[Feature][#67] Adds tslint autofix as a flag to ForkTsCheckerWebpackPlugin plugin

.prettierignore

@@ -0,0 +1 @@
+./test/integration/project/lintingError.ts

README.md

@@ -66,6 +66,9 @@ Allows overriding TypeScript options. Should be specified in the same format as
 * **tslint** `string | true`: 
 Path to *tslint.json* file or `true`. If `true`, uses `path.resolve(compiler.options.context, './tslint.json')`. Default: `undefined`.
 
+* **tslintAutoFix** `boolean`:
+Passes on `--fix` flag while running `tslint` to auto fix linting errors.
+
 * **watch** `string | string[]`: 
 Directories or files to watch by service. Not necessary but improves performance (reduces number of `fs.stat` calls).
 

src/IncrementalChecker.ts

@@ -24,6 +24,7 @@ export class IncrementalChecker {
   programConfigFile: string;
   compilerOptions: object;
   linterConfigFile: string | false;
+  linterAutoFix: boolean;
   watchPaths: string[];
   workNumber: number;
   workDivision: number;
@@ -44,6 +45,7 @@ export class IncrementalChecker {
     programConfigFile: string,
     compilerOptions: object,
     linterConfigFile: string | false,
+    linterAutoFix: boolean,
     watchPaths: string[],
     workNumber: number,
     workDivision: number,
@@ -53,6 +55,7 @@ export class IncrementalChecker {
     this.programConfigFile = programConfigFile;
     this.compilerOptions = compilerOptions;
     this.linterConfigFile = linterConfigFile;
+    this.linterAutoFix = linterAutoFix;
     this.watchPaths = watchPaths;
     this.workNumber = workNumber || 0;
     this.workDivision = workDivision || 1;
@@ -134,10 +137,10 @@ export class IncrementalChecker {
     );
   }
 
-  static createLinter(program: ts.Program) {
+  createLinter(program: ts.Program) {
     const tslint = require('tslint');
 
-    return new tslint.Linter({ fix: false }, program);
+    return new tslint.Linter({ fix: this.linterAutoFix }, program);
   }
 
   static isFileExcluded(
@@ -189,7 +192,7 @@ export class IncrementalChecker {
     this.program = this.vue ? this.loadVueProgram() : this.loadDefaultProgram();
 
     if (this.linterConfig) {
-      this.linter = IncrementalChecker.createLinter(this.program);
+      this.linter = this.createLinter(this.program);
     }
   }
 

src/index.ts

@@ -41,6 +41,7 @@ interface Options {
   tsconfig: string;
   compilerOptions: object;
   tslint: string | true;
+  tslintAutoFix: boolean;
   watch: string | string[];
   async: boolean;
   ignoreDiagnostics: number[];
@@ -74,6 +75,7 @@ class ForkTsCheckerWebpackPlugin {
   tsconfig: string;
   compilerOptions: object;
   tslint: string | true;
+  tslintAutoFix: boolean;
   watch: string[];
   ignoreDiagnostics: number[];
   ignoreLints: string[];
@@ -125,6 +127,7 @@ class ForkTsCheckerWebpackPlugin {
         ? './tslint.json'
         : options.tslint
       : undefined;
+    this.tslintAutoFix = options.tslintAutoFix || false;
     this.watch = isString(options.watch)
       ? [options.watch]
       : options.watch || [];
@@ -562,6 +565,7 @@ class ForkTsCheckerWebpackPlugin {
           TSCONFIG: this.tsconfigPath,
           COMPILER_OPTIONS: JSON.stringify(this.compilerOptions),
           TSLINT: this.tslintPath || '',
+          TSLINTAUTOFIX: this.tslintAutoFix,
           WATCH: this.isWatching ? this.watchPaths.join('|') : '',
           WORK_DIVISION: Math.max(1, this.workersNumber),
           MEMORY_LIMIT: this.memoryLimit,

