Merge pull request #10185 from Microsoft/pvb/codeaction/api

The API to support codefixes

src/compiler/diagnosticMessages.json

@@ -3073,7 +3073,6 @@
         "category": "Error",
         "code": 17010
     },
-
     "Circularity detected while resolving configuration: {0}": {
         "category": "Error",
         "code": 18000
@@ -3081,5 +3080,33 @@
     "The path in an 'extends' options must be relative or rooted.": {
         "category": "Error",
         "code": 18001
+    },
+    "Add missing 'super()' call.": {
+        "category": "Message",
+        "code": 90001
+    },
+    "Make 'super()' call the first statement in the constructor.": {
+        "category": "Message",
+        "code": 90002
+    },
+    "Change 'extends' to 'implements'": {
+        "category": "Message",
+        "code": 90003
+    },
+    "Remove unused identifiers": {
+        "category": "Message",
+        "code": 90004
+    },
+    "Implement interface on reference": {
+        "category": "Message",
+        "code": 90005
+    },
+    "Implement interface on class": {
+        "category": "Message",
+        "code": 90006
+    },
+    "Implement inherited abstract class": {
+        "category": "Message",
+        "code": 90007
     }
 }

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");
@@ -427,7 +427,7 @@ namespace FourSlash {
 
             if (exists !== negative) {
                 this.printErrorLog(negative, this.getAllDiagnostics());
-                throw new Error("Failure between markers: " + startMarkerName + ", " + endMarkerName);
+                throw new Error(`Failure between markers: '${startMarkerName}', '${endMarkerName}'`);
             }
         }
 
@@ -742,7 +742,6 @@ namespace FourSlash {
             }
         }
 
-
         public verifyCompletionListAllowsNewIdentifier(negative: boolean) {
             const completions = this.getCompletionListAtCaret();
 
@@ -1611,7 +1610,7 @@ namespace FourSlash {
             if (isFormattingEdit) {
                 const newContent = this.getFileContent(fileName);
 
-                if (newContent.replace(/\s/g, "") !== oldContent.replace(/\s/g, "")) {
+                if (this.removeWhitespace(newContent) !== this.removeWhitespace(oldContent)) {
                     this.raiseError("Formatting operation destroyed non-whitespace content");
                 }
             }
@@ -1677,6 +1676,10 @@ namespace FourSlash {
             }
         }
 
+        private removeWhitespace(text: string): string {
+            return text.replace(/\s/g, "");
+        }
+
         public goToBOF() {
             this.goToPosition(0);
         }
@@ -2038,6 +2041,47 @@ namespace FourSlash {
             }
         }
 
+        private getCodeFixes(errorCode?: number) {
+            const fileName = this.activeFile.fileName;
+            const diagnostics = this.getDiagnostics(fileName);
+
+            if (diagnostics.length === 0) {
+                this.raiseError("Errors expected.");
+            }
+
+            if (diagnostics.length > 1 && errorCode !== undefined) {
+                this.raiseError("When there's more than one error, you must specify the errror to fix.");
+            }
+
+            const diagnostic = !errorCode ? diagnostics[0] : ts.find(diagnostics, d => d.code == errorCode);
+
+            return this.languageService.getCodeFixesAtPosition(fileName, diagnostic.start, diagnostic.length, [diagnostic.code]);
+        }
+
+        public verifyCodeFixAtPosition(expectedText: string, errorCode?: number) {
+            const ranges = this.getRanges();
+            if (ranges.length == 0) {
+                this.raiseError("At least one range should be specified in the testfile.");
+            }
+
+            const actual = this.getCodeFixes(errorCode);
+
+            if (!actual || actual.length == 0) {
+                this.raiseError("No codefixes returned.");
+            }
+
+            if (actual.length > 1) {
+                this.raiseError("More than 1 codefix returned.");
+            }
+
+            this.applyEdits(actual[0].changes[0].fileName, actual[0].changes[0].textChanges, /*isFormattingEdit*/ false);
+            const actualText = this.rangeText(ranges[0]);
+
+            if (this.removeWhitespace(actualText) !== this.removeWhitespace(expectedText)) {
+                this.raiseError(`Actual text doesn't match expected text. Actual: '${actualText}' Expected: '${expectedText}'`);
+            }
+        }
+
         public verifyDocCommentTemplate(expected?: ts.TextInsertion) {
             const name = "verifyDocCommentTemplate";
             const actual = this.languageService.getDocCommentTemplateAtPosition(this.activeFile.fileName, this.currentCaretPosition);
@@ -2309,6 +2353,18 @@ namespace FourSlash {
             }
         }
 
