Add support to report errors in js files

Jakefile.js

@@ -942,7 +942,7 @@ task("generate-code-coverage", ["tests", builtLocalDirectory], function () {
 // Browser tests
 var nodeServerOutFile = "tests/webTestServer.js";
 var nodeServerInFile = "tests/webTestServer.ts";
-compileFile(nodeServerOutFile, [nodeServerInFile], [builtLocalDirectory, tscFile], [], /*useBuiltCompiler:*/ true, { noOutFile: true });
+compileFile(nodeServerOutFile, [nodeServerInFile], [builtLocalDirectory, tscFile], [], /*useBuiltCompiler:*/ true, { noOutFile: true, lib: "es6" });
 
 desc("Runs browserify on run.js to produce a file suitable for running tests in the browser");
 task("browserify", ["tests", builtLocalDirectory, nodeServerOutFile], function() {

src/compiler/commandLineParser.ts

@@ -481,6 +481,12 @@ namespace ts {
                 name: "plugin",
                 type: "object"
             }
+        },
+        {
+            name: "checkJs",
+            type: "boolean",
+            experimental: true,
+            description: Diagnostics.Report_errors_in_js_files
         }
     ];
 

src/compiler/diagnosticMessages.json

@@ -1,4 +1,4 @@
-{
+{
     "Unterminated string literal.": {
         "category": "Error",
         "code": 1002
@@ -3355,12 +3355,34 @@
         "category": "Message",
         "code": 90017
     },
+    "Disable checking for this file.": {
+        "category": "Message",
+        "code": 90018
+    },
+    "Suppress this error message.": {
+        "category": "Message",
+        "code": 90019
+    },
+    "Initialize property '{0}' in the constructor.": {
+        "category": "Message",
+        "code": 90020
+    },
+    "Initialize static property '{0}'.": {
+        "category": "Message",
+        "code": 90021
+    },
+
+
     "Octal literal types must use ES2015 syntax. Use the syntax '{0}'.": {
         "category": "Error",
         "code": 8017
     },
     "Octal literals are not allowed in enums members initializer. Use the syntax '{0}'.": {
         "category": "Error",
         "code": 8018
+    },
+    "Report errors in .js files.": {
+        "category": "Message",
+        "code": 8019
     }
 }

src/compiler/parser.ts

@@ -5817,6 +5817,7 @@ namespace ts {
             const typeReferenceDirectives: FileReference[] = [];
             const amdDependencies: { path: string; name: string }[] = [];
             let amdModuleName: string;
+            let checkJsDirective: CheckJsDirective = undefined;
 
             // Keep scanning all the leading trivia in the file until we get to something that
             // isn't trivia.  Any single line comment will be analyzed to see if it is a
@@ -5878,13 +5879,24 @@ namespace ts {
                             amdDependencies.push(amdDependency);
                         }
                     }
+
+                    const checkJsDirectiveRegEx = /^\/\/\/?\s*(@ts-check|@ts-nocheck)\s*$/gim;
+                    const checkJsDirectiveMatchResult = checkJsDirectiveRegEx.exec(comment);
+                    if (checkJsDirectiveMatchResult) {
+                        checkJsDirective = {
+                            enabled: compareStrings(checkJsDirectiveMatchResult[1], "@ts-check", /*ignoreCase*/ true) === Comparison.EqualTo,
+                            end: range.end,
+                            pos: range.pos
+                        };
+                    }
                 }
             }
 
             sourceFile.referencedFiles = referencedFiles;
             sourceFile.typeReferenceDirectives = typeReferenceDirectives;
             sourceFile.amdDependencies = amdDependencies;
             sourceFile.moduleName = amdModuleName;
+            sourceFile.checkJsDirective = checkJsDirective;
         }
 
         function setExternalModuleIndicator(sourceFile: SourceFile) {

src/compiler/program.ts

@@ -4,6 +4,7 @@
 
 namespace ts {
     const emptyArray: any[] = [];
+    const suppressDiagnosticCommentRegEx = /(^\s*$)|(^\s*\/\/\/?\s*(@ts-suppress)?)/;
 
     export function findConfigFile(searchPath: string, fileExists: (fileName: string) => boolean, configName = "tsconfig.json"): string {
         while (true) {
@@ -916,17 +917,43 @@ namespace ts {
 
