WebpackConfig.js

/*
 * 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 path = require('path');
const fs = require('fs');
const crypto = require('crypto');
const RuntimeConfig = require('./config/RuntimeConfig'); //eslint-disable-line no-unused-vars
const logger = require('./logger');

/**
 * @param {RuntimeConfig|null} runtimeConfig
 * @return {void}
 */
function validateRuntimeConfig(runtimeConfig) {
    // if you're using the encore executable, these things should never happen
    if (null === runtimeConfig) {
        throw new Error('RuntimeConfig must be initialized');
    }

    if (null === runtimeConfig.context) {
        throw new Error('RuntimeConfig.context must be set.');
    }

    if (null === runtimeConfig.babelRcFileExists) {
        throw new Error('RuntimeConfig.babelRcFileExists must be set.');
    }
}

/**
 * @param {RuntimeConfig} runtimeConfig
 * @return {void}
 */
function checkPackageJson(runtimeConfig) {
    // Display a warning if webpack is listed as a [dev-]dependency
    try {
        const packageInfo = JSON.parse(
            fs.readFileSync(path.resolve(runtimeConfig.context, 'package.json'), { encoding: 'utf-8' })
        );

        if (packageInfo) {
            const dependencies = new Set([
                ...(packageInfo.dependencies ? Object.keys(packageInfo.dependencies) : []),
                ...(packageInfo.devDependencies ? Object.keys(packageInfo.devDependencies) : []),
            ]);

            if (dependencies.has('webpack')) {
                logger.warning('Webpack is already provided by Webpack Encore, also adding it to your package.json file may cause issues.');
            }
        }
    } catch (e) {
        logger.warning('Could not read package.json file.');
    }
}

class WebpackConfig {
    constructor(runtimeConfig, enablePackageJsonCheck = false) {
        validateRuntimeConfig(runtimeConfig);

        if (runtimeConfig.verbose) {
            logger.verbose();
        }

        if (enablePackageJsonCheck) {
            checkPackageJson(runtimeConfig);
        }

        this.runtimeConfig = runtimeConfig;
        this.entries = new Map();
        this.styleEntries = new Map();
        this.plugins = [];
        this.loaders = [];

        // Global settings
        this.outputPath = null;
        this.publicPath = null;
        this.manifestKeyPrefix = null;
        this.sharedCommonsEntryName = null;
        this.sharedCommonsEntryFile = null;
        this.providedVariables = {};
        this.configuredFilenames = {};
        this.aliases = {};
        this.externals = [];
        this.integrityAlgorithms = [];
        this.shouldUseSingleRuntimeChunk = null;
        this.shouldSplitEntryChunks = false;

        // Features/Loaders flags
        this.useVersioning = false;
        this.useSourceMaps = false;
        this.cleanupOutput = false;
        this.extractCss = true;
        this.useImagesLoader = true;
        this.useFontsLoader = true;
        this.usePostCssLoader = false;
        this.useLessLoader = false;
        this.useStylusLoader = false;
        this.useSassLoader = false;
        this.useReact = false;
        this.usePreact = false;
        this.useVueLoader = false;
        this.useEslintLoader = false;
        this.useTypeScriptLoader = false;
        this.useForkedTypeScriptTypeChecking = false;
        this.useWebpackNotifier = false;
        this.useHandlebarsLoader = false;

        // Features/Loaders options
        this.copyFilesConfigs = [];
        this.sassOptions = {
            resolveUrlLoader: true,
            resolveUrlLoaderOptions: {
                engine: 'postcss',
                keepQuery: false,
                removeCR: false,
                debug: false,
                silent: false
            }
        };
        this.preactOptions = {
            preactCompat: false
        };
        this.urlLoaderOptions = {
            images: false,
            fonts: false
        };
        this.babelOptions = {
            exclude: /(node_modules|bower_components)/,
            useBuiltIns: false,
            corejs: null,
        };
        this.vueOptions = {
            useJsx: false,
        };