+        public verifyCodeFixAvailable(negative: boolean, errorCode?: number) {
+            const fixes = this.getCodeFixes(errorCode);
+
+            if (negative && fixes && fixes.length > 0) {
+                this.raiseError(`verifyCodeFixAvailable failed - expected no fixes, actual: ${fixes.length}`);
+            }
+
+            if (!negative && (fixes === undefined || fixes.length === 0)) {
+                this.raiseError(`verifyCodeFixAvailable failed - expected code fixes, actual: 0`);
+            }
+        }
+
         // Get the text of the entire line the caret is currently at
         private getCurrentLineContent() {
             const text = this.getFileContent(this.activeFile.fileName);
@@ -3096,6 +3152,10 @@ namespace FourSlashInterface {
         public isValidBraceCompletionAtPosition(openingBrace: string) {
             this.state.verifyBraceCompletionAtPosition(this.negative, openingBrace);
         }
+
+        public codeFixAvailable(errorCode?: number) {
+            this.state.verifyCodeFixAvailable(this.negative, errorCode);
+        }
     }
 
     export class Verify extends VerifyNegatable {
@@ -3275,6 +3335,10 @@ namespace FourSlashInterface {
             this.DocCommentTemplate(/*expectedText*/ undefined, /*expectedOffset*/ undefined, /*empty*/ true);
         }
 
+        public codeFixAtPosition(expectedText: string, errorCode?: number): void {
+            this.state.verifyCodeFixAtPosition(expectedText, errorCode);
+        }
+
         public navigationBar(json: any) {
             this.state.verifyNavigationBar(json);
         }

src/harness/harnessLanguageService.ts

@@ -486,6 +486,9 @@ namespace Harness.LanguageService {
         isValidBraceCompletionAtPosition(fileName: string, position: number, openingBrace: number): boolean {
             return unwrapJSONCallResult(this.shim.isValidBraceCompletionAtPosition(fileName, position, openingBrace));
         }
+        getCodeFixesAtPosition(fileName: string, start: number, end: number, errorCodes: number[]): ts.CodeAction[] {
+            throw new Error("Not supported on the shim.");
+        }
         getEmitOutput(fileName: string): ts.EmitOutput {
             return unwrapJSONCallResult(this.shim.getEmitOutput(fileName));
         }

src/server/client.ts

@@ -425,11 +425,35 @@ namespace ts.server {
         }
 
         getSyntacticDiagnostics(fileName: string): Diagnostic[] {
-            throw new Error("Not Implemented Yet.");
+            const args: protocol.SyntacticDiagnosticsSyncRequestArgs = { file: fileName };
+
+            const request = this.processRequest<protocol.SyntacticDiagnosticsSyncRequest>(CommandNames.SyntacticDiagnosticsSync, args);
+            const response = this.processResponse<protocol.SyntacticDiagnosticsSyncResponse>(request);
+
+            return (<protocol.Diagnostic[]>response.body).map(entry => this.convertDiagnostic(entry, fileName));
         }
 
