol(U, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 12))
 >T : Symbol(T, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 10))
 
     a15: <T>(x: T) => T[]; // ok
->a15 : Symbol(I.a15, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 37))
+>a15 : Symbol(I.a15, Decl(callSignatureAssignabilityInInheritance2.ts, 63, 40))
 >T : Symbol(T, Decl(callSignatureAssignabilityInInheritance2.ts, 64, 10))
 >x : Symbol(x, Decl(callSignatureAssignabilityInInheritance2.ts, 64, 13))
 >T : Symbol(T, Decl(callSignatureAssignabilityInInheritance2.ts, 64, 10))

tests/baselines/reference/callSignatureAssignabilityInInheritance2.types

@@ -230,11 +230,11 @@ interface I extends A {
 >x : Base[]
 >y : T
 
-    a14: <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
->a14 : <T>(x: { a: T; b: T; }) => T
->x : { a: T; b: T; }
+    a14: <T, U>(x: { a: T; b: U }) => T; // ok
+>a14 : <T, U>(x: { a: T; b: U; }) => T
+>x : { a: T; b: U; }
 >a : T
->b : T
+>b : U
 
     a15: <T>(x: T) => T[]; // ok
 >a15 : <T>(x: T) => T[]

tests/baselines/reference/callSignatureAssignabilityInInheritance3.errors.txt

@@ -14,8 +14,10 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/callSign
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/callSignatureAssignabilityInInheritance3.ts(76,19): error TS2430: Interface 'I6' incorrectly extends interface 'A'.
   Types of property 'a15' are incompatible.
     Type '<T>(x: { a: T; b: T; }) => T' is not assignable to type '(x: { a: string; b: number; }) => number'.
-      Type 'string | number' is not assignable to type 'number'.
-        Type 'string' is not assignable to type 'number'.
+      Types of parameters 'x' and 'x' are incompatible.
+        Type '{ a: string; b: number; }' is not assignable to type '{ a: string; b: string; }'.
+          Types of property 'b' are incompatible.
+            Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/callSignatureAssignabilityInInheritance3.ts(80,19): error TS2430: Interface 'I7' incorrectly extends interface 'A'.
   Types of property 'a15' are incompatible.
     Type '<T extends Base>(x: { a: T; b: T; }) => number' is not assignable to type '(x: { a: string; b: number; }) => number'.
@@ -131,8 +133,10 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/callSign
 !!! error TS2430: Interface 'I6' incorrectly extends interface 'A'.
 !!! error TS2430:   Types of property 'a15' are incompatible.
 !!! error TS2430:     Type '<T>(x: { a: T; b: T; }) => T' is not assignable to type '(x: { a: string; b: number; }) => number'.
-!!! error TS2430:       Type 'string | number' is not assignable to type 'number'.
-!!! error TS2430:         Type 'string' is not assignable to type 'number'.
+!!! error TS2430:       Types of parameters 'x' and 'x' are incompatible.
+!!! error TS2430:         Type '{ a: string; b: number; }' is not assignable to type '{ a: string; b: string; }'.
+!!! error TS2430:           Types of property 'b' are incompatible.
+!!! error TS2430:             Type 'number' is not assignable to type 'string'.
                 a15: <T>(x: { a: T; b: T }) => T; // error, T is {} which isn't an acceptable return type
             }
     

tests/baselines/reference/callSignatureAssignabilityInInheritance5.js

@@ -45,7 +45,7 @@ interface I extends B {
     a11: <T extends Base>(x: T, y: T) => T; // ok
     a12: <T extends Array<Base>>(x: Array<Base>, y: T) => Array<Derived>; // ok, less specific parameter type
     a13: <T extends Array<Derived>>(x: Array<Base>, y: T) => T; // ok, T = Array<Derived>, satisfies constraint, contextual signature instantiation succeeds
-    a14: <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: <T, U>(x: { a: T; b: U }) => T; // ok
 }
 
 //// [callSignatureAssignabilityInInheritance5.js]

tests/baselines/reference/callSignatureAssignabilityInInheritance5.symbols

@@ -302,13 +302,14 @@ interface I extends B {
 >T : Symbol(T, Decl(callSignatureAssignabilityInInheritance5.ts, 45, 10))
 >T : Symbol(T, Decl(callSignatureAssignabilityInInheritance5.ts, 45, 10))
 
-    a14: <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: <T, U>(x: { a: T; b: U }) => T; // ok
 >a14 : Symbol(I.a14, Decl(callSignatureAssignabilityInInheritance5.ts, 45, 63))
 >T : Symbol(T, Decl(callSignatureAssignabilityInInheritance5.ts, 46, 10))
->x : Symbol(x, Decl(callSignatureAssignabilityInInheritance5.ts, 46, 13))
->a : Symbol(a, Decl(callSignatureAssignabilityInInheritance5.ts, 46, 17))
->T : Symbol(T, Decl(callSignatureAssignabilityInInheritance5.ts, 46, 10))
->b : Symbol(b, Decl(callSignatureAssignabilityInInheritance5.ts, 46, 23))
+>U : Symbol(U, Decl(callSignatureAssignabilityInInheritance5.ts, 46, 12))
+>x : Symbol(x, Decl(callSignatureAssignabilityInInheritance5.ts, 46, 16))
+>a : Symbol(a, Decl(callSignatureAssignabilityInInheritance5.ts, 46, 20))
 >T : Symbol(T, Decl(callSignatureAssignabilityInInheritance5.ts, 46, 10))
+>b : Symbol(b, Decl(callSignatureAssignabilityInInheritance5.ts, 46, 26))
+>U : Symbol(U, Decl(callSignatureAssignabilityInInheritance5.ts, 46, 12))
 >T : Symbol(T, Decl(callSignatureAssignabilityInInheritance5.ts, 46, 10))
 }

tests/baselines/reference/callSignatureAssignabilityInInheritance5.types

@@ -180,9 +180,9 @@ interface I extends B {
 >x : Base[]
 >y : T
 
-    a14: <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
->a14 : <T>(x: { a: T; b: T; }) => T
->x : { a: T; b: T; }
+    a14: <T, U>(x: { a: T; b: U }) => T; // ok
+>a14 : <T, U>(x: { a: T; b: U; }) => T
+>x : { a: T; b: U; }
 >a : T
->b : T
+>b : U
 }

tests/baselines/reference/constructSignatureAssignabilityInInheritance2.js

@@ -62,7 +62,7 @@ interface I extends A {
     a11: new <T extends Base>(x: T, y: T) => T; // ok
     a12: new <T extends Array<Base>>(x: Array<Base>, y: T) => Array<Derived>; // ok, less specific parameter type
     a13: new <T extends Array<Derived>>(x: Array<Base>, y: T) => T; // ok, T = Array<Derived>, satisfies constraint, contextual signature instantiation succeeds
-    a14: new <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: new <T, U>(x: { a: T; b: U }) => T; // ok
     a15: new <T>(x: T) => T[]; // ok
     a16: new <T extends Base>(x: T) => number[]; // ok
     a17: new <T>(x: new (a: T) => T) => T[]; // ok

tests/baselines/reference/constructSignatureAssignabilityInInheritance2.symbols

@@ -354,18 +354,19 @@ interface I extends A {
 >T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance2.ts, 62, 14))
 >T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance2.ts, 62, 14))
 
-    a14: new <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: new <T, U>(x: { a: T; b: U }) => T; // ok
 >a14 : Symbol(I.a14, Decl(constructSignatureAssignabilityInInheritance2.ts, 62, 67))
 >T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 14))
->x : Symbol(x, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 17))
->a : Symbol(a, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 21))
->T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 14))
->b : Symbol(b, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 27))
+>U : Symbol(U, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 16))
+>x : Symbol(x, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 20))
+>a : Symbol(a, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 24))
 >T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 14))
+>b : Symbol(b, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 30))
+>U : Symbol(U, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 16))
 >T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 14))
 
     a15: new <T>(x: T) => T[]; // ok
->a15 : Symbol(I.a15, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 41))
+>a15 : Symbol(I.a15, Decl(constructSignatureAssignabilityInInheritance2.ts, 63, 44))
 >T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance2.ts, 64, 14))
 >x : Symbol(x, Decl(constructSignatureAssignabilityInInheritance2.ts, 64, 17))
 >T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance2.ts, 64, 14))

tests/baselines/reference/constructSignatureAssignabilityInInheritance2.types

@@ -230,11 +230,11 @@ interface I extends A {
 >x : Base[]
 >y : T
 
-    a14: new <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
->a14 : new <T>(x: { a: T; b: T; }) => T
->x : { a: T; b: T; }
+    a14: new <T, U>(x: { a: T; b: U }) => T; // ok
+>a14 : new <T, U>(x: { a: T; b: U; }) => T
+>x : { a: T; b: U; }
 >a : T
->b : T
+>b : U
 
     a15: new <T>(x: T) => T[]; // ok
 >a15 : new <T>(x: T) => T[]

tests/baselines/reference/constructSignatureAssignabilityInInheritance3.errors.txt

@@ -14,8 +14,10 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/construc
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/constructSignatureAssignabilityInInheritance3.ts(66,19): error TS2430: Interface 'I6' incorrectly extends interface 'A'.
   Types of property 'a15' are incompatible.
     Type 'new <T>(x: { a: T; b: T; }) => T' is not assignable to type 'new (x: { a: string; b: number; }) => number'.
-      Type 'string | number' is not assignable to type 'number'.
-        Type 'string' is not assignable to type 'number'.
+      Types of parameters 'x' and 'x' are incompatible.
+        Type '{ a: string; b: number; }' is not assignable to type '{ a: string; b: string; }'.
+          Types of property 'b' are incompatible.
+            Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/assignmentCompatibility/constructSignatureAssignabilityInInheritance3.ts(70,19): error TS2430: Interface 'I7' incorrectly extends interface 'A'.
   Types of property 'a15' are incompatible.
     Type 'new <T extends Base>(x: { a: T; b: T; }) => number' is not assignable to type 'new (x: { a: string; b: number; }) => number'.
@@ -121,8 +123,10 @@ tests/cases/conformance/types/typeRelationships/assignmentCompatibility/construc
 !!! error TS2430: Interface 'I6' incorrectly extends interface 'A'.
 !!! error TS2430:   Types of property 'a15' are incompatible.
 !!! error TS2430:     Type 'new <T>(x: { a: T; b: T; }) => T' is not assignable to type 'new (x: { a: string; b: number; }) => number'.
-!!! error TS2430:       Type 'string | number' is not assignable to type 'number'.
-!!! error TS2430:         Type 'string' is not assignable to type 'number'.
+!!! error TS2430:       Types of parameters 'x' and 'x' are incompatible.
+!!! error TS2430:         Type '{ a: string; b: number; }' is not assignable to type '{ a: string; b: string; }'.
+!!! error TS2430:           Types of property 'b' are incompatible.
+!!! error TS2430:             Type 'number' is not assignable to type 'string'.
                 a15: new <T>(x: { a: T; b: T }) => T; // error, T is {} which isn't an acceptable return type
             }
     

tests/baselines/reference/constructSignatureAssignabilityInInheritance5.js

@@ -45,7 +45,7 @@ interface I extends B {
     a11: new <T extends Base>(x: T, y: T) => T; // ok
     a12: new <T extends Array<Base>>(x: Array<Base>, y: T) => Array<Derived>; // ok, less specific parameter type
     a13: new <T extends Array<Derived>>(x: Array<Base>, y: T) => T; // ok, T = Array<Derived>, satisfies constraint, contextual signature instantiation succeeds
-    a14: new <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: new <T, U>(x: { a: T; b: U }) => T; // ok
 }
 
 //// [constructSignatureAssignabilityInInheritance5.js]

tests/baselines/reference/constructSignatureAssignabilityInInheritance5.symbols

@@ -302,13 +302,14 @@ interface I extends B {
 >T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance5.ts, 45, 14))
 >T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance5.ts, 45, 14))
 
-    a14: new <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: new <T, U>(x: { a: T; b: U }) => T; // ok
 >a14 : Symbol(I.a14, Decl(constructSignatureAssignabilityInInheritance5.ts, 45, 67))
 >T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance5.ts, 46, 14))
->x : Symbol(x, Decl(constructSignatureAssignabilityInInheritance5.ts, 46, 17))
->a : Symbol(a, Decl(constructSignatureAssignabilityInInheritance5.ts, 46, 21))
->T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance5.ts, 46, 14))
->b : Symbol(b, Decl(constructSignatureAssignabilityInInheritance5.ts, 46, 27))
+>U : Symbol(U, Decl(constructSignatureAssignabilityInInheritance5.ts, 46, 16))
+>x : Symbol(x, Decl(constructSignatureAssignabilityInInheritance5.ts, 46, 20))
+>a : Symbol(a, Decl(constructSignatureAssignabilityInInheritance5.ts, 46, 24))
 >T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance5.ts, 46, 14))
+>b : Symbol(b, Decl(constructSignatureAssignabilityInInheritance5.ts, 46, 30))
+>U : Symbol(U, Decl(constructSignatureAssignabilityInInheritance5.ts, 46, 16))
 >T : Symbol(T, Decl(constructSignatureAssignabilityInInheritance5.ts, 46, 14))
 }

tests/baselines/reference/constructSignatureAssignabilityInInheritance5.types

@@ -180,9 +180,9 @@ interface I extends B {
 >x : Base[]
 >y : T
 
-    a14: new <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
->a14 : new <T>(x: { a: T; b: T; }) => T
->x : { a: T; b: T; }
+    a14: new <T, U>(x: { a: T; b: U }) => T; // ok
+>a14 : new <T, U>(x: { a: T; b: U; }) => T
+>x : { a: T; b: U; }
 >a : T
->b : T
+>b : U
 }

