Add support for eslint-webpack-plugin, close #847

Author: Kocal

index.js

@@ -1279,6 +1279,38 @@ class Encore {
         return this;
     }
 
+    /**
+     * If enabled, the eslint-webpack-plugin is enabled.
+     *
+     * https://github.com/webpack-contrib/eslint-webpack-plugin
+     *
+     * ```
+     * // enables the eslint plugin using the default eslint configuration.
+     * Encore.enableEslintPlugin();
+     *
+     * // You can also pass in an object of options
+     * // that will be passed on to the eslint-webpack-plugin
+     * Encore.enableEslintPlugin({
+     *     emitWarning: false
+     * });
+     *
+     * // For a more advanced usage you can pass in a callback
+     * // https://github.com/webpack-contrib/eslint-webpack-plugin#options
+     * Encore.enableEslintPlugin((options) => {
+     *      options.extensions.push('vue'); // to lint Vue files
+     *      options.emitWarning = false;
+     * });
+     * ```
+     *
+     * @param {string|object|function} eslintPluginOptionsOrCallback
+     * @returns {Encore}
+     */
+    enableEslintPlugin(eslintPluginOptionsOrCallback = () => {}) {
+        webpackConfig.enableEslintPlugin(eslintPluginOptionsOrCallback);
+
+        return this;
+    }
+
     /**
      * If enabled, display build notifications using
      * webpack-notifier.

lib/WebpackConfig.js

@@ -120,6 +120,7 @@ class WebpackConfig {
         this.usePreact = false;
         this.useVueLoader = false;
         this.useEslintLoader = false;
+        this.useEslintPlugin = false;
         this.useTypeScriptLoader = false;
         this.useForkedTypeScriptTypeChecking = false;
         this.useBabelTypeScriptPreset = false;
@@ -171,6 +172,7 @@ class WebpackConfig {
         this.devServerOptionsConfigurationCallback = () => {};
         this.vueLoaderOptionsCallback = () => {};
         this.eslintLoaderOptionsCallback = () => {};
+        this.eslintPluginOptionsCallback = () => {};
         this.tsConfigurationCallback = () => {};
         this.handlebarsConfigurationCallback = () => {};
         this.miniCssExtractLoaderConfigurationCallback = () => {};
@@ -803,6 +805,10 @@ class WebpackConfig {
     }
 
     enableEslintLoader(eslintLoaderOptionsOrCallback = () => {}, eslintOptions = {}) {
+        if (this.useEslintPlugin) {
+            throw new Error('Encore.enableEslintLoader() can not be called when Encore.enableEslintPlugin() has been called.');
+        }
+
         this.useEslintLoader = true;
 
         if (typeof eslintLoaderOptionsOrCallback === 'function') {
@@ -831,6 +837,24 @@ class WebpackConfig {
         this.eslintOptions = eslintOptions;
     }
 
+    enableEslintPlugin(eslintPluginOptionsOrCallback = () => {}) {
+        if (this.useEslintLoader) {
+            throw new Error('Encore.enableEslintPlugin() can not be called when Encore.enableEslintLoader() has been called.');
+        }
+
+        this.useEslintPlugin = true;
+
+        if (typeof eslintPluginOptionsOrCallback === 'function') {
+            this.eslintPluginOptionsCallback = eslintPluginOptionsOrCallback;
+        } else if (typeof eslintPluginOptionsOrCallback === 'object') {
+            this.eslintPluginOptionsCallback = (options) => {
+                Object.assign(options, eslintPluginOptionsOrCallback);
+            };
+        } else {
+            throw new Error('Argument 1 to enableEslintPlugin() must be either an object or callback function.');
+        }
+    }
+
     enableBuildNotifications(enabled = true, notifierPluginOptionsCallback = () => {}) {
         if (typeof notifierPluginOptionsCallback !== 'function') {
             throw new Error('Argument 2 to enableBuildNotifications() must be a callback function.');

lib/config-generator.js

@@ -37,6 +37,7 @@ const vuePluginUtil = require('./plugins/vue');
 const friendlyErrorPluginUtil = require('./plugins/friendly-errors');
 const assetOutputDisplay = require('./plugins/asset-output-display');
 const notifierPluginUtil = require('./plugins/notifier');
+const eslintPluginUtil = require('./plugins/eslint');
 const PluginPriorities = require('./plugins/plugin-priorities');
 const stimulusBridge = require('./plugins/stimulus-bridge');
 const applyOptionsCallback = require('./utils/apply-options-callback');
@@ -457,6 +458,8 @@ class ConfigGenerator {
 
         vuePluginUtil(plugins, this.webpackConfig);
 