                 Debug.assert(!!sourceFile.bindDiagnostics);
                 const bindDiagnostics = sourceFile.bindDiagnostics;
-                // For JavaScript files, we don't want to report semantic errors.
-                // Instead, we'll report errors for using TypeScript-only constructs from within a
-                // JavaScript file when we get syntactic diagnostics for the file.
-                const checkDiagnostics = isSourceFileJavaScript(sourceFile) ? [] : typeChecker.getDiagnostics(sourceFile, cancellationToken);
+                // For JavaScript files, we don't want to report semantic errors unless explicitly requested.
+                const includeCheckDiagnostics = !isSourceFileJavaScript(sourceFile) ||
+                    (sourceFile.checkJsDirective ? sourceFile.checkJsDirective.enabled : options.checkJs);
+                const checkDiagnostics = includeCheckDiagnostics ? typeChecker.getDiagnostics(sourceFile, cancellationToken) : [];
                 const fileProcessingDiagnosticsInFile = fileProcessingDiagnostics.getDiagnostics(sourceFile.fileName);
                 const programDiagnosticsInFile = programDiagnostics.getDiagnostics(sourceFile.fileName);
 
-                return bindDiagnostics.concat(checkDiagnostics, fileProcessingDiagnosticsInFile, programDiagnosticsInFile);
+                const diagnostics = bindDiagnostics.concat(checkDiagnostics, fileProcessingDiagnosticsInFile, programDiagnosticsInFile);
+                return isSourceFileJavaScript(sourceFile)
+                    ? filter(diagnostics, shouldReportDiagnostic)
+                    : diagnostics;
             });
         }
 
+        /**
+         * Skip errors if previous line start with '// @ts-suppress' comment, not counting non-empty non-comment lines
+         */
+        function shouldReportDiagnostic(diagnostic: Diagnostic) {
+            const { file, start } = diagnostic;
+            const lineStarts = getLineStarts(file);
+            let { line } = computeLineAndCharacterOfPosition(lineStarts, start);
+            while (line > 0) {
+                const previousLineText = file.text.slice(lineStarts[line - 1], lineStarts[line]);
+                const result = suppressDiagnosticCommentRegEx.exec(previousLineText);
+                if (!result) {
+                    // non-empty line
+                    return true;
+                }
+                if (result[3]) {
+                    // @ts-suppress
+                    return false;
+                }
+                line--;
+            }
+            return true;
+        }
+
         function getJavaScriptSyntacticDiagnosticsForFile(sourceFile: SourceFile): Diagnostic[] {
             return runWithCancellationToken(() => {
                 const diagnostics: Diagnostic[] = [];
@@ -1727,6 +1754,10 @@ namespace ts {
                 programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_with_option_1, "allowJs", "declaration"));
             }
 
+            if (options.checkJs && !options.allowJs) {
+                programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_without_specifying_option_1, "checkJs", "allowJs"));
+            }
+
             if (options.emitDecoratorMetadata &&
                 !options.experimentalDecorators) {
                 programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_0_cannot_be_specified_without_specifying_option_1, "emitDecoratorMetadata", "experimentalDecorators"));

src/compiler/types.ts

@@ -1940,6 +1940,10 @@ namespace ts {
         fileName: string;
     }
 
+    export interface CheckJsDirective extends TextRange {
+        enabled: boolean;
+    }
+
     export type CommentKind = SyntaxKind.SingleLineCommentTrivia | SyntaxKind.MultiLineCommentTrivia;
 
     export interface CommentRange extends TextRange {
@@ -2282,6 +2286,7 @@ namespace ts {
         /* @internal */ moduleAugmentations: LiteralExpression[];
         /* @internal */ patternAmbientModules?: PatternAmbientModule[];
         /* @internal */ ambientModuleNames: string[];
+        /* @internal */ checkJsDirective: CheckJsDirective | undefined;
     }
 
     export interface Bundle extends Node {
@@ -3323,6 +3328,7 @@ namespace ts {
         alwaysStrict?: boolean;  // Always combine with strict property
         baseUrl?: string;
         charset?: string;
+        checkJs?: boolean;
         /* @internal */ configFilePath?: string;
         declaration?: boolean;
         declarationDir?: string;

src/harness/fourslash.ts

@@ -1,4 +1,4 @@
-//
+//
 // Copyright (c) Microsoft Corporation.  All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
@@ -2554,6 +2554,11 @@ namespace FourSlash {
             }
         }
 
+        public printAvailableCodeFixes() {
+            const codeFixes = this.getCodeFixActions(this.activeFile.fileName);
+            Harness.IO.log(stringify(codeFixes));
+        }
+
         // Get the text of the entire line the caret is currently at
         private getCurrentLineContent() {
             const text = this.getFileContent(this.activeFile.fileName);
@@ -3742,6 +3747,10 @@ namespace FourSlashInterface {
             this.state.printCompletionListMembers();
         }
 