tests/baselines/reference/contextualSignatureInstantiation.errors.txt

@@ -0,0 +1,53 @@
+tests/cases/conformance/types/typeRelationships/typeInference/contextualSignatureInstantiation.ts(19,13): error TS2345: Argument of type '<T>(x: T, y: T) => T' is not assignable to parameter of type '(x: number, y: string) => number'.
+  Types of parameters 'y' and 'y' are incompatible.
+    Type 'string' is not assignable to type 'number'.
+tests/cases/conformance/types/typeRelationships/typeInference/contextualSignatureInstantiation.ts(20,23): error TS2345: Argument of type '<T>(x: T, y: T) => T' is not assignable to parameter of type '(x: number, y: string) => number'.
+  Types of parameters 'y' and 'y' are incompatible.
+    Type 'string' is not assignable to type 'number'.
+tests/cases/conformance/types/typeRelationships/typeInference/contextualSignatureInstantiation.ts(21,23): error TS2345: Argument of type '<T>(x: T, y: T) => T' is not assignable to parameter of type '(x: string, y: number) => string'.
+  Types of parameters 'y' and 'y' are incompatible.
+    Type 'number' is not assignable to type 'string'.
+
+
+==== tests/cases/conformance/types/typeRelationships/typeInference/contextualSignatureInstantiation.ts (3 errors) ====
+    // TypeScript Spec, section 4.12.2:
+    // If e is an expression of a function type that contains exactly one generic call signature and no other members,
+    // and T is a function type with exactly one non - generic call signature and no other members, then any inferences
+    // made for type parameters referenced by the parameters of T's call signature are fixed, and e's type is changed
+    // to a function type with e's call signature instantiated in the context of T's call signature (section 3.8.5).
+    
+    declare function foo<T>(cb: (x: number, y: string) => T): T;
+    declare function bar<T, U, V>(x: T, y: U, cb: (x: T, y: U) => V): V;
+    declare function baz<T, U>(x: T, y: T, cb: (x: T, y: T) => U): U;
+    
+    declare function g<T>(x: T, y: T): T;
+    declare function h<T, U>(x: T, y: U): T[] | U[];
+    
+    var a: number;
+    var a = bar(1, 1, g);      // Should be number
+    var a = baz(1, 1, g);      // Should be number
+    
+    var b: number | string;
+    var b = foo(g);            // Error, number and string are disjoint types
+                ~
+!!! error TS2345: Argument of type '<T>(x: T, y: T) => T' is not assignable to parameter of type '(x: number, y: string) => number'.
+!!! error TS2345:   Types of parameters 'y' and 'y' are incompatible.
+!!! error TS2345:     Type 'string' is not assignable to type 'number'.
+    var b = bar(1, "one", g);  // Error, number and string are disjoint types
+                          ~
+!!! error TS2345: Argument of type '<T>(x: T, y: T) => T' is not assignable to parameter of type '(x: number, y: string) => number'.
+!!! error TS2345:   Types of parameters 'y' and 'y' are incompatible.
+!!! error TS2345:     Type 'string' is not assignable to type 'number'.
+    var b = bar("one", 1, g);  // Error, number and string are disjoint types
+                          ~
+!!! error TS2345: Argument of type '<T>(x: T, y: T) => T' is not assignable to parameter of type '(x: string, y: number) => string'.
+!!! error TS2345:   Types of parameters 'y' and 'y' are incompatible.
+!!! error TS2345:     Type 'number' is not assignable to type 'string'.
+    var b = baz(b, b, g);      // Should be number | string
+    
+    var d: number[] | string[];
+    var d = foo(h);            // Should be number[] | string[]
+    var d = bar(1, "one", h);  // Should be number[] | string[]
+    var d = bar("one", 1, h);  // Should be number[] | string[]
+    var d = baz(d, d, g);      // Should be number[] | string[]
+    

tests/baselines/reference/contextualSignatureInstantiation.js

@@ -17,9 +17,9 @@ var a = bar(1, 1, g);      // Should be number
 var a = baz(1, 1, g);      // Should be number
 
 var b: number | string;
-var b = foo(g);            // Should be number | string
-var b = bar(1, "one", g);  // Should be number | string
-var b = bar("one", 1, g);  // Should be number | string
+var b = foo(g);            // Error, number and string are disjoint types
+var b = bar(1, "one", g);  // Error, number and string are disjoint types
+var b = bar("one", 1, g);  // Error, number and string are disjoint types
 var b = baz(b, b, g);      // Should be number | string
 
 var d: number[] | string[];
@@ -39,9 +39,9 @@ var a;
 var a = bar(1, 1, g); // Should be number
 var a = baz(1, 1, g); // Should be number
 var b;
-var b = foo(g); // Should be number | string
-var b = bar(1, "one", g); // Should be number | string
-var b = bar("one", 1, g); // Should be number | string
+var b = foo(g); // Error, number and string are disjoint types
+var b = bar(1, "one", g); // Error, number and string are disjoint types
+var b = bar("one", 1, g); // Error, number and string are disjoint types
 var b = baz(b, b, g); // Should be number | string
 var d;
 var d = foo(h); // Should be number[] | string[]

tests/baselines/reference/contextualSignatureInstantiation.symbols

@@ -83,17 +83,17 @@ var a = baz(1, 1, g);      // Should be number
 var b: number | string;
 >b : Symbol(b, Decl(contextualSignatureInstantiation.ts, 17, 3), Decl(contextualSignatureInstantiation.ts, 18, 3), Decl(contextualSignatureInstantiation.ts, 19, 3), Decl(contextualSignatureInstantiation.ts, 20, 3), Decl(contextualSignatureInstantiation.ts, 21, 3))
 
-var b = foo(g);            // Should be number | string
+var b = foo(g);            // Error, number and string are disjoint types
 >b : Symbol(b, Decl(contextualSignatureInstantiation.ts, 17, 3), Decl(contextualSignatureInstantiation.ts, 18, 3), Decl(contextualSignatureInstantiation.ts, 19, 3), Decl(contextualSignatureInstantiation.ts, 20, 3), Decl(contextualSignatureInstantiation.ts, 21, 3))
 >foo : Symbol(foo, Decl(contextualSignatureInstantiation.ts, 0, 0))
 >g : Symbol(g, Decl(contextualSignatureInstantiation.ts, 8, 65))
 
-var b = bar(1, "one", g);  // Should be number | string
+var b = bar(1, "one", g);  // Error, number and string are disjoint types
 >b : Symbol(b, Decl(contextualSignatureInstantiation.ts, 17, 3), Decl(contextualSignatureInstantiation.ts, 18, 3), Decl(contextualSignatureInstantiation.ts, 19, 3), Decl(contextualSignatureInstantiation.ts, 20, 3), Decl(contextualSignatureInstantiation.ts, 21, 3))
 >bar : Symbol(bar, Decl(contextualSignatureInstantiation.ts, 6, 60))
 >g : Symbol(g, Decl(contextualSignatureInstantiation.ts, 8, 65))
 
-var b = bar("one", 1, g);  // Should be number | string
+var b = bar("one", 1, g);  // Error, number and string are disjoint types
 >b : Symbol(b, Decl(contextualSignatureInstantiation.ts, 17, 3), Decl(contextualSignatureInstantiation.ts, 18, 3), Decl(contextualSignatureInstantiation.ts, 19, 3), Decl(contextualSignatureInstantiation.ts, 20, 3), Decl(contextualSignatureInstantiation.ts, 21, 3))
 >bar : Symbol(bar, Decl(contextualSignatureInstantiation.ts, 6, 60))
 >g : Symbol(g, Decl(contextualSignatureInstantiation.ts, 8, 65))

tests/baselines/reference/contextualSignatureInstantiation.types

@@ -59,23 +59,23 @@ var a = baz(1, 1, g);      // Should be number
 var b: number | string;
 >b : string | number
 
-var b = foo(g);            // Should be number | string
+var b = foo(g);            // Error, number and string are disjoint types
 >b : string | number
->foo(g) : string | number
+>foo(g) : any
 >foo : <T>(cb: (x: number, y: string) => T) => T
 >g : <T>(x: T, y: T) => T
 
-var b = bar(1, "one", g);  // Should be number | string
+var b = bar(1, "one", g);  // Error, number and string are disjoint types
 >b : string | number
->bar(1, "one", g) : string | number
+>bar(1, "one", g) : any
 >bar : <T, U, V>(x: T, y: U, cb: (x: T, y: U) => V) => V
 >1 : 1
 >"one" : "one"
 >g : <T>(x: T, y: T) => T
 
-var b = bar("one", 1, g);  // Should be number | string
+var b = bar("one", 1, g);  // Error, number and string are disjoint types
 >b : string | number
->bar("one", 1, g) : string | number
+>bar("one", 1, g) : any
 >bar : <T, U, V>(x: T, y: U, cb: (x: T, y: U) => V) => V
 >"one" : "one"
 >1 : 1

tests/baselines/reference/contextualSignatureInstatiationContravariance.errors.txt

@@ -0,0 +1,23 @@
+tests/cases/compiler/contextualSignatureInstatiationContravariance.ts(8,1): error TS2322: Type '<T extends Animal>(x: T, y: T) => void' is not assignable to type '(g: Giraffe, e: Elephant) => void'.
+  Types of parameters 'y' and 'e' are incompatible.
+    Type 'Elephant' is not assignable to type 'Giraffe'.
+      Property 'y' is missing in type 'Elephant'.
+
+
+==== tests/cases/compiler/contextualSignatureInstatiationContravariance.ts (1 errors) ====
+    interface Animal { x }
+    interface Giraffe extends Animal { y }
+    interface Elephant extends Animal { y2 }
+    
+    var f2: <T extends Animal>(x: T, y: T) => void;
+    
+    var g2: (g: Giraffe, e: Elephant) => void;
+    g2 = f2; // error because Giraffe and Elephant are disjoint types
+    ~~
+!!! error TS2322: Type '<T extends Animal>(x: T, y: T) => void' is not assignable to type '(g: Giraffe, e: Elephant) => void'.
+!!! error TS2322:   Types of parameters 'y' and 'e' are incompatible.
+!!! error TS2322:     Type 'Elephant' is not assignable to type 'Giraffe'.
+!!! error TS2322:       Property 'y' is missing in type 'Elephant'.
+    
+    var h2: (g1: Giraffe, g2: Giraffe) => void;
+    h2 = f2; // valid because Giraffe satisfies the constraint. It is safe in the traditional contravariant fashion.

tests/baselines/reference/contextualSignatureInstatiationContravariance.js

@@ -6,7 +6,7 @@ interface Elephant extends Animal { y2 }
 var f2: <T extends Animal>(x: T, y: T) => void;
 
 var g2: (g: Giraffe, e: Elephant) => void;
-g2 = f2; // valid because both Giraffe and Elephant satisfy the constraint. T is Animal
+g2 = f2; // error because Giraffe and Elephant are disjoint types
 
 var h2: (g1: Giraffe, g2: Giraffe) => void;
 h2 = f2; // valid because Giraffe satisfies the constraint. It is safe in the traditional contravariant fashion.
@@ -14,6 +14,6 @@ h2 = f2; // valid because Giraffe satisfies the constraint. It is safe in the tr
 //// [contextualSignatureInstatiationContravariance.js]
 var f2;
 var g2;
-g2 = f2; // valid because both Giraffe and Elephant satisfy the constraint. T is Animal
+g2 = f2; // error because Giraffe and Elephant are disjoint types
 var h2;
 h2 = f2; // valid because Giraffe satisfies the constraint. It is safe in the traditional contravariant fashion.

tests/baselines/reference/contextualSignatureInstatiationContravariance.symbols

@@ -29,7 +29,7 @@ var g2: (g: Giraffe, e: Elephant) => void;
 >e : Symbol(e, Decl(contextualSignatureInstatiationContravariance.ts, 6, 20))
 >Elephant : Symbol(Elephant, Decl(contextualSignatureInstatiationContravariance.ts, 1, 38))
 
-g2 = f2; // valid because both Giraffe and Elephant satisfy the constraint. T is Animal
+g2 = f2; // error because Giraffe and Elephant are disjoint types
 >g2 : Symbol(g2, Decl(contextualSignatureInstatiationContravariance.ts, 6, 3))
 >f2 : Symbol(f2, Decl(contextualSignatureInstatiationContravariance.ts, 4, 3))
 

tests/baselines/reference/contextualSignatureInstatiationContravariance.types

@@ -18,7 +18,7 @@ var g2: (g: Giraffe, e: Elephant) => void;
 >g : Giraffe
 >e : Elephant
 
-g2 = f2; // valid because both Giraffe and Elephant satisfy the constraint. T is Animal
+g2 = f2; // error because Giraffe and Elephant are disjoint types
 >g2 = f2 : <T extends Animal>(x: T, y: T) => void
 >g2 : (g: Giraffe, e: Elephant) => void
 >f2 : <T extends Animal>(x: T, y: T) => void

tests/baselines/reference/declarationEmitWithComposite.js

@@ -0,0 +1,17 @@
+//// [test.ts]
+interface Foo {
+    x: number;
+}
+export default Foo;
+
+
+//// [/foo/out/test.js]
+"use strict";
+exports.__esModule = true;
+
+
+//// [/foo/out/test.d.ts]
+interface Foo {
+    x: number;
+}
+export default Foo;

tests/baselines/reference/declarationEmitWithComposite.symbols

@@ -0,0 +1,10 @@
+=== /foo/test.ts ===
+interface Foo {
+>Foo : Symbol(Foo, Decl(test.ts, 0, 0))
+
+    x: number;
+>x : Symbol(Foo.x, Decl(test.ts, 0, 15))
+}
+export default Foo;
+>Foo : Symbol(Foo, Decl(test.ts, 0, 0))
+

tests/baselines/reference/declarationEmitWithComposite.types

@@ -0,0 +1,8 @@
+=== /foo/test.ts ===
+interface Foo {
+    x: number;
+>x : number
+}
+export default Foo;
+>Foo : Foo
+

tests/baselines/reference/declarationsAndAssignments.errors.txt

@@ -17,10 +17,8 @@ tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(73,11):
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(73,14): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(74,11): error TS2459: Type 'undefined[]' has no property 'a' and no string index signature.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(74,14): error TS2459: Type 'undefined[]' has no property 'b' and no string index signature.
-tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(106,5): error TS2345: Argument of type '[number, [string, { y: false; }]]' is not assignable to parameter of type '[number, [string, { x: any; y?: boolean; }]]'.
-  Type '[string, { y: false; }]' is not assignable to type '[string, { x: any; y?: boolean; }]'.
-    Type '{ y: false; }' is not assignable to type '{ x: any; y?: boolean; }'.
-      Property 'x' is missing in type '{ y: false; }'.
+tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(106,17): error TS2322: Type '{ y: boolean; }' is not assignable to type '{ x: any; y?: boolean; }'.
+  Property 'x' is missing in type '{ y: boolean; }'.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(138,6): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(138,9): error TS2322: Type 'number' is not assignable to type 'string'.
 