        // Features/Loaders options callbacks
        this.postCssLoaderOptionsCallback = () => {};
        this.sassLoaderOptionsCallback = () => {};
        this.lessLoaderOptionsCallback = () => {};
        this.stylusLoaderOptionsCallback = () => {};
        this.babelConfigurationCallback = () => {};
        this.cssLoaderConfigurationCallback = () => {};
        this.splitChunksConfigurationCallback = () => {};
        this.watchOptionsConfigurationCallback = () => {};
        this.vueLoaderOptionsCallback = () => {};
        this.eslintLoaderOptionsCallback = () => {};
        this.tsConfigurationCallback = () => {};
        this.handlebarsConfigurationCallback = () => {};
        this.loaderConfigurationCallbacks = {
            javascript: () => {},
            css: () => {},
            images: () => {},
            fonts: () => {},
            sass: () => {},
            less: () => {},
            stylus: () => {},
            vue: () => {},
            eslint: () => {},
            typescript: () => {},
            handlebars: () => {},
        };

        // Plugins options
        this.cleanWebpackPluginPaths = ['**/*'];

        // Plugins callbacks
        this.cleanWebpackPluginOptionsCallback = () => {};
        this.definePluginOptionsCallback = () => {};
        this.forkedTypeScriptTypesCheckOptionsCallback = () => {};
        this.friendlyErrorsPluginOptionsCallback = () => {};
        this.manifestPluginOptionsCallback = () => {};
        this.terserPluginOptionsCallback = () => {};
        this.optimizeCssPluginOptionsCallback = () => {};
        this.notifierPluginOptionsCallback = () => {};
    }

    getContext() {
        return this.runtimeConfig.context;
    }

    doesBabelRcFileExist() {
        return this.runtimeConfig.babelRcFileExists;
    }

    setOutputPath(outputPath) {
        if (!path.isAbsolute(outputPath)) {
            outputPath = path.resolve(this.getContext(), outputPath);
        }

        if (!fs.existsSync(outputPath)) {
            // If the parent of the output directory does not exist either
            // check if it is located under the context directory before
            // creating it and its parent.
            const parentPath = path.dirname(outputPath);
            if (!fs.existsSync(parentPath)) {
                const context = path.resolve(this.getContext());
                if (outputPath.indexOf(context) !== 0) {
                    throw new Error(`outputPath directory "${outputPath}" does not exist and is not located under the context directory "${context}". Please check the path you're passing to setOutputPath() or create this directory.`);
                }

                parentPath.split(path.sep).reduce((previousPath, directory) => {
                    const newPath = path.resolve(previousPath, directory);
                    if (!fs.existsSync(newPath)) {
                        fs.mkdirSync(newPath);
                    }
                    return newPath;
                }, path.sep);
            }

            fs.mkdirSync(outputPath);
        }

        this.outputPath = outputPath;
    }

    setPublicPath(publicPath) {
        if (publicPath.includes('://') === false && publicPath.indexOf('/') !== 0) {
            // technically, not starting with "/" is legal, but not
            // what you want in most cases. Let's warn the user that
            // they might be making a mistake.
            logger.warning('The value passed to setPublicPath() should *usually* start with "/" or be a full URL (http://...). If you\'re not sure, then you should probably change your public path and make this message disappear.');
        }

        // guarantee a single trailing slash
        publicPath = publicPath.replace(/\/$/,'');
        publicPath = publicPath + '/';

        this.publicPath = publicPath;
    }

    setManifestKeyPrefix(manifestKeyPrefix) {
        /*
         * Normally, we make sure that the manifest keys don't start
         * with an opening "/" ever... for consistency. If you need
         * to manually specify the manifest key (e.g. because you're
         * publicPath is absolute), it's easy to accidentally add
         * an opening slash (thereby changing your key prefix) without
         * intending to. Hence, the warning.
         */
        if (manifestKeyPrefix.indexOf('/') === 0) {
            logger.warning(`The value passed to setManifestKeyPrefix "${manifestKeyPrefix}" starts with "/". This is allowed, but since the key prefix does not normally start with a "/", you may have just changed the prefix accidentally.`);
        }

