Merge branch 'master' into exportDefault

Conflicts:
	tests/baselines/reference/exportAssignDottedName.errors.txt

Author: ahejlsberg

CONTRIBUTING.md

@@ -9,7 +9,7 @@ Design changes will not be accepted at this time. If you have a design change pr
 ## Legal
 You will need to complete a Contributor License Agreement (CLA). Briefly, this agreement testifies that you are granting us permission to use the submitted change according to the terms of the project's license, and that the work being submitted is under appropriate copyright.
 
-Please submit a Contributor License Agreement (CLA) before submitting a pull request. Download the agreement ([Microsoft Contribution License Agreement.docx](https://www.codeplex.com/Download?ProjectName=typescript&DownloadId=822190) or [Microsoft Contribution License Agreement.pdf](https://www.codeplex.com/Download?ProjectName=typescript&DownloadId=921298)), sign, scan, and email it back to <[email protected]>. Be sure to include your github user name along with the agreement. Once we have received the signed CLA, we'll review the request. Please note that we're currently only accepting pull requests of bug fixes rather than new features.
+Please submit a Contributor License Agreement (CLA) before submitting a pull request. You may visit https://cla.microsoft.com to sign digitally. Alternatively, download the agreement ([Microsoft Contribution License Agreement.docx](https://www.codeplex.com/Download?ProjectName=typescript&DownloadId=822190) or [Microsoft Contribution License Agreement.pdf](https://www.codeplex.com/Download?ProjectName=typescript&DownloadId=921298)), sign, scan, and email it back to <[email protected]>. Be sure to include your github user name along with the agreement. Once we have received the signed CLA, we'll review the request. Please note that we're currently only accepting pull requests of bug fixes rather than new features.
 
 ## Housekeeping
 Your pull request should: 

scripts/VSDevMode.ps1

@@ -2,7 +2,7 @@
 .SYNOPSIS
 Run this PowerShell script to enable dev mode and/or a custom script for the TypeScript language service, e.g.
 
-PS C:\> .\scripts\VSDevMode.ps1 -enableDevMode -tsScript C:\src\TypeScript\built\local\typescriptServices.js
+PS C:\> .\scripts\VSDevMode.ps1 -enableDevMode -tsScript C:\src\TypeScript\built\local\
 
 Note: If you get security errors, try running powershell as an Administrator and with the "-executionPolicy remoteSigned" switch
 
@@ -13,7 +13,7 @@ Set to "12" for Dev12 (VS2013) or "14" (the default) for Dev14 (VS2015)
 Pass this switch to enable attaching a debugger to the language service
 
 .PARAMETER tsScript
-The path to a custom language service script to use, e.g. "C:\src\TypeScript\built\local\typescriptServices.js"
+The path to a directory containing a custom language service script to use (typescriptServices.js), e.g. "C:\src\TypeScript\built\local\"
 #>
 Param(
     [int]$vsVersion = 14,

src/compiler/checker.ts

@@ -8560,7 +8560,7 @@ module ts {
                             // since LHS will be block scoped name instead of function scoped
                             if (!namesShareScope) {
                                 var name = symbolToString(localDeclarationSymbol);
-                                error(getErrorSpanForNode(node), Diagnostics.Cannot_initialize_outer_scoped_variable_0_in_the_same_scope_as_block_scoped_declaration_1, name, name);
+                                error(node, Diagnostics.Cannot_initialize_outer_scoped_variable_0_in_the_same_scope_as_block_scoped_declaration_1, name, name);
                             }
                         }
                     }
@@ -9113,6 +9113,15 @@ module ts {
                         grammarErrorOnFirstToken(catchClause.variableDeclaration.initializer, Diagnostics.Catch_clause_variable_cannot_have_an_initializer);
                     }
                     else {
+                        var identifierName = (<Identifier>catchClause.variableDeclaration.name).text;
+                        var locals = catchClause.block.locals;
+                        if (locals && hasProperty(locals, identifierName)) {
+                            var localSymbol = locals[identifierName]
+                            if (localSymbol && (localSymbol.flags & SymbolFlags.BlockScopedVariable) !== 0) {
+                                grammarErrorOnNode(localSymbol.valueDeclaration, Diagnostics.Cannot_redeclare_identifier_0_in_catch_clause, identifierName);
+                            }
+                        }
+
                         // It is a SyntaxError if a TryStatement with a Catch occurs within strict code and the Identifier of the
                         // Catch production is eval or arguments
                         checkGrammarEvalOrArgumentsInStrictMode(node, <Identifier>catchClause.variableDeclaration.name);
@@ -11828,19 +11837,11 @@ module ts {
             return sourceFile.parseDiagnostics.length > 0;
         }
 