+        eslintPluginUtil(plugins, this.webpackConfig);
+
         if (!this.webpackConfig.runtimeConfig.outputJson) {
             const friendlyErrorPlugin = friendlyErrorPluginUtil(this.webpackConfig);
             plugins.push({

lib/features.js

@@ -126,6 +126,15 @@ const features = {
         ],
         description: 'Enable ESLint checks'
     },
+    eslint_plugin: {
+        method: 'enableEslintPlugin()',
+        // eslint is needed so the end-user can do things
+        packages: [
+            { name: 'eslint' },
+            { name: 'eslint-webpack-plugin', enforce_version: true },
+        ],
+        description: 'Enable ESLint checks'
+    },
     copy_files: {
         method: 'copyFiles()',
         packages: [

lib/plugins/eslint.js

@@ -0,0 +1,83 @@
+/*
+* This file is part of the Symfony Webpack Encore package.
+*
+* (c) Fabien Potencier <fabien@symfony.com>
+*
+* For the full copyright and license information, please view the LICENSE
+* file that was distributed with this source code.
+*/
+
+'use strict';
+
+const WebpackConfig = require('../WebpackConfig'); //eslint-disable-line no-unused-vars
+const EslintPlugin = require('eslint-webpack-plugin'); //eslint-disable-line node/no-unpublished-require
+const applyOptionsCallback = require('../utils/apply-options-callback');
+const pluginFeatures = require('../features');
+
+function isMissingConfigError(e) {
+    if (!e.message || !e.message.includes('No ESLint configuration found')) {
+        return false;
+    }
+
+    return true;
+}
+
+/**
+ * Support for ESLint.
+ *
+ * @param {Array} plugins
+ * @param {WebpackConfig} webpackConfig
+ * @return {void}
+ */
+module.exports = function(plugins, webpackConfig) {
+    if (webpackConfig.useEslintPlugin) {
+        pluginFeatures.ensurePackagesExistAndAreCorrectVersion('eslint_plugin');
+
+        const { ESLint } = require('eslint'); // eslint-disable-line node/no-unpublished-require
+        const eslint = new ESLint({
+            cwd: webpackConfig.runtimeConfig.context,
+        });
+
+        try {
+            (async function() {
+                await eslint.calculateConfigForFile('webpack.config.js');
+            })();
+        } catch (e) {
+            if (isMissingConfigError(e)) {
+                const chalk = require('chalk');
+                const packageHelper = require('../package-helper');
+
+                const message = `No ESLint configuration has been found.
+
+${chalk.bgGreen.black('', 'FIX', '')} Run command ${chalk.yellow('./node_modules/.bin/eslint --init')} or manually create a ${chalk.yellow('.eslintrc.js')} file at the root of your project.
+
+If you prefer to create a ${chalk.yellow('.eslintrc.js')} file by yourself, here is an example to get you started:
+
+${chalk.yellow(`// .eslintrc.js
+module.exports = {
+    parser: 'babel-eslint',
+    extends: ['eslint:recommended'],
+}
+`)}
+
+Install ${chalk.yellow('babel-eslint')} to prevent potential parsing issues: ${packageHelper.getInstallCommand([[{ name: 'babel-eslint' }]])}
+
+`;
+                throw new Error(message);
+            }
+
+            throw e;
+        }
+
+        const eslintPluginOptions = {
+            emitWarning: true,
+            extensions: ['js', 'jsx'],
+        };
+
+        plugins.push({
+            plugin: new EslintPlugin(
+                applyOptionsCallback(webpackConfig.eslintPluginOptionsCallback, eslintPluginOptions)
+            ),
+        });
+    }
+};

