webpack/lib/optimize/SplitChunksPlugin.js

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/

"use strict";

const ChunkCombination = require("../ChunkCombination");
const { STAGE_ADVANCED } = require("../OptimizationStages");
const WebpackError = require("../WebpackError");
const { requestToId } = require("../ids/IdHelpers");
const SortableSet = require("../util/SortableSet");
const {
	compareModulesByIdentifier,
	compareIterables
} = require("../util/comparators");
const createHash = require("../util/createHash");
const deterministicGrouping = require("../util/deterministicGrouping");
const { makePathsRelative } = require("../util/identifier");
const memoize = require("../util/memoize");
const MinMaxSizeWarning = require("./MinMaxSizeWarning");

/** @typedef {import("../../declarations/WebpackOptions").OptimizationSplitChunksCacheGroup} OptimizationSplitChunksCacheGroup */
/** @typedef {import("../../declarations/WebpackOptions").OptimizationSplitChunksGetCacheGroups} OptimizationSplitChunksGetCacheGroups */
/** @typedef {import("../../declarations/WebpackOptions").OptimizationSplitChunksOptions} OptimizationSplitChunksOptions */
/** @typedef {import("../../declarations/WebpackOptions").OptimizationSplitChunksSizes} OptimizationSplitChunksSizes */
/** @typedef {import("../../declarations/WebpackOptions").Output} OutputOptions */
/** @typedef {import("../Chunk")} Chunk */
/** @typedef {import("../ChunkGraph")} ChunkGraph */
/** @typedef {import("../ChunkGroup")} ChunkGroup */
/** @typedef {import("../Compilation").AssetInfo} AssetInfo */
/** @typedef {import("../Compilation").PathData} PathData */
/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("../Module")} Module */
/** @typedef {import("../ModuleGraph")} ModuleGraph */
/** @typedef {import("../util/deterministicGrouping").GroupedItems<Module>} DeterministicGroupingGroupedItemsForModule */
/** @typedef {import("../util/deterministicGrouping").Options<Module>} DeterministicGroupingOptionsForModule */

/** @typedef {Record<string, number>} SplitChunksSizes */

/**
 * @callback ChunkFilterFunction
 * @param {Chunk} chunk
 * @returns {boolean}
 */

/**
 * @callback CombineSizeFunction
 * @param {number} a
 * @param {number} b
 * @returns {number}
 */

/**
 * @typedef {Object} CacheGroupSource
 * @property {string=} key
 * @property {number=} priority
 * @property {GetName=} getName
 * @property {ChunkFilterFunction=} chunksFilter
 * @property {boolean=} enforce
 * @property {SplitChunksSizes} minSize
 * @property {SplitChunksSizes} minRemainingSize
 * @property {SplitChunksSizes} enforceSizeThreshold
 * @property {SplitChunksSizes} maxAsyncSize
 * @property {SplitChunksSizes} maxInitialSize
 * @property {number=} minChunks
 * @property {number=} maxAsyncRequests
 * @property {number=} maxInitialRequests
 * @property {(string | function(PathData, AssetInfo=): string)=} filename
 * @property {string=} idHint
 * @property {string} automaticNameDelimiter
 * @property {boolean=} reuseExistingChunk
 * @property {boolean=} usedExports
 */

/**
 * @typedef {Object} CacheGroup
 * @property {string} key
 * @property {number=} priority
 * @property {GetName=} getName
 * @property {ChunkFilterFunction=} chunksFilter
 * @property {SplitChunksSizes} minSize
 * @property {SplitChunksSizes} minRemainingSize
 * @property {SplitChunksSizes} enforceSizeThreshold
 * @property {SplitChunksSizes} maxAsyncSize
 * @property {SplitChunksSizes} maxInitialSize
 * @property {number=} minChunks
 * @property {number=} maxAsyncRequests
 * @property {number=} maxInitialRequests
 * @property {(string | function(PathData, AssetInfo=): string)=} filename
 * @property {string=} idHint
 * @property {string} automaticNameDelimiter
 * @property {boolean} reuseExistingChunk
 * @property {boolean} usedExports
 * @property {boolean} _validateSize
 * @property {boolean} _validateRemainingSize
 * @property {SplitChunksSizes} _minSizeForMaxSize
 * @property {boolean} _conditionalEnforce
 */