@@ -170,11 +168,9 @@ tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(138,9):
     f14([2, ["abc", { x: 0, y: true }]]);
     f14([2, ["abc", { x: 0 }]]);
     f14([2, ["abc", { y: false }]]);  // Error, no x
-        ~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '[number, [string, { y: false; }]]' is not assignable to parameter of type '[number, [string, { x: any; y?: boolean; }]]'.
-!!! error TS2345:   Type '[string, { y: false; }]' is not assignable to type '[string, { x: any; y?: boolean; }]'.
-!!! error TS2345:     Type '{ y: false; }' is not assignable to type '{ x: any; y?: boolean; }'.
-!!! error TS2345:       Property 'x' is missing in type '{ y: false; }'.
+                    ~~~~~~~~~~~~
+!!! error TS2322: Type '{ y: boolean; }' is not assignable to type '{ x: any; y?: boolean; }'.
+!!! error TS2322:   Property 'x' is missing in type '{ y: boolean; }'.
     
     module M {
         export var [a, b] = [1, 2];

tests/baselines/reference/destructuringParameterDeclaration2.errors.txt

@@ -1,38 +1,21 @@
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(7,4): error TS2345: Argument of type '[number, string, string[][]]' is not assignable to parameter of type '[number, number, string[][]]'.
-  Type 'string' is not assignable to type 'number'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(7,8): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(7,29): error TS1005: ',' expected.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(8,4): error TS2345: Argument of type '[number, number, string[][], string]' is not assignable to parameter of type '[number, number, string[][]]'.
   Types of property 'length' are incompatible.
     Type '4' is not assignable to type '3'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(16,8): error TS2371: A parameter initializer is only allowed in a function or constructor implementation.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(16,16): error TS2371: A parameter initializer is only allowed in a function or constructor implementation.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(23,14): error TS2345: Argument of type '{ x: string; y: boolean; }' is not assignable to parameter of type '{ x: number; y: any; }'.
-  Types of property 'x' are incompatible.
-    Type 'string' is not assignable to type 'number'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(23,16): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(30,14): error TS2300: Duplicate identifier 'z'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(30,18): error TS2300: Duplicate identifier 'z'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(34,4): error TS2345: Argument of type '{ z: number; }' is not assignable to parameter of type '{ z: { x: any; y: { j: any; }; }; }'.
-  Types of property 'z' are incompatible.
-    Type 'number' is not assignable to type '{ x: any; y: { j: any; }; }'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(34,6): error TS2322: Type 'number' is not assignable to type '{ x: any; y: { j: any; }; }'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(35,4): error TS2345: Argument of type '{}' is not assignable to parameter of type '{ z: number; }'.
   Property 'z' is missing in type '{}'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(36,4): error TS2345: Argument of type '{ z: boolean; }' is not assignable to parameter of type '{ z: number; }'.
-  Types of property 'z' are incompatible.
-    Type 'boolean' is not assignable to type 'number'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(37,4): error TS2345: Argument of type '{ z: boolean; }' is not assignable to parameter of type '{ z?: number; }'.
-  Types of property 'z' are incompatible.
-    Type 'boolean' is not assignable to type 'number'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(38,4): error TS2345: Argument of type '{ b: boolean; }' is not assignable to parameter of type '{ b: string | number; }'.
-  Types of property 'b' are incompatible.
-    Type 'boolean' is not assignable to type 'string | number'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(39,4): error TS2345: Argument of type '[number, number, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]]]'.
-  Types of property '2' are incompatible.
-    Type 'boolean' is not assignable to type '[[any]]'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(40,4): error TS2345: Argument of type '[number, number, [[string]]]' is not assignable to parameter of type '[any, any, [[number?]]]'.
-  Type '[[string]]' is not assignable to type '[[number?]]'.
-    Type '[string]' is not assignable to type '[number?]'.
-      Types of property '0' are incompatible.
-        Type 'string' is not assignable to type 'number'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(36,6): error TS2322: Type 'true' is not assignable to type 'number'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(37,6): error TS2322: Type 'false' is not assignable to type 'number'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(38,6): error TS2322: Type 'true' is not assignable to type 'string | number'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(39,11): error TS2322: Type 'false' is not assignable to type '[[any]]'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(40,13): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(46,13): error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(47,13): error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(56,8): error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
@@ -54,9 +37,8 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(
     // If the declaration includes a type annotation, the parameter is of that type
     function a0([a, b, [[c]]]: [number, number, string[][]]) { }
     a0([1, "string", [["world"]]);      // Error
-       ~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '[number, string, string[][]]' is not assignable to parameter of type '[number, number, string[][]]'.
-!!! error TS2345:   Type 'string' is not assignable to type 'number'.
+           ~~~~~~~~
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
                                 ~
 !!! error TS1005: ',' expected.
     a0([1, 2, [["world"]], "string"]);  // Error
@@ -83,10 +65,9 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(
     function b3([[a], b, [[c, d]]] = [[undefined], undefined, [[undefined, undefined]]]) { }
     
     b1("string", { x: "string", y: true });  // Error
-                 ~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ x: string; y: boolean; }' is not assignable to parameter of type '{ x: number; y: any; }'.
-!!! error TS2345:   Types of property 'x' are incompatible.
-!!! error TS2345:     Type 'string' is not assignable to type 'number'.
+                   ~
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! related TS6500 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts:19:29: The expected type comes from property 'x' which is declared here on type '{ x: number; y: any; }'
     
     // If the declaration specifies a binding pattern, the parameter type is the implied type of that binding pattern (section 5.1.3)
     function c0({z: {x, y: {j}}}) { }
@@ -102,41 +83,29 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(
     function c6([a, b, [[c = 1]]]) { }
     
     c0({ z: 1 });      // Error, implied type is { z: {x: any, y: {j: any}} }
-       ~~~~~~~~
-!!! error TS2345: Argument of type '{ z: number; }' is not assignable to parameter of type '{ z: { x: any; y: { j: any; }; }; }'.
-!!! error TS2345:   Types of property 'z' are incompatible.
-!!! error TS2345:     Type 'number' is not assignable to type '{ x: any; y: { j: any; }; }'.
+         ~
+!!! error TS2322: Type 'number' is not assignable to type '{ x: any; y: { j: any; }; }'.
     c1({});            // Error, implied type is {z:number}?
        ~~
 !!! error TS2345: Argument of type '{}' is not assignable to parameter of type '{ z: number; }'.
 !!! error TS2345:   Property 'z' is missing in type '{}'.
     c1({ z: true });   // Error, implied type is {z:number}?
-       ~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ z: boolean; }' is not assignable to parameter of type '{ z: number; }'.
-!!! error TS2345:   Types of property 'z' are incompatible.
-!!! error TS2345:     Type 'boolean' is not assignable to type 'number'.
+         ~
+!!! error TS2322: Type 'true' is not assignable to type 'number'.
+!!! related TS6500 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts:27:21: The expected type comes from property 'z' which is declared here on type '{ z: number; }'
     c2({ z: false });  // Error, implied type is {z?: number}
-       ~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ z: boolean; }' is not assignable to parameter of type '{ z?: number; }'.
-!!! error TS2345:   Types of property 'z' are incompatible.
-!!! error TS2345:     Type 'boolean' is not assignable to type 'number'.
+         ~
+!!! error TS2322: Type 'false' is not assignable to type 'number'.
     c3({ b: true });   // Error, implied type is { b: number|string }. 
-       ~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ b: boolean; }' is not assignable to parameter of type '{ b: string | number; }'.
-!!! error TS2345:   Types of property 'b' are incompatible.
-!!! error TS2345:     Type 'boolean' is not assignable to type 'string | number'.
+         ~
+!!! error TS2322: Type 'true' is not assignable to type 'string | number'.
+!!! related TS6500 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts:29:20: The expected type comes from property 'b' which is declared here on type '{ b: string | number; }'
     c5([1, 2, false, true]);   // Error, implied type is [any, any, [[any]]]
-       ~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '[number, number, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]]]'.
-!!! error TS2345:   Types of property '2' are incompatible.
-!!! error TS2345:     Type 'boolean' is not assignable to type '[[any]]'.
+              ~~~~~
+!!! error TS2322: Type 'false' is not assignable to type '[[any]]'.
     c6([1, 2, [["string"]]]);  // Error, implied type is [any, any, [[number]]]  // Use initializer
-       ~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '[number, number, [[string]]]' is not assignable to parameter of type '[any, any, [[number?]]]'.
-!!! error TS2345:   Type '[[string]]' is not assignable to type '[[number?]]'.
-!!! error TS2345:     Type '[string]' is not assignable to type '[number?]'.
-!!! error TS2345:       Types of property '0' are incompatible.
-!!! error TS2345:         Type 'string' is not assignable to type 'number'.
+                ~~~~~~~~
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
     
     // A parameter can be marked optional by following its name or binding pattern with a question mark (?)
     // or by including an initializer.  Initializers (including binding property or element initializers) are

tests/baselines/reference/destructuringParameterDeclaration3ES5.errors.txt

@@ -1,9 +1,7 @@
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES5.ts(26,4): error TS2345: Argument of type '[number, number, [[string]], boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]]]'.
   Types of property 'length' are incompatible.
     Type '5' is not assignable to type '3'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES5.ts(29,5): error TS2345: Argument of type '[number, number, number, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]], ...any[]]'.
-  Types of property '2' are incompatible.
-    Type 'number' is not assignable to type '[[any]]'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES5.ts(29,12): error TS2322: Type 'number' is not assignable to type '[[any]]'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES5.ts(30,5): error TS2345: Argument of type '[number, number]' is not assignable to parameter of type '[any, any, [[any]], ...any[]]'.
   Property '2' is missing in type '[number, number]'.
 
@@ -42,10 +40,8 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES5.
     
     a10([1, 2, [["string"]], false, true]);   // Parameter type is any[]
     a10([1, 2, 3, false, true]);              // Parameter type is any[]
-        ~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '[number, number, number, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]], ...any[]]'.
-!!! error TS2345:   Types of property '2' are incompatible.
-!!! error TS2345:     Type 'number' is not assignable to type '[[any]]'.
+               ~
+!!! error TS2322: Type 'number' is not assignable to type '[[any]]'.
     a10([1, 2]);                              // Parameter type is any[]
         ~~~~~~
 !!! error TS2345: Argument of type '[number, number]' is not assignable to parameter of type '[any, any, [[any]], ...any[]]'.

tests/baselines/reference/destructuringParameterDeclaration3ES5iterable.errors.txt

@@ -1,9 +1,7 @@
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES5iterable.ts(26,4): error TS2345: Argument of type '[number, number, [[string]], boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]]]'.
   Types of property 'length' are incompatible.
     Type '5' is not assignable to type '3'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES5iterable.ts(29,5): error TS2345: Argument of type '[number, number, number, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]], ...any[]]'.
-  Types of property '2' are incompatible.
-    Type 'number' is not assignable to type '[[any]]'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES5iterable.ts(29,12): error TS2322: Type 'number' is not assignable to type '[[any]]'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES5iterable.ts(30,5): error TS2345: Argument of type '[number, number]' is not assignable to parameter of type '[any, any, [[any]], ...any[]]'.
   Property '2' is missing in type '[number, number]'.
 
@@ -42,10 +40,8 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES5i
     
     a10([1, 2, [["string"]], false, true]);   // Parameter type is any[]
     a10([1, 2, 3, false, true]);              // Parameter type is any[]
-        ~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '[number, number, number, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]], ...any[]]'.
-!!! error TS2345:   Types of property '2' are incompatible.
-!!! error TS2345:     Type 'number' is not assignable to type '[[any]]'.
+               ~
+!!! error TS2322: Type 'number' is not assignable to type '[[any]]'.
     a10([1, 2]);                              // Parameter type is any[]
         ~~~~~~
 !!! error TS2345: Argument of type '[number, number]' is not assignable to parameter of type '[any, any, [[any]], ...any[]]'.

tests/baselines/reference/destructuringParameterDeclaration3ES6.errors.txt

@@ -1,9 +1,7 @@
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES6.ts(26,4): error TS2345: Argument of type '[number, number, [[string]], boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]]]'.
   Types of property 'length' are incompatible.
     Type '5' is not assignable to type '3'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES6.ts(29,5): error TS2345: Argument of type '[number, number, number, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]], ...any[]]'.
-  Types of property '2' are incompatible.
-    Type 'number' is not assignable to type '[[any]]'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES6.ts(29,12): error TS2322: Type 'number' is not assignable to type '[[any]]'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES6.ts(30,5): error TS2345: Argument of type '[number, number]' is not assignable to parameter of type '[any, any, [[any]], ...any[]]'.
   Property '2' is missing in type '[number, number]'.
 
@@ -42,10 +40,8 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration3ES6.
     
     a10([1, 2, [["string"]], false, true]);   // Parameter type is any[]
     a10([1, 2, 3, false, true]);              // Parameter type is any[]
-        ~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '[number, number, number, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]], ...any[]]'.
-!!! error TS2345:   Types of property '2' are incompatible.
-!!! error TS2345:     Type 'number' is not assignable to type '[[any]]'.
+               ~
+!!! error TS2322: Type 'number' is not assignable to type '[[any]]'.
     a10([1, 2]);                              // Parameter type is any[]
         ~~~~~~
 !!! error TS2345: Argument of type '[number, number]' is not assignable to parameter of type '[any, any, [[any]], ...any[]]'.

tests/baselines/reference/destructuringParameterDeclaration4.errors.txt

@@ -2,9 +2,7 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(15,16): error TS1048: A rest parameter cannot have an initializer.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(20,19): error TS2345: Argument of type 'true' is not assignable to parameter of type 'string | number'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(21,7): error TS2552: Cannot find name 'array2'. Did you mean 'Array'?
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(22,4): error TS2345: Argument of type '[number, number, string, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]]]'.
-  Types of property '2' are incompatible.
-    Type 'string' is not assignable to type '[[any]]'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(22,11): error TS2322: Type 'string' is not assignable to type '[[any]]'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(23,4): error TS2345: Argument of type '[number, number]' is not assignable to parameter of type '[any, any, [[any]]]'.
   Property '2' is missing in type '[number, number]'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(24,4): error TS2345: Argument of type '(string | number)[]' is not assignable to parameter of type 'number[]'.
@@ -47,10 +45,8 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration4.ts(
 !!! error TS2552: Cannot find name 'array2'. Did you mean 'Array'?
 !!! related TS2728 /.ts/lib.es5.d.ts:1298:15: 'Array' is declared here.
     a5([1, 2, "string", false, true]);       // Error, parameter type is [any, any, [[any]]]
-       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '[number, number, string, boolean, boolean]' is not assignable to parameter of type '[any, any, [[any]]]'.
-!!! error TS2345:   Types of property '2' are incompatible.
-!!! error TS2345:     Type 'string' is not assignable to type '[[any]]'.
+              ~~~~~~~~
+!!! error TS2322: Type 'string' is not assignable to type '[[any]]'.
     a5([1, 2]);                              // Error, parameter type is [any, any, [[any]]]
        ~~~~~~
 !!! error TS2345: Argument of type '[number, number]' is not assignable to parameter of type '[any, any, [[any]]]'.