-        function scanToken(scanner: Scanner, pos: number) {
-            scanner.setTextPos(pos);
-            scanner.scan();
-            var start = scanner.getTokenPos();
-            return start;
-        }
-
         function grammarErrorOnFirstToken(node: Node, message: DiagnosticMessage, arg0?: any, arg1?: any, arg2?: any): boolean {
             var sourceFile = getSourceFileOfNode(node);
             if (!hasParseDiagnostics(sourceFile)) {
-                var scanner = createScanner(languageVersion, /*skipTrivia*/ true, sourceFile.text);
-                var start = scanToken(scanner, node.pos);
-                diagnostics.add(createFileDiagnostic(sourceFile, start, scanner.getTextPos() - start, message, arg0, arg1, arg2));
+                var span = getSpanOfTokenAtPosition(sourceFile, node.pos);
+                diagnostics.add(createFileDiagnostic(sourceFile, span.start, span.length, message, arg0, arg1, arg2));
                 return true;
             }
         }
@@ -11855,9 +11856,7 @@ module ts {
         function grammarErrorOnNode(node: Node, message: DiagnosticMessage, arg0?: any, arg1?: any, arg2?: any): boolean {
             var sourceFile = getSourceFileOfNode(node);
             if (!hasParseDiagnostics(sourceFile)) {
-                var span = getErrorSpanForNode(node);
-                var start = span.end > span.pos ? skipTrivia(sourceFile.text, span.pos) : span.pos;
-                diagnostics.add(createFileDiagnostic(sourceFile, start, span.end - start, message, arg0, arg1, arg2));
+                diagnostics.add(createDiagnosticForNode(node, message, arg0, arg1, arg2));
                 return true;
             }
         }
@@ -11994,9 +11993,8 @@ module ts {
         function grammarErrorAfterFirstToken(node: Node, message: DiagnosticMessage, arg0?: any, arg1?: any, arg2?: any): boolean {
             var sourceFile = getSourceFileOfNode(node);
             if (!hasParseDiagnostics(sourceFile)) {
-                var scanner = createScanner(languageVersion, /*skipTrivia*/ true, sourceFile.text);
-                scanToken(scanner, node.pos);
-                diagnostics.add(createFileDiagnostic(sourceFile, scanner.getTextPos(), 0, message, arg0, arg1, arg2));
+                var span = getSpanOfTokenAtPosition(sourceFile, node.pos);
+                diagnostics.add(createFileDiagnostic(sourceFile, textSpanEnd(span), /*length*/ 0, message, arg0, arg1, arg2));
                 return true;
             }
         }

src/compiler/core.ts

@@ -430,7 +430,11 @@ module ts {
                     normalized.pop();
                 }
                 else {
-                    normalized.push(part);
+                    // A part may be an empty string (which is 'falsy') if the path had consecutive slashes,
+                    // e.g. "path//file.ts".  Drop these before re-joining the parts.
+                    if(part) {
+                        normalized.push(part);
+                    }
                 }
             }
         }

src/compiler/diagnosticInformationMap.generated.ts

@@ -337,6 +337,7 @@ module ts {
         The_iterator_returned_by_the_right_hand_side_of_a_for_of_statement_must_have_a_next_method: { code: 2489, category: DiagnosticCategory.Error, key: "The iterator returned by the right-hand side of a 'for...of' statement must have a 'next()' method." },
         The_type_returned_by_the_next_method_of_an_iterator_must_have_a_value_property: { code: 2490, category: DiagnosticCategory.Error, key: "The type returned by the 'next()' method of an iterator must have a 'value' property." },
         The_left_hand_side_of_a_for_in_statement_cannot_be_a_destructuring_pattern: { code: 2491, category: DiagnosticCategory.Error, key: "The left-hand side of a 'for...in' statement cannot be a destructuring pattern." },
+        Cannot_redeclare_identifier_0_in_catch_clause: { code: 2492, category: DiagnosticCategory.Error, key: "Cannot redeclare identifier '{0}' in catch clause" },
         Import_declaration_0_is_using_private_name_1: { code: 4000, category: DiagnosticCategory.Error, key: "Import declaration '{0}' is using private name '{1}'." },
         Type_parameter_0_of_exported_class_has_or_is_using_private_name_1: { code: 4002, category: DiagnosticCategory.Error, key: "Type parameter '{0}' of exported class has or is using private name '{1}'." },
         Type_parameter_0_of_exported_interface_has_or_is_using_private_name_1: { code: 4004, category: DiagnosticCategory.Error, key: "Type parameter '{0}' of exported interface has or is using private name '{1}'." },

