webpack/lib/Chunk.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 ChunkGraph = require("./ChunkGraph");
const Entrypoint = require("./Entrypoint");
const { intersect } = require("./util/SetHelpers");
const SortableSet = require("./util/SortableSet");
const StringXor = require("./util/StringXor");
const {
	compareChunkGroupsByIndex,
	compareModulesById,
	compareModulesByIdentifier
} = require("./util/comparators");
const { createArrayToSetDeprecationSet } = require("./util/deprecation");
const { mergeRuntime } = require("./util/runtime");

/** @typedef {import("./ChunkGraph").ChunkFilterPredicate} ChunkFilterPredicate */
/** @typedef {import("./ChunkGraph").ChunkSizeOptions} ChunkSizeOptions */
/** @typedef {import("./ChunkGraph").ModuleFilterPredicate} ModuleFilterPredicate */
/** @typedef {import("./ChunkGraph").ModuleId} ModuleId */
/** @typedef {import("./ChunkGroup")} ChunkGroup */
/** @typedef {import("./ChunkGroup").ChunkGroupOptions} ChunkGroupOptions */
/** @typedef {import("./Entrypoint").EntryOptions} EntryOptions */
/** @typedef {import("./Module")} Module */
/** @typedef {import("./TemplatedPathPlugin").TemplatePath} TemplatePath */
/** @typedef {import("./util/Hash")} Hash */
/** @typedef {import("./util/runtime").RuntimeSpec} RuntimeSpec */

/** @typedef {string | null} ChunkName */
/** @typedef {string | number} ChunkId */
/** @typedef {SortableSet<string>} IdNameHints */

const ChunkFilesSet = createArrayToSetDeprecationSet("chunk.files");

/**
 * Defines the chunk maps type used by this module.
 * @deprecated
 * @typedef {object} ChunkMaps
 * @property {Record<ChunkId, string>} hash
 * @property {Record<ChunkId, Record<string, string>>} contentHash
 * @property {Record<ChunkId, string>} name
 */

/**
 * Defines the chunk module id map type used by this module.
 * @deprecated
 * @typedef {Record<ChunkId, ChunkId[]>} ChunkModuleIdMap
 */

/**
 * Defines the chunk module hash map type used by this module.
 * @deprecated
 * @typedef {Record<ModuleId, string>} chunkModuleHashMap
 */

/**
 * Defines the chunk module maps type used by this module.
 * @deprecated
 * @typedef {object} ChunkModuleMaps
 * @property {ChunkModuleIdMap} id
 * @property {chunkModuleHashMap} hash
 */

/** @typedef {Set<Chunk>} Chunks */
/** @typedef {Set<Entrypoint>} Entrypoints */
/** @typedef {Set<ChunkGroup>} Queue */
/** @typedef {SortableSet<ChunkGroup>} SortableChunkGroups */
/** @typedef {Record<string, ChunkId[]>} ChunkChildIdsByOrdersMap */
/** @typedef {Record<string, ChunkChildIdsByOrdersMap>} ChunkChildIdsByOrdersMapByData */
/** @typedef {{ onChunks: Chunk[], chunks: Chunks }} ChunkChildOfTypeInOrder */

let debugId = 1000;

/**
 * A Chunk is a unit of encapsulation for Modules.
 * Chunks are "rendered" into bundles that get emitted when the build completes.
 */
class Chunk {
	/**
	 * Creates an instance of Chunk.
	 * @param {ChunkName=} name of chunk being created, is optional (for subclasses)
	 * @param {boolean} backCompat enable backward-compatibility
	 */
	constructor(name, backCompat = true) {
		/** @type {ChunkId | null} */
		this.id = null;
		/** @type {ChunkId[] | null} */
		this.ids = null;
		/** @type {number} */
		this.debugId = debugId++;
		/** @type {ChunkName | undefined} */
		this.name = name;
		/** @type {IdNameHints} */
		this.idNameHints = new SortableSet();
		/** @type {boolean} */
		this.preventIntegration = false;
		/** @type {TemplatePath | undefined} */
		this.filenameTemplate = undefined;
		/** @type {TemplatePath | undefined} */
		this.cssFilenameTemplate = undefined;
		/**
		 * @private
		 * @type {SortableChunkGroups}
		 */
		this._groups = new SortableSet(undefined, compareChunkGroupsByIndex);
		/** @type {RuntimeSpec} */
		this.runtime = undefined;
		/** @type {Set<string>} */
		this.files = backCompat ? new ChunkFilesSet() : new Set();
		/** @type {Set<string>} */
		this.auxiliaryFiles = new Set();
		/** @type {boolean} */
		this.rendered = false;
		/** @type {string=} */
		this.hash = undefined;
		/** @type {Record<string, string>} */
		this.contentHash = Object.create(null);
		/** @type {string=} */
		this.renderedHash = undefined;
		/** @type {string=} */
		this.chunkReason = undefined;
		/** @type {boolean} */
		this.extraAsync = false;
	}

