webpack/lib/LibManifestPlugin.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

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

const path = require("path");
const asyncLib = require("neo-async");
const SingleEntryDependency = require("./dependencies/SingleEntryDependency");

class LibManifestPlugin {
	constructor(options) {
		this.options = options;
	}

	apply(compiler) {
		compiler.hooks.emit.tapAsync(
			"LibManifestPlugin",
			(compilation, callback) => {
				asyncLib.forEach(
					compilation.chunks,
					(chunk, callback) => {
						if (!chunk.isOnlyInitial()) {
							callback();
							return;
						}
						const targetPath = compilation.getPath(this.options.path, {
							hash: compilation.hash,
							chunk
						});
						const name =
							this.options.name &&
							compilation.getPath(this.options.name, {
								hash: compilation.hash,
								chunk
							});
						const manifest = {
							name,
							type: this.options.type,
							content: Array.from(chunk.modulesIterable, module => {
								if (
									this.options.entryOnly &&
									!module.reasons.some(
										r => r.dependency instanceof SingleEntryDependency
									)
								) {
									return;
								}
								if (module.libIdent) {
									const ident = module.libIdent({
										context: this.options.context || compiler.options.context
									});
									if (ident) {
										return {
											ident,
											data: {
												id: module.id,
												buildMeta: module.buildMeta
											}
										};
									}
								}
							})
								.filter(Boolean)
								.reduce((obj, item) => {
									obj[item.ident] = item.data;
									return obj;
								}, Object.create(null))
						};
						// Apply formatting to content if format flag is true;
						const manifestContent = this.options.format
							? JSON.stringify(manifest, null, 2)
							: JSON.stringify(manifest);
						const content = Buffer.from(manifestContent, "utf8");
						compiler.outputFileSystem.mkdirp(path.dirname(targetPath), err => {
							if (err) return callback(err);
							compiler.outputFileSystem.writeFile(
								targetPath,
								content,
								callback
							);
						});
					},
					callback
				);
			}
		);
	}
}
module.exports = LibManifestPlugin;