webpack/lib/library/AbstractLibraryPlugin.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 RuntimeGlobals = require("../RuntimeGlobals");
const JavascriptModulesPlugin = require("../javascript/JavascriptModulesPlugin");

/** @typedef {import("webpack-sources").Source} Source */
/** @typedef {import("../../declarations/WebpackOptions").LibraryOptions} LibraryOptions */
/** @typedef {import("../../declarations/WebpackOptions").LibraryType} LibraryType */
/** @typedef {import("../Chunk")} Chunk */
/** @typedef {import("../Compilation")} Compilation */
/** @typedef {import("../Compilation").ChunkHashContext} ChunkHashContext */
/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("../Module")} Module */
/** @typedef {import("../javascript/JavascriptModulesPlugin").RenderContext} RenderContext */
/** @typedef {import("../util/Hash")} Hash */

/**
 * @template T
 * @typedef {Object} LibraryContext
 * @property {Compilation} compilation
 * @property {T} options
 */

/**
 * @template T
 */
class AbstractLibraryPlugin {
	/**
	 * @param {Object} options options
	 * @param {string} options.pluginName name of the plugin
	 * @param {LibraryType} options.type used library type
	 */
	constructor({ pluginName, type }) {
		this._pluginName = pluginName;
		this._type = type;
		this._parseCache = new WeakMap();
	}

	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		const { _pluginName } = this;
		compiler.hooks.thisCompilation.tap(_pluginName, compilation => {
			compilation.hooks.finishModules.tap(_pluginName, () => {
				for (const [
					name,
					{
						dependencies: deps,
						options: { library }
					}
				] of compilation.entries) {
					const options = this._parseOptionsCached(
						library !== undefined ? library : compilation.outputOptions.library
					);
					if (options !== false) {
						const dep = deps[deps.length - 1];
						if (dep) {
							const module = compilation.moduleGraph.getModule(dep);
							if (module) {
								this.finishEntryModule(module, name, { options, compilation });
							}
						}
					}
				}
			});

			const getOptionsForChunk = chunk => {
				if (compilation.chunkGraph.getNumberOfEntryModules(chunk) === 0)
					return false;
				const options = chunk.getEntryOptions();
				const library = options && options.library;
				return this._parseOptionsCached(
					library !== undefined ? library : compilation.outputOptions.library
				);
			};

			compilation.hooks.additionalChunkRuntimeRequirements.tap(
				_pluginName,
				(chunk, set) => {
					const options = getOptionsForChunk(chunk);
					if (options !== false) {
						this.runtimeRequirements(chunk, set, { options, compilation });
					}
				}
			);

			const hooks = JavascriptModulesPlugin.getCompilationHooks(compilation);

			hooks.render.tap(_pluginName, (source, renderContext) => {
				const options = getOptionsForChunk(renderContext.chunk);
				if (options === false) return source;
				return this.render(source, renderContext, { options, compilation });
			});

			hooks.chunkHash.tap(_pluginName, (chunk, hash, context) => {
				const options = getOptionsForChunk(chunk);
				if (options === false) return;
				this.chunkHash(chunk, hash, context, { options, compilation });
			});
		});
	}

	/**
	 * @param {LibraryOptions=} library normalized library option
	 * @returns {T | false} preprocess as needed by overriding
	 */
	_parseOptionsCached(library) {
		if (!library) return false;
		if (library.type !== this._type) return false;
		const cacheEntry = this._parseCache.get(library);
		if (cacheEntry !== undefined) return cacheEntry;
		const result = this.parseOptions(library);
		this._parseCache.set(library, result);
		return result;
	}

	/* istanbul ignore next */
	/**
	 * @abstract
	 * @param {LibraryOptions} library normalized library option
	 * @returns {T | false} preprocess as needed by overriding
	 */
	parseOptions(library) {
		const AbstractMethodError = require("../AbstractMethodError");
		throw new AbstractMethodError();
	}

	/**
	 * @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, libraryContext) {}

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

	/**
	 * @param {Source} source source
	 * @param {RenderContext} renderContext render context
	 * @param {LibraryContext<T>} libraryContext context
	 * @returns {Source} source with library export
	 */
	render(source, renderContext, libraryContext) {
		return source;
	}

	/**
	 * @param {Chunk} chunk the chunk
	 * @param {Hash} hash hash
	 * @param {ChunkHashContext} chunkHashContext chunk hash context
	 * @param {LibraryContext<T>} libraryContext context
	 * @returns {void}
	 */
	chunkHash(chunk, hash, chunkHashContext, libraryContext) {
		const options = this._parseOptionsCached(
			libraryContext.compilation.outputOptions.library
		);
		hash.update(this._pluginName);
		hash.update(JSON.stringify(options));
	}
}

module.exports = AbstractLibraryPlugin;