        // guarantee a single trailing slash, except for blank strings
        if (manifestKeyPrefix !== '') {
            manifestKeyPrefix = manifestKeyPrefix.replace(/\/$/, '');
            manifestKeyPrefix = manifestKeyPrefix + '/';
        }

        this.manifestKeyPrefix = manifestKeyPrefix;
    }

    configureDefinePlugin(definePluginOptionsCallback = () => {}) {
        if (typeof definePluginOptionsCallback !== 'function') {
            throw new Error('Argument 1 to configureDefinePlugin() must be a callback function');
        }

        this.definePluginOptionsCallback = definePluginOptionsCallback;
    }

    configureFriendlyErrorsPlugin(friendlyErrorsPluginOptionsCallback = () => {}) {
        if (typeof friendlyErrorsPluginOptionsCallback !== 'function') {
            throw new Error('Argument 1 to configureFriendlyErrorsPlugin() must be a callback function');
        }

        this.friendlyErrorsPluginOptionsCallback = friendlyErrorsPluginOptionsCallback;
    }

    configureManifestPlugin(manifestPluginOptionsCallback = () => {}) {
        if (typeof manifestPluginOptionsCallback !== 'function') {
            throw new Error('Argument 1 to configureManifestPlugin() must be a callback function');
        }

        this.manifestPluginOptionsCallback = manifestPluginOptionsCallback;
    }

    configureTerserPlugin(terserPluginOptionsCallback = () => {}) {
        if (typeof terserPluginOptionsCallback !== 'function') {
            throw new Error('Argument 1 to configureTerserPlugin() must be a callback function');
        }

        this.terserPluginOptionsCallback = terserPluginOptionsCallback;
    }

    configureOptimizeCssPlugin(optimizeCssPluginOptionsCallback = () => {}) {
        if (typeof optimizeCssPluginOptionsCallback !== 'function') {
            throw new Error('Argument 1 to configureOptimizeCssPlugin() must be a callback function');
        }

        this.optimizeCssPluginOptionsCallback = optimizeCssPluginOptionsCallback;
    }

    /**
     * Returns the value that should be used as the publicPath,
     * which can be overridden by enabling the webpackDevServer
     *
     * @returns {string}
     */
    getRealPublicPath() {
        if (!this.useDevServer()) {
            return this.publicPath;
        }

        if (this.runtimeConfig.devServerKeepPublicPath) {
            return this.publicPath;
        }

        if (this.publicPath.includes('://')) {
            return this.publicPath;
        }

        // if using dev-server, prefix the publicPath with the dev server URL
        return this.runtimeConfig.devServerUrl.replace(/\/$/,'') + this.publicPath;
    }

    addEntry(name, src) {
        if (this.entries.has(name)) {
            throw new Error(`Duplicate name "${name}" passed to addEntry(): entries must be unique.`);
        }

        // also check for styleEntries duplicates
        if (this.styleEntries.has(name)) {
            throw new Error(`The "${name}" passed to addEntry conflicts with a name passed to addStyleEntry(). The entry names between addEntry() and addStyleEntry() must be unique.`);
        }

        this.entries.set(name, src);
    }

    addStyleEntry(name, src) {
        if (this.styleEntries.has(name)) {
            throw new Error(`Duplicate name "${name}" passed to addStyleEntry(): entries must be unique.`);
        }

        // also check for entries duplicates
        if (this.entries.has(name)) {
            throw new Error(`The "${name}" passed to addStyleEntry() conflicts with a name passed to addEntry(). The entry names between addEntry() and addStyleEntry() must be unique.`);
        }

        this.styleEntries.set(name, src);
    }

    addPlugin(plugin, priority = 0) {
        if (typeof priority !== 'number') {
            throw new Error('Argument 2 to addPlugin() must be a number.');
        }

        this.plugins.push({
            plugin: plugin,
            priority: priority
        });
    }

    addLoader(loader) {
        this.loaders.push(loader);
    }

    addAliases(aliases = {}) {
        if (typeof aliases !== 'object') {
            throw new Error('Argument 1 to addAliases() must be an object.');
        }

