webpack/lib/cache/AddBuildDependenciesPlugin.js

Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports 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";

/** @import Compiler from "../Compiler" */

const PLUGIN_NAME = "AddBuildDependenciesPlugin";

/**
 * @typedef {object} NormalizedBuildDependencyItem
 * @property {string} dependency request to resolve
 * @property {boolean} optional when true the dependency may be missing
 */

/**
 * @param {string | { dependency: string, optional?: boolean }} item build dependency
 * @returns {NormalizedBuildDependencyItem} normalized build dependency
 */
const normalizeBuildDependencyItem = (item) => {
	if (typeof item === "string") {
		return { dependency: item, optional: false };
	}
	return {
		dependency: item.dependency,
		optional: Boolean(item.optional)
	};
};

class AddBuildDependenciesPlugin {
	/**
	 * Creates an instance of AddBuildDependenciesPlugin.
	 * @param {Iterable<string | { dependency: string, optional?: boolean }>} buildDependencies list of build dependencies
	 */
	constructor(buildDependencies) {
		/** @type {NormalizedBuildDependencyItem[]} */
		this.buildDependencies = [...buildDependencies].map(
			normalizeBuildDependencyItem
		);
	}

	/**
	 * Applies the plugin by registering its hooks on the compiler.
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap(PLUGIN_NAME, (compilation) => {
			for (const { dependency, optional } of this.buildDependencies) {
				compilation.buildDependencies.add(dependency);
				if (optional) {
					compilation.optionalBuildDependencies.add(dependency);
					compilation.missingDependencies.add(dependency);
					compilation.fileDependencies.add(dependency);
				}
			}
		});
	}
}

module.exports = AddBuildDependenciesPlugin;