Indent disable rule according to current line's indentation

Fixes #73

Author: mjbvz

e2e/tests/codeFixes.test.js

@@ -9,11 +9,11 @@ const { openMockFile, getFirstResponseOfType } = require('./helpers');
 const mockFileName = path.join(__dirname, '..', 'project-fixture', 'main.ts').replace(/\\/g, '/');
 
 /**
- * @param {string} fileContents 
+ * @param {string[]} fileContents 
  */
-function createServerForFile(fileContents) {
+function createServerForFile(...fileContents) {
     const server = createServer();
-    openMockFile(server, mockFileName, fileContents);
+    openMockFile(server, mockFileName, fileContents.join('\n'));
     return server;
 }
 
@@ -394,4 +394,29 @@ describe('CodeFixes', () => {
         assert.deepEqual(codeFixesResponse.body[0].fixName, 'spelling');
         assert.deepEqual(codeFixesResponse.body[1].fixName, 'tslint:disable:no-unused-expression');
     });
+
+    it('disable comment should be correctly indented', async () => {
+        server = createServerForFile(
+            '{',
+            '    const a = 1',
+            '}'
+        );
+        await getCodeFixes(server, {
+            startLine: 2,
+            startOffset: 16,
+            endLine: 2,
+            endOffset: 16,
+            additionalErrorCodes: [2552]
+        });
+        await server.close();
+        const codeFixesResponse = await getFirstResponseOfType('getCodeFixes', server);
+
+        assert.isTrue(codeFixesResponse.success);
+        assert.deepEqual(codeFixesResponse.body.length, 3);
+        const disableFix = codeFixesResponse.body[2];
+        const change = disableFix.changes[0].textChanges[0];
+        assert.strictEqual(change.start.line, 2);
+        assert.strictEqual(change.start.offset, 1);
+        assert.strictEqual(change.newText, '    // tslint:disable-next-line: semicolon\n');
+    });
 });

src/index.ts

@@ -24,7 +24,7 @@ export = function init({ typescript }: { typescript: typeof ts_module }) {
                 return info.languageService;
             }
 
-            return new TSLintPlugin(typescript, logger, info.project, configManager)
+            return new TSLintPlugin(typescript, info.languageServiceHost, logger, info.project, configManager)
                 .decorate(info.languageService);
         },
         onConfigurationChanged(config: any) {

src/plugin.ts

@@ -56,6 +56,7 @@ export class TSLintPlugin {
 
     public constructor(
         private readonly ts: typeof ts_module,
+        private readonly languageServiceHost: ts_module.LanguageServiceHost,
         private readonly logger: Logger,
         private readonly project: ts_module.server.Project,
         private readonly configurationManager: ConfigurationManager,
@@ -320,14 +321,28 @@ export class TSLintPlugin {
     }
 
     private getDisableRuleQuickFix(failure: tslint.RuleFailure, fileName: string, file: ts_module.SourceFile): ts_module.CodeFixAction {
+        const line = failure.getStartPosition().getLineAndCharacter().line;
+        const lineStarts = file.getLineStarts();
+        const lineStart = lineStarts[line];
+        let prefix = '';
+        const snapshot = this.languageServiceHost.getScriptSnapshot(fileName);
+        if (snapshot) {
+            const lineEnd = line < lineStarts.length - 1 ? lineStarts[line + 1] : file.end;
+            const lineText = snapshot.getText(lineStart, lineEnd);
+            const leadingSpace = lineText.match(/^([ \t]+)/);
+            if (leadingSpace) {
+                prefix = leadingSpace[0];
+            }
+        }
+
         return {
             description: `Disable rule '${failure.getRuleName()}'`,
             fixName: `tslint:disable:${failure.getRuleName()}`,
             changes: [{
                 fileName,
                 textChanges: [{
-                    newText: `// tslint:disable-next-line: ${failure.getRuleName()}\n`,
-                    span: { start: file.getLineStarts()[failure.getStartPosition().getLineAndCharacter().line], length: 0 },
+                    newText: `${prefix}// tslint:disable-next-line: ${failure.getRuleName()}\n`,
+                    span: { start: lineStart, length: 0 },
                 }],
             }],
         };