         getSemanticDiagnostics(fileName: string): Diagnostic[] {
-            throw new Error("Not Implemented Yet.");
+            const args: protocol.SemanticDiagnosticsSyncRequestArgs = { file: fileName };
+
+            const request = this.processRequest<protocol.SemanticDiagnosticsSyncRequest>(CommandNames.SemanticDiagnosticsSync, args);
+            const response = this.processResponse<protocol.SemanticDiagnosticsSyncResponse>(request);
+
+            return (<protocol.Diagnostic[]>response.body).map(entry => this.convertDiagnostic(entry, fileName));
+        }
+
+        convertDiagnostic(entry: protocol.Diagnostic, fileName: string): Diagnostic {
+            const start = this.lineOffsetToPosition(fileName, entry.start);
+            const end = this.lineOffsetToPosition(fileName, entry.end);
+
+            return {
+                file: undefined,
+                start: start,
+                length: end - start,
+                messageText: entry.text,
+                category: undefined,
+                code: entry.code
+            };
         }
 
         getCompilerOptionsDiagnostics(): Diagnostic[] {
@@ -630,6 +654,48 @@ namespace ts.server {
             throw new Error("Not Implemented Yet.");
         }
 
+        getCodeFixesAtPosition(fileName: string, start: number, end: number, errorCodes: number[]): CodeAction[] {
+            const startLineOffset = this.positionToOneBasedLineOffset(fileName, start);
+            const endLineOffset = this.positionToOneBasedLineOffset(fileName, end);
+
+            const args: protocol.CodeFixRequestArgs = {
+                file: fileName,
+                startLine: startLineOffset.line,
+                startOffset: startLineOffset.offset,
+                endLine: endLineOffset.line,
+                endOffset: endLineOffset.offset,
+                errorCodes: errorCodes,
+            };
+
+            const request = this.processRequest<protocol.CodeFixRequest>(CommandNames.GetCodeFixes, args);
+            const response = this.processResponse<protocol.CodeFixResponse>(request);
+
+            return response.body.map(entry => this.convertCodeActions(entry, fileName));
+        }
+
+        convertCodeActions(entry: protocol.CodeAction, fileName: string): CodeAction {
+            return {
+                description: entry.description,
+                changes: entry.changes.map(change => ({
+                    fileName: change.fileName,
+                    textChanges: change.textChanges.map(textChange => this.convertTextChangeToCodeEdit(textChange, fileName))
+                }))
+            };
+        }
+
+        convertTextChangeToCodeEdit(change: protocol.CodeEdit, fileName: string): ts.TextChange {
+            const start = this.lineOffsetToPosition(fileName, change.start);
+            const end = this.lineOffsetToPosition(fileName, change.end);
+
+            return {
+                span: {
+                    start: start,
+                    length: end - start
+                },
+                newText: change.newText ? change.newText : ""
+            };
+        }
+
         getBraceMatchingAtPosition(fileName: string, position: number): TextSpan[] {
             const lineOffset = this.positionToOneBasedLineOffset(fileName, position);
             const args: protocol.FileLocationRequestArgs = {

src/server/protocol.d.ts

@@ -1,4 +1,4 @@
-/**
+/**
   * Declaration module describing the TypeScript Server protocol
   */
 declare namespace ts.server.protocol {
@@ -236,6 +236,53 @@ declare namespace ts.server.protocol {
         position?: number;
     }
 
+    /**
+      * Request for the available codefixes at a specific position.
+      */
+    export interface CodeFixRequest extends Request {
+        arguments: CodeFixRequestArgs;
+    }
+
+    /**
+      * Instances of this interface specify errorcodes on a specific location in a sourcefile.
+      */
+    export interface CodeFixRequestArgs extends FileRequestArgs {
+        /**
+          * The line number for the request (1-based).
+          */
+        startLine?: number;
+
+        /**
+          * The character offset (on the line) for the request (1-based).
+          */
+        startOffset?: number;
+
+        /**
+         * Position (can be specified instead of line/offset pair) 
+         */
+        startPosition?: number;
+
+        /**
+          * The line number for the request (1-based).
+          */
+        endLine?: number;
+
+        /**
+          * The character offset (on the line) for the request (1-based).
+          */
+        endOffset?: number;
+
+        /**
+         * Position (can be specified instead of line/offset pair) 
+         */
+        endPosition?: number;
+
+        /**
+          * Errorcodes we want to get the fixes for.
+          */
+        errorCodes?: number[];
+    }
+
     /**
       * A request whose arguments specify a file location (file, line, col).
       */
@@ -1133,6 +1180,23 @@ declare namespace ts.server.protocol {
         newText: string;
     }
 
