Merge branch 'release-1.8' into checksuperbeforethislexically

Author: Kanchalai Tanglertsampan

src/compiler/binder.ts

@@ -1384,7 +1384,7 @@ namespace ts {
                 // Export assignment in some sort of block construct
                 bindAnonymousDeclaration(node, SymbolFlags.Alias, getDeclarationName(node));
             }
-            else if (boundExpression.kind === SyntaxKind.Identifier) {
+            else if (boundExpression.kind === SyntaxKind.Identifier && node.kind === SyntaxKind.ExportAssignment) {
                 // An export default clause with an identifier exports all meanings of that identifier
                 declareSymbol(container.symbol.exports, container.symbol, node, SymbolFlags.Alias, SymbolFlags.PropertyExcludes | SymbolFlags.AliasExcludes);
             }
@@ -1435,7 +1435,8 @@ namespace ts {
             // Declare a 'member' in case it turns out the container was an ES5 class
             if (container.kind === SyntaxKind.FunctionExpression || container.kind === SyntaxKind.FunctionDeclaration) {
                 container.symbol.members = container.symbol.members || {};
-                declareSymbol(container.symbol.members, container.symbol, node, SymbolFlags.Property, SymbolFlags.PropertyExcludes);
+                // It's acceptable for multiple 'this' assignments of the same identifier to occur
+                declareSymbol(container.symbol.members, container.symbol, node, SymbolFlags.Property, SymbolFlags.PropertyExcludes & ~SymbolFlags.Property);
             }
         }
 
@@ -1444,8 +1445,16 @@ namespace ts {
 
             // Look up the function in the local scope, since prototype assignments should
             // follow the function declaration
-            const classId = <Identifier>(<PropertyAccessExpression>(<PropertyAccessExpression>node.left).expression).expression;
-            const funcSymbol = container.locals[classId.text];
+            const leftSideOfAssignment = node.left as PropertyAccessExpression;
+            const classPrototype = leftSideOfAssignment.expression as PropertyAccessExpression;
+            const constructorFunction = classPrototype.expression as Identifier;
+
+            // Fix up parent pointers since we're going to use these nodes before we bind into them
+            leftSideOfAssignment.parent = node;
+            constructorFunction.parent = classPrototype;
+            classPrototype.parent = leftSideOfAssignment;
+
+            const funcSymbol = container.locals[constructorFunction.text];
             if (!funcSymbol || !(funcSymbol.flags & SymbolFlags.Function)) {
                 return;
             }
@@ -1456,7 +1465,7 @@ namespace ts {
             }
 
             // Declare the method/property
-            declareSymbol(funcSymbol.members, funcSymbol, <PropertyAccessExpression>node.left, SymbolFlags.Property, SymbolFlags.PropertyExcludes);
+            declareSymbol(funcSymbol.members, funcSymbol, leftSideOfAssignment, SymbolFlags.Property, SymbolFlags.PropertyExcludes);
         }
 
         function bindCallExpression(node: CallExpression) {

src/compiler/checker.ts

@@ -2845,7 +2845,7 @@ namespace ts {
                 }
                 // Handle module.exports = expr
                 if (declaration.kind === SyntaxKind.BinaryExpression) {
-                    return links.type = checkExpression((<BinaryExpression>declaration).right);
+                    return links.type = getUnionType(map(symbol.declarations, (decl: BinaryExpression) => checkExpressionCached(decl.right)));
                 }
                 if (declaration.kind === SyntaxKind.PropertyAccessExpression) {
                     // Declarations only exist for property access expressions for certain
@@ -7242,6 +7242,15 @@ namespace ts {
                     // mark iteration statement as containing block-scoped binding captured in some function
                     getNodeLinks(current).flags |= NodeCheckFlags.LoopWithCapturedBlockScopedBinding;
                 }
+
+                // mark variables that are declared in loop initializer and reassigned inside the body of ForStatement.
+                // if body of ForStatement will be converted to function then we'll need a extra machinery to propagate reassigned values back.
+                if (container.kind === SyntaxKind.ForStatement &&
+                    getAncestor(symbol.valueDeclaration, SyntaxKind.VariableDeclarationList).parent === container &&
+                    isAssignedInBodyOfForStatement(node, <ForStatement>container)) {
+                    getNodeLinks(symbol.valueDeclaration).flags |= NodeCheckFlags.NeedsLoopOutParameter;
+                }
+
                 // set 'declared inside loop' bit on the block-scoped binding
                 getNodeLinks(symbol.valueDeclaration).flags |= NodeCheckFlags.BlockScopedBindingInLoop;
             }
@@ -7251,6 +7260,41 @@ namespace ts {
             }
         }
 
+        function isAssignedInBodyOfForStatement(node: Identifier, container: ForStatement): boolean {
+            let current: Node = node;
+            // skip parenthesized nodes
+            while (current.parent.kind === SyntaxKind.ParenthesizedExpression) {
+                current = current.parent;
+            }
+
+            // check if node is used as LHS in some assignment expression
+            let isAssigned = false;
+            if (current.parent.kind === SyntaxKind.BinaryExpression) {
+                isAssigned = (<BinaryExpression>current.parent).left === current && isAssignmentOperator((<BinaryExpression>current.parent).operatorToken.kind);
+            }
+
+            if ((current.parent.kind === SyntaxKind.PrefixUnaryExpression || current.parent.kind === SyntaxKind.PostfixUnaryExpression)) {
+                const expr = <PrefixUnaryExpression | PostfixUnaryExpression>current.parent;
+                isAssigned = expr.operator === SyntaxKind.PlusPlusToken || expr.operator === SyntaxKind.MinusMinusToken;
+            }
+
+            if (!isAssigned) {
+                return false;
+            }
+
+            // at this point we know that node is the target of assignment
+            // now check that modification happens inside the statement part of the ForStatement
+            while (current !== container) {
+                if (current === container.statement) {
+                    return true;
+                }
+                else {
+                    current = current.parent;
+                }
+            }
+            return false;
+        }
+
         function captureLexicalThis(node: Node, container: Node): void {
             getNodeLinks(node).flags |= NodeCheckFlags.LexicalThis;
             if (container.kind === SyntaxKind.PropertyDeclaration || container.kind === SyntaxKind.Constructor) {
@@ -10412,9 +10456,11 @@ namespace ts {
 
