webpack/lib/optimize/RemoveEmptyChunksPlugin.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 { STAGE_BASIC, STAGE_ADVANCED } = require("../OptimizationStages");

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

class RemoveEmptyChunksPlugin {
	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap("RemoveEmptyChunksPlugin", 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: "RemoveEmptyChunksPlugin",
					stage: STAGE_BASIC
				},
				handler
			);
			compilation.hooks.optimizeChunks.tap(
				{
					name: "RemoveEmptyChunksPlugin",
					stage: STAGE_ADVANCED
				},
				handler
			);
		});
	}
}
module.exports = RemoveEmptyChunksPlugin;