        Object.assign(this.aliases, aliases);
    }

    addExternals(externals = []) {
        if (!Array.isArray(externals)) {
            externals = [externals];
        }

        this.externals = this.externals.concat(externals);
    }

    enableVersioning(enabled = true) {
        this.useVersioning = enabled;
    }

    enableSourceMaps(enabled = true) {
        this.useSourceMaps = enabled;
    }

    configureBabel(callback, options = {}) {
        if (callback) {
            if (typeof callback !== 'function') {
                throw new Error('Argument 1 to configureBabel() must be a callback function or null.');
            }

            if (this.doesBabelRcFileExist()) {
                logger.warning('The "callback" argument of configureBabel() will not be used because your app already provides an external Babel configuration (a ".babelrc" file, ".babelrc.js" file or "babel" key in "package.json"). Use null as a first argument to remove that warning.');
            }
        }

        this.babelConfigurationCallback = callback || (() => {});

        // Whitelist some options that can be used even if there
        // is an external Babel config. The other ones won't be
        // applied and a warning message will be displayed instead.
        const allowedOptionsWithExternalConfig = ['includeNodeModules', 'exclude'];

        for (const optionKey of Object.keys(options)) {
            let normalizedOptionKey = optionKey;
            if (optionKey === 'include_node_modules') {
                logger.deprecation('configureBabel: "include_node_modules" is deprecated. Please use "includeNodeModules" instead.');
                normalizedOptionKey = 'includeNodeModules';
            }

            if (this.doesBabelRcFileExist() && !allowedOptionsWithExternalConfig.includes(normalizedOptionKey)) {
                logger.warning(`The "${normalizedOptionKey}" option of configureBabel() will not be used because your app already provides an external Babel configuration (a ".babelrc" file, ".babelrc.js" file or "babel" key in "package.json").`);
                continue;
            }

            if (normalizedOptionKey === 'includeNodeModules') {
                if (Object.keys(options).includes('exclude')) {
                    throw new Error('"includeNodeModules" and "exclude" options can\'t be used together when calling configureBabel().');
                }

                if (!Array.isArray(options[optionKey])) {
                    throw new Error('Option "includeNodeModules" passed to configureBabel() must be an Array.');
                }

                this.babelOptions['exclude'] = (filePath) => {
                    // Don't exclude modules outside of node_modules/bower_components
                    if (!/(node_modules|bower_components)/.test(filePath)) {
                        return false;
                    }

                    // Don't exclude whitelisted Node modules
                    const whitelistedModules = options[optionKey].map(
                        module => path.join('node_modules', module) + path.sep
                    );

                    for (const modulePath of whitelistedModules) {
                        if (filePath.includes(modulePath)) {
                            return false;
                        }
                    }

                    // Exclude other modules
                    return true;
                };
            } else if (!(normalizedOptionKey in this.babelOptions)) {
                throw new Error(`Invalid option "${normalizedOptionKey}" passed to configureBabel(). Valid keys are ${[...Object.keys(this.babelOptions), 'includeNodeModules'].join(', ')}`);
            } else {
                this.babelOptions[normalizedOptionKey] = options[optionKey];
            }
        }
    }

    configureCssLoader(callback) {
        if (typeof callback !== 'function') {
            throw new Error('Argument 1 to configureCssLoader() must be a callback function.');
        }

        this.cssLoaderConfigurationCallback = callback;
    }

    enableSingleRuntimeChunk() {
        this.shouldUseSingleRuntimeChunk = true;
    }

    disableSingleRuntimeChunk() {
        this.shouldUseSingleRuntimeChunk = false;
    }

    splitEntryChunks() {
        if (this.sharedCommonsEntryName) {
            throw new Error('Using splitEntryChunks() and createSharedEntry() together is not supported. Use one of these strategies only to optimize your build.');
        }

        this.shouldSplitEntryChunks = true;
    }

    configureSplitChunks(callback) {
        if (typeof callback !== 'function') {
            throw new Error('Argument 1 to configureSplitChunks() must be a callback function.');
        }

        this.splitChunksConfigurationCallback = callback;
    }

    configureWatchOptions(callback) {
        if (typeof callback !== 'function') {
            throw new Error('Argument 1 to configureWatchOptions() must be a callback function.');
        }

        this.watchOptionsConfigurationCallback = callback;
    }

    createSharedEntry(name, file) {
        if (this.shouldSplitEntryChunks) {
            throw new Error('Using splitEntryChunks() and createSharedEntry() together is not supported. Use one of these strategies only to optimize your build.');
        }

