webpack/lib/library/ExportPropertyLibraryPlugin.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 { ConcatSource } = require("webpack-sources");
const { UsageState } = require("../ExportsInfo");
const propertyAccess = require("../util/propertyAccess");
const { getEntryRuntime } = require("../util/runtime");
const AbstractLibraryPlugin = require("./AbstractLibraryPlugin");

/** @typedef {import("webpack-sources").Source} Source */
/** @typedef {import("../../declarations/WebpackOptions").LibraryOptions} LibraryOptions */
/** @typedef {import("../../declarations/WebpackOptions").LibraryType} LibraryType */
/** @typedef {import("../Chunk")} Chunk */
/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("../Module")} Module */
/** @typedef {import("../javascript/JavascriptModulesPlugin").StartupRenderContext} StartupRenderContext */
/** @template T @typedef {import("./AbstractLibraryPlugin").LibraryContext<T>} LibraryContext<T> */

/**
 * @typedef {Object} ExportPropertyLibraryPluginParsed
 * @property {string | string[]} export
 */

/**
 * @typedef {Object} ExportPropertyLibraryPluginOptions
 * @property {LibraryType} type
 * @property {boolean} nsObjectUsed the namespace object is used
 */
/**
 * @typedef {ExportPropertyLibraryPluginParsed} T
 * @extends {AbstractLibraryPlugin<ExportPropertyLibraryPluginParsed>}
 */
class ExportPropertyLibraryPlugin extends AbstractLibraryPlugin {
	/**
	 * @param {ExportPropertyLibraryPluginOptions} options options
	 */
	constructor({ type, nsObjectUsed }) {
		super({
			pluginName: "ExportPropertyLibraryPlugin",
			type
		});
		this.nsObjectUsed = nsObjectUsed;
	}

	/**
	 * @param {LibraryOptions} library normalized library option
	 * @returns {T | false} preprocess as needed by overriding
	 */
	parseOptions(library) {
		return {
			export: library.export
		};
	}

	/**
	 * @param {Module} module the exporting entry module
	 * @param {string} entryName the name of the entrypoint
	 * @param {LibraryContext<T>} libraryContext context
	 * @returns {void}
	 */
	finishEntryModule(
		module,
		entryName,
		{ options, compilation, compilation: { moduleGraph } }
	) {
		const runtime = getEntryRuntime(compilation, entryName);
		if (options.export) {
			const exportsInfo = moduleGraph.getExportInfo(
				module,
				Array.isArray(options.export) ? options.export[0] : options.export
			);
			exportsInfo.setUsed(UsageState.Used, runtime);
			exportsInfo.canMangleUse = false;
		} else {
			const exportsInfo = moduleGraph.getExportsInfo(module);
			if (this.nsObjectUsed) {
				exportsInfo.setUsedInUnknownWay(runtime);
			} else {
				exportsInfo.setAllKnownExportsUsed(runtime);
			}
		}
		moduleGraph.addExtraReason(module, "used as library export");
	}

	/**
	 * @param {Chunk} chunk the chunk
	 * @param {Set<string>} set runtime requirements
	 * @param {LibraryContext<T>} libraryContext context
	 * @returns {void}
	 */
	runtimeRequirements(chunk, set, libraryContext) {}

	/**
	 * @param {Source} source source
	 * @param {Module} module module
	 * @param {StartupRenderContext} renderContext render context
	 * @param {LibraryContext<T>} libraryContext context
	 * @returns {Source} source with library export
	 */
	renderStartup(source, module, renderContext, { options }) {
		if (!options.export) return source;
		const postfix = `__webpack_exports__ = __webpack_exports__${propertyAccess(
			Array.isArray(options.export) ? options.export : [options.export]
		)};\n`;
		return new ConcatSource(source, postfix);
	}
}

module.exports = ExportPropertyLibraryPlugin;