+    export interface FileCodeEdits {
+        fileName: string;
+        textChanges: CodeEdit[];
+    }
+
+    export interface CodeFixResponse extends Response {
+        /** The code actions that are available */
+        body?: CodeAction[];
+    }
+
+    export interface CodeAction {
+        /** Description of the code action to display in the UI of the editor */
+        description: string;
+        /** Text changes to apply to each file as part of the code action */
+        changes: FileCodeEdits[];
+    }
+
     /**
       * Format and format on key response message.
       */
@@ -1507,6 +1571,11 @@ declare namespace ts.server.protocol {
           * Text of diagnostic message.
           */
         text: string;
+
+        /**
+          * The error code of the diagnostic message.
+          */
+        code?: number;
     }
 
     export interface DiagnosticEventBody {

src/server/session.ts

@@ -1,4 +1,4 @@
-/// <reference path="..\compiler\commandLineParser.ts" />
+/// <reference path="..\compiler\commandLineParser.ts" />
 /// <reference path="..\services\services.ts" />
 /// <reference path="protocol.d.ts" />
 /// <reference path="editorServices.ts" />
@@ -55,7 +55,8 @@ namespace ts.server {
         return {
             start: scriptInfo.positionToLineOffset(diag.start),
             end: scriptInfo.positionToLineOffset(diag.start + diag.length),
-            text: ts.flattenDiagnosticMessageText(diag.messageText, "\n")
+            text: ts.flattenDiagnosticMessageText(diag.messageText, "\n"),
+            code: diag.code
         };
     }
 
@@ -145,6 +146,9 @@ namespace ts.server {
         export const NameOrDottedNameSpan = "nameOrDottedNameSpan";
         export const BreakpointStatement = "breakpointStatement";
         export const CompilerOptionsForInferredProjects = "compilerOptionsForInferredProjects";
+        export const GetCodeFixes = "getCodeFixes";
+        export const GetCodeFixesFull = "getCodeFixes-full";
+        export const GetSupportedCodeFixes = "getSupportedCodeFixes";
     }
 
     export function formatMessage<T extends protocol.Message>(msg: T, logger: server.Logger, byteLength: (s: string, encoding: string) => number, newLine: string): string {
@@ -772,7 +776,7 @@ namespace ts.server {
             return this.getFileAndProjectWorker(args.file, args.projectFileName, /*refreshInferredProjects*/ false, errorOnMissingProject);
         }
 
-        private getFileAndProjectWorker(uncheckedFileName: string, projectFileName: string, refreshInferredProjects: boolean,  errorOnMissingProject: boolean) {
+        private getFileAndProjectWorker(uncheckedFileName: string, projectFileName: string, refreshInferredProjects: boolean, errorOnMissingProject: boolean) {
             const file = toNormalizedPath(uncheckedFileName);
             const project: Project = this.getProject(projectFileName) || this.projectService.getDefaultProjectForFile(file, refreshInferredProjects);
             if (!project && errorOnMissingProject) {
@@ -863,13 +867,7 @@ namespace ts.server {
                 return undefined;
             }
 
