source: frontend/node_modules/webpack/lib/dll/LibManifestPlugin.js

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

"use strict";

const asyncLib = require("neo-async");
const EntryDependency = require("../dependencies/EntryDependency");
const { someInIterable } = require("../util/IterableHelpers");
const { compareModulesById } = require("../util/comparators");
const { dirname, mkdirp } = require("../util/fs");

/** @typedef {import("../ChunkGraph").ModuleId} ModuleId */
/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("../Compiler").IntermediateFileSystem} IntermediateFileSystem */
/** @typedef {import("../Module").BuildMeta} BuildMeta */
/** @typedef {import("../ExportsInfo").ExportInfoName} ExportInfoName */

/**
 * Defines the manifest module data type used by this module.
 * @typedef {object} ManifestModuleData
 * @property {ModuleId} id
 * @property {BuildMeta=} buildMeta
 * @property {ExportInfoName[]=} exports
 */

/**
 * Defines the lib manifest plugin options type used by this module.
 * @typedef {object} LibManifestPluginOptions
 * @property {string=} context Context of requests in the manifest file (defaults to the webpack context).
 * @property {boolean=} entryOnly If true, only entry points will be exposed (default: true).
 * @property {boolean=} format If true, manifest json file (output) will be formatted.
 * @property {string=} name Name of the exposed dll function (external name, use value of 'output.library').
 * @property {string} path Absolute path to the manifest json file (output).
 * @property {string=} type Type of the dll bundle (external type, use value of 'output.libraryTarget').
 */

const PLUGIN_NAME = "LibManifestPlugin";

class LibManifestPlugin {
        /**
         * Creates an instance of LibManifestPlugin.
         * @param {LibManifestPluginOptions} options the options
         */
        constructor(options) {
                this.options = options;
        }

        /**
         * Applies the plugin by registering its hooks on the compiler.
         * @param {Compiler} compiler the compiler instance
         * @returns {void}
         */
        apply(compiler) {
                compiler.hooks.emit.tapAsync(
                        { name: PLUGIN_NAME, stage: 110 },
                        (compilation, callback) => {
                                const moduleGraph = compilation.moduleGraph;
                                // store used paths to detect issue and output an error. #18200
                                /** @type {Set<string>} */
                                const usedPaths = new Set();
                                asyncLib.each(
                                        [...compilation.chunks],
                                        (chunk, callback) => {
                                                if (!chunk.canBeInitial()) {
                                                        callback();
                                                        return;
                                                }
                                                const chunkGraph = compilation.chunkGraph;
                                                const targetPath = compilation.getPath(this.options.path, {
                                                        chunk
                                                });
                                                if (usedPaths.has(targetPath)) {
                                                        callback(new Error("each chunk must have a unique path"));
                                                        return;
                                                }
                                                usedPaths.add(targetPath);
                                                const name =
                                                        this.options.name &&
                                                        compilation.getPath(this.options.name, {
                                                                chunk,
                                                                contentHashType: "javascript"
                                                        });
                                                const content = Object.create(null);
                                                for (const module of chunkGraph.getOrderedChunkModulesIterable(
                                                        chunk,
                                                        compareModulesById(chunkGraph)
                                                )) {
                                                        if (
                                                                this.options.entryOnly &&
                                                                !someInIterable(
                                                                        moduleGraph.getIncomingConnections(module),
                                                                        (c) => c.dependency instanceof EntryDependency
                                                                )
                                                        ) {
                                                                continue;
                                                        }
                                                        const ident = module.libIdent({
                                                                context: this.options.context || compiler.context,
                                                                associatedObjectForCache: compiler.root
                                                        });
                                                        if (ident) {
                                                                const exportsInfo = moduleGraph.getExportsInfo(module);
                                                                const providedExports = exportsInfo.getProvidedExports();
                                                                /** @type {ManifestModuleData} */
                                                                const data = {
                                                                        id: /** @type {ModuleId} */ (chunkGraph.getModuleId(module)),
                                                                        buildMeta: /** @type {BuildMeta} */ (module.buildMeta),
                                                                        exports: Array.isArray(providedExports)
                                                                                ? providedExports
                                                                                : undefined
                                                                };
                                                                content[ident] = data;
                                                        }
                                                }
                                                const manifest = {
                                                        name,
                                                        type: this.options.type,
                                                        content
                                                };
                                                // Apply formatting to content if format flag is true;
                                                const manifestContent = this.options.format
                                                        ? JSON.stringify(manifest, null, 2)
                                                        : JSON.stringify(manifest);
                                                const buffer = Buffer.from(manifestContent, "utf8");
                                                const intermediateFileSystem =
                                                        /** @type {IntermediateFileSystem} */ (
                                                                compiler.intermediateFileSystem
                                                        );
                                                mkdirp(
                                                        intermediateFileSystem,
                                                        dirname(intermediateFileSystem, targetPath),
                                                        (err) => {
                                                                if (err) return callback(err);
                                                                intermediateFileSystem.writeFile(targetPath, buffer, callback);
                                                        }
                                                );
                                        },
                                        callback
                                );
                        }
                );
        }
}

module.exports = LibManifestPlugin;