tests/baselines/reference/destructuringParameterDeclaration5.errors.txt

@@ -1,15 +1,9 @@
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration5.ts(47,4): error TS2345: Argument of type '{ y: Class; }' is not assignable to parameter of type '{ y: D; }'.
-  Types of property 'y' are incompatible.
-    Type 'Class' is not assignable to type 'D'.
-      Property 'foo' is missing in type 'Class'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration5.ts(47,6): error TS2322: Type 'Class' is not assignable to type 'D'.
+  Property 'foo' is missing in type 'Class'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration5.ts(48,4): error TS2345: Argument of type '{}' is not assignable to parameter of type '{ y: D; }'.
   Property 'y' is missing in type '{}'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration5.ts(49,4): error TS2345: Argument of type '{ y: number; }' is not assignable to parameter of type '{ y: D; }'.
-  Types of property 'y' are incompatible.
-    Type 'number' is not assignable to type 'D'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration5.ts(50,4): error TS2345: Argument of type '{ y: string; }' is not assignable to parameter of type '{ y: D; }'.
-  Types of property 'y' are incompatible.
-    Type 'string' is not assignable to type 'D'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration5.ts(49,6): error TS2322: Type 'number' is not assignable to type 'D'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration5.ts(50,6): error TS2322: Type 'string' is not assignable to type 'D'.
 
 
 ==== tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration5.ts (4 errors) ====
@@ -60,22 +54,19 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration5.ts(
     d3({ y: new SubClass() });
     // Error
     d3({ y: new Class() });
-       ~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ y: Class; }' is not assignable to parameter of type '{ y: D; }'.
-!!! error TS2345:   Types of property 'y' are incompatible.
-!!! error TS2345:     Type 'Class' is not assignable to type 'D'.
-!!! error TS2345:       Property 'foo' is missing in type 'Class'.
+         ~
+!!! error TS2322: Type 'Class' is not assignable to type 'D'.
+!!! error TS2322:   Property 'foo' is missing in type 'Class'.
+!!! related TS6500 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration5.ts:29:33: The expected type comes from property 'y' which is declared here on type '{ y: D; }'
     d3({});
        ~~
 !!! error TS2345: Argument of type '{}' is not assignable to parameter of type '{ y: D; }'.
 !!! error TS2345:   Property 'y' is missing in type '{}'.
     d3({ y: 1 });
-       ~~~~~~~~
-!!! error TS2345: Argument of type '{ y: number; }' is not assignable to parameter of type '{ y: D; }'.
-!!! error TS2345:   Types of property 'y' are incompatible.
-!!! error TS2345:     Type 'number' is not assignable to type 'D'.
+         ~
+!!! error TS2322: Type 'number' is not assignable to type 'D'.
+!!! related TS6500 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration5.ts:29:33: The expected type comes from property 'y' which is declared here on type '{ y: D; }'
     d3({ y: "world" });
-       ~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ y: string; }' is not assignable to parameter of type '{ y: D; }'.
-!!! error TS2345:   Types of property 'y' are incompatible.
-!!! error TS2345:     Type 'string' is not assignable to type 'D'.
+         ~
+!!! error TS2322: Type 'string' is not assignable to type 'D'.
+!!! related TS6500 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration5.ts:29:33: The expected type comes from property 'y' which is declared here on type '{ y: D; }'

tests/baselines/reference/destructuringParameterDeclaration8.errors.txt

@@ -1,11 +1,7 @@
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration8.ts(4,5): error TS2322: Type '"z"' is not assignable to type '"x" | "y"'.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration8.ts(5,15): error TS2322: Type '"c"' is not assignable to type '"a" | "b"'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration8.ts(17,6): error TS2345: Argument of type '{ method: "z"; nested: { p: "b"; }; }' is not assignable to parameter of type '{ method?: "x" | "y"; nested?: { p: "a" | "b"; }; }'.
-  Types of property 'method' are incompatible.
-    Type '"z"' is not assignable to type '"x" | "y"'.
-tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration8.ts(18,6): error TS2345: Argument of type '{ method: "one"; nested: { p: "a"; }; }' is not assignable to parameter of type '{ method?: "x" | "y"; nested?: { p: "a" | "b"; }; }'.
-  Types of property 'method' are incompatible.
-    Type '"one"' is not assignable to type '"x" | "y"'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration8.ts(17,8): error TS2322: Type '"z"' is not assignable to type '"x" | "y"'.
+tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration8.ts(18,8): error TS2322: Type '"one"' is not assignable to type '"x" | "y"'.
 
 
 ==== tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration8.ts (4 errors) ====
@@ -30,13 +26,11 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration8.ts(
     test({});
     test({ method: 'x', nested: { p: 'a' } })
     test({ method: 'z', nested: { p: 'b' } })
-         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ method: "z"; nested: { p: "b"; }; }' is not assignable to parameter of type '{ method?: "x" | "y"; nested?: { p: "a" | "b"; }; }'.
-!!! error TS2345:   Types of property 'method' are incompatible.
-!!! error TS2345:     Type '"z"' is not assignable to type '"x" | "y"'.
+           ~~~~~~
+!!! error TS2322: Type '"z"' is not assignable to type '"x" | "y"'.
+!!! related TS6500 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration8.ts:7:5: The expected type comes from property 'method' which is declared here on type '{ method?: "x" | "y"; nested?: { p: "a" | "b"; }; }'
     test({ method: 'one', nested: { p: 'a' } })
-         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ method: "one"; nested: { p: "a"; }; }' is not assignable to parameter of type '{ method?: "x" | "y"; nested?: { p: "a" | "b"; }; }'.
-!!! error TS2345:   Types of property 'method' are incompatible.
-!!! error TS2345:     Type '"one"' is not assignable to type '"x" | "y"'.
+           ~~~~~~
+!!! error TS2322: Type '"one"' is not assignable to type '"x" | "y"'.
+!!! related TS6500 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration8.ts:7:5: The expected type comes from property 'method' which is declared here on type '{ method?: "x" | "y"; nested?: { p: "a" | "b"; }; }'
     

tests/baselines/reference/destructuringParameterProperties2.errors.txt

@@ -5,8 +5,7 @@ tests/cases/conformance/es6/destructuring/destructuringParameterProperties2.ts(4
 tests/cases/conformance/es6/destructuring/destructuringParameterProperties2.ts(9,21): error TS2339: Property 'a' does not exist on type 'C1'.
 tests/cases/conformance/es6/destructuring/destructuringParameterProperties2.ts(13,21): error TS2339: Property 'b' does not exist on type 'C1'.
 tests/cases/conformance/es6/destructuring/destructuringParameterProperties2.ts(17,21): error TS2339: Property 'c' does not exist on type 'C1'.
-tests/cases/conformance/es6/destructuring/destructuringParameterProperties2.ts(21,27): error TS2345: Argument of type '[number, undefined, string]' is not assignable to parameter of type '[number, string, boolean]'.
-  Type 'string' is not assignable to type 'boolean'.
+tests/cases/conformance/es6/destructuring/destructuringParameterProperties2.ts(21,42): error TS2322: Type 'string' is not assignable to type 'boolean'.
 
 
 ==== tests/cases/conformance/es6/destructuring/destructuringParameterProperties2.ts (8 errors) ====
@@ -45,9 +44,8 @@ tests/cases/conformance/es6/destructuring/destructuringParameterProperties2.ts(2
     }
     
     var x = new C1(undefined, [0, undefined, ""]);
-                              ~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '[number, undefined, string]' is not assignable to parameter of type '[number, string, boolean]'.
-!!! error TS2345:   Type 'string' is not assignable to type 'boolean'.
+                                             ~~
+!!! error TS2322: Type 'string' is not assignable to type 'boolean'.
     var [x_a, x_b, x_c] = [x.getA(), x.getB(), x.getC()];
     
     var y = new C1(10, [0, "", true]);

tests/baselines/reference/destructuringParameterProperties5.errors.txt

@@ -7,12 +7,13 @@ tests/cases/conformance/es6/destructuring/destructuringParameterProperties5.ts(7
 tests/cases/conformance/es6/destructuring/destructuringParameterProperties5.ts(7,51): error TS2339: Property 'x3' does not exist on type 'C1'.
 tests/cases/conformance/es6/destructuring/destructuringParameterProperties5.ts(7,62): error TS2339: Property 'y' does not exist on type 'C1'.
 tests/cases/conformance/es6/destructuring/destructuringParameterProperties5.ts(7,72): error TS2339: Property 'z' does not exist on type 'C1'.
-tests/cases/conformance/es6/destructuring/destructuringParameterProperties5.ts(11,19): error TS2345: Argument of type '[{ x1: number; x2: string; x3: boolean; }, string, boolean]' is not assignable to parameter of type '[ObjType1, number, string]'.
-  Type '{ x1: number; x2: string; x3: boolean; }' is not assignable to type 'ObjType1'.
-    Object literal may only specify known properties, and 'x1' does not exist in type 'ObjType1'.
+tests/cases/conformance/es6/destructuring/destructuringParameterProperties5.ts(11,19): error TS2322: Type '{ x1: number; x2: string; x3: boolean; }' is not assignable to type 'ObjType1'.
+  Object literal may only specify known properties, and 'x1' does not exist in type 'ObjType1'.
+tests/cases/conformance/es6/destructuring/destructuringParameterProperties5.ts(11,47): error TS2322: Type 'string' is not assignable to type 'number'.
+tests/cases/conformance/es6/destructuring/destructuringParameterProperties5.ts(11,51): error TS2322: Type 'false' is not assignable to type 'string'.
 
 
-==== tests/cases/conformance/es6/destructuring/destructuringParameterProperties5.ts (10 errors) ====
+==== tests/cases/conformance/es6/destructuring/destructuringParameterProperties5.ts (12 errors) ====
     type ObjType1 = { x: number; y: string; z: boolean }
     type TupleType1 = [ObjType1, number, string]
     
@@ -43,7 +44,10 @@ tests/cases/conformance/es6/destructuring/destructuringParameterProperties5.ts(1
     
     var a = new C1([{ x1: 10, x2: "", x3: true }, "", false]);
                       ~~~~~~
-!!! error TS2345: Argument of type '[{ x1: number; x2: string; x3: boolean; }, string, boolean]' is not assignable to parameter of type '[ObjType1, number, string]'.
-!!! error TS2345:   Type '{ x1: number; x2: string; x3: boolean; }' is not assignable to type 'ObjType1'.
-!!! error TS2345:     Object literal may only specify known properties, and 'x1' does not exist in type 'ObjType1'.
+!!! error TS2322: Type '{ x1: number; x2: string; x3: boolean; }' is not assignable to type 'ObjType1'.
+!!! error TS2322:   Object literal may only specify known properties, and 'x1' does not exist in type 'ObjType1'.
+                                                  ~~
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
+                                                      ~~~~~
+!!! error TS2322: Type 'false' is not assignable to type 'string'.
     var [a_x1, a_x2, a_x3, a_y, a_z] = [a.x1, a.x2, a.x3, a.y, a.z];

tests/baselines/reference/genericCallWithFunctionTypedArguments5.errors.txt

@@ -1,9 +1,5 @@
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments5.ts(10,14): error TS2345: Argument of type '{ cb: <T>(x: T, y: T) => string; }' is not assignable to parameter of type '{ cb: (t: {}) => string; }'.
-  Types of property 'cb' are incompatible.
-    Type '<T>(x: T, y: T) => string' is not assignable to type '(t: {}) => string'.
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments5.ts(11,14): error TS2345: Argument of type '{ cb: (x: string, y: number) => string; }' is not assignable to parameter of type '{ cb: (t: string) => string; }'.
-  Types of property 'cb' are incompatible.
-    Type '(x: string, y: number) => string' is not assignable to type '(t: string) => string'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments5.ts(10,16): error TS2322: Type '<T>(x: T, y: T) => string' is not assignable to type '(t: {}) => string'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments5.ts(11,16): error TS2322: Type '(x: string, y: number) => string' is not assignable to type '(t: string) => string'.
 
