source: imaps-frontend/node_modules/webpack/lib/webpack.js

/*
        MIT License http://www.opensource.org/licenses/mit-license.php
        Author Tobias Koppers @sokra
*/

"use strict";

const util = require("util");
const webpackOptionsSchemaCheck = require("../schemas/WebpackOptions.check.js");
const webpackOptionsSchema = require("../schemas/WebpackOptions.json");
const Compiler = require("./Compiler");
const MultiCompiler = require("./MultiCompiler");
const WebpackOptionsApply = require("./WebpackOptionsApply");
const {
        applyWebpackOptionsDefaults,
        applyWebpackOptionsBaseDefaults
} = require("./config/defaults");
const { getNormalizedWebpackOptions } = require("./config/normalization");
const NodeEnvironmentPlugin = require("./node/NodeEnvironmentPlugin");
const memoize = require("./util/memoize");

/** @typedef {import("../declarations/WebpackOptions").WebpackOptions} WebpackOptions */
/** @typedef {import("../declarations/WebpackOptions").WebpackPluginFunction} WebpackPluginFunction */
/** @typedef {import("./Compiler").WatchOptions} WatchOptions */
/** @typedef {import("./MultiCompiler").MultiCompilerOptions} MultiCompilerOptions */
/** @typedef {import("./MultiStats")} MultiStats */
/** @typedef {import("./Stats")} Stats */

const getValidateSchema = memoize(() => require("./validateSchema"));

/**
 * @template T
 * @callback Callback
 * @param {Error | null} err
 * @param {T=} stats
 * @returns {void}
 */

/**
 * @param {ReadonlyArray<WebpackOptions>} childOptions options array
 * @param {MultiCompilerOptions} options options
 * @returns {MultiCompiler} a multi-compiler
 */
const createMultiCompiler = (childOptions, options) => {
        const compilers = childOptions.map((options, index) =>
                createCompiler(options, index)
        );
        const compiler = new MultiCompiler(compilers, options);
        for (const childCompiler of compilers) {
                if (childCompiler.options.dependencies) {
                        compiler.setDependencies(
                                childCompiler,
                                childCompiler.options.dependencies
                        );
                }
        }
        return compiler;
};

/**
 * @param {WebpackOptions} rawOptions options object
 * @param {number} [compilerIndex] index of compiler
 * @returns {Compiler} a compiler
 */
const createCompiler = (rawOptions, compilerIndex) => {
        const options = getNormalizedWebpackOptions(rawOptions);
        applyWebpackOptionsBaseDefaults(options);
        const compiler = new Compiler(
                /** @type {string} */ (options.context),
                options
        );
        new NodeEnvironmentPlugin({
                infrastructureLogging: options.infrastructureLogging
        }).apply(compiler);
        if (Array.isArray(options.plugins)) {
                for (const plugin of options.plugins) {
                        if (typeof plugin === "function") {
                                /** @type {WebpackPluginFunction} */
                                (plugin).call(compiler, compiler);
                        } else if (plugin) {
                                plugin.apply(compiler);
                        }
                }
        }
        const resolvedDefaultOptions = applyWebpackOptionsDefaults(
                options,
                compilerIndex
        );
        if (resolvedDefaultOptions.platform) {
                compiler.platform = resolvedDefaultOptions.platform;
        }
        compiler.hooks.environment.call();
        compiler.hooks.afterEnvironment.call();
        new WebpackOptionsApply().process(options, compiler);
        compiler.hooks.initialize.call();
        return compiler;
};

/**
 * @callback WebpackFunctionSingle
 * @param {WebpackOptions} options options object
 * @param {Callback<Stats>=} callback callback
 * @returns {Compiler} the compiler object
 */

/**
 * @callback WebpackFunctionMulti
 * @param {ReadonlyArray<WebpackOptions> & MultiCompilerOptions} options options objects
 * @param {Callback<MultiStats>=} callback callback
 * @returns {MultiCompiler} the multi compiler object
 */

/**
 * @template T
 * @param {Array<T> | T} options options
 * @returns {Array<T>} array of options
 */
const asArray = options =>
        Array.isArray(options) ? Array.from(options) : [options];

const webpack = /** @type {WebpackFunctionSingle & WebpackFunctionMulti} */ (
        /**
         * @param {WebpackOptions | (ReadonlyArray<WebpackOptions> & MultiCompilerOptions)} options options
         * @param {Callback<Stats> & Callback<MultiStats>=} callback callback
         * @returns {Compiler | MultiCompiler | null} Compiler or MultiCompiler
         */
        (options, callback) => {
                const create = () => {
                        if (!asArray(options).every(webpackOptionsSchemaCheck)) {
                                getValidateSchema()(webpackOptionsSchema, options);
                                util.deprecate(
                                        () => {},
                                        "webpack bug: Pre-compiled schema reports error while real schema is happy. This has performance drawbacks.",
                                        "DEP_WEBPACK_PRE_COMPILED_SCHEMA_INVALID"
                                )();
                        }
                        /** @type {MultiCompiler|Compiler} */
                        let compiler;
                        /** @type {boolean | undefined} */
                        let watch = false;
                        /** @type {WatchOptions|WatchOptions[]} */
                        let watchOptions;
                        if (Array.isArray(options)) {
                                /** @type {MultiCompiler} */
                                compiler = createMultiCompiler(
                                        options,
                                        /** @type {MultiCompilerOptions} */ (options)
                                );
                                watch = options.some(options => options.watch);
                                watchOptions = options.map(options => options.watchOptions || {});
                        } else {
                                const webpackOptions = /** @type {WebpackOptions} */ (options);
                                /** @type {Compiler} */
                                compiler = createCompiler(webpackOptions);
                                watch = webpackOptions.watch;
                                watchOptions = webpackOptions.watchOptions || {};
                        }
                        return { compiler, watch, watchOptions };
                };
                if (callback) {
                        try {
                                const { compiler, watch, watchOptions } = create();
                                if (watch) {
                                        compiler.watch(watchOptions, callback);
                                } else {
                                        compiler.run((err, stats) => {
                                                compiler.close(err2 => {
                                                        callback(
                                                                err || err2,
                                                                /** @type {options extends WebpackOptions ? Stats : MultiStats} */
                                                                (stats)
                                                        );
                                                });
                                        });
                                }
                                return compiler;
                        } catch (err) {
                                process.nextTick(() => callback(/** @type {Error} */ (err)));
                                return null;
                        }
                } else {
                        const { compiler, watch } = create();
                        if (watch) {
                                util.deprecate(
                                        () => {},
                                        "A 'callback' argument needs to be provided to the 'webpack(options, callback)' function when the 'watch' option is set. There is no way to handle the 'watch' option without a callback.",
                                        "DEP_WEBPACK_WATCH_WITHOUT_CALLBACK"
                                )();
                        }
                        return compiler;
                }
        }
);

module.exports = webpack;