Merge branch 'master' of https://github.com/Microsoft/TypeScript into feature/eslint

Author: a-tarasyuk

README.md

@@ -1,8 +1,8 @@
 
 # TypeScript
 
-[![Join the chat at https://gitter.im/Microsoft/TypeScript](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/Microsoft/TypeScript?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[![Build Status](https://travis-ci.org/microsoft/TypeScript.svg?branch=master)](https://travis-ci.org/Microsoft/TypeScript)
+[![Join the chat at https://gitter.im/microsoft/TypeScript](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/microsoft/TypeScript?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![Build Status](https://travis-ci.org/microsoft/TypeScript.svg?branch=master)](https://travis-ci.org/microsoft/TypeScript)
 [![VSTS Build Status](https://dev.azure.com/typescript/TypeScript/_apis/build/status/Typescript/node10)](https://dev.azure.com/typescript/TypeScript/_build/latest?definitionId=4&view=logs)
 [![npm version](https://badge.fury.io/js/typescript.svg)](https://www.npmjs.com/package/typescript)
 [![Downloads](https://img.shields.io/npm/dm/typescript.svg)](https://www.npmjs.com/package/typescript)
@@ -27,14 +27,14 @@ npm install -g typescript@next
 
 ## Contribute
 
-There are many ways to [contribute](https://github.com/Microsoft/TypeScript/blob/master/CONTRIBUTING.md) to TypeScript.
-* [Submit bugs](https://github.com/Microsoft/TypeScript/issues) and help us verify fixes as they are checked in.
-* Review the [source code changes](https://github.com/Microsoft/TypeScript/pulls).
+There are many ways to [contribute](https://github.com/microsoft/TypeScript/blob/master/CONTRIBUTING.md) to TypeScript.
+* [Submit bugs](https://github.com/microsoft/TypeScript/issues) and help us verify fixes as they are checked in.
+* Review the [source code changes](https://github.com/microsoft/TypeScript/pulls).
 * Engage with other TypeScript users and developers on [StackOverflow](https://stackoverflow.com/questions/tagged/typescript).
 * Join the [#typescript](https://twitter.com/search?q=%23TypeScript) discussion on Twitter.
-* [Contribute bug fixes](https://github.com/Microsoft/TypeScript/blob/master/CONTRIBUTING.md).
-* Read the language specification ([docx](https://github.com/Microsoft/TypeScript/blob/master/doc/TypeScript%20Language%20Specification.docx?raw=true),
- [pdf](https://github.com/Microsoft/TypeScript/blob/master/doc/TypeScript%20Language%20Specification.pdf?raw=true), [md](https://github.com/Microsoft/TypeScript/blob/master/doc/spec.md)).
+* [Contribute bug fixes](https://github.com/microsoft/TypeScript/blob/master/CONTRIBUTING.md).
+* Read the language specification ([docx](https://github.com/microsoft/TypeScript/blob/master/doc/TypeScript%20Language%20Specification.docx?raw=true),
+ [pdf](https://github.com/microsoft/TypeScript/blob/master/doc/TypeScript%20Language%20Specification.pdf?raw=true), [md](https://github.com/microsoft/TypeScript/blob/master/doc/spec.md)).
 
 This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/). For more information see
 the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact [[email protected]](mailto:[email protected])
@@ -44,7 +44,7 @@ with any additional questions or comments.
 
 *  [Quick tutorial](https://www.typescriptlang.org/docs/tutorial.html)
 *  [Programming handbook](https://www.typescriptlang.org/docs/handbook/basic-types.html)
-*  [Language specification](https://github.com/Microsoft/TypeScript/blob/master/doc/spec.md)
+*  [Language specification](https://github.com/microsoft/TypeScript/blob/master/doc/spec.md)
 *  [Homepage](https://www.typescriptlang.org/)
 
 ## Building
@@ -54,7 +54,7 @@ In order to build the TypeScript compiler, ensure that you have [Git](https://gi
 Clone a copy of the repo:
 
 ```bash
-git clone https://github.com/Microsoft/TypeScript.git
+git clone https://github.com/microsoft/TypeScript.git
 ```
 