        // don't allow to call this twice
        if (this.sharedCommonsEntryName) {
            throw new Error('createSharedEntry() cannot be called multiple times: you can only create *one* shared entry.');
        }

        if (Array.isArray(file)) {
            throw new Error('Argument 2 to createSharedEntry() must be a single string file: not an array of files. Try creating one file that requires/imports all the modules that should be included.');
        }

        this.sharedCommonsEntryName = name;
        this.sharedCommonsEntryFile = file;

        this.addEntry(name, file);
    }

    copyFiles(configs = []) {
        if (!Array.isArray(configs)) {
            configs = [configs];
        }

        if (configs.some(elt => typeof elt !== 'object')) {
            throw new Error('copyFiles() must be called with either a config object or an array of config objects.');
        }

        const defaultConfig = {
            from: null,
            pattern: /.*/,
            to: null,
            includeSubdirectories: true,
            context: null,
        };

        for (const config of configs) {
            if (!config.from) {
                throw new Error('Config objects passed to copyFiles() must have a "from" property.');
            }

            for (const configKey of Object.keys(config)) {
                if (!(configKey in defaultConfig)) {
                    throw new Error(`Invalid config option "${configKey}" passed to copyFiles(). Valid keys are ${Object.keys(defaultConfig).join(', ')}`);
                }
            }

            if (typeof config.pattern !== 'undefined' && !(config.pattern instanceof RegExp)) {
                let validPattern = false;
                if (typeof config.pattern === 'string') {
                    const regexPattern = /^\/(.*)\/([a-z]*)?$/;
                    if (regexPattern.test(config.pattern)) {
                        validPattern = true;
                    }
                }

                if (!validPattern) {
                    throw new Error(`Invalid pattern "${config.pattern}" passed to copyFiles(). Make sure it contains a valid regular expression.`);
                }
            }

            this.copyFilesConfigs.push(
                Object.assign({}, defaultConfig, config)
            );
        }
    }

    enablePostCssLoader(postCssLoaderOptionsCallback = () => {}) {
        this.usePostCssLoader = true;

        if (typeof postCssLoaderOptionsCallback !== 'function') {
            throw new Error('Argument 1 to enablePostCssLoader() must be a callback function.');
        }

        this.postCssLoaderOptionsCallback = postCssLoaderOptionsCallback;
    }

    enableSassLoader(sassLoaderOptionsCallback = () => {}, options = {}) {
        this.useSassLoader = true;

        if (typeof sassLoaderOptionsCallback !== 'function') {
            throw new Error('Argument 1 to enableSassLoader() must be a callback function.');
        }

        this.sassLoaderOptionsCallback = sassLoaderOptionsCallback;

        for (const optionKey of Object.keys(options)) {
            let normalizedOptionKey = optionKey;
            if (optionKey === 'resolve_url_loader') {
                logger.deprecation('enableSassLoader: "resolve_url_loader" is deprecated. Please use "resolveUrlLoader" instead.');
                normalizedOptionKey = 'resolveUrlLoader';
            }

            if (!(normalizedOptionKey in this.sassOptions)) {
                throw new Error(`Invalid option "${normalizedOptionKey}" passed to enableSassLoader(). Valid keys are ${Object.keys(this.sassOptions).join(', ')}`);
            }

            this.sassOptions[normalizedOptionKey] = options[optionKey];
        }
    }

    enableLessLoader(lessLoaderOptionsCallback = () => {}) {
        this.useLessLoader = true;

        if (typeof lessLoaderOptionsCallback !== 'function') {
            throw new Error('Argument 1 to enableLessLoader() must be a callback function.');
        }

        this.lessLoaderOptionsCallback = lessLoaderOptionsCallback;
    }

    enableStylusLoader(stylusLoaderOptionsCallback = () => {}) {
        this.useStylusLoader = true;

        if (typeof stylusLoaderOptionsCallback !== 'function') {
            throw new Error('Argument 1 to enableStylusLoader() must be a callback function.');
        }

        this.stylusLoaderOptionsCallback = stylusLoaderOptionsCallback;
    }

    enableReactPreset() {
        this.useReact = true;
    }

    enablePreactPreset(options = {}) {
        this.usePreact = true;