/**
 * @typedef {Object} FallbackCacheGroup
 * @property {SplitChunksSizes} minSize
 * @property {SplitChunksSizes} maxAsyncSize
 * @property {SplitChunksSizes} maxInitialSize
 * @property {string} automaticNameDelimiter
 */

/**
 * @typedef {Object} CacheGroupsContext
 * @property {ModuleGraph} moduleGraph
 * @property {ChunkGraph} chunkGraph
 */

/**
 * @callback GetCacheGroups
 * @param {Module} module
 * @param {CacheGroupsContext} context
 * @returns {CacheGroupSource[]}
 */

/**
 * @callback GetName
 * @param {Module=} module
 * @param {Chunk[]=} chunks
 * @param {string=} key
 * @returns {string=}
 */

/**
 * @typedef {Object} SplitChunksOptions
 * @property {ChunkFilterFunction} chunksFilter
 * @property {string[]} defaultSizeTypes
 * @property {SplitChunksSizes} minSize
 * @property {SplitChunksSizes} minRemainingSize
 * @property {SplitChunksSizes} enforceSizeThreshold
 * @property {SplitChunksSizes} maxInitialSize
 * @property {SplitChunksSizes} maxAsyncSize
 * @property {number} minChunks
 * @property {number} maxAsyncRequests
 * @property {number} maxInitialRequests
 * @property {boolean} hidePathInfo
 * @property {string | function(PathData, AssetInfo=): string} filename
 * @property {string} automaticNameDelimiter
 * @property {GetCacheGroups} getCacheGroups
 * @property {GetName} getName
 * @property {boolean} usedExports
 * @property {FallbackCacheGroup} fallbackCacheGroup
 */

/**
 * @typedef {Object} ChunksInfoItem
 * @property {SortableSet<Module>} modules
 * @property {CacheGroup} cacheGroup
 * @property {number} cacheGroupIndex
 * @property {string} name
 * @property {Record<string, number>} sizes
 * @property {ChunkCombination} chunks
 * @property {Set<Chunk>} reuseableChunks
 * @property {Set<ChunkCombination>} chunkCombinations
 */

const defaultGetName = /** @type {GetName} */ (() => {});

const deterministicGroupingForModules =
	/** @type {function(DeterministicGroupingOptionsForModule): DeterministicGroupingGroupedItemsForModule[]} */ (
		deterministicGrouping
	);

/** @type {WeakMap<Module, string>} */
const getKeyCache = new WeakMap();

/**
 * @param {string} name a filename to hash
 * @param {OutputOptions} outputOptions hash function used
 * @returns {string} hashed filename
 */
const hashFilename = (name, outputOptions) => {
	const digest = /** @type {string} */ (
		createHash(outputOptions.hashFunction)
			.update(name)
			.digest(outputOptions.hashDigest)
	);
	return digest.slice(0, 8);
};

/**
 * @param {Chunk} chunk the chunk
 * @returns {number} the number of requests
 */
const getRequests = chunk => {
	let requests = 0;
	for (const chunkGroup of chunk.groupsIterable) {
		requests = Math.max(requests, chunkGroup.chunks.length);
	}
	return requests;
};

const mapObject = (obj, fn) => {
	const newObj = Object.create(null);
	for (const key of Object.keys(obj)) {
		newObj[key] = fn(obj[key], key);
	}
	return newObj;
};

const compareModuleIterables = compareIterables(compareModulesByIdentifier);

/**
 * @param {ChunksInfoItem} a item
 * @param {ChunksInfoItem} b item
 * @returns {number} compare result
 */
const compareEntries = (a, b) => {
	// 1. by priority
	const diffPriority = a.cacheGroup.priority - b.cacheGroup.priority;
	if (diffPriority) return diffPriority;
	// 2. by number of chunks
	const diffCount = a.chunks.size - b.chunks.size;
	if (diffCount) return diffCount;
	// 3. by size reduction
	const aSizeReduce = totalSize(a.sizes) * (a.chunks.size - 1);
	const bSizeReduce = totalSize(b.sizes) * (b.chunks.size - 1);
	const diffSizeReduce = aSizeReduce - bSizeReduce;
	if (diffSizeReduce) return diffSizeReduce;
	// 4. by cache group index
	const indexDiff = b.cacheGroupIndex - a.cacheGroupIndex;
	if (indexDiff) return indexDiff;
	// 5. by number of modules (to be able to compare by identifier)
	const modulesA = a.modules;
	const modulesB = b.modules;
	const diff = modulesA.size - modulesB.size;
	if (diff) return diff;
	// 6. by module identifiers
	modulesA.sort();
	modulesB.sort();
	return compareModuleIterables(modulesA, modulesB);
};