	// TODO remove in webpack 6
	// BACKWARD-COMPAT START
	/**
	 * Returns entry module.
	 * @deprecated
	 * @returns {Module | undefined} entry module
	 */
	get entryModule() {
		const entryModules = [
			...ChunkGraph.getChunkGraphForChunk(
				this,
				"Chunk.entryModule",
				"DEP_WEBPACK_CHUNK_ENTRY_MODULE"
			).getChunkEntryModulesIterable(this)
		];
		if (entryModules.length === 0) {
			return undefined;
		} else if (entryModules.length === 1) {
			return entryModules[0];
		}

		throw new Error(
			"Module.entryModule: Multiple entry modules are not supported by the deprecated API (Use the new ChunkGroup API)"
		);
	}

	/**
	 * Checks whether this chunk has an entry module.
	 * @deprecated
	 * @returns {boolean} true, if the chunk contains an entry module
	 */
	hasEntryModule() {
		return (
			ChunkGraph.getChunkGraphForChunk(
				this,
				"Chunk.hasEntryModule",
				"DEP_WEBPACK_CHUNK_HAS_ENTRY_MODULE"
			).getNumberOfEntryModules(this) > 0
		);
	}

	/**
	 * Adds the provided module to the chunk.
	 * @deprecated
	 * @param {Module} module the module
	 * @returns {boolean} true, if the chunk could be added
	 */
	addModule(module) {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.addModule",
			"DEP_WEBPACK_CHUNK_ADD_MODULE"
		);
		if (chunkGraph.isModuleInChunk(module, this)) return false;
		chunkGraph.connectChunkAndModule(this, module);
		return true;
	}

	/**
	 * Removes the provided module from the chunk.
	 * @deprecated
	 * @param {Module} module the module
	 * @returns {void}
	 */
	removeModule(module) {
		ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.removeModule",
			"DEP_WEBPACK_CHUNK_REMOVE_MODULE"
		).disconnectChunkAndModule(this, module);
	}

	/**
	 * Gets the number of modules in this chunk.
	 * @deprecated
	 * @returns {number} the number of module which are contained in this chunk
	 */
	getNumberOfModules() {
		return ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.getNumberOfModules",
			"DEP_WEBPACK_CHUNK_GET_NUMBER_OF_MODULES"
		).getNumberOfChunkModules(this);
	}

	/**
	 * @deprecated
	 * @returns {Iterable<Module>} modules
	 */
	get modulesIterable() {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.modulesIterable",
			"DEP_WEBPACK_CHUNK_MODULES_ITERABLE"
		);
		return chunkGraph.getOrderedChunkModulesIterable(
			this,
			compareModulesByIdentifier
		);
	}

	/**
	 * Compares this chunk with another chunk.
	 * @deprecated
	 * @param {Chunk} otherChunk the chunk to compare with
	 * @returns {-1 | 0 | 1} the comparison result
	 */
	compareTo(otherChunk) {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.compareTo",
			"DEP_WEBPACK_CHUNK_COMPARE_TO"
		);
		return chunkGraph.compareChunks(this, otherChunk);
	}

	/**
	 * Checks whether this chunk contains the module.
	 * @deprecated
	 * @param {Module} module the module
	 * @returns {boolean} true, if the chunk contains the module
	 */
	containsModule(module) {
		return ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.containsModule",
			"DEP_WEBPACK_CHUNK_CONTAINS_MODULE"
		).isModuleInChunk(module, this);
	}

