fix: respect eslint extensions in incremental check

Author: piotr-oles

.DS_Store

@@ -15,3 +15,6 @@ node_modules
 
 # Editor directories and files
 .idea
+
+# Mac OS
+.DS_Store

.gitignore

@@ -65,6 +65,10 @@ module.exports = {
 If you are using **TypeScript >= 2.8.0**, it's recommended to set `"importsNotUsedAsValues": "preserve"` [compiler option](https://www.typescriptlang.org/docs/handbook/compiler-options.html) 
 in the `tsconfig.json`. [Here is an explanation.](#type-only-modules-watching)
 
+> You can find examples how to configure it with [babel-loader](https://github.com/babel/babel-loader), [ts-loader](https://github.com/TypeStrong/ts-loader),
+> [eslint](https://github.com/eslint/eslint) and [Visual Studio Code](https://code.visualstudio.com/) in the 
+> [**examples**](./examples) directory.
+
 ## Modules resolution
 
 It's very important to be aware that **this plugin uses [TypeScript](https://github.com/Microsoft/TypeScript)'s, not
@@ -97,7 +101,7 @@ module.exports = {
   plugins: [
     new ForkTsCheckerWebpackPlugin({
       eslint: {
-        files: './src/**/*.ts' // required - same as command `eslint ./src/**/*.ts`
+        files: './src/**/*' // required - same as command `eslint ./src/**/* --ext .ts,.tsx,.js,.jsx`
       }
     })
   ]
@@ -108,19 +112,15 @@ You should also have an ESLint configuration file in your root project directory
 Here is a sample `.eslintrc.js` configuration for a TypeScript project:
 
 ```js
-const path = require('path');
-
 module.exports = {
-  parser: '@typescript-eslint/parser', // specifies the ESLint parser
-  extends: [
-    'plugin:@typescript-eslint/recommended' // uses the recommended rules from the @typescript-eslint/eslint-plugin
-  ],
+  parser: '@typescript-eslint/parser',
   parserOptions: {
-    project: path.resolve(__dirname, './tsconfig.json'),
-    tsconfigRootDir: __dirname,
-    ecmaVersion: 2018, // allows for the parsing of modern ECMAScript features
-    sourceType: 'module', // allows for the use of imports
+    ecmaVersion: 2018,
+    sourceType: 'module',
   },
+  extends: [
+    'plugin:@typescript-eslint/recommended'
+  ],
   rules: {
     // place to specify ESLint rules - can be used to overwrite rules specified from the extended configs
     // e.g. "@typescript-eslint/explicit-function-return-type": "off",

README.md

@@ -0,0 +1,8 @@
+module.exports = {
+  parser: '@typescript-eslint/parser',
+  parserOptions: {
+    ecmaVersion: 2018,
+    sourceType: 'module'
+  },
+  extends: ['plugin:@typescript-eslint/recommended']
+};

examples/.DS_Store

@@ -0,0 +1,3 @@
+## eslint configuration example
+
+It's a basic configuration of the plugin and [eslint](https://github.com/eslint/eslint).

examples/eslint/.eslintrc.js

@@ -0,0 +1,22 @@
+{
+  "name": "fork-ts-checker-webpack-plugin-ts-loader-example",
+  "version": "0.0.0",
+  "main": "dist/index.js",
+  "license": "MIT",
+  "scripts": {
+    "dev": "webpack-dev-server",
+    "build": "webpack -p"
+  },
+  "devDependencies": {
+    "@types/eslint": "^6.8.0",
+    "@typescript-eslint/eslint-plugin": "^2.27.0",
+    "@typescript-eslint/parser": "^2.27.0",
+    "eslint": "^6.8.0",
+    "fork-ts-checker-webpack-plugin": "^5.0.0-alpha.9",
+    "ts-loader": "^7.0.0",
+    "typescript": "^3.8.0",
+    "webpack": "^4.0.0",
+    "webpack-cli": "^3.0.0",
+    "webpack-dev-server": "^3.0.0"
+  }
+}

examples/eslint/README.md

@@ -0,0 +1 @@
+console.log('Hello world');

examples/eslint/package.json

@@ -0,0 +1,18 @@
+{
+  "compilerOptions": {
+    "target": "ES5",
+    "module": "CommonJS",
+    "lib": ["ES5", "ScriptHost"],
+    "moduleResolution": "Node",
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "skipDefaultLibCheck": true,
+    "strict": true,
+    "baseUrl": "./src",
+    "outDir": "./dist",
+    "forceConsistentCasingInFileNames": true,
+    "importsNotUsedAsValues": "preserve" // this is important for proper files watching
+  },
+  "include": ["./src"],
+  "exclude": ["node_modules"]
+}

examples/eslint/src/index.ts

@@ -0,0 +1,29 @@
+const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin');
+
+module.exports = {
+  context: __dirname,
+  entry: './src/index.ts',
+  resolve: {
+    extensions: ['.ts', '.tsx', '.js'],
+  },
+  module: {
+    rules: [
+      {
+        test: /\.tsx?$/,
+        loader: 'ts-loader',
+        exclude: /node_modules/,
+        options: {
+          transpileOnly: true,
+        },
+      },
+    ],
+  },
+  plugins: [
+    new ForkTsCheckerWebpackPlugin({
+      eslint: {
+        enabled: true,
+        files: './src/**/*',
+      },
+    }),
+  ],
+};