const INITIAL_CHUNK_FILTER = chunk => chunk.canBeInitial();
const ASYNC_CHUNK_FILTER = chunk => !chunk.canBeInitial();
const ALL_CHUNK_FILTER = chunk => true;

/**
 * @param {OptimizationSplitChunksSizes} value the sizes
 * @param {string[]} defaultSizeTypes the default size types
 * @returns {SplitChunksSizes} normalized representation
 */
const normalizeSizes = (value, defaultSizeTypes) => {
	if (typeof value === "number") {
		/** @type {Record<string, number>} */
		const o = {};
		for (const sizeType of defaultSizeTypes) o[sizeType] = value;
		return o;
	} else if (typeof value === "object" && value !== null) {
		return { ...value };
	} else {
		return {};
	}
};

/**
 * @param {...SplitChunksSizes} sizes the sizes
 * @returns {SplitChunksSizes} the merged sizes
 */
const mergeSizes = (...sizes) => {
	/** @type {SplitChunksSizes} */
	let merged = {};
	for (let i = sizes.length - 1; i >= 0; i--) {
		merged = Object.assign(merged, sizes[i]);
	}
	return merged;
};

/**
 * @param {SplitChunksSizes} sizes the sizes
 * @returns {boolean} true, if there are sizes > 0
 */
const hasNonZeroSizes = sizes => {
	for (const key of Object.keys(sizes)) {
		if (sizes[key] > 0) return true;
	}
	return false;
};

/**
 * @param {SplitChunksSizes} a first sizes
 * @param {SplitChunksSizes} b second sizes
 * @param {CombineSizeFunction} combine a function to combine sizes
 * @returns {SplitChunksSizes} the combine sizes
 */
const combineSizes = (a, b, combine) => {
	const aKeys = new Set(Object.keys(a));
	const bKeys = new Set(Object.keys(b));
	/** @type {SplitChunksSizes} */
	const result = {};
	for (const key of aKeys) {
		if (bKeys.has(key)) {
			result[key] = combine(a[key], b[key]);
		} else {
			result[key] = a[key];
		}
	}
	for (const key of bKeys) {
		if (!aKeys.has(key)) {
			result[key] = b[key];
		}
	}
	return result;
};

/**
 * @param {SplitChunksSizes} sizes the sizes
 * @param {SplitChunksSizes} minSize the min sizes
 * @returns {boolean} true if there are sizes and all existing sizes are at least `minSize`
 */
const checkMinSize = (sizes, minSize) => {
	for (const key of Object.keys(minSize)) {
		const size = sizes[key];
		if (size === undefined || size === 0) continue;
		if (size < minSize[key]) return false;
	}
	return true;
};

/**
 * @param {SplitChunksSizes} sizes the sizes
 * @param {SplitChunksSizes} minSize the min sizes
 * @returns {undefined | string[]} list of size types that are below min size
 */
const getViolatingMinSizes = (sizes, minSize) => {
	let list;
	for (const key of Object.keys(minSize)) {
		const size = sizes[key];
		if (size === undefined || size === 0) continue;
		if (size < minSize[key]) {
			if (list === undefined) list = [key];
			else list.push(key);
		}
	}
	return list;
};

/**
 * @param {SplitChunksSizes} sizes the sizes
 * @returns {number} the total size
 */
const totalSize = sizes => {
	let size = 0;
	for (const key of Object.keys(sizes)) {
		size += sizes[key];
	}
	return size;
};

/**
 * @param {false|string|Function} name the chunk name
 * @returns {GetName} a function to get the name of the chunk
 */
const normalizeName = name => {
	if (typeof name === "string") {
		return () => name;
	}
	if (typeof name === "function") {
		return /** @type {GetName} */ (name);
	}
};