        for (const optionKey of Object.keys(options)) {
            if (!(optionKey in this.preactOptions)) {
                throw new Error(`Invalid option "${optionKey}" passed to enablePreactPreset(). Valid keys are ${Object.keys(this.preactOptions).join(', ')}`);
            }

            this.preactOptions[optionKey] = options[optionKey];
        }
    }

    enableTypeScriptLoader(callback = () => {}) {
        this.useTypeScriptLoader = true;

        if (typeof callback !== 'function') {
            throw new Error('Argument 1 to enableTypeScriptLoader() must be a callback function.');
        }

        this.tsConfigurationCallback = callback;
    }

    enableForkedTypeScriptTypesChecking(forkedTypeScriptTypesCheckOptionsCallback = () => {}) {

        if (typeof forkedTypeScriptTypesCheckOptionsCallback !== 'function') {
            throw new Error('Argument 1 to enableForkedTypeScriptTypesChecking() must be a callback function.');
        }

        this.useForkedTypeScriptTypeChecking = true;
        this.forkedTypeScriptTypesCheckOptionsCallback =
            forkedTypeScriptTypesCheckOptionsCallback;
    }

    enableVueLoader(vueLoaderOptionsCallback = () => {}, vueOptions = {}) {
        this.useVueLoader = true;

        if (typeof vueLoaderOptionsCallback !== 'function') {
            throw new Error('Argument 1 to enableVueLoader() must be a callback function.');
        }

        this.vueLoaderOptionsCallback = vueLoaderOptionsCallback;

        // Check allowed keys
        for (const key of Object.keys(vueOptions)) {
            if (!(key in this.vueOptions)) {
                throw new Error(`"${key}" is not a valid key for enableVueLoader(). Valid keys: ${Object.keys(this.vueOptions).join(', ')}.`);
            }
        }

        this.vueOptions = vueOptions;
    }

    enableEslintLoader(eslintLoaderOptionsOrCallback = () => {}) {
        this.useEslintLoader = true;

        if (typeof eslintLoaderOptionsOrCallback === 'function') {
            this.eslintLoaderOptionsCallback = eslintLoaderOptionsOrCallback;
            return;
        }

        if (typeof eslintLoaderOptionsOrCallback === 'string') {
            this.eslintLoaderOptionsCallback = (options) => {
                options.extends = eslintLoaderOptionsOrCallback;
            };
            return;
        }

        if (typeof eslintLoaderOptionsOrCallback === 'object') {
            this.eslintLoaderOptionsCallback = (options) => {
                Object.assign(options, eslintLoaderOptionsOrCallback);
            };
            return;
        }

        throw new Error('Argument 1 to enableEslintLoader() must be either a string, object or callback function.');
    }

    enableBuildNotifications(enabled = true, notifierPluginOptionsCallback = () => {}) {
        if (typeof notifierPluginOptionsCallback !== 'function') {
            throw new Error('Argument 2 to enableBuildNotifications() must be a callback function.');
        }

        this.useWebpackNotifier = enabled;
        this.notifierPluginOptionsCallback = notifierPluginOptionsCallback;
    }

    enableHandlebarsLoader(callback = () => {}) {
        this.useHandlebarsLoader = true;

        if (typeof callback !== 'function') {
            throw new Error('Argument 1 to enableHandlebarsLoader() must be a callback function.');
        }

        this.handlebarsConfigurationCallback = callback;
    }

    disableImagesLoader() {
        this.useImagesLoader = false;
    }

    disableFontsLoader() {
        this.useFontsLoader = false;
    }

    disableCssExtraction() {
        this.extractCss = false;
    }

    configureFilenames(configuredFilenames = {}) {
        if (typeof configuredFilenames !== 'object') {
            throw new Error('Argument 1 to configureFilenames() must be an object.');
        }

        // Check allowed keys
        const validKeys = ['js', 'css', 'images', 'fonts'];
        for (const key of Object.keys(configuredFilenames)) {
            if (!validKeys.includes(key)) {
                throw new Error(`"${key}" is not a valid key for configureFilenames(). Valid keys: ${validKeys.join(', ')}.`);
            }
        }

        if (typeof configuredFilenames.js !== 'undefined' && configuredFilenames.js.includes('[chunkhash')) {
            logger.deprecation('Using the [chunkhash] placeholder in any filenames is deprecated: use [contenthash] instead.');
        }

        this.configuredFilenames = configuredFilenames;
    }

    configureUrlLoader(urlLoaderOptions = {}) {
        if (typeof urlLoaderOptions !== 'object') {
            throw new Error('Argument 1 to configureUrlLoader() must be an object.');
        }