+        public printAvailableCodeFixes() {
+            this.state.printAvailableCodeFixes();
+        }
+
         public printBreakpointLocation(pos: number) {
             this.state.printBreakpointLocation(pos);
         }

src/harness/harness.ts

@@ -202,7 +202,7 @@ namespace Utils {
             for (const childName in node) {
                 if (childName === "parent" || childName === "nextContainer" || childName === "modifiers" || childName === "externalModuleIndicator" ||
                     // for now ignore jsdoc comments
-                    childName === "jsDocComment") {
+                    childName === "jsDocComment" || childName === "checkJsDirective") {
                     continue;
                 }
                 const child = (<any>node)[childName];

src/harness/tsconfig.json

@@ -1,4 +1,4 @@
-{
+{
     "extends": "../tsconfig-base",
     "compilerOptions": {
         "removeComments": false,
@@ -81,6 +81,7 @@
         "../services/codefixes/helpers.ts",
         "../services/codefixes/importFixes.ts",
         "../services/codefixes/unusedIdentifierFixes.ts",
+        "../services/codefixes/disableJsDiagnostics.ts",
 
         "harness.ts",
         "sourceMapRecorder.ts",

src/services/codefixes/disableJsDiagnostics.ts

@@ -0,0 +1,74 @@
+/* @internal */
+namespace ts.codefix {
+    registerCodeFix({
+        errorCodes: getApplicableDiagnosticCodes(),
+        getCodeActions: getDisableJsDiagnosticsCodeActions
+    });
+
+    function getApplicableDiagnosticCodes(): number[] {
+        const allDiagnostcs = <MapLike<DiagnosticMessage>>Diagnostics;
+        return Object.keys(allDiagnostcs)
+            .filter(d => allDiagnostcs[d] && allDiagnostcs[d].category === DiagnosticCategory.Error)
+            .map(d => allDiagnostcs[d].code);
+    }
+
+    function shouldCheckJsFile(sourceFile: SourceFile, compilerOptions: CompilerOptions) {
+        return sourceFile.checkJsDirective ? sourceFile.checkJsDirective.enabled : compilerOptions.checkJs;
+    }
+
+    function getSuppressCommentLocationForLocation(sourceFile: SourceFile, position: number, newLineCharacter: string) {
+        let { line } = getLineAndCharacterOfPosition(sourceFile, position);
+        const lineStartPosition = getStartPositionOfLine(line, sourceFile);
+        const startPosition = getFirstNonSpaceCharacterPosition(sourceFile.text, lineStartPosition);
+
+        // First try to see if we can put the '// @ts-suppress' on the previous line.
+        // We need to make sure that we are not in the middle of a string literal or a comment.
+        // We also want to check if the previous line holds a comment for a node on the next line
+        // if so, we do not want to separate the node from its comment if we can.
+        if (!isInComment(sourceFile, startPosition) && !isInString(sourceFile, startPosition) && !isInTemplateString(sourceFile, startPosition)) {
+            const token = getTouchingToken(sourceFile, startPosition);
+            const tokenLeadingCommnets = getLeadingCommentRangesOfNode(token, sourceFile);
+            if (!tokenLeadingCommnets || !tokenLeadingCommnets.length || tokenLeadingCommnets[0].pos >= startPosition) {
+                return {
+                    span: { start: startPosition, length: 0 },
+                    newText: `// @ts-suppress${newLineCharacter}`
+                };
+            }
+        }
+
+        // If all fails, add an extra new line immediatlly before the error span.
+        return {
+            span: { start: position, length: 0 },
+            newText: `${position === startPosition ? "" : newLineCharacter}// @ts-suppress${newLineCharacter}`
+        };
+    }
+
+    function getDisableJsDiagnosticsCodeActions(context: CodeFixContext): CodeAction[] | undefined {
+        const { sourceFile, program, newLineCharacter, span } = context;
+
+        if (!isInJavaScriptFile(sourceFile) || !shouldCheckJsFile(sourceFile, program.getCompilerOptions())) {
+            return undefined;
+        }
+
+        return [{
+            description: getLocaleSpecificMessage(Diagnostics.Suppress_this_error_message),
+            changes: [{
+                fileName: sourceFile.fileName,
+                textChanges: [getSuppressCommentLocationForLocation(sourceFile, span.start, newLineCharacter)]
+            }]
+        },
+        {
+            description: getLocaleSpecificMessage(Diagnostics.Disable_checking_for_this_file),
+            changes: [{
+                fileName: sourceFile.fileName,
+                textChanges: [{
+                    span: {
+                        start: sourceFile.checkJsDirective ? sourceFile.checkJsDirective.pos : 0,
+                        length: sourceFile.checkJsDirective ? sourceFile.checkJsDirective.end - sourceFile.checkJsDirective.pos : 0
+                    },
+                    newText: `// @ts-nocheck${newLineCharacter}`
+                }]
+            }]
+        }];
+    }
+}