/**
 * @param {OptimizationSplitChunksCacheGroup["chunks"]} chunks the chunk filter option
 * @returns {ChunkFilterFunction} the chunk filter function
 */
const normalizeChunksFilter = chunks => {
	if (chunks === "initial") {
		return INITIAL_CHUNK_FILTER;
	}
	if (chunks === "async") {
		return ASYNC_CHUNK_FILTER;
	}
	if (chunks === "all") {
		return ALL_CHUNK_FILTER;
	}
	if (typeof chunks === "function") {
		return chunks;
	}
};

/**
 * @param {GetCacheGroups | Record<string, false|string|RegExp|OptimizationSplitChunksGetCacheGroups|OptimizationSplitChunksCacheGroup>} cacheGroups the cache group options
 * @param {string[]} defaultSizeTypes the default size types
 * @returns {GetCacheGroups} a function to get the cache groups
 */
const normalizeCacheGroups = (cacheGroups, defaultSizeTypes) => {
	if (typeof cacheGroups === "function") {
		return cacheGroups;
	}
	if (typeof cacheGroups === "object" && cacheGroups !== null) {
		/** @type {(function(Module, CacheGroupsContext, CacheGroupSource[]): void)[]} */
		const handlers = [];
		for (const key of Object.keys(cacheGroups)) {
			const option = cacheGroups[key];
			if (option === false) {
				continue;
			}
			if (typeof option === "string" || option instanceof RegExp) {
				const source = createCacheGroupSource({}, key, defaultSizeTypes);
				handlers.push((module, context, results) => {
					if (checkTest(option, module, context)) {
						results.push(source);
					}
				});
			} else if (typeof option === "function") {
				const cache = new WeakMap();
				handlers.push((module, context, results) => {
					const result = option(module);
					if (result) {
						const groups = Array.isArray(result) ? result : [result];
						for (const group of groups) {
							const cachedSource = cache.get(group);
							if (cachedSource !== undefined) {
								results.push(cachedSource);
							} else {
								const source = createCacheGroupSource(
									group,
									key,
									defaultSizeTypes
								);
								cache.set(group, source);
								results.push(source);
							}
						}
					}
				});
			} else {
				const source = createCacheGroupSource(option, key, defaultSizeTypes);
				handlers.push((module, context, results) => {
					if (
						checkTest(option.test, module, context) &&
						checkModuleType(option.type, module) &&
						checkModuleLayer(option.layer, module)
					) {
						results.push(source);
					}
				});
			}
		}
		/**
		 * @param {Module} module the current module
		 * @param {CacheGroupsContext} context the current context
		 * @returns {CacheGroupSource[]} the matching cache groups
		 */
		const fn = (module, context) => {
			/** @type {CacheGroupSource[]} */
			let results = [];
			for (const fn of handlers) {
				fn(module, context, results);
			}
			return results;
		};
		return fn;
	}
	return () => null;
};

/**
 * @param {undefined|boolean|string|RegExp|Function} test test option
 * @param {Module} module the module
 * @param {CacheGroupsContext} context context object
 * @returns {boolean} true, if the module should be selected
 */
const checkTest = (test, module, context) => {
	if (test === undefined) return true;
	if (typeof test === "function") {
		return test(module, context);
	}
	if (typeof test === "boolean") return test;
	if (typeof test === "string") {
		const name = module.nameForCondition();
		return name && name.startsWith(test);
	}
	if (test instanceof RegExp) {
		const name = module.nameForCondition();
		return name && test.test(name);
	}
	return false;
};

/**
 * @param {undefined|string|RegExp|Function} test type option
 * @param {Module} module the module
 * @returns {boolean} true, if the module should be selected
 */
const checkModuleType = (test, module) => {
	if (test === undefined) return true;
	if (typeof test === "function") {
		return test(module.type);
	}
	if (typeof test === "string") {
		const type = module.type;
		return test === type;
	}
	if (test instanceof RegExp) {
		const type = module.type;
		return test.test(type);
	}
	return false;
};