 
 ==== tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments5.ts (2 errors) ====
@@ -17,15 +13,13 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFun
     var r = foo(arg); // {}
     // more args not allowed
     var r2 = foo({ cb: <T>(x: T, y: T) => '' }); // error
-                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ cb: <T>(x: T, y: T) => string; }' is not assignable to parameter of type '{ cb: (t: {}) => string; }'.
-!!! error TS2345:   Types of property 'cb' are incompatible.
-!!! error TS2345:     Type '<T>(x: T, y: T) => string' is not assignable to type '(t: {}) => string'.
+                   ~~
+!!! error TS2322: Type '<T>(x: T, y: T) => string' is not assignable to type '(t: {}) => string'.
+!!! related TS6500 tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments5.ts:3:27: The expected type comes from property 'cb' which is declared here on type '{ cb: (t: {}) => string; }'
     var r3 = foo({ cb: (x: string, y: number) => '' }); // error
-                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ cb: (x: string, y: number) => string; }' is not assignable to parameter of type '{ cb: (t: string) => string; }'.
-!!! error TS2345:   Types of property 'cb' are incompatible.
-!!! error TS2345:     Type '(x: string, y: number) => string' is not assignable to type '(t: string) => string'.
+                   ~~
+!!! error TS2322: Type '(x: string, y: number) => string' is not assignable to type '(t: string) => string'.
+!!! related TS6500 tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithFunctionTypedArguments5.ts:3:27: The expected type comes from property 'cb' which is declared here on type '{ cb: (t: string) => string; }'
     
     function foo2<T, U>(arg: { cb: (t: T, t2: T) => U }) {
         return arg.cb(null, null);

tests/baselines/reference/genericCallWithObjectLiteralArgs.errors.txt

@@ -1,6 +1,4 @@
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithObjectLiteralArgs.ts(5,13): error TS2345: Argument of type '{ bar: number; baz: string; }' is not assignable to parameter of type '{ bar: number; baz: number; }'.
-  Types of property 'baz' are incompatible.
-    Type 'string' is not assignable to type 'number'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithObjectLiteralArgs.ts(5,23): error TS2322: Type 'string' is not assignable to type 'number'.
 
 
 ==== tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithObjectLiteralArgs.ts (1 errors) ====
@@ -9,10 +7,9 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithObj
     }
     
     var r = foo({ bar: 1, baz: '' }); // error
-                ~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ bar: number; baz: string; }' is not assignable to parameter of type '{ bar: number; baz: number; }'.
-!!! error TS2345:   Types of property 'baz' are incompatible.
-!!! error TS2345:     Type 'string' is not assignable to type 'number'.
+                          ~~~
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! related TS6500 tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithObjectLiteralArgs.ts:1:30: The expected type comes from property 'baz' which is declared here on type '{ bar: number; baz: number; }'
     var r2 = foo({ bar: 1, baz: 1 }); // T = number
     var r3 = foo({ bar: foo, baz: foo }); // T = typeof foo
     var r4 = foo<Object>({ bar: 1, baz: '' }); // T = Object

tests/baselines/reference/genericCallWithObjectLiteralArguments1.errors.txt

@@ -1,45 +1,30 @@
-tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts(3,13): error TS2345: Argument of type '{ x: number; y: string; }' is not assignable to parameter of type '{ x: number; y: number; }'.
-  Types of property 'y' are incompatible.
-    Type 'string' is not assignable to type 'number'.
-tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts(4,22): error TS2345: Argument of type '{ x: number; y: string; }' is not assignable to parameter of type '{ x: number; y: number; }'.
-  Types of property 'y' are incompatible.
-    Type 'string' is not assignable to type 'number'.
-tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts(5,22): error TS2345: Argument of type '{ x: number; y: string; }' is not assignable to parameter of type '{ x: string; y: string; }'.
-  Types of property 'x' are incompatible.
-    Type 'number' is not assignable to type 'string'.
-tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts(6,22): error TS2345: Argument of type '{ x: string; y: number; }' is not assignable to parameter of type '{ x: number; y: number; }'.
-  Types of property 'x' are incompatible.
-    Type 'string' is not assignable to type 'number'.
-tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts(7,22): error TS2345: Argument of type '{ x: string; y: number; }' is not assignable to parameter of type '{ x: string; y: string; }'.
-  Types of property 'y' are incompatible.
-    Type 'number' is not assignable to type 'string'.
+tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts(3,21): error TS2322: Type 'string' is not assignable to type 'number'.
+tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts(4,30): error TS2322: Type 'string' is not assignable to type 'number'.
+tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts(5,24): error TS2322: Type 'number' is not assignable to type 'string'.
+tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts(6,24): error TS2322: Type 'string' is not assignable to type 'number'.
+tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts(7,31): error TS2322: Type 'number' is not assignable to type 'string'.
 
 
 ==== tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts (5 errors) ====
     function foo<T>(n: { x: T; y: T }, m: T) { return m; }
     // these are all errors
     var x = foo({ x: 3, y: "" }, 4);
-                ~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ x: number; y: string; }' is not assignable to parameter of type '{ x: number; y: number; }'.
-!!! error TS2345:   Types of property 'y' are incompatible.
-!!! error TS2345:     Type 'string' is not assignable to type 'number'.
+                        ~
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! related TS6500 tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts:1:28: The expected type comes from property 'y' which is declared here on type '{ x: number; y: number; }'
     var x2 = foo<number>({ x: 3, y: "" }, 4); 
-                         ~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ x: number; y: string; }' is not assignable to parameter of type '{ x: number; y: number; }'.
-!!! error TS2345:   Types of property 'y' are incompatible.
-!!! error TS2345:     Type 'string' is not assignable to type 'number'.
+                                 ~
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! related TS6500 tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts:1:28: The expected type comes from property 'y' which is declared here on type '{ x: number; y: number; }'
     var x3 = foo<string>({ x: 3, y: "" }, 4); 
-                         ~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ x: number; y: string; }' is not assignable to parameter of type '{ x: string; y: string; }'.
-!!! error TS2345:   Types of property 'x' are incompatible.
-!!! error TS2345:     Type 'number' is not assignable to type 'string'.
+                           ~
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
+!!! related TS6500 tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts:1:22: The expected type comes from property 'x' which is declared here on type '{ x: string; y: string; }'
     var x4 = foo<number>({ x: "", y: 4 }, "");
-                         ~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ x: string; y: number; }' is not assignable to parameter of type '{ x: number; y: number; }'.
-!!! error TS2345:   Types of property 'x' are incompatible.
-!!! error TS2345:     Type 'string' is not assignable to type 'number'.
+                           ~
+!!! error TS2322: Type 'string' is not assignable to type 'number'.
+!!! related TS6500 tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts:1:22: The expected type comes from property 'x' which is declared here on type '{ x: number; y: number; }'
     var x5 = foo<string>({ x: "", y: 4 }, "");
-                         ~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ x: string; y: number; }' is not assignable to parameter of type '{ x: string; y: string; }'.
-!!! error TS2345:   Types of property 'y' are incompatible.
-!!! error TS2345:     Type 'number' is not assignable to type 'string'.
+                                  ~
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
+!!! related TS6500 tests/cases/compiler/genericCallWithObjectLiteralArguments1.ts:1:28: The expected type comes from property 'y' which is declared here on type '{ x: string; y: string; }'

tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints3.errors.txt

@@ -1,7 +1,5 @@
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithObjectTypeArgsAndConstraints3.ts(18,12): error TS2345: Argument of type '{ x: Derived; y: Derived2; }' is not assignable to parameter of type '{ x: Derived; y: Derived; }'.
-  Types of property 'y' are incompatible.
-    Type 'Derived2' is not assignable to type 'Derived'.
-      Property 'y' is missing in type 'Derived2'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithObjectTypeArgsAndConstraints3.ts(18,32): error TS2322: Type 'Derived2' is not assignable to type 'Derived'.
+  Property 'y' is missing in type 'Derived2'.
 
 
 ==== tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithObjectTypeArgsAndConstraints3.ts (1 errors) ====
@@ -23,11 +21,10 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithObj
     }
     
     var r1 = f({ x: new Derived(), y: new Derived2() }); // error because neither is supertype of the other
-               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ x: Derived; y: Derived2; }' is not assignable to parameter of type '{ x: Derived; y: Derived; }'.
-!!! error TS2345:   Types of property 'y' are incompatible.
-!!! error TS2345:     Type 'Derived2' is not assignable to type 'Derived'.
-!!! error TS2345:       Property 'y' is missing in type 'Derived2'.
+                                   ~
+!!! error TS2322: Type 'Derived2' is not assignable to type 'Derived'.
+!!! error TS2322:   Property 'y' is missing in type 'Derived2'.
+!!! related TS6500 tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithObjectTypeArgsAndConstraints3.ts:13:39: The expected type comes from property 'y' which is declared here on type '{ x: Derived; y: Derived; }'
     
     function f2<T extends Base, U extends { x: T; y: T }>(a: U) {
         var r: T;

tests/baselines/reference/genericConstraintSatisfaction1.errors.txt

@@ -1,6 +1,4 @@
-tests/cases/compiler/genericConstraintSatisfaction1.ts(6,5): error TS2345: Argument of type '{ s: number; }' is not assignable to parameter of type '{ s: string; }'.
-  Types of property 's' are incompatible.
-    Type 'number' is not assignable to type 'string'.
+tests/cases/compiler/genericConstraintSatisfaction1.ts(6,6): error TS2322: Type 'number' is not assignable to type 'string'.
 
 
 ==== tests/cases/compiler/genericConstraintSatisfaction1.ts (1 errors) ====
@@ -10,8 +8,7 @@ tests/cases/compiler/genericConstraintSatisfaction1.ts(6,5): error TS2345: Argum
      
     var x: I<{s: string}>
     x.f({s: 1})
-        ~~~~~~
-!!! error TS2345: Argument of type '{ s: number; }' is not assignable to parameter of type '{ s: string; }'.
-!!! error TS2345:   Types of property 's' are incompatible.
-!!! error TS2345:     Type 'number' is not assignable to type 'string'.
+         ~
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
+!!! related TS6500 tests/cases/compiler/genericConstraintSatisfaction1.ts:5:11: The expected type comes from property 's' which is declared here on type '{ s: string; }'
     

tests/baselines/reference/indexedAccessRelation.errors.txt

@@ -1,10 +1,8 @@
-tests/cases/compiler/indexedAccessRelation.ts(16,23): error TS2345: Argument of type '{ a: T; }' is not assignable to parameter of type 'Pick<S & State<T>, "a">'.
-  Types of property 'a' are incompatible.
-    Type 'T' is not assignable to type 'S["a"] & T'.
-      Type 'Foo' is not assignable to type 'S["a"] & T'.
+tests/cases/compiler/indexedAccessRelation.ts(16,25): error TS2322: Type 'T' is not assignable to type 'S["a"] & T'.
+  Type 'Foo' is not assignable to type 'S["a"] & T'.
+    Type 'Foo' is not assignable to type 'S["a"]'.
+      Type 'T' is not assignable to type 'S["a"]'.
         Type 'Foo' is not assignable to type 'S["a"]'.
-          Type 'T' is not assignable to type 'S["a"]'.
-            Type 'Foo' is not assignable to type 'S["a"]'.
 
 
 ==== tests/cases/compiler/indexedAccessRelation.ts (1 errors) ====
@@ -24,14 +22,13 @@ tests/cases/compiler/indexedAccessRelation.ts(16,23): error TS2345: Argument of
     {
         foo(a: T) {
             this.setState({ a: a });
-                          ~~~~~~~~
-!!! error TS2345: Argument of type '{ a: T; }' is not assignable to parameter of type 'Pick<S & State<T>, "a">'.
-!!! error TS2345:   Types of property 'a' are incompatible.
-!!! error TS2345:     Type 'T' is not assignable to type 'S["a"] & T'.
-!!! error TS2345:       Type 'Foo' is not assignable to type 'S["a"] & T'.
-!!! error TS2345:         Type 'Foo' is not assignable to type 'S["a"]'.
-!!! error TS2345:           Type 'T' is not assignable to type 'S["a"]'.
-!!! error TS2345:             Type 'Foo' is not assignable to type 'S["a"]'.
+                            ~
+!!! error TS2322: Type 'T' is not assignable to type 'S["a"] & T'.
+!!! error TS2322:   Type 'Foo' is not assignable to type 'S["a"] & T'.
+!!! error TS2322:     Type 'Foo' is not assignable to type 'S["a"]'.
+!!! error TS2322:       Type 'T' is not assignable to type 'S["a"]'.
+!!! error TS2322:         Type 'Foo' is not assignable to type 'S["a"]'.
+!!! related TS6500 tests/cases/compiler/indexedAccessRelation.ts:8:5: The expected type comes from property 'a' which is declared here on type 'Pick<S & State<T>, "a">'
         }
     }
     

tests/baselines/reference/infiniteConstraints.errors.txt

@@ -55,10 +55,12 @@ tests/cases/compiler/infiniteConstraints.ts(36,71): error TS2536: Type '"foo"' c
 !!! error TS2345:     Type 'Record<"val", "test">' is not assignable to type 'never'.
     
     const shouldBeError = ensureNoDuplicates({main: value("dup"), alternate: value("dup")});
-                                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ main: Record<"val", "dup">; alternate: Record<"val", "dup">; }' is not assignable to parameter of type '{ main: never; alternate: never; }'.
-!!! error TS2345:   Types of property 'main' are incompatible.
-!!! error TS2345:     Type 'Record<"val", "dup">' is not assignable to type 'never'.
+                                              ~~~~
+!!! error TS2322: Type 'Record<"val", "dup">' is not assignable to type 'never'.
+!!! related TS6500 tests/cases/compiler/infiniteConstraints.ts:31:43: The expected type comes from property 'main' which is declared here on type '{ main: never; alternate: never; }'
+                                                                  ~~~~~~~~~
+!!! error TS2322: Type 'Record<"val", "dup">' is not assignable to type 'never'.
+!!! related TS6500 tests/cases/compiler/infiniteConstraints.ts:31:63: The expected type comes from property 'alternate' which is declared here on type '{ main: never; alternate: never; }'
     
     // Repro from #26448
     

tests/baselines/reference/invariantGenericErrorElaboration.errors.txt

@@ -8,9 +8,7 @@ tests/cases/compiler/invariantGenericErrorElaboration.ts(3,7): error TS2322: Typ
               Type 'Constraint<Constraint<Runtype<any>>>' is not assignable to type 'Constraint<Constraint<Num>>'.
                 Types of property 'underlying' are incompatible.
                   Type 'Constraint<Runtype<any>>' is not assignable to type 'Constraint<Num>'.
-tests/cases/compiler/invariantGenericErrorElaboration.ts(4,17): error TS2345: Argument of type '{ foo: Num; }' is not assignable to parameter of type '{ [_: string]: Runtype<any>; }'.
-  Property 'foo' is incompatible with index signature.
-    Type 'Num' is not assignable to type 'Runtype<any>'.
+tests/cases/compiler/invariantGenericErrorElaboration.ts(4,19): error TS2322: Type 'Num' is not assignable to type 'Runtype<any>'.
 
 
 ==== tests/cases/compiler/invariantGenericErrorElaboration.ts (2 errors) ====
@@ -29,10 +27,9 @@ tests/cases/compiler/invariantGenericErrorElaboration.ts(4,17): error TS2345: Ar
 !!! error TS2322:                 Types of property 'underlying' are incompatible.
 !!! error TS2322:                   Type 'Constraint<Runtype<any>>' is not assignable to type 'Constraint<Num>'.
     const Foo = Obj({ foo: Num })
-                    ~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ foo: Num; }' is not assignable to parameter of type '{ [_: string]: Runtype<any>; }'.
-!!! error TS2345:   Property 'foo' is incompatible with index signature.
-!!! error TS2345:     Type 'Num' is not assignable to type 'Runtype<any>'.
+                      ~~~
+!!! error TS2322: Type 'Num' is not assignable to type 'Runtype<any>'.
+!!! related TS6501 tests/cases/compiler/invariantGenericErrorElaboration.ts:17:34: The expected type comes from this index signature.
     