         function getReturnTypeFromJSDocComment(func: SignatureDeclaration | FunctionDeclaration): Type {
             const returnTag = getJSDocReturnTag(func);
-            if (returnTag) {
+            if (returnTag && returnTag.typeExpression) {
                 return getTypeFromTypeNode(returnTag.typeExpression.type);
             }
+
+            return undefined;
         }
 
         function createPromiseType(promisedType: Type): Type {
@@ -10489,7 +10535,8 @@ namespace ts {
                     }
                     else {
                         error(func, Diagnostics.No_best_common_type_exists_among_return_expressions);
-                        return unknownType;
+                        // Defer to unioning the return types so we get a) downstream errors earlier and b) better Salsa experience
+                        return getUnionType(types);
                     }
                 }
 
@@ -15400,6 +15447,20 @@ namespace ts {
                 return getSymbolOfNode(entityName.parent);
             }
 
+            if (isInJavaScriptFile(entityName) && entityName.parent.kind === SyntaxKind.PropertyAccessExpression) {
+                const specialPropertyAssignmentKind = getSpecialPropertyAssignmentKind(entityName.parent.parent);
+                switch (specialPropertyAssignmentKind) {
+                    case SpecialPropertyAssignmentKind.ExportsProperty:
+                    case SpecialPropertyAssignmentKind.PrototypeProperty:
+                        return getSymbolOfNode(entityName.parent);
+                    case SpecialPropertyAssignmentKind.ThisProperty:
+                    case SpecialPropertyAssignmentKind.ModuleExports:
+                        return getSymbolOfNode(entityName.parent.parent);
+                    default:
+                        // Fall through if it is not a special property assignment
+                }
+            }
+
             if (entityName.parent.kind === SyntaxKind.ExportAssignment) {
                 return resolveEntityName(<Identifier>entityName,
                     /*all meanings*/ SymbolFlags.Value | SymbolFlags.Type | SymbolFlags.Namespace | SymbolFlags.Alias);

src/compiler/commandLineParser.ts

@@ -294,6 +294,11 @@ namespace ts {
             name: "allowJs",
             type: "boolean",
             description: Diagnostics.Allow_javascript_files_to_be_compiled
+        },
+        {
+            name: "noImplicitUseStrict",
+            type: "boolean",
+            description: Diagnostics.Do_not_emit_use_strict_directives_in_module_output
         }
     ];
 

src/compiler/declarationEmitter.ts

@@ -695,10 +695,6 @@ namespace ts {
         }
 
         function writeImportDeclaration(node: ImportDeclaration) {
-            if (!node.importClause && !(node.flags & NodeFlags.Export)) {
-                // do not write non-exported import declarations that don't have import clauses
-                return;
-            }
             emitJsDocComments(node);
             if (node.flags & NodeFlags.Export) {
                 write("export ");

src/compiler/diagnosticMessages.json

@@ -1,4 +1,4 @@
- {
+{
     "Unterminated string literal.": {
         "category": "Error",
         "code": 1002
@@ -2171,6 +2171,7 @@
         "category": "Error",
         "code": 5059
     },
+
 
     "Concatenate and emit output to single file.": {
         "category": "Message",
@@ -2216,10 +2217,10 @@
         "category": "Message",
         "code": 6011
     },
-  "Specify ECMAScript target version: 'ES3' (default), 'ES5', or 'ES2015' (experimental)": {
-    "category": "Message",
-    "code": 6015
-  },
+    "Specify ECMAScript target version: 'ES3' (default), 'ES5', or 'ES2015' (experimental)": {
+        "category": "Message",
+        "code": 6015
+    },
     "Specify module code generation: 'commonjs', 'amd', 'system', 'umd' or 'es2015'": {
         "category": "Message",
         "code": 6016
@@ -2445,6 +2446,10 @@
         "category": "Message",
         "code": 6084
     },
+    "Do not emit 'use strict' directives in module output.": {
+        "category": "Message",
+        "code": 6112
+    },
 
     "Variable '{0}' implicitly has an '{1}' type.": {
         "category": "Error",
@@ -2632,23 +2637,23 @@
         "code": 17004
     },
     "A constructor cannot contain a 'super' call when its class extends 'null'": {
-      "category": "Error",
-      "code": 17005
+        "category": "Error",
+        "code": 17005
     },
     "An unary expression with the '{0}' operator is not allowed in the left-hand side of an exponentiation expression. Consider enclosing the expression in parentheses.": {
-      "category": "Error",
-      "code": 17006
+        "category": "Error",
+        "code": 17006
     },
     "A type assertion expression is not allowed in the left-hand side of an exponentiation expression. Consider enclosing the expression in parentheses.": {
-      "category": "Error",
-      "code": 17007
+        "category": "Error",
+        "code": 17007
     },
     "JSX element '{0}' has no corresponding closing tag.": {
-      "category": "Error",
-      "code": 17008
+        "category": "Error",
+        "code": 17008
     },
     "'super' must be called before accessing 'this' in the constructor of a derived class.": {
-      "category": "Error",
-      "code": 17009
+        "category": "Error",
+        "code": 17009
     }
-}
+}