-            return edits.map((edit) => {
-                return {
-                    start: scriptInfo.positionToLineOffset(edit.span.start),
-                    end: scriptInfo.positionToLineOffset(ts.textSpanEnd(edit.span)),
-                    newText: edit.newText ? edit.newText : ""
-                };
-            });
+            return edits.map(edit => this.convertTextChangeToCodeEdit(edit, scriptInfo));
         }
 
         private getFormattingEditsForRangeFull(args: protocol.FormatRequestArgs) {
@@ -1220,6 +1218,55 @@ namespace ts.server {
             }
         }
 
+        private getSupportedCodeFixes(): string[] {
+            return ts.getSupportedCodeFixes();
+        }
+
+        private getCodeFixes(args: protocol.CodeFixRequestArgs, simplifiedResult: boolean): protocol.CodeAction[] | CodeAction[] {
+            const { file, project } = this.getFileAndProjectWithoutRefreshingInferredProjects(args);
+
+            const scriptInfo = project.getScriptInfoForNormalizedPath(file);
+            const startPosition = getStartPosition();
+            const endPosition = getEndPosition();
+
+            const codeActions = project.getLanguageService().getCodeFixesAtPosition(file, startPosition, endPosition, args.errorCodes);
+            if (!codeActions) {
+                return undefined;
+            }
+            if (simplifiedResult) {
+                return codeActions.map(codeAction => this.mapCodeAction(codeAction, scriptInfo));
+            }
+            else {
+                return codeActions;
+            }
+
+            function getStartPosition() {
+                return args.startPosition !== undefined ? args.startPosition : scriptInfo.lineOffsetToPosition(args.startLine, args.startOffset);
+            }
+
+            function getEndPosition() {
+                return args.endPosition !== undefined ? args.endPosition : scriptInfo.lineOffsetToPosition(args.endLine, args.endOffset);
+            }
+        }
+
+        private mapCodeAction(codeAction: CodeAction, scriptInfo: ScriptInfo): protocol.CodeAction {
+            return {
+                description: codeAction.description,
+                changes: codeAction.changes.map(change => ({
+                    fileName: change.fileName,
+                    textChanges: change.textChanges.map(textChange => this.convertTextChangeToCodeEdit(textChange, scriptInfo))
+                }))
+            };
+        }
+
+        private convertTextChangeToCodeEdit(change: ts.TextChange, scriptInfo: ScriptInfo): protocol.CodeEdit {
+            return {
+                start: scriptInfo.positionToLineOffset(change.span.start),
+                end: scriptInfo.positionToLineOffset(change.span.start + change.span.length),
+                newText: change.newText ? change.newText : ""
+            };
+        }
+
         private getBraceMatching(args: protocol.FileLocationRequestArgs, simplifiedResult: boolean): protocol.TextSpan[] | TextSpan[] {
             const { file, project } = this.getFileAndProjectWithoutRefreshingInferredProjects(args);
 
@@ -1542,6 +1589,15 @@ namespace ts.server {
             [CommandNames.ReloadProjects]: (request: protocol.ReloadProjectsRequest) => {
                 this.projectService.reloadProjects();
                 return this.notRequired();
+            },
+            [CommandNames.GetCodeFixes]: (request: protocol.CodeFixRequest) => {
+                return this.requiredResponse(this.getCodeFixes(request.arguments, /*simplifiedResult*/ true));
+            },
+            [CommandNames.GetCodeFixesFull]: (request: protocol.CodeFixRequest) => {
+                return this.requiredResponse(this.getCodeFixes(request.arguments, /*simplifiedResult*/ false));
+            },
+            [CommandNames.GetSupportedCodeFixes]: (request: protocol.Request) => {
+                return this.requiredResponse(this.getSupportedCodeFixes());
             }
         });
 

src/server/utilities.ts

@@ -201,7 +201,8 @@ namespace ts.server {
         dispose: (): any => throwLanguageServiceIsDisabledError(),
         getCompletionEntrySymbol: (): any => throwLanguageServiceIsDisabledError(),
         getImplementationAtPosition: (): any => throwLanguageServiceIsDisabledError(),
-        getSourceFile: (): any => throwLanguageServiceIsDisabledError()
+        getSourceFile: (): any => throwLanguageServiceIsDisabledError(),
+        getCodeFixesAtPosition: (): any => throwLanguageServiceIsDisabledError()
     };
 