src/service.ts

@@ -8,6 +8,7 @@ const checker = new IncrementalChecker(
   process.env.TSCONFIG,
   JSON.parse(process.env.COMPILER_OPTIONS),
   process.env.TSLINT === '' ? false : process.env.TSLINT,
+  process.env.TSLINTAUTOFIX === 'true',
   process.env.WATCH === '' ? [] : process.env.WATCH.split('|'),
   parseInt(process.env.WORK_NUMBER, 10),
   parseInt(process.env.WORK_DIVISION, 10),

test/integration/index.spec.js

@@ -1,3 +1,4 @@
+var fs = require('fs');
 var describe = require('mocha').describe;
 var it = require('mocha').it;
 var chai = require('chai');
@@ -9,12 +10,31 @@ chai.config.truncateThreshold = 0;
 var expect = chai.expect;
 
 var webpackMajorVersion = require('./webpackVersion')();
+const writeContentsToLintingErrorFile = (fileName, data) => {
+  const promise = new Promise((resolve, reject) => {
+    try {
+      fs.writeFileSync(
+        path.resolve(__dirname, `./project/src/${fileName}.ts`),
+        data,
+        { flag: 'w' }
+      );
+    } catch (e) {
+      return reject(e);
+    }
+    return resolve();
+  });
+  return promise;
+};
 
 describe('[INTEGRATION] index', function() {
   this.timeout(60000);
   var plugin;
 
-  function createCompiler(options, happyPackMode) {
+  function createCompiler(
+    options,
+    happyPackMode,
+    entryPoint = './src/index.ts'
+  ) {
     plugin = new ForkTsCheckerWebpackPlugin(
       Object.assign({}, options, { silent: true })
     );
@@ -26,7 +46,7 @@ describe('[INTEGRATION] index', function() {
     return webpack({
       ...(webpackMajorVersion >= 4 ? { mode: 'development' } : {}),
       context: path.resolve(__dirname, './project'),
-      entry: './src/index.ts',
+      entry: entryPoint,
       output: {
         path: path.resolve(__dirname, '../../tmp')
       },
@@ -92,6 +112,58 @@ describe('[INTEGRATION] index', function() {
     });
   });
 
+  it('should fix linting errors with tslintAutofix flag set to true', function(callback) {
+    const lintErrorFileContents = `function someFunctionName(param1,param2){return param1+param2};
+`;
+    const fileName = 'lintingError1';
+    writeContentsToLintingErrorFile(fileName, lintErrorFileContents).then(
+      () => {
+        var compiler = createCompiler(
+          {
+            tslintAutoFix: true,
+            tslint: true
+          },
+          false,
+          `./src/${fileName}.ts`
+        );
+        compiler.run(function(err, stats) {
+          expect(stats.compilation.warnings.length).to.be.eq(0);
+          fs.unlinkSync(
+            path.resolve(__dirname, `./project/src/${fileName}.ts`)
+          );
+          callback();
+        });
+      },
+      err => {
+        throw err;
+      }
+    );
+  });
+  it('should not fix linting by default', function(callback) {
+    const lintErrorFileContents = `function someFunctionName(param1,param2){return param1+param2};
+`;
+    const fileName = 'lintingError2';
+    writeContentsToLintingErrorFile(fileName, lintErrorFileContents).then(
+      () => {
+        var compiler = createCompiler(
+          { tslint: true },
+          false,
+          `./src/${fileName}.ts`
+        );
+        compiler.run(function(err, stats) {
+          expect(stats.compilation.warnings.length).to.be.eq(6);
+          fs.unlinkSync(
+            path.resolve(__dirname, `./project/src/${fileName}.ts`)
+          );
+          callback();
+        });
+      },
+      err => {
+        throw err;
+      }
+    );
+  });
+
   it('should block emit on build mode', function(callback) {
     var compiler = createCompiler();
 

test/integration/vue.spec.js

@@ -78,6 +78,7 @@ describe('[INTEGRATION] vue', function() {
       plugin.tsconfigPath,
       {},
       plugin.tslintPath || false,
+      plugin.tslintAutoFix || false,
       [compiler.context],
       ForkTsCheckerWebpackPlugin.ONE_CPU,
       1,