/**
 * @param {undefined|string|RegExp|Function} test type option
 * @param {Module} module the module
 * @returns {boolean} true, if the module should be selected
 */
const checkModuleLayer = (test, module) => {
	if (test === undefined) return true;
	if (typeof test === "function") {
		return test(module.layer);
	}
	if (typeof test === "string") {
		const layer = module.layer;
		return test === "" ? !layer : layer && layer.startsWith(test);
	}
	if (test instanceof RegExp) {
		const layer = module.layer;
		return test.test(layer);
	}
	return false;
};

/**
 * @param {OptimizationSplitChunksCacheGroup} options the group options
 * @param {string} key key of cache group
 * @param {string[]} defaultSizeTypes the default size types
 * @returns {CacheGroupSource} the normalized cached group
 */
const createCacheGroupSource = (options, key, defaultSizeTypes) => {
	const minSize = normalizeSizes(options.minSize, defaultSizeTypes);
	const maxSize = normalizeSizes(options.maxSize, defaultSizeTypes);
	return {
		key,
		priority: options.priority,
		getName: normalizeName(options.name),
		chunksFilter: normalizeChunksFilter(options.chunks),
		enforce: options.enforce,
		minSize,
		minRemainingSize: mergeSizes(
			normalizeSizes(options.minRemainingSize, defaultSizeTypes),
			minSize
		),
		enforceSizeThreshold: normalizeSizes(
			options.enforceSizeThreshold,
			defaultSizeTypes
		),
		maxAsyncSize: mergeSizes(
			normalizeSizes(options.maxAsyncSize, defaultSizeTypes),
			maxSize
		),
		maxInitialSize: mergeSizes(
			normalizeSizes(options.maxInitialSize, defaultSizeTypes),
			maxSize
		),
		minChunks: options.minChunks,
		maxAsyncRequests: options.maxAsyncRequests,
		maxInitialRequests: options.maxInitialRequests,
		filename: options.filename,
		idHint: options.idHint,
		automaticNameDelimiter: options.automaticNameDelimiter,
		reuseExistingChunk: options.reuseExistingChunk,
		usedExports: options.usedExports
	};
};

module.exports = class SplitChunksPlugin {
	/**
	 * @param {OptimizationSplitChunksOptions=} options plugin options
	 */
	constructor(options = {}) {
		const defaultSizeTypes = options.defaultSizeTypes || [
			"javascript",
			"unknown"
		];
		const fallbackCacheGroup = options.fallbackCacheGroup || {};
		const minSize = normalizeSizes(options.minSize, defaultSizeTypes);
		const maxSize = normalizeSizes(options.maxSize, defaultSizeTypes);

		/** @type {SplitChunksOptions} */
		this.options = {
			chunksFilter: normalizeChunksFilter(options.chunks || "all"),
			defaultSizeTypes,
			minSize,
			minRemainingSize: mergeSizes(
				normalizeSizes(options.minRemainingSize, defaultSizeTypes),
				minSize
			),
			enforceSizeThreshold: normalizeSizes(
				options.enforceSizeThreshold,
				defaultSizeTypes
			),
			maxAsyncSize: mergeSizes(
				normalizeSizes(options.maxAsyncSize, defaultSizeTypes),
				maxSize
			),
			maxInitialSize: mergeSizes(
				normalizeSizes(options.maxInitialSize, defaultSizeTypes),
				maxSize
			),
			minChunks: options.minChunks || 1,
			maxAsyncRequests: options.maxAsyncRequests || 1,
			maxInitialRequests: options.maxInitialRequests || 1,
			hidePathInfo: options.hidePathInfo || false,
			filename: options.filename || undefined,
			getCacheGroups: normalizeCacheGroups(
				options.cacheGroups,
				defaultSizeTypes
			),
			getName: options.name ? normalizeName(options.name) : defaultGetName,
			automaticNameDelimiter: options.automaticNameDelimiter,
			usedExports: options.usedExports,
			fallbackCacheGroup: {
				minSize: mergeSizes(
					normalizeSizes(fallbackCacheGroup.minSize, defaultSizeTypes),
					minSize
				),
				maxAsyncSize: mergeSizes(
					normalizeSizes(fallbackCacheGroup.maxAsyncSize, defaultSizeTypes),
					normalizeSizes(fallbackCacheGroup.maxSize, defaultSizeTypes),
					normalizeSizes(options.maxAsyncSize, defaultSizeTypes),
					normalizeSizes(options.maxSize, defaultSizeTypes)
				),
				maxInitialSize: mergeSizes(
					normalizeSizes(fallbackCacheGroup.maxInitialSize, defaultSizeTypes),
					normalizeSizes(fallbackCacheGroup.maxSize, defaultSizeTypes),
					normalizeSizes(options.maxInitialSize, defaultSizeTypes),
					normalizeSizes(options.maxSize, defaultSizeTypes)
				),
				automaticNameDelimiter:
					fallbackCacheGroup.automaticNameDelimiter ||
					options.automaticNameDelimiter ||
					"~"
			}
		};