	/**
	 * Returns the modules for this chunk.
	 * @deprecated
	 * @returns {Module[]} the modules for this chunk
	 */
	getModules() {
		return ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.getModules",
			"DEP_WEBPACK_CHUNK_GET_MODULES"
		).getChunkModules(this);
	}

	/**
	 * Removes this chunk from the chunk graph and chunk groups.
	 * @deprecated
	 * @returns {void}
	 */
	remove() {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.remove",
			"DEP_WEBPACK_CHUNK_REMOVE"
		);
		chunkGraph.disconnectChunk(this);
		this.disconnectFromGroups();
	}

	/**
	 * Moves a module from this chunk to another chunk.
	 * @deprecated
	 * @param {Module} module the module
	 * @param {Chunk} otherChunk the target chunk
	 * @returns {void}
	 */
	moveModule(module, otherChunk) {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.moveModule",
			"DEP_WEBPACK_CHUNK_MOVE_MODULE"
		);
		chunkGraph.disconnectChunkAndModule(this, module);
		chunkGraph.connectChunkAndModule(otherChunk, module);
	}

	/**
	 * Integrates another chunk into this chunk when possible.
	 * @deprecated
	 * @param {Chunk} otherChunk the other chunk
	 * @returns {boolean} true, if the specified chunk has been integrated
	 */
	integrate(otherChunk) {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.integrate",
			"DEP_WEBPACK_CHUNK_INTEGRATE"
		);
		if (chunkGraph.canChunksBeIntegrated(this, otherChunk)) {
			chunkGraph.integrateChunks(this, otherChunk);
			return true;
		}

		return false;
	}

	/**
	 * Checks whether this chunk can be integrated with another chunk.
	 * @deprecated
	 * @param {Chunk} otherChunk the other chunk
	 * @returns {boolean} true, if chunks could be integrated
	 */
	canBeIntegrated(otherChunk) {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.canBeIntegrated",
			"DEP_WEBPACK_CHUNK_CAN_BE_INTEGRATED"
		);
		return chunkGraph.canChunksBeIntegrated(this, otherChunk);
	}

	/**
	 * Checks whether this chunk is empty.
	 * @deprecated
	 * @returns {boolean} true, if this chunk contains no module
	 */
	isEmpty() {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.isEmpty",
			"DEP_WEBPACK_CHUNK_IS_EMPTY"
		);
		return chunkGraph.getNumberOfChunkModules(this) === 0;
	}

	/**
	 * Returns the total size of all modules in this chunk.
	 * @deprecated
	 * @returns {number} total size of all modules in this chunk
	 */
	modulesSize() {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.modulesSize",
			"DEP_WEBPACK_CHUNK_MODULES_SIZE"
		);
		return chunkGraph.getChunkModulesSize(this);
	}

	/**
	 * Returns the estimated size for the requested source type.
	 * @deprecated
	 * @param {ChunkSizeOptions} options options object
	 * @returns {number} total size of this chunk
	 */
	size(options = {}) {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.size",
			"DEP_WEBPACK_CHUNK_SIZE"
		);
		return chunkGraph.getChunkSize(this, options);
	}

	/**
	 * Returns the integrated size with another chunk.
	 * @deprecated
	 * @param {Chunk} otherChunk the other chunk
	 * @param {ChunkSizeOptions} options options object
	 * @returns {number} total size of the chunk or false if the chunk can't be integrated
	 */
	integratedSize(otherChunk, options) {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.integratedSize",
			"DEP_WEBPACK_CHUNK_INTEGRATED_SIZE"
		);
		return chunkGraph.getIntegratedChunksSize(this, otherChunk, options);
	}