     interface Runtype<A> {
       constraint: Constraint<this>

tests/baselines/reference/jsContainerMergeJsContainer.types

@@ -6,18 +6,18 @@ const a = {};
 
 a.d = function() {};
 >a.d = function() {} : { (): void; prototype: {}; }
->a.d : { (): void; prototype: {}; }
+>a.d : typeof a.d
 >a : typeof a
->d : { (): void; prototype: {}; }
+>d : typeof a.d
 >function() {} : { (): void; prototype: {}; }
 
 === tests/cases/conformance/salsa/b.js ===
 a.d.prototype = {};
 >a.d.prototype = {} : {}
 >a.d.prototype : {}
->a.d : { (): void; prototype: {}; }
+>a.d : typeof a.d
 >a : typeof a
->d : { (): void; prototype: {}; }
+>d : typeof a.d
 >prototype : {}
 >{} : {}
 

tests/baselines/reference/lastPropertyInLiteralWins.errors.txt

@@ -1,13 +1,12 @@
-tests/cases/compiler/lastPropertyInLiteralWins.ts(7,6): error TS2345: Argument of type '{ thunk: (num: number) => void; }' is not assignable to parameter of type 'Thing'.
-  Types of property 'thunk' are incompatible.
-    Type '(num: number) => void' is not assignable to type '(str: string) => void'.
-      Types of parameters 'num' and 'str' are incompatible.
-        Type 'string' is not assignable to type 'number'.
+tests/cases/compiler/lastPropertyInLiteralWins.ts(8,5): error TS2322: Type '(num: number) => void' is not assignable to type '(str: string) => void'.
+  Types of parameters 'num' and 'str' are incompatible.
+    Type 'string' is not assignable to type 'number'.
 tests/cases/compiler/lastPropertyInLiteralWins.ts(9,5): error TS2300: Duplicate identifier 'thunk'.
+tests/cases/compiler/lastPropertyInLiteralWins.ts(9,5): error TS2322: Type '(num: number) => void' is not assignable to type '(str: string) => void'.
 tests/cases/compiler/lastPropertyInLiteralWins.ts(14,5): error TS2300: Duplicate identifier 'thunk'.
 
 
-==== tests/cases/compiler/lastPropertyInLiteralWins.ts (3 errors) ====
+==== tests/cases/compiler/lastPropertyInLiteralWins.ts (4 errors) ====
     interface Thing {
         thunk: (str: string) => void;
     }
@@ -15,20 +14,19 @@ tests/cases/compiler/lastPropertyInLiteralWins.ts(14,5): error TS2300: Duplicate
         thing.thunk("str");
     }
     test({ // Should error, as last one wins, and is wrong type
-         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         thunk: (str: string) => {},
-    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+        ~~~~~
+!!! error TS2322: Type '(num: number) => void' is not assignable to type '(str: string) => void'.
+!!! error TS2322:   Types of parameters 'num' and 'str' are incompatible.
+!!! error TS2322:     Type 'string' is not assignable to type 'number'.
+!!! related TS6500 tests/cases/compiler/lastPropertyInLiteralWins.ts:2:5: The expected type comes from property 'thunk' which is declared here on type 'Thing'
         thunk: (num: number) => {}
-    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         ~~~~~
 !!! error TS2300: Duplicate identifier 'thunk'.
+        ~~~~~
+!!! error TS2322: Type '(num: number) => void' is not assignable to type '(str: string) => void'.
+!!! related TS6500 tests/cases/compiler/lastPropertyInLiteralWins.ts:2:5: The expected type comes from property 'thunk' which is declared here on type 'Thing'
     });
-    ~
-!!! error TS2345: Argument of type '{ thunk: (num: number) => void; }' is not assignable to parameter of type 'Thing'.
-!!! error TS2345:   Types of property 'thunk' are incompatible.
-!!! error TS2345:     Type '(num: number) => void' is not assignable to type '(str: string) => void'.
-!!! error TS2345:       Types of parameters 'num' and 'str' are incompatible.
-!!! error TS2345:         Type 'string' is not assignable to type 'number'.
     
     test({ // Should be OK.  Last 'thunk' is of correct type
         thunk: (num: number) => {},

tests/baselines/reference/mappedTypeErrors.errors.txt

@@ -27,14 +27,10 @@ tests/cases/conformance/types/mapped/mappedTypeErrors.ts(77,59): error TS2345: A
   Object literal may only specify known properties, and 'z' does not exist in type 'Readonly<{ x: number; y: number; }>'.
 tests/cases/conformance/types/mapped/mappedTypeErrors.ts(83,58): error TS2345: Argument of type '{ x: number; y: number; z: number; }' is not assignable to parameter of type 'Partial<{ x: number; y: number; }>'.
   Object literal may only specify known properties, and 'z' does not exist in type 'Partial<{ x: number; y: number; }>'.
-tests/cases/conformance/types/mapped/mappedTypeErrors.ts(105,15): error TS2345: Argument of type '{ a: undefined; }' is not assignable to parameter of type 'Pick<Foo, "a">'.
-  Types of property 'a' are incompatible.
-    Type 'undefined' is not assignable to type 'string'.
+tests/cases/conformance/types/mapped/mappedTypeErrors.ts(105,17): error TS2322: Type 'undefined' is not assignable to type 'string'.
 tests/cases/conformance/types/mapped/mappedTypeErrors.ts(106,17): error TS2345: Argument of type '{ c: boolean; }' is not assignable to parameter of type 'Pick<Foo, "a" | "b">'.
   Object literal may only specify known properties, and 'c' does not exist in type 'Pick<Foo, "a" | "b">'.
-tests/cases/conformance/types/mapped/mappedTypeErrors.ts(123,12): error TS2345: Argument of type '{ a: undefined; }' is not assignable to parameter of type 'Pick<Foo, "a">'.
-  Types of property 'a' are incompatible.
-    Type 'undefined' is not assignable to type 'string'.
+tests/cases/conformance/types/mapped/mappedTypeErrors.ts(123,14): error TS2322: Type 'undefined' is not assignable to type 'string'.
 tests/cases/conformance/types/mapped/mappedTypeErrors.ts(124,14): error TS2345: Argument of type '{ c: boolean; }' is not assignable to parameter of type 'Pick<Foo, "a" | "b">'.
   Object literal may only specify known properties, and 'c' does not exist in type 'Pick<Foo, "a" | "b">'.
 tests/cases/conformance/types/mapped/mappedTypeErrors.ts(128,16): error TS2322: Type 'string' is not assignable to type 'number | undefined'.
@@ -196,10 +192,9 @@ tests/cases/conformance/types/mapped/mappedTypeErrors.ts(136,21): error TS2536:
     setState(foo, { });
     setState(foo, foo);
     setState(foo, { a: undefined });  // Error
-                  ~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ a: undefined; }' is not assignable to parameter of type 'Pick<Foo, "a">'.
-!!! error TS2345:   Types of property 'a' are incompatible.
-!!! error TS2345:     Type 'undefined' is not assignable to type 'string'.
+                    ~
+!!! error TS2322: Type 'undefined' is not assignable to type 'string'.
+!!! related TS6500 tests/cases/conformance/types/mapped/mappedTypeErrors.ts:89:5: The expected type comes from property 'a' which is declared here on type 'Pick<Foo, "a">'
     setState(foo, { c: true });  // Error
                     ~~~~~~~
 !!! error TS2345: Argument of type '{ c: boolean; }' is not assignable to parameter of type 'Pick<Foo, "a" | "b">'.
@@ -221,10 +216,9 @@ tests/cases/conformance/types/mapped/mappedTypeErrors.ts(136,21): error TS2536:
     c.setState({ });
     c.setState(foo);
     c.setState({ a: undefined });  // Error
-               ~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ a: undefined; }' is not assignable to parameter of type 'Pick<Foo, "a">'.
-!!! error TS2345:   Types of property 'a' are incompatible.
-!!! error TS2345:     Type 'undefined' is not assignable to type 'string'.
+                 ~
+!!! error TS2322: Type 'undefined' is not assignable to type 'string'.
+!!! related TS6500 tests/cases/conformance/types/mapped/mappedTypeErrors.ts:89:5: The expected type comes from property 'a' which is declared here on type 'Pick<Foo, "a">'
     c.setState({ c: true });  // Error
                  ~~~~~~~
 !!! error TS2345: Argument of type '{ c: boolean; }' is not assignable to parameter of type 'Pick<Foo, "a" | "b">'.

tests/baselines/reference/mappedTypeInferenceErrors.errors.txt

@@ -1,9 +1,4 @@
-tests/cases/conformance/types/mapped/mappedTypeInferenceErrors.ts(9,5): error TS2345: Argument of type '{ props: { x: number; y: number; }; computed: { bar(): number; baz: number; }; }' is not assignable to parameter of type '{ props: { x: number; y: number; }; computed: ComputedOf<{ bar: number; baz: {}; }>; } & ThisType<{ x: number; y: number; } & { bar: number; baz: {}; }>'.
-  Type '{ props: { x: number; y: number; }; computed: { bar(): number; baz: number; }; }' is not assignable to type '{ props: { x: number; y: number; }; computed: ComputedOf<{ bar: number; baz: {}; }>; }'.
-    Types of property 'computed' are incompatible.
-      Type '{ bar(): number; baz: number; }' is not assignable to type 'ComputedOf<{ bar: number; baz: {}; }>'.
-        Types of property 'baz' are incompatible.
-          Type 'number' is not assignable to type '() => {}'.
+tests/cases/conformance/types/mapped/mappedTypeInferenceErrors.ts(16,9): error TS2322: Type 'number' is not assignable to type '() => {}'.
 
 
 ==== tests/cases/conformance/types/mapped/mappedTypeInferenceErrors.ts (1 errors) ====
@@ -16,29 +11,16 @@ tests/cases/conformance/types/mapped/mappedTypeInferenceErrors.ts(9,5): error TS
     declare function foo<P, C>(options: { props: P, computed: ComputedOf<C> } & ThisType<P & C>): void;
     
     foo({
-        ~
         props: { x: 10, y: 20 },
-    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         computed: {
-    ~~~~~~~~~~~~~~~
             bar(): number {
-    ~~~~~~~~~~~~~~~~~~~~~~~
                 let z = this.bar;
-    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                 return 42;
-    ~~~~~~~~~~~~~~~~~~~~~~
             },
-    ~~~~~~~~~~
             baz: 42
-    ~~~~~~~~~~~~~~~
+            ~~~
+!!! error TS2322: Type 'number' is not assignable to type '() => {}'.
+!!! related TS6500 tests/cases/conformance/types/mapped/mappedTypeInferenceErrors.ts:16:9: The expected type comes from property 'baz' which is declared here on type 'ComputedOf<{ bar: number; baz: {}; }>'
         }
-    ~~~~~
     });
-    ~
-!!! error TS2345: Argument of type '{ props: { x: number; y: number; }; computed: { bar(): number; baz: number; }; }' is not assignable to parameter of type '{ props: { x: number; y: number; }; computed: ComputedOf<{ bar: number; baz: {}; }>; } & ThisType<{ x: number; y: number; } & { bar: number; baz: {}; }>'.
-!!! error TS2345:   Type '{ props: { x: number; y: number; }; computed: { bar(): number; baz: number; }; }' is not assignable to type '{ props: { x: number; y: number; }; computed: ComputedOf<{ bar: number; baz: {}; }>; }'.
-!!! error TS2345:     Types of property 'computed' are incompatible.
-!!! error TS2345:       Type '{ bar(): number; baz: number; }' is not assignable to type 'ComputedOf<{ bar: number; baz: {}; }>'.
-!!! error TS2345:         Types of property 'baz' are incompatible.
-!!! error TS2345:           Type 'number' is not assignable to type '() => {}'.
     

tests/baselines/reference/objectLitTargetTypeCallSite.errors.txt

@@ -1,6 +1,4 @@
-tests/cases/compiler/objectLitTargetTypeCallSite.ts(5,9): error TS2345: Argument of type '{ a: boolean; b: string; }' is not assignable to parameter of type '{ a: number; b: string; }'.
-  Types of property 'a' are incompatible.
-    Type 'boolean' is not assignable to type 'number'.
+tests/cases/compiler/objectLitTargetTypeCallSite.ts(5,10): error TS2322: Type 'true' is not assignable to type 'number'.
 
