webpack/lib/optimize/RemoveEmptyChunksPlugin.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";

const { STAGE_BASIC, STAGE_ADVANCED } = require("../OptimizationStages");

/** @typedef {import("../Chunk")} Chunk */
/** @typedef {import("../Compiler")} Compiler */

const PLUGIN_NAME = "RemoveEmptyChunksPlugin";

class RemoveEmptyChunksPlugin {
	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap(PLUGIN_NAME, compilation => {
			/**
			 * @param {Iterable<Chunk>} chunks the chunks array
			 * @returns {void}
			 */
			const handler = chunks => {
				const chunkGraph = compilation.chunkGraph;
				for (const chunk of chunks) {
					if (
						chunkGraph.getNumberOfChunkModules(chunk) === 0 &&
						!chunk.hasRuntime() &&
						chunkGraph.getNumberOfEntryModules(chunk) === 0
					) {
						compilation.chunkGraph.disconnectChunk(chunk);
						compilation.chunks.delete(chunk);
					}
				}
			};

			// TODO do it once
			compilation.hooks.optimizeChunks.tap(
				{
					name: PLUGIN_NAME,
					stage: STAGE_BASIC
				},
				handler
			);
			compilation.hooks.optimizeChunks.tap(
				{
					name: PLUGIN_NAME,
					stage: STAGE_ADVANCED
				},
				handler
			);
		});
	}
}
module.exports = RemoveEmptyChunksPlugin;