     export interface ServerLanguageServiceHost {

src/services/codefixes/codeFixProvider.ts

@@ -0,0 +1,48 @@
+/* @internal */
+namespace ts {
+    export interface CodeFix {
+        errorCodes: number[];
+        getCodeActions(context: CodeFixContext): CodeAction[] | undefined;
+    }
+
+    export interface CodeFixContext {
+        errorCode: number;
+        sourceFile: SourceFile;
+        span: TextSpan;
+        program: Program;
+        newLineCharacter: string;
+    }
+
+    export namespace codefix {
+        const codeFixes = createMap<CodeFix[]>();
+
+        export function registerCodeFix(action: CodeFix) {
+            forEach(action.errorCodes, error => {
+                let fixes = codeFixes[error];
+                if (!fixes) {
+                    fixes = [];
+                    codeFixes[error] = fixes;
+                }
+                fixes.push(action);
+            });
+        }
+
+        export function getSupportedErrorCodes() {
+            return Object.keys(codeFixes);
+        }
+
+        export function getFixes(context: CodeFixContext): CodeAction[] {
+            const fixes = codeFixes[context.errorCode];
+            let allActions: CodeAction[] = [];
+
+            forEach(fixes, f => {
+                const actions = f.getCodeActions(context);
+                if (actions && actions.length > 0) {
+                    allActions = allActions.concat(actions);
+                }
+            });
+
+            return allActions;
+        }
+    }
+}

src/services/codefixes/fixes.ts

@@ -0,0 +1 @@
+///<reference path='superFixes.ts' />

src/services/codefixes/superFixes.ts

@@ -0,0 +1,81 @@
+/* @internal */
+namespace ts.codefix {
+    function getOpenBraceEnd(constructor: ConstructorDeclaration, sourceFile: SourceFile) {
+        // First token is the open curly, this is where we want to put the 'super' call.
+        return constructor.body.getFirstToken(sourceFile).getEnd();
+    }
+
+    registerCodeFix({
+        errorCodes: [Diagnostics.Constructors_for_derived_classes_must_contain_a_super_call.code],
+        getCodeActions: (context: CodeFixContext) => {
+            const sourceFile = context.sourceFile;
+            const token = getTokenAtPosition(sourceFile, context.span.start);
+
+            if (token.kind !== SyntaxKind.ConstructorKeyword) {
+                return undefined;
+            }
+
+            const newPosition = getOpenBraceEnd(<ConstructorDeclaration>token.parent, sourceFile);
+            return [{
+                description: getLocaleSpecificMessage(Diagnostics.Add_missing_super_call),
+                changes: [{ fileName: sourceFile.fileName, textChanges: [{ newText: "super();", span: { start: newPosition, length: 0 } }] }]
+            }];
+        }
+    });
+
+    registerCodeFix({
+        errorCodes: [Diagnostics.super_must_be_called_before_accessing_this_in_the_constructor_of_a_derived_class.code],
+        getCodeActions: (context: CodeFixContext) => {
+            const sourceFile = context.sourceFile;
+
+            const token = getTokenAtPosition(sourceFile, context.span.start);
+            if (token.kind !== SyntaxKind.ThisKeyword) {
+                return undefined;
+            }
+
+            const constructor = getContainingFunction(token);
+            const superCall = findSuperCall((<ConstructorDeclaration>constructor).body);
+            if (!superCall) {
+                return undefined;
+            }
+
+            // figure out if the this access is actuall inside the supercall
+            // i.e. super(this.a), since in that case we won't suggest a fix
+            if (superCall.expression && superCall.expression.kind == SyntaxKind.CallExpression) {
+                const arguments = (<CallExpression>superCall.expression).arguments;
+                for (let i = 0; i < arguments.length; i++) {
+                    if ((<PropertyAccessExpression>arguments[i]).expression === token) {
+                        return undefined;
+                    }
+                }
+            }
+
+            const newPosition = getOpenBraceEnd(<ConstructorDeclaration>constructor, sourceFile);
+            const changes = [{
+                fileName: sourceFile.fileName, textChanges: [{
+                    newText: superCall.getText(sourceFile),
+                    span: { start: newPosition, length: 0 }
+                },
+                {
+                    newText: "",
+                    span: { start: superCall.getStart(sourceFile), length: superCall.getWidth(sourceFile) }
+                }]
+            }];
+
+            return [{
+                description: getLocaleSpecificMessage(Diagnostics.Make_super_call_the_first_statement_in_the_constructor),
+                changes
+            }];
+
+            function findSuperCall(n: Node): ExpressionStatement {
+                if (n.kind === SyntaxKind.ExpressionStatement && isSuperCall((<ExpressionStatement>n).expression)) {
+                    return <ExpressionStatement>n;
+                }
+                if (isFunctionLike(n)) {
+                    return undefined;
+                }
+                return forEachChild(n, findSuperCall);
+            }
+        }
+    });
+}