 Change to the TypeScript directory:
@@ -73,17 +73,25 @@ npm install
 Use one of the following to build and test:
 
 ```
-gulp local            # Build the compiler into built/local
-gulp clean            # Delete the built compiler
-gulp LKG              # Replace the last known good with the built one.
-                      # Bootstrapping step to be executed when the built compiler reaches a stable state.
-gulp tests            # Build the test infrastructure using the built compiler.
-gulp runtests         # Run tests using the built compiler and test infrastructure.
-                      # You can override the host or specify a test for this command.
-                      # Use --host=<hostName> or --tests=<testPath>.
-gulp baseline-accept  # This replaces the baseline test results with the results obtained from gulp runtests.
-gulp lint             # Runs eslint on the TypeScript source.
-gulp help             # List the above commands.
+gulp local             # Build the compiler into built/local.
+gulp clean             # Delete the built compiler.
+gulp LKG               # Replace the last known good with the built one.
+                       # Bootstrapping step to be executed when the built compiler reaches a stable state.
+gulp tests             # Build the test infrastructure using the built compiler.
+gulp runtests          # Run tests using the built compiler and test infrastructure.
+                       # Some low-value tests are skipped when not on a CI machine - you can use the
+                       # --skipPercent=0 command to override this behavior and run all tests locally.
+                       # You can override the specific suite runner used or specify a test for this command.
+                       # Use --tests=<testPath> for a specific test and/or --runner=<runnerName> for a specific suite.
+                       # Valid runners include conformance, compiler, fourslash, project, user, and docker
+                       # The user and docker runners are extended test suite runners - the user runner
+                       # works on disk in the tests/cases/user directory, while the docker runner works in containers.
+                       # You'll need to have the docker executable in your system path for the docker runner to work.
+gulp runtests-parallel # Like runtests, but split across multiple threads. Uses a number of threads equal to the system
+                       # core count by default. Use --workers=<number> to adjust this.
+gulp baseline-accept   # This replaces the baseline test results with the results obtained from gulp runtests.
+gulp lint              # Runs eslint on the TypeScript source.
+gulp help              # List the above commands.
 ```
 
 
@@ -96,4 +104,4 @@ node built/local/tsc.js hello.ts
 
 ## Roadmap
 
-For details on our planned features and future direction please refer to our [roadmap](https://github.com/Microsoft/TypeScript/wiki/Roadmap).
+For details on our planned features and future direction please refer to our [roadmap](https://github.com/microsoft/TypeScript/wiki/Roadmap).

scripts/build/options.js

@@ -15,6 +15,7 @@ module.exports = minimist(process.argv.slice(2), {
         "r": "reporter",
         "c": "colors", "color": "colors",
         "skip-percent": "skipPercent",
+        "skippercent": "skipPercent",
         "w": "workers",
         "f": "fix"
     },

scripts/open-cherry-pick-pr.ts

@@ -11,6 +11,7 @@ const userName = process.env.GH_USERNAME;
 const reviewers = process.env.REQUESTING_USER ? [process.env.REQUESTING_USER] : ["weswigham", "RyanCavanaugh"];
 const branchName = `pick/${process.env.SOURCE_ISSUE}/${process.env.TARGET_BRANCH}`;
 const remoteUrl = `https://${process.argv[2]}@github.com/${userName}/TypeScript.git`;
+const produceLKG = !!process.env.PRODUCE_LKG;
 
 async function main() {
     if (!process.env.TARGET_BRANCH) {
@@ -52,7 +53,16 @@ ${logText.trim()}`;
     runSequence([
         ["git", ["checkout", process.env.TARGET_BRANCH]], // checkout the target branch
         ["git", ["checkout", "-b", branchName]], // create a new branch
-        ["git", ["cherry-pick", squashSha.trim()]], //
+        ["git", ["cherry-pick", squashSha.trim()]],
+    ]);
+    if (produceLKG) {
+        runSequence([
+            ["gulp", ["LKG"]],
+            ["git", ["add", "lib"]],
+            ["git", ["commit", "-m", `"Update LKG"`]]
+        ]);
+    }
+    runSequence([
         ["git", ["remote", "add", "fork", remoteUrl]], // Add the remote fork
         ["git", ["push", "--set-upstream", "fork", branchName, "-f"]] // push the branch
     ]);
@@ -71,7 +81,7 @@ ${logText.trim()}`;
         base: process.env.TARGET_BRANCH,
         body:
     `This cherry-pick was triggerd by a request on https://github.com/Microsoft/TypeScript/pull/${process.env.SOURCE_ISSUE}
-Please review the diff and merge if no changes are unexpected.
+Please review the diff and merge if no changes are unexpected.${produceLKG ? ` An LKG update commit is included seperately from the base change.` : ""}
 You can view the cherry-pick log [here](https://typescript.visualstudio.com/TypeScript/_build/index?buildId=${process.env.BUILD_BUILDID}&_a=summary).
 