		/** @type {WeakMap<CacheGroupSource, CacheGroup>} */
		this._cacheGroupCache = new WeakMap();
	}

	/**
	 * @param {CacheGroupSource} cacheGroupSource source
	 * @returns {CacheGroup} the cache group (cached)
	 */
	_getCacheGroup(cacheGroupSource) {
		const cacheEntry = this._cacheGroupCache.get(cacheGroupSource);
		if (cacheEntry !== undefined) return cacheEntry;
		const minSize = mergeSizes(
			cacheGroupSource.minSize,
			cacheGroupSource.enforce ? undefined : this.options.minSize
		);
		const minRemainingSize = mergeSizes(
			cacheGroupSource.minRemainingSize,
			cacheGroupSource.enforce ? undefined : this.options.minRemainingSize
		);
		const enforceSizeThreshold = mergeSizes(
			cacheGroupSource.enforceSizeThreshold,
			cacheGroupSource.enforce ? undefined : this.options.enforceSizeThreshold
		);
		const cacheGroup = {
			key: cacheGroupSource.key,
			priority: cacheGroupSource.priority || 0,
			chunksFilter: cacheGroupSource.chunksFilter || this.options.chunksFilter,
			minSize,
			minRemainingSize,
			enforceSizeThreshold,
			maxAsyncSize: mergeSizes(
				cacheGroupSource.maxAsyncSize,
				cacheGroupSource.enforce ? undefined : this.options.maxAsyncSize
			),
			maxInitialSize: mergeSizes(
				cacheGroupSource.maxInitialSize,
				cacheGroupSource.enforce ? undefined : this.options.maxInitialSize
			),
			minChunks:
				cacheGroupSource.minChunks !== undefined
					? cacheGroupSource.minChunks
					: cacheGroupSource.enforce
					? 1
					: this.options.minChunks,
			maxAsyncRequests:
				cacheGroupSource.maxAsyncRequests !== undefined
					? cacheGroupSource.maxAsyncRequests
					: cacheGroupSource.enforce
					? Infinity
					: this.options.maxAsyncRequests,
			maxInitialRequests:
				cacheGroupSource.maxInitialRequests !== undefined
					? cacheGroupSource.maxInitialRequests
					: cacheGroupSource.enforce
					? Infinity
					: this.options.maxInitialRequests,
			getName:
				cacheGroupSource.getName !== undefined
					? cacheGroupSource.getName
					: this.options.getName,
			usedExports:
				cacheGroupSource.usedExports !== undefined
					? cacheGroupSource.usedExports
					: this.options.usedExports,
			filename:
				cacheGroupSource.filename !== undefined
					? cacheGroupSource.filename
					: this.options.filename,
			automaticNameDelimiter:
				cacheGroupSource.automaticNameDelimiter !== undefined
					? cacheGroupSource.automaticNameDelimiter
					: this.options.automaticNameDelimiter,
			idHint:
				cacheGroupSource.idHint !== undefined
					? cacheGroupSource.idHint
					: cacheGroupSource.key,
			reuseExistingChunk: cacheGroupSource.reuseExistingChunk || false,
			_validateSize: hasNonZeroSizes(minSize),
			_validateRemainingSize: hasNonZeroSizes(minRemainingSize),
			_minSizeForMaxSize: mergeSizes(
				cacheGroupSource.minSize,
				this.options.minSize
			),
			_conditionalEnforce: hasNonZeroSizes(enforceSizeThreshold)
		};
		this._cacheGroupCache.set(cacheGroupSource, cacheGroup);
		return cacheGroup;
	}