src/services/services.ts

@@ -24,6 +24,8 @@
 /// <reference path='transpile.ts' />
 /// <reference path='formatting\formatting.ts' />
 /// <reference path='formatting\smartIndenter.ts' />
+/// <reference path='codefixes\codeFixProvider.ts' />
+/// <reference path='codefixes\fixes.ts' />
 
 namespace ts {
     /** The version of the language service API */
@@ -664,6 +666,7 @@ namespace ts {
         return {
             getNodeConstructor: () => NodeObject,
             getTokenConstructor: () => TokenObject,
+
             getIdentifierConstructor: () => IdentifierObject,
             getSourceFileConstructor: () => SourceFileObject,
             getSymbolConstructor: () => SymbolObject,
@@ -730,9 +733,13 @@ namespace ts {
         };
     }
 
-    // Cache host information about script should be refreshed
+    export function getSupportedCodeFixes() {
+        return codefix.getSupportedErrorCodes();
+    }
+
+    // Cache host information about script Should be refreshed
     // at each language service public entry point, since we don't know when
-    // set of scripts handled by the host changes.
+    // the set of scripts handled by the host changes.
     class HostCache {
         private fileNameToEntry: FileMap<HostFileInformation>;
         private _compilationSettings: CompilerOptions;
@@ -1654,6 +1661,34 @@ namespace ts {
             return [];
         }
 
+        function getCodeFixesAtPosition(fileName: string, start: number, end: number, errorCodes: number[]): CodeAction[] {
+            synchronizeHostData();
+            const sourceFile = getValidSourceFile(fileName);
+            const span = { start, length: end - start };
+            const newLineChar = getNewLineOrDefaultFromHost(host);
+
+            let allFixes: CodeAction[] = [];
+
+            forEach(errorCodes, error => {
+                cancellationToken.throwIfCancellationRequested();
+
+                const context = {
+                    errorCode: error,
+                    sourceFile: sourceFile,
+                    span: span,
+                    program: program,
+                    newLineCharacter: newLineChar
+                };
+
+                const fixes = codefix.getFixes(context);
+                if (fixes) {
+                    allFixes = allFixes.concat(fixes);
+                }
+            });
+
+            return allFixes;
+        }
+
         function getDocCommentTemplateAtPosition(fileName: string, position: number): TextInsertion {
             return JsDoc.getDocCommentTemplateAtPosition(getNewLineOrDefaultFromHost(host), syntaxTreeCache.getCurrentSourceFile(fileName), position);
         }
@@ -1877,6 +1912,7 @@ namespace ts {
             getFormattingEditsAfterKeystroke,
             getDocCommentTemplateAtPosition,
             isValidBraceCompletionAtPosition,
+            getCodeFixesAtPosition,
             getEmitOutput,
             getNonBoundSourceFile,
             getSourceFile,