 cc ${reviewers.map(r => "@" + r).join(" ")}`,

src/compiler/checker.ts

@@ -9332,10 +9332,10 @@ namespace ts {
                         return globalFunctionType;
                     case "Array":
                     case "array":
-                        return !typeArgs || !typeArgs.length ? anyArrayType : undefined;
+                        return (!typeArgs || !typeArgs.length) && !noImplicitAny ? anyArrayType : undefined;
                     case "Promise":
                     case "promise":
-                        return !typeArgs || !typeArgs.length ? createPromiseType(anyType) : undefined;
+                        return (!typeArgs || !typeArgs.length) && !noImplicitAny ? createPromiseType(anyType) : undefined;
                     case "Object":
                         if (typeArgs && typeArgs.length === 2) {
                             if (isJSDocIndexSignature(node)) {
@@ -9347,7 +9347,7 @@ namespace ts {
                             return anyType;
                         }
                         checkNoTypeArguments(node);
-                        return anyType;
+                        return !noImplicitAny ? anyType : undefined;
                 }
             }
         }
@@ -15484,8 +15484,7 @@ namespace ts {
             let visited: Map<number>;
             let bivariant = false;
             let propagationType: Type;
-            let inferenceMatch = false;
-            let inferenceIncomplete = false;
+            let inferencePriority = InferencePriority.MaxValue;
             let allowComplexConstraintInference = true;
             inferFromTypes(originalSource, originalTarget);
 
@@ -15598,7 +15597,7 @@ namespace ts {
                                 clearCachedInferences(inferences);
                             }
                         }
-                        inferenceMatch = true;
+                        inferencePriority = Math.min(inferencePriority, priority);
                         return;
                     }
                     else {
@@ -15692,19 +15691,15 @@ namespace ts {
                 const key = source.id + "," + target.id;
                 const status = visited && visited.get(key);
                 if (status !== undefined) {
-                    if (status & 1) inferenceMatch = true;
-                    if (status & 2) inferenceIncomplete = true;
+                    inferencePriority = Math.min(inferencePriority, status);
                     return;
                 }
-                (visited || (visited = createMap<number>())).set(key, 0);
-                const saveInferenceMatch = inferenceMatch;
-                const saveInferenceIncomplete = inferenceIncomplete;
-                inferenceMatch = false;
-                inferenceIncomplete = false;
+                (visited || (visited = createMap<number>())).set(key, InferencePriority.Circularity);
+                const saveInferencePriority = inferencePriority;
+                inferencePriority = InferencePriority.MaxValue;
                 action(source, target);
-                visited.set(key, (inferenceMatch ? 1 : 0) | (inferenceIncomplete ? 2 : 0));
-                inferenceMatch = inferenceMatch || saveInferenceMatch;
-                inferenceIncomplete = inferenceIncomplete || saveInferenceIncomplete;
+                visited.set(key, inferencePriority);
+                inferencePriority = Math.min(inferencePriority, saveInferencePriority);
             }
 
