Merge branch 'master' of https://github.com/Microsoft/TypeScript into bug/29880

Author: a-tarasyuk

README.md

@@ -1,11 +1,13 @@
-[![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)
 
 # 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)
+
+
 
 [TypeScript](https://www.typescriptlang.org/) is a language for application-scale JavaScript. TypeScript adds optional types to JavaScript that support tools for large-scale JavaScript applications for any browser, for any host, on any OS. TypeScript compiles to readable, standards-based JavaScript. Try it out at the [playground](https://www.typescriptlang.org/play/), and stay up to date via [our blog](https://blogs.msdn.microsoft.com/typescript) and [Twitter account](https://twitter.com/typescript).
 
@@ -28,14 +30,14 @@ npm install -g typescript@next
 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). 
+* 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)).
 
-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]) 
+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])
 with any additional questions or comments.
 
 ## Documentation
@@ -71,17 +73,17 @@ 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 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 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 tslint on the TypeScript source.
-gulp help             # List the above commands. 
+gulp help             # List the above commands.
 ```
 
 

src/compiler/binder.ts

@@ -2515,7 +2515,7 @@ namespace ts {
                     break;
 
                 default:
-                    Debug.fail(Debug.showSyntaxKind(thisContainer));
+                    Debug.failBadSyntaxKind(thisContainer);
             }
         }
 
@@ -2581,7 +2581,7 @@ namespace ts {
             // Fix up parent pointers since we're going to use these nodes before we bind into them
             node.left.parent = node;
             node.right.parent = node;
-            if (isIdentifier(lhs.expression) && container === file && isNameOfExportsOrModuleExportsAliasDeclaration(file, lhs.expression)) {
+            if (isIdentifier(lhs.expression) && container === file && isExportsOrModuleExportsOrAlias(file, lhs.expression)) {
                 // This can be an alias for the 'exports' or 'module.exports' names, e.g.
                 //    var util = module.exports;
                 //    util.property = function ...
@@ -2975,21 +2975,27 @@ namespace ts {
     }
 
     export function isExportsOrModuleExportsOrAlias(sourceFile: SourceFile, node: Expression): boolean {
-        return isExportsIdentifier(node) ||
-            isModuleExportsPropertyAccessExpression(node) ||
-            isIdentifier(node) && isNameOfExportsOrModuleExportsAliasDeclaration(sourceFile, node);
-    }
-
-    function isNameOfExportsOrModuleExportsAliasDeclaration(sourceFile: SourceFile, node: Identifier): boolean {
-        const symbol = lookupSymbolForNameWorker(sourceFile, node.escapedText);
-        return !!symbol && !!symbol.valueDeclaration && isVariableDeclaration(symbol.valueDeclaration) &&
-            !!symbol.valueDeclaration.initializer && isExportsOrModuleExportsOrAliasOrAssignment(sourceFile, symbol.valueDeclaration.initializer);
-    }
-
-    function isExportsOrModuleExportsOrAliasOrAssignment(sourceFile: SourceFile, node: Expression): boolean {
-        return isExportsOrModuleExportsOrAlias(sourceFile, node) ||
-            (isAssignmentExpression(node, /*excludeCompoundAssignment*/ true) && (
-                isExportsOrModuleExportsOrAliasOrAssignment(sourceFile, node.left) || isExportsOrModuleExportsOrAliasOrAssignment(sourceFile, node.right)));
+        let i = 0;
+        const q = [node];
+        while (q.length && i < 100) {
+            i++;
+            node = q.shift()!;
+            if (isExportsIdentifier(node) || isModuleExportsPropertyAccessExpression(node)) {
+                return true;
+            }
+            else if (isIdentifier(node)) {
+                const symbol = lookupSymbolForNameWorker(sourceFile, node.escapedText);
+                if (!!symbol && !!symbol.valueDeclaration && isVariableDeclaration(symbol.valueDeclaration) && !!symbol.valueDeclaration.initializer) {
+                    const init = symbol.valueDeclaration.initializer;
+                    q.push(init);
+                    if (isAssignmentExpression(init, /*excludeCompoundAssignment*/ true)) {
+                        q.push(init.left);
+                        q.push(init.right);
+                    }
+                }
+            }
+        }
+        return false;
     }
 
     function lookupSymbolForNameWorker(container: Node, name: __String): Symbol | undefined {