 
 ==== tests/cases/compiler/objectLitTargetTypeCallSite.ts (1 errors) ====
@@ -9,7 +7,6 @@ tests/cases/compiler/objectLitTargetTypeCallSite.ts(5,9): error TS2345: Argument
     }
     
     process({a:true,b:"y"});
-            ~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ a: boolean; b: string; }' is not assignable to parameter of type '{ a: number; b: string; }'.
-!!! error TS2345:   Types of property 'a' are incompatible.
-!!! error TS2345:     Type 'boolean' is not assignable to type 'number'.
+             ~
+!!! error TS2322: Type 'true' is not assignable to type 'number'.
+!!! related TS6500 tests/cases/compiler/objectLitTargetTypeCallSite.ts:1:23: The expected type comes from property 'a' which is declared here on type '{ a: number; b: string; }'

tests/baselines/reference/objectLiteralFunctionArgContextualTyping2.errors.txt

@@ -4,12 +4,9 @@ tests/cases/compiler/objectLiteralFunctionArgContextualTyping2.ts(9,4): error TS
   Property 'doStuff' is missing in type '{ value: string; }'.
 tests/cases/compiler/objectLiteralFunctionArgContextualTyping2.ts(10,17): error TS2345: Argument of type '{ value: string; what: number; }' is not assignable to parameter of type 'I2'.
   Object literal may only specify known properties, and 'what' does not exist in type 'I2'.
-tests/cases/compiler/objectLiteralFunctionArgContextualTyping2.ts(11,6): error TS2345: Argument of type '{ toString: (s: any) => any; }' is not assignable to parameter of type 'I2'.
-  Object literal may only specify known properties, and 'toString' does not exist in type 'I2'.
-tests/cases/compiler/objectLiteralFunctionArgContextualTyping2.ts(12,6): error TS2345: Argument of type '{ toString: (s: string) => string; }' is not assignable to parameter of type 'I2'.
-  Object literal may only specify known properties, and 'toString' does not exist in type 'I2'.
-tests/cases/compiler/objectLiteralFunctionArgContextualTyping2.ts(13,17): error TS2345: Argument of type '{ value: string; toString: (s: any) => any; }' is not assignable to parameter of type 'I2'.
-  Object literal may only specify known properties, and 'toString' does not exist in type 'I2'.
+tests/cases/compiler/objectLiteralFunctionArgContextualTyping2.ts(11,6): error TS2322: Type '(s: any) => any' is not assignable to type '() => string'.
+tests/cases/compiler/objectLiteralFunctionArgContextualTyping2.ts(12,6): error TS2322: Type '(s: string) => string' is not assignable to type '() => string'.
+tests/cases/compiler/objectLiteralFunctionArgContextualTyping2.ts(13,17): error TS2322: Type '(s: any) => any' is not assignable to type '() => string'.
 
 
 ==== tests/cases/compiler/objectLiteralFunctionArgContextualTyping2.ts (6 errors) ====
@@ -33,14 +30,14 @@ tests/cases/compiler/objectLiteralFunctionArgContextualTyping2.ts(13,17): error
 !!! error TS2345: Argument of type '{ value: string; what: number; }' is not assignable to parameter of type 'I2'.
 !!! error TS2345:   Object literal may only specify known properties, and 'what' does not exist in type 'I2'.
     f2({ toString: (s) => s }) 
-         ~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ toString: (s: any) => any; }' is not assignable to parameter of type 'I2'.
-!!! error TS2345:   Object literal may only specify known properties, and 'toString' does not exist in type 'I2'.
+         ~~~~~~~~
+!!! error TS2322: Type '(s: any) => any' is not assignable to type '() => string'.
+!!! related TS6500 /.ts/lib.es5.d.ts:125:5: The expected type comes from property 'toString' which is declared here on type 'I2'
     f2({ toString: (s: string) => s }) 
-         ~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ toString: (s: string) => string; }' is not assignable to parameter of type 'I2'.
-!!! error TS2345:   Object literal may only specify known properties, and 'toString' does not exist in type 'I2'.
+         ~~~~~~~~
+!!! error TS2322: Type '(s: string) => string' is not assignable to type '() => string'.
+!!! related TS6500 /.ts/lib.es5.d.ts:125:5: The expected type comes from property 'toString' which is declared here on type 'I2'
     f2({ value: '', toString: (s) => s.uhhh }) 
-                    ~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ value: string; toString: (s: any) => any; }' is not assignable to parameter of type 'I2'.
-!!! error TS2345:   Object literal may only specify known properties, and 'toString' does not exist in type 'I2'.
+                    ~~~~~~~~
+!!! error TS2322: Type '(s: any) => any' is not assignable to type '() => string'.
+!!! related TS6500 /.ts/lib.es5.d.ts:125:5: The expected type comes from property 'toString' which is declared here on type 'I2'

tests/baselines/reference/objectLiteralShorthandPropertiesAssignmentError.errors.txt

@@ -2,9 +2,7 @@ tests/cases/conformance/es6/shorthandPropertyAssignment/objectLiteralShorthandPr
   Object literal may only specify known properties, and 'name' does not exist in type '{ b: string; id: number; }'.
 tests/cases/conformance/es6/shorthandPropertyAssignment/objectLiteralShorthandPropertiesAssignmentError.ts(6,81): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/conformance/es6/shorthandPropertyAssignment/objectLiteralShorthandPropertiesAssignmentError.ts(6,87): error TS2322: Type 'number' is not assignable to type 'string'.
-tests/cases/conformance/es6/shorthandPropertyAssignment/objectLiteralShorthandPropertiesAssignmentError.ts(8,5): error TS2345: Argument of type '{ name: string; id: number; }' is not assignable to parameter of type '{ name: string; id: boolean; }'.
-  Types of property 'id' are incompatible.
-    Type 'number' is not assignable to type 'boolean'.
+tests/cases/conformance/es6/shorthandPropertyAssignment/objectLiteralShorthandPropertiesAssignmentError.ts(8,13): error TS2322: Type 'number' is not assignable to type 'boolean'.
 
 
 ==== tests/cases/conformance/es6/shorthandPropertyAssignment/objectLiteralShorthandPropertiesAssignmentError.ts (4 errors) ====
@@ -25,9 +23,8 @@ tests/cases/conformance/es6/shorthandPropertyAssignment/objectLiteralShorthandPr
 !!! related TS6500 tests/cases/conformance/es6/shorthandPropertyAssignment/objectLiteralShorthandPropertiesAssignmentError.ts:6:43: The expected type comes from property 'id' which is declared here on type '{ id: string; name: number; }'
     function bar(obj: { name: string; id: boolean }) { }
     bar({ name, id });  // error
-        ~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ name: string; id: number; }' is not assignable to parameter of type '{ name: string; id: boolean; }'.
-!!! error TS2345:   Types of property 'id' are incompatible.
-!!! error TS2345:     Type 'number' is not assignable to type 'boolean'.
+                ~~
+!!! error TS2322: Type 'number' is not assignable to type 'boolean'.
+!!! related TS6500 tests/cases/conformance/es6/shorthandPropertyAssignment/objectLiteralShorthandPropertiesAssignmentError.ts:7:35: The expected type comes from property 'id' which is declared here on type '{ name: string; id: boolean; }'
     
     

tests/baselines/reference/objectSpreadNegative.errors.txt

@@ -18,15 +18,9 @@ tests/cases/conformance/types/spread/objectSpreadNegative.ts(53,9): error TS2339
 tests/cases/conformance/types/spread/objectSpreadNegative.ts(58,11): error TS2339: Property 'a' does not exist on type '{}'.
 tests/cases/conformance/types/spread/objectSpreadNegative.ts(62,14): error TS2698: Spread types may only be created from object types.
 tests/cases/conformance/types/spread/objectSpreadNegative.ts(65,14): error TS2698: Spread types may only be created from object types.
-tests/cases/conformance/types/spread/objectSpreadNegative.ts(79,37): error TS2322: Type '{ a: string; b: string; extra: string; }' is not assignable to type 'A'.
-  Object literal may only specify known properties, and 'extra' does not exist in type 'A'.
-tests/cases/conformance/types/spread/objectSpreadNegative.ts(82,7): error TS2322: Type '{ a: string; b: string; extra: string; }' is not assignable to type 'A'.
-  Object literal may only specify known properties, and 'extra' does not exist in type 'A'.
-tests/cases/conformance/types/spread/objectSpreadNegative.ts(84,7): error TS2322: Type '{ a: string; b: string; extra: string; }' is not assignable to type 'A'.
-  Object literal may only specify known properties, and 'extra' does not exist in type 'A'.
 
 
-==== tests/cases/conformance/types/spread/objectSpreadNegative.ts (20 errors) ====
+==== tests/cases/conformance/types/spread/objectSpreadNegative.ts (17 errors) ====
     let o = { a: 1, b: 'no' }
     
     /// private propagates
@@ -138,23 +132,4 @@ tests/cases/conformance/types/spread/objectSpreadNegative.ts(84,7): error TS2322
         f({ a: 1 }, { a: 'mismatch' })
     let overwriteId: { id: string, a: number, c: number, d: string } =
         f({ a: 1, id: true }, { c: 1, d: 'no' })
-    
-    // excess property checks
-    type A = { a: string, b: string };
-    type Extra = { a: string, b: string, extra: string };
-    const extra1: A = { a: "a", b: "b", extra: "extra" };
-                                        ~~~~~~~~~~~~~~
-!!! error TS2322: Type '{ a: string; b: string; extra: string; }' is not assignable to type 'A'.
-!!! error TS2322:   Object literal may only specify known properties, and 'extra' does not exist in type 'A'.
-    const extra2 = { a: "a", b: "b", extra: "extra" };
-    const a1: A = { ...extra1 }; // error spans should be here
-    const a2: A = { ...extra2 }; // not on the symbol declarations above
-          ~~
-!!! error TS2322: Type '{ a: string; b: string; extra: string; }' is not assignable to type 'A'.
-!!! error TS2322:   Object literal may only specify known properties, and 'extra' does not exist in type 'A'.
-    const extra3: Extra = { a: "a", b: "b", extra: "extra" };
-    const a3: A = { ...extra3 }; // same here
-          ~~
-!!! error TS2322: Type '{ a: string; b: string; extra: string; }' is not assignable to type 'A'.
-!!! error TS2322:   Object literal may only specify known properties, and 'extra' does not exist in type 'A'.
     

tests/baselines/reference/objectSpreadNegative.js

@@ -73,16 +73,6 @@ let overlapConflict: { id:string, a: string } =
     f({ a: 1 }, { a: 'mismatch' })
 let overwriteId: { id: string, a: number, c: number, d: string } =
     f({ a: 1, id: true }, { c: 1, d: 'no' })
-
-// excess property checks
-type A = { a: string, b: string };
-type Extra = { a: string, b: string, extra: string };
-const extra1: A = { a: "a", b: "b", extra: "extra" };
-const extra2 = { a: "a", b: "b", extra: "extra" };
-const a1: A = { ...extra1 }; // error spans should be here
-const a2: A = { ...extra2 }; // not on the symbol declarations above
-const extra3: Extra = { a: "a", b: "b", extra: "extra" };
-const a3: A = { ...extra3 }; // same here
 
 
 //// [objectSpreadNegative.js]
@@ -167,9 +157,3 @@ var exclusive = f({ a: 1, b: 'yes' }, { c: 'no', d: false });
 var overlap = f({ a: 1 }, { a: 2, b: 'extra' });
 var overlapConflict = f({ a: 1 }, { a: 'mismatch' });
 var overwriteId = f({ a: 1, id: true }, { c: 1, d: 'no' });
-var extra1 = { a: "a", b: "b", extra: "extra" };
-var extra2 = { a: "a", b: "b", extra: "extra" };
-var a1 = __assign({}, extra1); // error spans should be here
-var a2 = __assign({}, extra2); // not on the symbol declarations above
-var extra3 = { a: "a", b: "b", extra: "extra" };
-var a3 = __assign({}, extra3); // same here

tests/baselines/reference/objectSpreadNegative.symbols

@@ -243,50 +243,3 @@ let overwriteId: { id: string, a: number, c: number, d: string } =
 >c : Symbol(c, Decl(objectSpreadNegative.ts, 73, 27))
 >d : Symbol(d, Decl(objectSpreadNegative.ts, 73, 33))
 
-// excess property checks
-type A = { a: string, b: string };
->A : Symbol(A, Decl(objectSpreadNegative.ts, 73, 44))
->a : Symbol(a, Decl(objectSpreadNegative.ts, 76, 10))
->b : Symbol(b, Decl(objectSpreadNegative.ts, 76, 21))
-
-type Extra = { a: string, b: string, extra: string };
->Extra : Symbol(Extra, Decl(objectSpreadNegative.ts, 76, 34))
->a : Symbol(a, Decl(objectSpreadNegative.ts, 77, 14))
->b : Symbol(b, Decl(objectSpreadNegative.ts, 77, 25))
->extra : Symbol(extra, Decl(objectSpreadNegative.ts, 77, 36))
-
-const extra1: A = { a: "a", b: "b", extra: "extra" };
->extra1 : Symbol(extra1, Decl(objectSpreadNegative.ts, 78, 5))
->A : Symbol(A, Decl(objectSpreadNegative.ts, 73, 44))
->a : Symbol(a, Decl(objectSpreadNegative.ts, 78, 19))
->b : Symbol(b, Decl(objectSpreadNegative.ts, 78, 27))
->extra : Symbol(extra, Decl(objectSpreadNegative.ts, 78, 35))
-
-const extra2 = { a: "a", b: "b", extra: "extra" };
->extra2 : Symbol(extra2, Decl(objectSpreadNegative.ts, 79, 5))
->a : Symbol(a, Decl(objectSpreadNegative.ts, 79, 16))
->b : Symbol(b, Decl(objectSpreadNegative.ts, 79, 24))
->extra : Symbol(extra, Decl(objectSpreadNegative.ts, 79, 32))
-
-const a1: A = { ...extra1 }; // error spans should be here
->a1 : Symbol(a1, Decl(objectSpreadNegative.ts, 80, 5))
->A : Symbol(A, Decl(objectSpreadNegative.ts, 73, 44))
->extra1 : Symbol(extra1, Decl(objectSpreadNegative.ts, 78, 5))
-
-const a2: A = { ...extra2 }; // not on the symbol declarations above
->a2 : Symbol(a2, Decl(objectSpreadNegative.ts, 81, 5))
->A : Symbol(A, Decl(objectSpreadNegative.ts, 73, 44))
->extra2 : Symbol(extra2, Decl(objectSpreadNegative.ts, 79, 5))
-
-const extra3: Extra = { a: "a", b: "b", extra: "extra" };
->extra3 : Symbol(extra3, Decl(objectSpreadNegative.ts, 82, 5))
->Extra : Symbol(Extra, Decl(objectSpreadNegative.ts, 76, 34))
->a : Symbol(a, Decl(objectSpreadNegative.ts, 82, 23))
->b : Symbol(b, Decl(objectSpreadNegative.ts, 82, 31))
->extra : Symbol(extra, Decl(objectSpreadNegative.ts, 82, 39))
-
-const a3: A = { ...extra3 }; // same here
->a3 : Symbol(a3, Decl(objectSpreadNegative.ts, 83, 5))
->A : Symbol(A, Decl(objectSpreadNegative.ts, 73, 44))
->extra3 : Symbol(extra3, Decl(objectSpreadNegative.ts, 82, 5))
-

tests/baselines/reference/objectSpreadNegative.types

@@ -325,60 +325,3 @@ let overwriteId: { id: string, a: number, c: number, d: string } =
 >d : string
 >'no' : "no"
 