             function inferFromMatchingType(source: Type, targets: Type[], matches: (s: Type, t: Type) => boolean) {
@@ -15776,31 +15771,32 @@ namespace ts {
                     let nakedTypeVariable: Type | undefined;
                     const sources = source.flags & TypeFlags.Union ? (<UnionType>source).types : [source];
                     const matched = new Array<boolean>(sources.length);
-                    const saveInferenceIncomplete = inferenceIncomplete;
-                    inferenceIncomplete = false;
+                    let inferenceCircularity = false;
                     // First infer to types that are not naked type variables. For each source type we
-                    // track whether inferences were made from that particular type to some target.
+                    // track whether inferences were made from that particular type to some target with
+                    // equal priority (i.e. of equal quality) to what we would infer for a naked type
+                    // parameter.
                     for (const t of targets) {
                         if (getInferenceInfoForType(t)) {
                             nakedTypeVariable = t;
                             typeVariableCount++;
                         }
                         else {
                             for (let i = 0; i < sources.length; i++) {
-                                const saveInferenceMatch = inferenceMatch;
-                                inferenceMatch = false;
+                                const saveInferencePriority = inferencePriority;
+                                inferencePriority = InferencePriority.MaxValue;
                                 inferFromTypes(sources[i], t);
-                                if (inferenceMatch) matched[i] = true;
-                                inferenceMatch = inferenceMatch || saveInferenceMatch;
+                                if (inferencePriority === priority) matched[i] = true;
+                                inferenceCircularity = inferenceCircularity || inferencePriority === InferencePriority.Circularity;
+                                inferencePriority = Math.min(inferencePriority, saveInferencePriority);
                             }
                         }
                     }
-                    const inferenceComplete = !inferenceIncomplete;
-                    inferenceIncomplete = inferenceIncomplete || saveInferenceIncomplete;
-                    // If the target has a single naked type variable and inference completed (meaning we
-                    // explored the types fully), create a union of the source types from which no inferences
-                    // have been made so far and infer from that union to the naked type variable.
-                    if (typeVariableCount === 1 && inferenceComplete) {
+                    // If the target has a single naked type variable and no inference circularities were
+                    // encountered above (meaning we explored the types fully), create a union of the source
+                    // types from which no inferences have been made so far and infer from that union to the
+                    // naked type variable.
+                    if (typeVariableCount === 1 && !inferenceCircularity) {
                         const unmatched = flatMap(sources, (s, i) => matched[i] ? undefined : s);
                         if (unmatched.length) {
                             inferFromTypes(getUnionType(unmatched), nakedTypeVariable!);
@@ -15903,7 +15899,7 @@ namespace ts {
                 const symbol = isNonConstructorObject ? target.symbol : undefined;
                 if (symbol) {
                     if (contains(symbolStack, symbol)) {
-                        inferenceIncomplete = true;
+                        inferencePriority = InferencePriority.Circularity;
                         return;
                     }
                     (symbolStack || (symbolStack = [])).push(symbol);

src/compiler/diagnosticMessages.json

@@ -5112,6 +5112,10 @@
         "category": "Message",
         "code": 95087
     },
+    "Enable the '--jsx' flag in your configuration file": {
+        "category": "Message",
+        "code": 95088
+    },
 
     "No value exists in scope for the shorthand property '{0}'. Either declare one or provide an initializer.": {
         "category": "Error",

src/compiler/scanner.ts

@@ -1484,7 +1484,7 @@ namespace ts {
 
         function scan(): SyntaxKind {
             startPos = pos;
-            tokenFlags = 0;
+            tokenFlags = TokenFlags.None;
             let asteriskSeen = false;
             while (true) {
                 tokenPos = pos;
@@ -2116,7 +2116,7 @@ namespace ts {
 
         function scanJsDocToken(): JSDocSyntaxKind {
             startPos = tokenPos = pos;
-            tokenFlags = 0;
+            tokenFlags = TokenFlags.None;
             if (pos >= end) {
                 return token = SyntaxKind.EndOfFileToken;
             }
@@ -2277,7 +2277,7 @@ namespace ts {
             tokenPos = textPos;
             token = SyntaxKind.Unknown;
             tokenValue = undefined!;
-            tokenFlags = 0;
+            tokenFlags = TokenFlags.None;
         }
 
         function setInJSDocType(inType: boolean) {

src/compiler/types.ts

@@ -4524,8 +4524,10 @@ namespace ts {
         LiteralKeyof                 = 1 << 5,  // Inference made from a string literal to a keyof T
         NoConstraints                = 1 << 6,  // Don't infer from constraints of instantiable types
         AlwaysStrict                 = 1 << 7,  // Always use strict rules for contravariant inferences
+        MaxValue                     = 1 << 8,  // Seed for inference priority tracking
 
         PriorityImpliesCombination = ReturnType | MappedTypeConstraint | LiteralKeyof,  // These priorities imply that the resulting type should be a combination of all candidates
+        Circularity = -1,  // Inference circularity (value less than all other priorities)
     }
 
     /* @internal */

src/compiler/utilities.ts

@@ -2345,7 +2345,7 @@ namespace ts {
     export function getTypeParameterFromJsDoc(node: TypeParameterDeclaration & { parent: JSDocTemplateTag }): TypeParameterDeclaration | undefined {
         const name = node.name.escapedText;
         const { typeParameters } = (node.parent.parent.parent as SignatureDeclaration | InterfaceDeclaration | ClassDeclaration);
-        return find(typeParameters!, p => p.name.escapedText === name);
+        return typeParameters && find(typeParameters, p => p.name.escapedText === name);
     }
 
     export function hasRestParameter(s: SignatureDeclaration | JSDocSignature): boolean {