	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		const cachedMakePathsRelative = makePathsRelative.bindContextCache(
			compiler.context,
			compiler.root
		);
		compiler.hooks.thisCompilation.tap("SplitChunksPlugin", compilation => {
			const logger = compilation.getLogger("webpack.SplitChunksPlugin");
			let alreadyOptimized = false;
			compilation.hooks.unseal.tap("SplitChunksPlugin", () => {
				alreadyOptimized = false;
			});
			compilation.hooks.optimizeChunks.tap(
				{
					name: "SplitChunksPlugin",
					stage: STAGE_ADVANCED
				},
				chunks => {
					if (alreadyOptimized) return;
					alreadyOptimized = true;
					logger.time("prepare");
					const chunkGraph = compilation.chunkGraph;
					const moduleGraph = compilation.moduleGraph;

					const getChunkCombinationsInGraph = memoize(() => {
						/** @type {Set<ChunkCombination>} */
						const chunkCombinationsInGraph = new Set();
						for (const module of compilation.modules) {
							const chunkCombination =
								chunkGraph.getModuleChunkCombination(module);
							chunkCombinationsInGraph.add(chunkCombination);
						}
						return chunkCombinationsInGraph;
					});

					/**
					 * @param {Module} module the module
					 * @returns {Iterable<ChunkCombination>} groups of chunks with equal exports
					 */
					const groupChunksByExports = module => {
						const exportsInfo = moduleGraph.getExportsInfo(module);
						const groupedByUsedExports = new Map();
						for (const chunk of chunkGraph.getModuleChunksIterable(module)) {
							const key = exportsInfo.getUsageKey(chunk.runtime);
							const combination =
								groupedByUsedExports.get(key) || ChunkCombination.empty;
							groupedByUsedExports.set(key, combination.with(chunk));
						}
						return groupedByUsedExports.values();
					};

					/** @type {Map<Module, Iterable<ChunkCombination>>} */
					const groupedByExportsMap = new Map();

					const getExportsChunkCombinationsInGraph = memoize(() => {
						/** @type {Set<ChunkCombination>} */
						const chunkCombinationsInGraph = new Set();
						for (const module of compilation.modules) {
							const groupedChunks = Array.from(groupChunksByExports(module));
							groupedByExportsMap.set(module, groupedChunks);
							for (const chunkCombination of groupedChunks) {
								chunkCombinationsInGraph.add(chunkCombination);
							}
						}
						return chunkCombinationsInGraph;
					});

					// group these set of chunks by count
					// to allow to check less sets via isSubset
					// (only smaller sets can be subset)
					const groupChunkCombinationsByCount = chunkCombinations => {
						/** @type {Map<number, ChunkCombination[]>} */
						const chunkCombinationsByCount = new Map();
						for (const chunksSet of chunkCombinations) {
							const count = chunksSet.size;
							let array = chunkCombinationsByCount.get(count);
							if (array === undefined) {
								array = [];
								chunkCombinationsByCount.set(count, array);
							}
							array.push(chunksSet);
						}
						return chunkCombinationsByCount;
					};
					const getChunkCombinationsByCount = memoize(() =>
						groupChunkCombinationsByCount(getChunkCombinationsInGraph())
					);
					const getExportsChunkCombinationsByCount = memoize(() =>
						groupChunkCombinationsByCount(getExportsChunkCombinationsInGraph())
					);

					/**
					 * Create a list of possible combinations
					 * @param {Map<number, ChunkCombination[]>} chunkCombinationsByCount by count
					 * @returns {function(ChunkCombination): ChunkCombination[]} get combinations function
					 */
					const createGetCombinations = chunkCombinationsByCount => {
						/** @type {Map<ChunkCombination, ChunkCombination[]>} */
						const combinationsCache = new Map();

