webpack/lib/javascript/ChunkFormatHelpers.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 Natsu @xiaoxiaojx
*/

"use strict";

const { updateHashForEntryStartup } = require("./StartupHelpers");

/** @import ChunkGraph from "../ChunkGraph" */
/** @import Module from "../Module" */
/** @import Chunk from "../Chunk" */
/** @import Entrypoint from "../Entrypoint" */
/** @import Hash from "../util/Hash" */
/** @import { ChunkHashContext } from "../Compilation" */

/**
 * Returns } Object containing chunk entries and runtime chunk.
 * @param {Chunk} chunk The chunk to get information for
 * @param {ChunkGraph} chunkGraph The chunk graph containing the chunk
 * @returns {{ entries: [Module, Entrypoint | undefined][], runtimeChunk: Chunk | null }} Object containing chunk entries and runtime chunk
 */
function getChunkInfo(chunk, chunkGraph) {
	const entries = [
		...chunkGraph.getChunkEntryModulesWithChunkGroupIterable(chunk)
	];
	const runtimeChunk =
		entries.length > 0
			? /** @type {Entrypoint[][]} */
				(entries)[0][1].getRuntimeChunk()
			: null;

	return {
		entries,
		runtimeChunk
	};
}

/**
 * Creates a chunk hash handler
 * @param {string} name The name of the chunk
 * @returns {(chunk: Chunk, hash: Hash, { chunkGraph }: ChunkHashContext) => void} The chunk hash handler
 */
function createChunkHashHandler(name) {
	/**
	 * Processes the provided chunk.
	 * @param {Chunk} chunk The chunk to get information for
	 * @param {Hash} hash The hash to update
	 * @param {ChunkHashContext} chunkHashContext The chunk hash context
	 * @returns {void}
	 */
	return (chunk, hash, { chunkGraph }) => {
		if (chunk.hasRuntime()) return;
		const { entries, runtimeChunk } = getChunkInfo(chunk, chunkGraph);
		hash.update(name);
		hash.update("1");
		if (runtimeChunk && runtimeChunk.hash) {
			// WHY: any change to the runtime chunk must move this hash, and its
			// internal implementation is not ours to depend on or inspect — the import
			// names its hashed filename:
			// import __webpack_require__ from "./runtime-main.e9400aee33633a3973bd.js";
			// https://github.com/webpack/webpack/issues/19439
			hash.update(runtimeChunk.hash);
		}
		updateHashForEntryStartup(hash, chunkGraph, entries, chunk);
	};
}

module.exports = {
	createChunkHashHandler,
	getChunkInfo
};