-// excess property checks
-type A = { a: string, b: string };
->A : A
->a : string
->b : string
-
-type Extra = { a: string, b: string, extra: string };
->Extra : Extra
->a : string
->b : string
->extra : string
-
-const extra1: A = { a: "a", b: "b", extra: "extra" };
->extra1 : A
->{ a: "a", b: "b", extra: "extra" } : { a: string; b: string; extra: string; }
->a : string
->"a" : "a"
->b : string
->"b" : "b"
->extra : string
->"extra" : "extra"
-
-const extra2 = { a: "a", b: "b", extra: "extra" };
->extra2 : { a: string; b: string; extra: string; }
->{ a: "a", b: "b", extra: "extra" } : { a: string; b: string; extra: string; }
->a : string
->"a" : "a"
->b : string
->"b" : "b"
->extra : string
->"extra" : "extra"
-
-const a1: A = { ...extra1 }; // error spans should be here
->a1 : A
->{ ...extra1 } : { a: string; b: string; }
->extra1 : A
-
-const a2: A = { ...extra2 }; // not on the symbol declarations above
->a2 : A
->{ ...extra2 } : { a: string; b: string; extra: string; }
->extra2 : { a: string; b: string; extra: string; }
-
-const extra3: Extra = { a: "a", b: "b", extra: "extra" };
->extra3 : Extra
->{ a: "a", b: "b", extra: "extra" } : { a: string; b: string; extra: string; }
->a : string
->"a" : "a"
->b : string
->"b" : "b"
->extra : string
->"extra" : "extra"
-
-const a3: A = { ...extra3 }; // same here
->a3 : A
->{ ...extra3 } : { a: string; b: string; extra: string; }
->extra3 : Extra
-

tests/baselines/reference/optionalBindingParameters1.errors.txt

@@ -1,9 +1,9 @@
 tests/cases/conformance/es6/destructuring/optionalBindingParameters1.ts(1,14): error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
-tests/cases/conformance/es6/destructuring/optionalBindingParameters1.ts(7,5): error TS2345: Argument of type '[boolean, number, string]' is not assignable to parameter of type '[string, number, boolean]'.
-  Type 'boolean' is not assignable to type 'string'.
+tests/cases/conformance/es6/destructuring/optionalBindingParameters1.ts(7,6): error TS2322: Type 'false' is not assignable to type 'string'.
+tests/cases/conformance/es6/destructuring/optionalBindingParameters1.ts(7,16): error TS2322: Type 'string' is not assignable to type 'boolean'.
 
 
-==== tests/cases/conformance/es6/destructuring/optionalBindingParameters1.ts (2 errors) ====
+==== tests/cases/conformance/es6/destructuring/optionalBindingParameters1.ts (3 errors) ====
     function foo([x,y,z]?: [string, number, boolean]) {
                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
@@ -13,6 +13,7 @@ tests/cases/conformance/es6/destructuring/optionalBindingParameters1.ts(7,5): er
     foo(["", 0, false]);
     
     foo([false, 0, ""]);
-        ~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '[boolean, number, string]' is not assignable to parameter of type '[string, number, boolean]'.
-!!! error TS2345:   Type 'boolean' is not assignable to type 'string'.
+         ~~~~~
+!!! error TS2322: Type 'false' is not assignable to type 'string'.
+                   ~~
+!!! error TS2322: Type 'string' is not assignable to type 'boolean'.

tests/baselines/reference/optionalBindingParameters2.errors.txt

@@ -1,10 +1,9 @@
 tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts(1,14): error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
-tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts(7,5): error TS2345: Argument of type '{ x: boolean; y: number; z: string; }' is not assignable to parameter of type '{ x: string; y: number; z: boolean; }'.
-  Types of property 'x' are incompatible.
-    Type 'boolean' is not assignable to type 'string'.
+tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts(7,7): error TS2322: Type 'false' is not assignable to type 'string'.
+tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts(7,23): error TS2322: Type 'string' is not assignable to type 'boolean'.
 
 
-==== tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts (2 errors) ====
+==== tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts (3 errors) ====
     function foo({ x, y, z }?: { x: string; y: number; z: boolean }) {
                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
@@ -14,7 +13,9 @@ tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts(7,5): er
     foo({ x: "", y: 0, z: false });
     
     foo({ x: false, y: 0, z: "" });
-        ~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ x: boolean; y: number; z: string; }' is not assignable to parameter of type '{ x: string; y: number; z: boolean; }'.
-!!! error TS2345:   Types of property 'x' are incompatible.
-!!! error TS2345:     Type 'boolean' is not assignable to type 'string'.
+          ~
+!!! error TS2322: Type 'false' is not assignable to type 'string'.
+!!! related TS6500 tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts:1:30: The expected type comes from property 'x' which is declared here on type '{ x: string; y: number; z: boolean; }'
+                          ~
+!!! error TS2322: Type 'string' is not assignable to type 'boolean'.
+!!! related TS6500 tests/cases/conformance/es6/destructuring/optionalBindingParameters2.ts:1:52: The expected type comes from property 'z' which is declared here on type '{ x: string; y: number; z: boolean; }'

tests/baselines/reference/optionalBindingParametersInOverloads1.errors.txt

@@ -1,8 +1,8 @@
-tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads1.ts(8,5): error TS2345: Argument of type '[boolean, number, string]' is not assignable to parameter of type '[string, number, boolean]'.
-  Type 'boolean' is not assignable to type 'string'.
+tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads1.ts(8,6): error TS2322: Type 'false' is not assignable to type 'string'.
+tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads1.ts(8,16): error TS2322: Type 'string' is not assignable to type 'boolean'.
 
 
-==== tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads1.ts (1 errors) ====
+==== tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads1.ts (2 errors) ====
     function foo([x, y, z] ?: [string, number, boolean]);
     function foo(...rest: any[]) {
     
@@ -11,6 +11,7 @@ tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads1.
     foo(["", 0, false]);
     
     foo([false, 0, ""]);
-        ~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '[boolean, number, string]' is not assignable to parameter of type '[string, number, boolean]'.
-!!! error TS2345:   Type 'boolean' is not assignable to type 'string'.
+         ~~~~~
+!!! error TS2322: Type 'false' is not assignable to type 'string'.
+                   ~~
+!!! error TS2322: Type 'string' is not assignable to type 'boolean'.

tests/baselines/reference/optionalBindingParametersInOverloads2.errors.txt

@@ -1,9 +1,8 @@
-tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads2.ts(8,5): error TS2345: Argument of type '{ x: boolean; y: number; z: string; }' is not assignable to parameter of type '{ x: string; y: number; z: boolean; }'.
-  Types of property 'x' are incompatible.
-    Type 'boolean' is not assignable to type 'string'.
+tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads2.ts(8,7): error TS2322: Type 'false' is not assignable to type 'string'.
+tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads2.ts(8,23): error TS2322: Type 'string' is not assignable to type 'boolean'.
 
 
-==== tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads2.ts (1 errors) ====
+==== tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads2.ts (2 errors) ====
     function foo({ x, y, z }?: { x: string; y: number; z: boolean });
     function foo(...rest: any[]) {
     
@@ -12,7 +11,9 @@ tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads2.
     foo({ x: "", y: 0, z: false });
     
     foo({ x: false, y: 0, z: "" });
-        ~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ x: boolean; y: number; z: string; }' is not assignable to parameter of type '{ x: string; y: number; z: boolean; }'.
-!!! error TS2345:   Types of property 'x' are incompatible.
-!!! error TS2345:     Type 'boolean' is not assignable to type 'string'.
+          ~
+!!! error TS2322: Type 'false' is not assignable to type 'string'.
+!!! related TS6500 tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads2.ts:1:30: The expected type comes from property 'x' which is declared here on type '{ x: string; y: number; z: boolean; }'
+                          ~
+!!! error TS2322: Type 'string' is not assignable to type 'boolean'.
+!!! related TS6500 tests/cases/conformance/es6/destructuring/optionalBindingParametersInOverloads2.ts:1:52: The expected type comes from property 'z' which is declared here on type '{ x: string; y: number; z: boolean; }'

tests/baselines/reference/overloadResolutionTest1.errors.txt

@@ -2,12 +2,8 @@ tests/cases/compiler/overloadResolutionTest1.ts(7,16): error TS2345: Argument of
   Type '{ a: string; }' is not assignable to type '{ a: boolean; }'.
     Types of property 'a' are incompatible.
       Type 'string' is not assignable to type 'boolean'.
-tests/cases/compiler/overloadResolutionTest1.ts(18,15): error TS2345: Argument of type '{ a: string; }' is not assignable to parameter of type '{ a: boolean; }'.
-  Types of property 'a' are incompatible.
-    Type 'string' is not assignable to type 'boolean'.
-tests/cases/compiler/overloadResolutionTest1.ts(24,14): error TS2345: Argument of type '{ a: boolean; }' is not assignable to parameter of type '{ a: string; }'.
-  Types of property 'a' are incompatible.
-    Type 'boolean' is not assignable to type 'string'.
+tests/cases/compiler/overloadResolutionTest1.ts(18,16): error TS2322: Type 'string' is not assignable to type 'boolean'.
+tests/cases/compiler/overloadResolutionTest1.ts(24,15): error TS2322: Type 'true' is not assignable to type 'string'.
 
 
 ==== tests/cases/compiler/overloadResolutionTest1.ts (3 errors) ====
@@ -34,17 +30,15 @@ tests/cases/compiler/overloadResolutionTest1.ts(24,14): error TS2345: Argument o
     var x2 = foo2({a:0}); // works
     var x3 = foo2({a:true}); // works
     var x4 = foo2({a:"s"}); // error
-                  ~~~~~~~
-!!! error TS2345: Argument of type '{ a: string; }' is not assignable to parameter of type '{ a: boolean; }'.
-!!! error TS2345:   Types of property 'a' are incompatible.
-!!! error TS2345:     Type 'string' is not assignable to type 'boolean'.
+                   ~
+!!! error TS2322: Type 'string' is not assignable to type 'boolean'.
+!!! related TS6500 tests/cases/compiler/overloadResolutionTest1.ts:13:20: The expected type comes from property 'a' which is declared here on type '{ a: boolean; }'
     
     
     function foo4(bar:{a:number;}):number;
     function foo4(bar:{a:string;}):string;
     function foo4(bar:{a:any;}):any{ return bar };
     var x = foo4({a:true}); // error
-                 ~~~~~~~~
-!!! error TS2345: Argument of type '{ a: boolean; }' is not assignable to parameter of type '{ a: string; }'.
-!!! error TS2345:   Types of property 'a' are incompatible.
-!!! error TS2345:     Type 'boolean' is not assignable to type 'string'.
+                  ~
+!!! error TS2322: Type 'true' is not assignable to type 'string'.
+!!! related TS6500 tests/cases/compiler/overloadResolutionTest1.ts:22:20: The expected type comes from property 'a' which is declared here on type '{ a: string; }'

tests/baselines/reference/parameterInitializersForwardReferencing1.errors.txt

@@ -55,4 +55,6 @@ tests/cases/conformance/functions/parameterInitializersForwardReferencing1.ts(29
     class Foo {
         constructor(public x = 12, public y = x) {}
     }
+    
+    function f8(foo1: string, bar = foo1) { }
     

tests/baselines/reference/parameterInitializersForwardReferencing1.js

@@ -34,6 +34,8 @@ function f7({[foo]: bar}: any[]) {
 class Foo {
     constructor(public x = 12, public y = x) {}
 }
+
+function f8(foo1: string, bar = foo1) { }
 
 
 //// [parameterInitializersForwardReferencing1.js]
@@ -81,3 +83,6 @@ var Foo = /** @class */ (function () {
     }
     return Foo;
 }());
+function f8(foo1, bar) {
+    if (bar === void 0) { bar = foo1; }
+}

tests/baselines/reference/parameterInitializersForwardReferencing1.symbols

@@ -84,3 +84,9 @@ class Foo {
 >x : Symbol(x, Decl(parameterInitializersForwardReferencing1.ts, 33, 16))
 }
 
+function f8(foo1: string, bar = foo1) { }
+>f8 : Symbol(f8, Decl(parameterInitializersForwardReferencing1.ts, 34, 1))
+>foo1 : Symbol(foo1, Decl(parameterInitializersForwardReferencing1.ts, 36, 12))
+>bar : Symbol(bar, Decl(parameterInitializersForwardReferencing1.ts, 36, 25))
+>foo1 : Symbol(foo1, Decl(parameterInitializersForwardReferencing1.ts, 36, 12))
+

tests/baselines/reference/parameterInitializersForwardReferencing1.types

@@ -92,3 +92,9 @@ class Foo {
 >x : number
 }
 
+function f8(foo1: string, bar = foo1) { }
+>f8 : (foo1: string, bar?: string) => void
+>foo1 : string
+>bar : string
+>foo1 : string
+

tests/baselines/reference/parameterInitializersForwardReferencing1_es6.errors.txt

@@ -42,4 +42,6 @@ tests/cases/conformance/functions/parameterInitializersForwardReferencing1_es6.t
     class Foo {
         constructor(public x = 12, public y = x) {}
     }
+    
+    function f8(foo1: string, bar = foo1) { }