	/**
	 * Gets chunk module maps.
	 * @deprecated
	 * @param {ModuleFilterPredicate} filterFn function used to filter modules
	 * @returns {ChunkModuleMaps} module map information
	 */
	getChunkModuleMaps(filterFn) {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.getChunkModuleMaps",
			"DEP_WEBPACK_CHUNK_GET_CHUNK_MODULE_MAPS"
		);
		/** @type {ChunkModuleIdMap} */
		const chunkModuleIdMap = Object.create(null);
		/** @type {chunkModuleHashMap} */
		const chunkModuleHashMap = Object.create(null);

		for (const asyncChunk of this.getAllAsyncChunks()) {
			/** @type {ChunkId[] | undefined} */
			let array;
			for (const module of chunkGraph.getOrderedChunkModulesIterable(
				asyncChunk,
				compareModulesById(chunkGraph)
			)) {
				if (filterFn(module)) {
					if (array === undefined) {
						array = [];
						chunkModuleIdMap[/** @type {ChunkId} */ (asyncChunk.id)] = array;
					}
					const moduleId =
						/** @type {ModuleId} */
						(chunkGraph.getModuleId(module));
					array.push(moduleId);
					chunkModuleHashMap[moduleId] = chunkGraph.getRenderedModuleHash(
						module,
						undefined
					);
				}
			}
		}

		return {
			id: chunkModuleIdMap,
			hash: chunkModuleHashMap
		};
	}

	/**
	 * Checks whether this chunk contains a matching module in the graph.
	 * @deprecated
	 * @param {ModuleFilterPredicate} filterFn predicate function used to filter modules
	 * @param {ChunkFilterPredicate=} filterChunkFn predicate function used to filter chunks
	 * @returns {boolean} return true if module exists in graph
	 */
	hasModuleInGraph(filterFn, filterChunkFn) {
		const chunkGraph = ChunkGraph.getChunkGraphForChunk(
			this,
			"Chunk.hasModuleInGraph",
			"DEP_WEBPACK_CHUNK_HAS_MODULE_IN_GRAPH"
		);
		return chunkGraph.hasModuleInGraph(this, filterFn, filterChunkFn);
	}

	/**
	 * Returns the chunk map information.
	 * @deprecated
	 * @param {boolean} realHash whether the full hash or the rendered hash is to be used
	 * @returns {ChunkMaps} the chunk map information
	 */
	getChunkMaps(realHash) {
		/** @type {Record<ChunkId, string>} */
		const chunkHashMap = Object.create(null);
		/** @type {Record<string, Record<ChunkId, string>>} */
		const chunkContentHashMap = Object.create(null);
		/** @type {Record<ChunkId, string>} */
		const chunkNameMap = Object.create(null);

		for (const chunk of this.getAllAsyncChunks()) {
			const id = /** @type {ChunkId} */ (chunk.id);
			chunkHashMap[id] =
				/** @type {string} */
				(realHash ? chunk.hash : chunk.renderedHash);
			for (const key of Object.keys(chunk.contentHash)) {
				if (!chunkContentHashMap[key]) {
					chunkContentHashMap[key] = Object.create(null);
				}
				chunkContentHashMap[key][id] = chunk.contentHash[key];
			}
			if (chunk.name) {
				chunkNameMap[id] = chunk.name;
			}
		}

		return {
			hash: chunkHashMap,
			contentHash: chunkContentHashMap,
			name: chunkNameMap
		};
	}
	// BACKWARD-COMPAT END

	/**
	 * Checks whether this chunk has runtime.
	 * @returns {boolean} whether or not the Chunk will have a runtime
	 */
	hasRuntime() {
		for (const chunkGroup of this._groups) {
			if (
				chunkGroup instanceof Entrypoint &&
				chunkGroup.getRuntimeChunk() === this
			) {
				return true;
			}
		}
		return false;
	}

	/**
	 * Checks whether it can be initial.
	 * @returns {boolean} whether or not this chunk can be an initial chunk
	 */
	canBeInitial() {
		for (const chunkGroup of this._groups) {
			if (chunkGroup.isInitial()) return true;
		}
		return false;
	}

	/**
	 * Checks whether this chunk is only initial.
	 * @returns {boolean} whether this chunk can only be an initial chunk
	 */
	isOnlyInitial() {
		if (this._groups.size <= 0) return false;
		for (const chunkGroup of this._groups) {
			if (!chunkGroup.isInitial()) return false;
		}
		return true;
	}

	/**
	 * Gets entry options.
	 * @returns {EntryOptions | undefined} the entry options for this chunk
	 */
	getEntryOptions() {
		for (const chunkGroup of this._groups) {
			if (chunkGroup instanceof Entrypoint) {
				return chunkGroup.options;
			}
		}
		return undefined;
	}