src/services/tsconfig.json

@@ -78,6 +78,8 @@
         "formatting/rulesMap.ts",
         "formatting/rulesProvider.ts",
         "formatting/smartIndenter.ts",
-        "formatting/tokenRange.ts"
+        "formatting/tokenRange.ts",
+        "codeFixes/codeFixProvider.ts",
+        "codeFixes/fixes.ts"
     ]
 }

src/services/types.ts

@@ -239,6 +239,8 @@ namespace ts {
 
         isValidBraceCompletionAtPosition(fileName: string, position: number, openingBrace: number): boolean;
 
+        getCodeFixesAtPosition(fileName: string, start: number, end: number, errorCodes: number[]): CodeAction[];
+
         getEmitOutput(fileName: string, emitOnlyDtsFiles?: boolean): EmitOutput;
 
         getProgram(): Program;
@@ -291,6 +293,18 @@ namespace ts {
         newText: string;
     }
 
+    export interface FileTextChanges {
+        fileName: string;
+        textChanges: TextChange[];
+    }
+
+    export interface CodeAction {
+        /** Description of the code action to display in the UI of the editor */
+        description: string;
+        /** Text changes to apply to each file as part of the code action */
+        changes: FileTextChanges[];
+    }
+
     export interface TextInsertion {
         newText: string;
         /** The position in newText the caret should point to after the insertion. */

tests/cases/fourslash/fourslash.ts

@@ -136,6 +136,7 @@ declare namespace FourSlashInterface {
         typeDefinitionCountIs(expectedCount: number): void;
         implementationListIsEmpty(): void;
         isValidBraceCompletionAtPosition(openingBrace?: string): void;
+        codeFixAvailable(): void;
     }
     class verify extends verifyNegatable {
         assertHasRanges(ranges: Range[]): void;
@@ -208,6 +209,7 @@ declare namespace FourSlashInterface {
         noMatchingBracePositionInCurrentFile(bracePosition: number): void;
         DocCommentTemplate(expectedText: string, expectedOffset: number, empty?: boolean): void;
         noDocCommentTemplate(): void;
+        codeFixAtPosition(expectedText: string, errorCode?: number): void;
 
         navigationBar(json: any): void;
         navigationItemsListCount(count: number, searchValue: string, matchKind?: string, fileName?: string): void;

tests/cases/fourslash/server/codefix.ts

@@ -0,0 +1,10 @@
+/// <reference path='fourslash.ts' />
+
+////class Base{
+////}
+////class C extends Base{
+////    constructor() {[| |]
+////    }
+////}
+
+verify.codeFixAtPosition('super();');

tests/cases/fourslash/superFix1.ts

@@ -0,0 +1,10 @@
+/// <reference path='fourslash.ts' />
+
+////class Base{
+////}
+////class C extends Base{
+////    constructor() {[| |]
+////    }
+////}
+
+verify.codeFixAtPosition('super();');

tests/cases/fourslash/superFix2.ts

@@ -0,0 +1,13 @@
+/// <reference path='fourslash.ts' />
+
+////class Base{
+////}
+////class C extends Base{
+////    private a:number;
+////    constructor() {[|
+////        this.a = 12;
+////        super();|]
+////    }
+////}
+
+verify.codeFixAtPosition("super(); this.a = 12;");

tests/cases/fourslash/superFix3.ts

@@ -0,0 +1,12 @@
+/// <reference path='fourslash.ts' />
+
+////class Base{
+////    constructor(id: number) { }
+////}
+////class C extends Base{
+////    constructor(private a:number) {
+////        super(this.a);
+////    }
+////}
+
+verify.not.codeFixAvailable();