        // Check allowed keys
        const validKeys = ['images', 'fonts'];
        for (const key of Object.keys(urlLoaderOptions)) {
            if (!validKeys.includes(key)) {
                throw new Error(`"${key}" is not a valid key for configureUrlLoader(). Valid keys: ${validKeys.join(', ')}.`);
            }
        }

        this.urlLoaderOptions = urlLoaderOptions;
    }

    cleanupOutputBeforeBuild(paths = ['**/*'], cleanWebpackPluginOptionsCallback = () => {}) {
        if (!Array.isArray(paths)) {
            throw new Error('Argument 1 to cleanupOutputBeforeBuild() must be an Array of paths - e.g. [\'**/*\']');
        }

        if (typeof cleanWebpackPluginOptionsCallback !== 'function') {
            throw new Error('Argument 2 to cleanupOutputBeforeBuild() must be a callback function');
        }

        this.cleanupOutput = true;
        this.cleanWebpackPluginPaths = paths;
        this.cleanWebpackPluginOptionsCallback = cleanWebpackPluginOptionsCallback;
    }

    autoProvideVariables(variables) {
        // do a few sanity checks, so we can give better user errors
        if (typeof variables === 'string' || Array.isArray(variables)) {
            throw new Error('Invalid argument passed to autoProvideVariables: you must pass an object map - e.g. { $: "jquery" }');
        }

        // merge new variables into the object
        this.providedVariables = Object.assign(
            {},
            this.providedVariables,
            variables
        );
    }

    autoProvidejQuery() {
        this.autoProvideVariables({
            $: 'jquery',
            jQuery: 'jquery',
            'window.jQuery': 'jquery',
        });
    }

    configureLoaderRule(name, callback) {
        logger.warning('Be careful when using Encore.configureLoaderRule(), this is a low-level method that can potentially break Encore and Webpack when not used carefully.');

        // Key: alias, Value: existing loader in `this.loaderConfigurationCallbacks`
        const aliases = {
            js: 'javascript',
            ts: 'typescript',
            scss: 'sass',
        };

        if (name in aliases) {
            name = aliases[name];
        }

        if (!(name in this.loaderConfigurationCallbacks)) {
            throw new Error(`Loader "${name}" is not configurable. Valid loaders are "${Object.keys(this.loaderConfigurationCallbacks).join('", "')}" and the aliases "${Object.keys(aliases).join('", "')}".`);
        }

        if (typeof callback !== 'function') {
            throw new Error('Argument 2 to configureLoaderRule() must be a callback function.');
        }

        this.loaderConfigurationCallbacks[name] = callback;
    }

    enableIntegrityHashes(enabled = true, algorithms = ['sha384']) {
        if (!Array.isArray(algorithms)) {
            algorithms = [algorithms];
        }

        const availableHashes = crypto.getHashes();
        for (const algorithm of algorithms) {
            if (typeof algorithm !== 'string') {
                throw new Error('Argument 2 to enableIntegrityHashes() must be a string or an array of strings.');
            }

            if (!availableHashes.includes(algorithm)) {
                throw new Error(`Invalid hash algorithm "${algorithm}" passed to enableIntegrityHashes().`);
            }
        }

        this.integrityAlgorithms = enabled ? algorithms : [];
    }

    useDevServer() {
        return this.runtimeConfig.useDevServer;
    }

    useDevServerInHttps() {
        return this.runtimeConfig.devServerHttps;
    }

    useHotModuleReplacementPlugin() {
        return this.runtimeConfig.useHotModuleReplacement;
    }

    isProduction() {
        return this.runtimeConfig.environment === 'production';
    }

    isDev() {
        return this.runtimeConfig.environment === 'dev';
    }

    isDevServer() {
        return this.isDev() && this.runtimeConfig.useDevServer;
    }
}

module.exports = WebpackConfig;