	/**
	 * Adds the provided chunk group to the chunk.
	 * @param {ChunkGroup} chunkGroup the chunkGroup the chunk is being added
	 * @returns {void}
	 */
	addGroup(chunkGroup) {
		this._groups.add(chunkGroup);
	}

	/**
	 * Removes the provided chunk group from the chunk.
	 * @param {ChunkGroup} chunkGroup the chunkGroup the chunk is being removed from
	 * @returns {void}
	 */
	removeGroup(chunkGroup) {
		this._groups.delete(chunkGroup);
	}

	/**
	 * Checks whether this chunk is in group.
	 * @param {ChunkGroup} chunkGroup the chunkGroup to check
	 * @returns {boolean} returns true if chunk has chunkGroup reference and exists in chunkGroup
	 */
	isInGroup(chunkGroup) {
		return this._groups.has(chunkGroup);
	}

	/**
	 * Gets number of groups.
	 * @returns {number} the amount of groups that the said chunk is in
	 */
	getNumberOfGroups() {
		return this._groups.size;
	}

	/**
	 * Gets groups iterable.
	 * @returns {SortableChunkGroups} the chunkGroups that the said chunk is referenced in
	 */
	get groupsIterable() {
		this._groups.sort();
		return this._groups;
	}

	/**
	 * Disconnects from groups.
	 * @returns {void}
	 */
	disconnectFromGroups() {
		for (const chunkGroup of this._groups) {
			chunkGroup.removeChunk(this);
		}
	}

	/**
	 * Processes the provided new chunk.
	 * @param {Chunk} newChunk the new chunk that will be split out of
	 * @returns {void}
	 */
	split(newChunk) {
		for (const chunkGroup of this._groups) {
			chunkGroup.insertChunk(newChunk, this);
			newChunk.addGroup(chunkGroup);
		}
		for (const idHint of this.idNameHints) {
			newChunk.idNameHints.add(idHint);
		}
		newChunk.runtime = mergeRuntime(newChunk.runtime, this.runtime);
	}

	/**
	 * Updates the hash with the data contributed by this instance.
	 * @param {Hash} hash hash (will be modified)
	 * @param {ChunkGraph} chunkGraph the chunk graph
	 * @returns {void}
	 */
	updateHash(hash, chunkGraph) {
		hash.update(
			`${this.id} ${this.ids ? this.ids.join() : ""} ${this.name || ""} `
		);
		const xor = new StringXor();
		for (const m of chunkGraph.getChunkModulesIterable(this)) {
			xor.add(chunkGraph.getModuleHash(m, this.runtime));
		}
		xor.updateHash(hash);
		const entryModules =
			chunkGraph.getChunkEntryModulesWithChunkGroupIterable(this);
		for (const [m, chunkGroup] of entryModules) {
			hash.update(
				`entry${chunkGraph.getModuleId(m)}${
					/** @type {ChunkGroup} */ (chunkGroup).id
				}`
			);
		}
	}

	/**
	 * Gets all async chunks.
	 * @returns {Chunks} a set of all the async chunks
	 */
	getAllAsyncChunks() {
		/** @type {Queue} */
		const queue = new Set();
		/** @type {Chunks} */
		const chunks = new Set();

		const initialChunks = intersect(
			Array.from(this.groupsIterable, (g) => new Set(g.chunks))
		);

		/** @type {Queue} */
		const initialQueue = new Set(this.groupsIterable);

		for (const chunkGroup of initialQueue) {
			for (const child of chunkGroup.childrenIterable) {
				if (child instanceof Entrypoint) {
					initialQueue.add(child);
				} else {
					queue.add(child);
				}
			}
		}

		for (const chunkGroup of queue) {
			for (const chunk of chunkGroup.chunks) {
				if (!initialChunks.has(chunk)) {
					chunks.add(chunk);
				}
			}
			for (const child of chunkGroup.childrenIterable) {
				queue.add(child);
			}
		}

		return chunks;
	}

	/**
	 * Gets all initial chunks.
	 * @returns {Chunks} a set of all the initial chunks (including itself)
	 */
	getAllInitialChunks() {
		/** @type {Chunks} */
		const chunks = new Set();
		/** @type {Queue} */
		const queue = new Set(this.groupsIterable);
		for (const group of queue) {
			if (group.isInitial()) {
				for (const c of group.chunks) chunks.add(c);
				for (const g of group.childrenIterable) queue.add(g);
			}
		}
		return chunks;
	}

