webpack/lib/ids/OccurrenceChunkIdsPlugin.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 { compareChunksNatural } = require("../util/comparators");
const createSchemaValidation = require("../util/create-schema-validation");
const { assignAscendingChunkIds } = require("./IdHelpers");

/** @typedef {import("../../declarations/plugins/ids/OccurrenceChunkIdsPlugin").OccurrenceChunkIdsPluginOptions} OccurrenceChunkIdsPluginOptions */
/** @typedef {import("../Chunk")} Chunk */
/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("../Module")} Module */

const validate = createSchemaValidation(
	require("../../schemas/plugins/ids/OccurrenceChunkIdsPlugin.check.js"),
	() => require("../../schemas/plugins/ids/OccurrenceChunkIdsPlugin.json"),
	{
		name: "Occurrence Order Chunk Ids Plugin",
		baseDataPath: "options"
	}
);

class OccurrenceChunkIdsPlugin {
	/**
	 * @param {OccurrenceChunkIdsPluginOptions=} options options object
	 */
	constructor(options = {}) {
		validate(options);
		this.options = options;
	}

	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		const prioritiseInitial = this.options.prioritiseInitial;
		compiler.hooks.compilation.tap("OccurrenceChunkIdsPlugin", compilation => {
			compilation.hooks.chunkIds.tap("OccurrenceChunkIdsPlugin", chunks => {
				const chunkGraph = compilation.chunkGraph;

				/** @type {Map<Chunk, number>} */
				const occursInInitialChunksMap = new Map();

				const compareNatural = compareChunksNatural(chunkGraph);

				for (const c of chunks) {
					let occurs = 0;
					for (const chunkGroup of c.groupsIterable) {
						for (const parent of chunkGroup.parentsIterable) {
							if (parent.isInitial()) occurs++;
						}
					}
					occursInInitialChunksMap.set(c, occurs);
				}

				const chunksInOccurrenceOrder = Array.from(chunks).sort((a, b) => {
					if (prioritiseInitial) {
						const aEntryOccurs = occursInInitialChunksMap.get(a);
						const bEntryOccurs = occursInInitialChunksMap.get(b);
						if (aEntryOccurs > bEntryOccurs) return -1;
						if (aEntryOccurs < bEntryOccurs) return 1;
					}
					const aOccurs = a.getNumberOfGroups();
					const bOccurs = b.getNumberOfGroups();
					if (aOccurs > bOccurs) return -1;
					if (aOccurs < bOccurs) return 1;
					return compareNatural(a, b);
				});
				assignAscendingChunkIds(chunksInOccurrenceOrder, compilation);
			});
		});
	}
}

module.exports = OccurrenceChunkIdsPlugin;