package.json

@@ -71,6 +71,7 @@
     "eslint-plugin-header": "^3.0.0",
     "eslint-plugin-import": "^2.8.0",
     "eslint-plugin-node": "^11.1.0",
+    "eslint-webpack-plugin": "^2.5.4",
     "file-loader": "^6.0.0",
     "fork-ts-checker-webpack-plugin": "^5.0.0 || ^6.0.0",
     "fs-extra": "^9.0.0",

test/WebpackConfig.js

@@ -1512,5 +1512,24 @@ describe('WebpackConfig object', () => {
                 });
             }).to.throw('"notExisting" is not a valid key for enableEslintLoader(). Valid keys: lintVue.');
         });
+
+        it('ESLint loader can not be enabled if ESLint Webpack Plugin is already enabled', () => {
+            const config = createConfig();
+            config.enableEslintPlugin();
+
+            expect(function() {
+                config.enableEslintLoader();
+            }).to.throw('Encore.enableEslintLoader() can not be called when Encore.enableEslintPlugin() has been called.');
+        });
+    });
+    describe('enableEslintPlugin', () => {
+        it('ESLint loader can not be enabled if ESLint Webpack Plugin is already enabled', () => {
+            const config = createConfig();
+            config.enableEslintLoader();
+
+            expect(function() {
+                config.enableEslintPlugin();
+            }).to.throw('Encore.enableEslintPlugin() can not be called when Encore.enableEslintLoader() has been called.');
+        });
     });
 });

test/config-generator.js

@@ -16,6 +16,7 @@ const configGenerator = require('../lib/config-generator');
 const MiniCssExtractPlugin = require('mini-css-extract-plugin');
 const { WebpackManifestPlugin } = require('../lib/webpack-manifest-plugin');
 const { CleanWebpackPlugin } = require('clean-webpack-plugin');
+const ESLintWebpackPlugin = require('eslint-webpack-plugin');
 const webpack = require('webpack');
 const path = require('path');
 const logger = require('../lib/logger');
@@ -437,6 +438,61 @@ describe('The config-generator function', () => {
         });
     });
 
+    describe('enableEslintPlugin() adds the eslint-webpack-plugin', () => {
+        it('without enableEslintPlugin()', () => {
+            const config = createConfig();
+            config.addEntry('main', './main');
+            config.publicPath = '/';
+            config.outputPath = '/tmp';
+
+            const actualConfig = configGenerator(config);
+
+            const eslintPlugin = findPlugin(ESLintWebpackPlugin, actualConfig.plugins);
+            expect(eslintPlugin).to.be.undefined;
+        });
+
+        it('enableEslintPlugin()', () => {
+            const config = createConfig();
+            config.addEntry('main', './main');
+            config.publicPath = '/';
+            config.outputPath = '/tmp';
+            config.enableEslintPlugin();
+
+            const actualConfig = configGenerator(config);
+
+            const eslintPlugin = findPlugin(ESLintWebpackPlugin, actualConfig.plugins);
+            expect(eslintPlugin).to.not.be.undefined;
+        });
+
+        it('enableEslintPlugin({baseConfig: {extends: "extends-name"}})', () => {
+            const config = createConfig();
+            config.addEntry('main', './main');
+            config.publicPath = '/';
+            config.outputPath = '/tmp';
+            config.enableEslintPlugin({ baseConfig: { extends: 'extends-name' } });
+
+            const actualConfig = configGenerator(config);
+
+            const eslintPlugin = findPlugin(ESLintWebpackPlugin, actualConfig.plugins);
+            expect(eslintPlugin.options.baseConfig.extends).to.equal('extends-name');
+        });
+
+        it('enableEslintPlugin((options) => ...)', () => {
+            const config = createConfig();
+            config.addEntry('main', './main');
+            config.publicPath = '/';
+            config.outputPath = '/tmp';
+            config.enableEslintPlugin((options) => {
+                options.extensions.push('vue');
+            });
+
+            const actualConfig = configGenerator(config);
+
+            const eslintPlugin = findPlugin(ESLintWebpackPlugin, actualConfig.plugins);
+            expect(eslintPlugin.options.extensions).to.deep.equal(['js', 'jsx', 'vue']);
+        });
+    });
+
     describe('addLoader() adds a custom loader', () => {
         it('addLoader()', () => {
             const config = createConfig();