	/**
	 * Gets all referenced chunks.
	 * @returns {Chunks} a set of all the referenced chunks (including itself)
	 */
	getAllReferencedChunks() {
		/** @type {Queue} */
		const queue = new Set(this.groupsIterable);
		/** @type {Chunks} */
		const chunks = new Set();

		for (const chunkGroup of queue) {
			for (const chunk of chunkGroup.chunks) {
				chunks.add(chunk);
			}
			for (const child of chunkGroup.childrenIterable) {
				queue.add(child);
			}
		}

		return chunks;
	}

	/**
	 * Gets all referenced async entrypoints.
	 * @returns {Entrypoints} a set of all the referenced entrypoints
	 */
	getAllReferencedAsyncEntrypoints() {
		/** @type {Queue} */
		const queue = new Set(this.groupsIterable);
		/** @type {Entrypoints} */
		const entrypoints = new Set();

		for (const chunkGroup of queue) {
			for (const entrypoint of chunkGroup.asyncEntrypointsIterable) {
				entrypoints.add(/** @type {Entrypoint} */ (entrypoint));
			}
			for (const child of chunkGroup.childrenIterable) {
				queue.add(child);
			}
		}

		return entrypoints;
	}

	/**
	 * Checks whether this chunk has async chunks.
	 * @returns {boolean} true, if the chunk references async chunks
	 */
	hasAsyncChunks() {
		/** @type {Queue} */
		const queue = new Set();

		const initialChunks = intersect(
			Array.from(this.groupsIterable, (g) => new Set(g.chunks))
		);

		for (const chunkGroup of this.groupsIterable) {
			for (const child of chunkGroup.childrenIterable) {
				queue.add(child);
			}
		}

		for (const chunkGroup of queue) {
			for (const chunk of chunkGroup.chunks) {
				if (!initialChunks.has(chunk)) {
					return true;
				}
			}
			for (const child of chunkGroup.childrenIterable) {
				queue.add(child);
			}
		}

		return false;
	}

	/**
	 * Gets child ids by orders.
	 * @param {ChunkGraph} chunkGraph the chunk graph
	 * @param {ChunkFilterPredicate=} filterFn function used to filter chunks
	 * @returns {Record<string, ChunkId[]>} a record object of names to lists of child ids(?)
	 */
	getChildIdsByOrders(chunkGraph, filterFn) {
		/** @type {Map<string, { order: number, group: ChunkGroup }[]>} */
		const lists = new Map();
		for (const group of this.groupsIterable) {
			if (group.chunks[group.chunks.length - 1] === this) {
				for (const childGroup of group.childrenIterable) {
					for (const key of Object.keys(childGroup.options)) {
						if (key.endsWith("Order")) {
							const name = key.slice(0, key.length - "Order".length);
							let list = lists.get(name);
							if (list === undefined) {
								list = [];
								lists.set(name, list);
							}
							list.push({
								order:
									/** @type {number} */
									(
										childGroup.options[
											/** @type {keyof ChunkGroupOptions} */
											(key)
										]
									),
								group: childGroup
							});
						}
					}
				}
			}
		}
		/** @type {Record<string, ChunkId[]>} */
		const result = Object.create(null);
		for (const [name, list] of lists) {
			list.sort((a, b) => {
				const cmp = b.order - a.order;
				if (cmp !== 0) return cmp;
				return a.group.compareTo(chunkGraph, b.group);
			});
			/** @type {Set<ChunkId>} */
			const chunkIdSet = new Set();
			for (const item of list) {
				for (const chunk of item.group.chunks) {
					if (filterFn && !filterFn(chunk, chunkGraph)) continue;
					chunkIdSet.add(/** @type {ChunkId} */ (chunk.id));
				}
			}
			if (chunkIdSet.size > 0) {
				result[name] = [...chunkIdSet];
			}
		}
		return result;
	}