src/compiler/diagnosticMessages.json

@@ -1339,6 +1339,10 @@
         "category": "Error",
         "code": 2491
     },
+    "Cannot redeclare identifier '{0}' in catch clause": {
+        "category": "Error",
+        "code": 2492
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",

src/compiler/program.ts

@@ -423,21 +423,19 @@ module ts {
                 return;
             }
 
-            var firstExternalModule = forEach(files, f => isExternalModule(f) ? f : undefined);
-            if (firstExternalModule && !options.module) {
-                // We cannot use createDiagnosticFromNode because nodes do not have parents yet
-                var externalModuleErrorSpan = getErrorSpanForNode(firstExternalModule.externalModuleIndicator);
-                var errorStart = skipTrivia(firstExternalModule.text, externalModuleErrorSpan.pos);
-                var errorLength = externalModuleErrorSpan.end - errorStart;
-                diagnostics.add(createFileDiagnostic(firstExternalModule, errorStart, errorLength, Diagnostics.Cannot_compile_external_modules_unless_the_module_flag_is_provided));
+            var firstExternalModuleSourceFile = forEach(files, f => isExternalModule(f) ? f : undefined);
+            if (firstExternalModuleSourceFile && !options.module) {
+                // We cannot use createDiagnosticFromNode because nodes do not have parents yet       
+                var span = getErrorSpanForNode(firstExternalModuleSourceFile, firstExternalModuleSourceFile.externalModuleIndicator);
+                diagnostics.add(createFileDiagnostic(firstExternalModuleSourceFile, span.start, span.length, Diagnostics.Cannot_compile_external_modules_unless_the_module_flag_is_provided));
             }
 
             // there has to be common source directory if user specified --outdir || --sourcRoot
             // if user specified --mapRoot, there needs to be common source directory if there would be multiple files being emitted
             if (options.outDir || // there is --outDir specified
                 options.sourceRoot || // there is --sourceRoot specified
                 (options.mapRoot &&  // there is --mapRoot Specified and there would be multiple js files generated
-                    (!options.out || firstExternalModule !== undefined))) {
+                    (!options.out || firstExternalModuleSourceFile !== undefined))) {
 
                 var commonPathComponents: string[];
                 forEach(files, sourceFile => {

src/compiler/tsc.ts

@@ -250,7 +250,7 @@ module ts {
 
             var compileResult = compile(rootFileNames, compilerOptions, compilerHost);
 
-            if (!commandLine.options.watch) {
+            if (!compilerOptions.watch) {
                 return sys.exit(compileResult.exitStatus);
             }
 
@@ -269,7 +269,7 @@ module ts {
             }
             // Use default host function
             var sourceFile = hostGetSourceFile(fileName, languageVersion, onError);
-            if (sourceFile && commandLine.options.watch) {
+            if (sourceFile && compilerOptions.watch) {
                 // Attach a file watcher
                 sourceFile.fileWatcher = sys.watchFile(sourceFile.fileName, () => sourceFileChanged(sourceFile));
             }

src/compiler/utilities.ts

@@ -218,32 +218,35 @@ module ts {
     }
 
     export function createDiagnosticForNode(node: Node, message: DiagnosticMessage, arg0?: any, arg1?: any, arg2?: any): Diagnostic {
-        node = getErrorSpanForNode(node);
-        var file = getSourceFileOfNode(node);
-
-        var start = getTokenPosOfNode(node, file);
-        var length = node.end - start;
-
-        return createFileDiagnostic(file, start, length, message, arg0, arg1, arg2);
+        var sourceFile = getSourceFileOfNode(node);
+        var span = getErrorSpanForNode(sourceFile, node);
+        return createFileDiagnostic(sourceFile, span.start, span.length, message, arg0, arg1, arg2);
     }
 
     export function createDiagnosticForNodeFromMessageChain(node: Node, messageChain: DiagnosticMessageChain): Diagnostic {
-        node = getErrorSpanForNode(node);
-        var file = getSourceFileOfNode(node);
-        var start = skipTrivia(file.text, node.pos);
-        var length = node.end - start;
+        var sourceFile = getSourceFileOfNode(node);
+        var span = getErrorSpanForNode(sourceFile, node);
         return {
-            file,
-            start,
-            length,
+            file: sourceFile,
+            start: span.start,
+            length: span.length,
             code: messageChain.code,
             category: messageChain.category,
             messageText: messageChain.next ? messageChain : messageChain.messageText
         };
     }
 
-    export function getErrorSpanForNode(node: Node): Node {
-        var errorSpan: Node;
+    /* @internal */
+    export function getSpanOfTokenAtPosition(sourceFile: SourceFile, pos: number): TextSpan {
+        var scanner = createScanner(sourceFile.languageVersion, /*skipTrivia*/ true, sourceFile.text);
+        scanner.setTextPos(pos);
+        scanner.scan();
+        var start = scanner.getTokenPos();
+        return createTextSpanFromBounds(start, scanner.getTextPos());
+    }
+
+    export function getErrorSpanForNode(sourceFile: SourceFile, node: Node): TextSpan {
+        var errorNode = node;
         switch (node.kind) {
             // This list is a work in progress. Add missing node kinds to improve their error
             // spans.
@@ -254,16 +257,23 @@ module ts {
             case SyntaxKind.ModuleDeclaration:
             case SyntaxKind.EnumDeclaration:
             case SyntaxKind.EnumMember:
-                errorSpan = (<Declaration>node).name;
+            case SyntaxKind.FunctionDeclaration:
+            case SyntaxKind.FunctionExpression:
+                errorNode = (<Declaration>node).name;
                 break;
         }
+        
+        if (errorNode === undefined) {
+            // If we don't have a better node, then just set the error on the first token of 
+            // construct.
+            return getSpanOfTokenAtPosition(sourceFile, node.pos);
+        }
+
+        var pos = nodeIsMissing(errorNode)
+            ? errorNode.pos
+            : skipTrivia(sourceFile.text, errorNode.pos);
 
-        // We now have the ideal error span, but it may be a node that is optional and absent
-        // (e.g. the name of a function expression), in which case errorSpan will be undefined.
-        // Alternatively, it might be required and missing (e.g. the name of a module), in which
-        // case its pos will equal its end (length 0). In either of these cases, we should fall
-        // back to the original node that the error was issued on.
-        return errorSpan && errorSpan.pos < errorSpan.end ? errorSpan : node;
+        return createTextSpanFromBounds(pos, errorNode.end);
     }
 
     export function isExternalModule(file: SourceFile): boolean {

src/services/signatureHelp.ts

@@ -264,12 +264,16 @@ module ts.SignatureHelp {
                     // the comma. That amounts to taking the ceiling of half the index.
                     var argumentIndex = (listItemInfo.listItemIndex + 1) >> 1;
 
+                    var argumentCount = getCommaBasedArgCount(list);
+
+                    Debug.assert(argumentIndex === 0 || argumentIndex < argumentCount, `argumentCount < argumentIndex, ${argumentCount} < ${argumentIndex}`); 
+
                     return {
                         kind: isTypeArgList ? ArgumentListKind.TypeArguments : ArgumentListKind.CallArguments,
                         invocation: callExpression,
                         argumentsSpan: getApplicableSpanForArguments(list),
                         argumentIndex: argumentIndex,
-                        argumentCount: getCommaBasedArgCount(list)
+                        argumentCount: argumentCount
                     };
                 }
             }
@@ -347,6 +351,8 @@ module ts.SignatureHelp {
                 ? 1
                 : (<TemplateExpression>tagExpression.template).templateSpans.length + 1;
 
+            Debug.assert(argumentIndex === 0 || argumentIndex < argumentCount, `argumentCount < argumentIndex, ${argumentCount} < ${argumentIndex}`); 
+
             return {
                 kind: ArgumentListKind.TaggedTemplateArguments,
                 invocation: tagExpression,
@@ -512,6 +518,8 @@ module ts.SignatureHelp {
                 selectedItemIndex = selectBestInvalidOverloadIndex(candidates, argumentCount);
             }
 
+            Debug.assert(argumentIndex === 0 || argumentIndex < argumentCount, `argumentCount < argumentIndex, ${argumentCount} < ${argumentIndex}`); 
+
             return {
                 items,
                 applicableSpan,