	/**
	 * Gets children of type in order.
	 * @param {ChunkGraph} chunkGraph the chunk graph
	 * @param {string} type option name
	 * @returns {ChunkChildOfTypeInOrder[] | undefined} referenced chunks for a specific type
	 */
	getChildrenOfTypeInOrder(chunkGraph, type) {
		/** @type {{ order: number, group: ChunkGroup, childGroup: ChunkGroup }[]} */
		const list = [];
		for (const group of this.groupsIterable) {
			for (const childGroup of group.childrenIterable) {
				const order =
					/** @type {number} */
					(childGroup.options[/** @type {keyof ChunkGroupOptions} */ (type)]);
				if (order === undefined) continue;
				list.push({
					order,
					group,
					childGroup
				});
			}
		}
		if (list.length === 0) return;
		list.sort((a, b) => {
			const cmp = b.order - a.order;
			if (cmp !== 0) return cmp;
			return a.group.compareTo(chunkGraph, b.group);
		});
		/** @type {ChunkChildOfTypeInOrder[]} */
		const result = [];
		/** @type {undefined | ChunkChildOfTypeInOrder} */
		let lastEntry;
		for (const { group, childGroup } of list) {
			if (lastEntry && lastEntry.onChunks === group.chunks) {
				for (const chunk of childGroup.chunks) {
					lastEntry.chunks.add(chunk);
				}
			} else {
				result.push(
					(lastEntry = {
						onChunks: group.chunks,
						chunks: new Set(childGroup.chunks)
					})
				);
			}
		}
		return result;
	}

	/**
	 * Gets child ids by orders map.
	 * @param {ChunkGraph} chunkGraph the chunk graph
	 * @param {boolean=} includeDirectChildren include direct children (by default only children of async children are included)
	 * @param {ChunkFilterPredicate=} filterFn function used to filter chunks
	 * @returns {ChunkChildIdsByOrdersMapByData} a record object of names to lists of child ids(?) by chunk id
	 */
	getChildIdsByOrdersMap(chunkGraph, includeDirectChildren, filterFn) {
		/** @type {ChunkChildIdsByOrdersMapByData} */
		const chunkMaps = Object.create(null);

		/**
		 * Adds child ids by orders to map.
		 * @param {Chunk} chunk a chunk
		 * @returns {void}
		 */
		const addChildIdsByOrdersToMap = (chunk) => {
			const data = chunk.getChildIdsByOrders(chunkGraph, filterFn);
			for (const key of Object.keys(data)) {
				let chunkMap = chunkMaps[key];
				if (chunkMap === undefined) {
					chunkMaps[key] = chunkMap = Object.create(null);
				}
				chunkMap[/** @type {ChunkId} */ (chunk.id)] = data[key];
			}
		};

		if (includeDirectChildren) {
			/** @type {Chunks} */
			const chunks = new Set();
			for (const chunkGroup of this.groupsIterable) {
				for (const chunk of chunkGroup.chunks) {
					chunks.add(chunk);
				}
			}
			for (const chunk of chunks) {
				addChildIdsByOrdersToMap(chunk);
			}
		}

		for (const chunk of this.getAllAsyncChunks()) {
			addChildIdsByOrdersToMap(chunk);
		}

		return chunkMaps;
	}

	/**
	 * Checks whether this chunk contains the chunk graph.
	 * @param {ChunkGraph} chunkGraph the chunk graph
	 * @param {string} type option name
	 * @param {boolean=} includeDirectChildren include direct children (by default only children of async children are included)
	 * @param {ChunkFilterPredicate=} filterFn function used to filter chunks
	 * @returns {boolean} true when the child is of type order, otherwise false
	 */
	hasChildByOrder(chunkGraph, type, includeDirectChildren, filterFn) {
		if (includeDirectChildren) {
			/** @type {Chunks} */
			const chunks = new Set();
			for (const chunkGroup of this.groupsIterable) {
				for (const chunk of chunkGroup.chunks) {
					chunks.add(chunk);
				}
			}
			for (const chunk of chunks) {
				const data = chunk.getChildIdsByOrders(chunkGraph, filterFn);
				if (data[type] !== undefined) return true;
			}
		}

		for (const chunk of this.getAllAsyncChunks()) {
			const data = chunk.getChildIdsByOrders(chunkGraph, filterFn);
			if (data[type] !== undefined) return true;
		}

		return false;
	}
}

module.exports = Chunk;