						/**
						 * @param {ChunkCombination} chunkCombination chunkCombination
						 * @returns {ChunkCombination[]} combinations
						 */
						return chunkCombination => {
							const cacheEntry = combinationsCache.get(chunkCombination);
							if (cacheEntry !== undefined) return cacheEntry;
							if (chunkCombination.size === 1) {
								const result = [chunkCombination];
								combinationsCache.set(chunkCombination, result);
								return result;
							}
							/** @type {ChunkCombination[]} */
							const array = [chunkCombination];
							for (const [count, setArray] of chunkCombinationsByCount) {
								// "equal" is not needed because they would have been merge in the first step
								if (count < chunkCombination.size) {
									for (const set of setArray) {
										if (chunkCombination.isSubset(set)) {
											array.push(set);
										}
									}
								}
							}
							combinationsCache.set(chunkCombination, array);
							return array;
						};
					};

					const getCombinationsFactory = memoize(() => {
						return createGetCombinations(getChunkCombinationsByCount());
					});
					const getCombinations = key => getCombinationsFactory()(key);

					const getExportsCombinationsFactory = memoize(() => {
						return createGetCombinations(getExportsChunkCombinationsByCount());
					});
					const getExportsCombinations = key =>
						getExportsCombinationsFactory()(key);

					/** @type {WeakMap<ChunkCombination, WeakMap<ChunkFilterFunction, ChunkCombination>>} */
					const selectedChunksCacheByChunksSet = new WeakMap();

					/**
					 * get chunks by applying the filter function to the list
					 * It is cached for performance reasons
					 * @param {ChunkCombination} chunks list of chunks
					 * @param {ChunkFilterFunction} chunkFilter filter function for chunks
					 * @returns {ChunkCombination} selected chunks
					 */
					const getSelectedChunks = (chunks, chunkFilter) => {
						let entry = selectedChunksCacheByChunksSet.get(chunks);
						if (entry === undefined) {
							entry = new WeakMap();
							selectedChunksCacheByChunksSet.set(chunks, entry);
						}
						/** @type {ChunkCombination} */
						let entry2 = entry.get(chunkFilter);
						if (entry2 === undefined) {
							/** @type {ChunkCombination} */
							let selectedChunks = ChunkCombination.empty;
							for (const chunk of chunks.chunksIterable) {
								if (chunkFilter(chunk))
									selectedChunks = selectedChunks.with(chunk);
							}
							entry2 = selectedChunks;
							entry.set(chunkFilter, entry2);
						}
						return entry2;
					};

					/** @type {Map<string, boolean>} */
					const alreadyValidatedParents = new Map();
					/** @type {Set<string>} */
					const alreadyReportedErrors = new Set();

					// Map a list of chunks to a list of modules
					// For the key the chunk "index" is used, the value is a SortableSet of modules
					/** @type {Map<string, ChunksInfoItem>} */
					const chunksInfoMap = new Map();

					/**
					 * @param {CacheGroup} cacheGroup the current cache group
					 * @param {number} cacheGroupIndex the index of the cache group of ordering
					 * @param {ChunkCombination} selectedChunks chunks selected for this module
					 * @param {Module} module the current module
					 * @returns {void}
					 */
					const addModuleToChunksInfoMap = (
						cacheGroup,
						cacheGroupIndex,
						selectedChunks,
						module
					) => {
						// Break if minimum number of chunks is not reached
						if (selectedChunks.size < cacheGroup.minChunks) return;
						// Determine name for split chunk
						const name = cacheGroup.getName(
							module,
							selectedChunks.getChunks(),
							cacheGroup.key
						);
						// Check if the name is ok
						const existingChunk = compilation.namedChunks.get(name);
						if (existingChunk) {
							const parentValidationKey = `${name}|${selectedChunks.debugId}`;
							const valid = alreadyValidatedParents.get(parentValidationKey);
							if (valid === false) return;
							if (valid === undefined) {
								// Module can only be moved into the existing chunk if the existing chunk
								// is a parent of all selected chunks
								let isInAllParents = true;
								/** @type {Set<ChunkGroup>} */
								const queue = new Set();
								for (const chunk of selectedChunks.chunksIterable) {
									for (const group of chunk.groupsIterable) {
										queue.add(group);
									}
								}
								for (const group of queue) {
									if (existingChunk.isInGroup(group)) continue;
									let hasParent = false;
									for (const parent of group.parentsIterable) {
										hasParent = true;
										queue.add(parent);
									}
									if (!hasParent) {
										isInAllParents = false;
									}
								}
								const valid = isInAllParents;
								alreadyValidatedParents.set(parentValidationKey, valid);
								if (!valid) {
									if (!alreadyReportedErrors.has(name)) {
										alreadyReportedErrors.add(name);
										compilation.errors.push(
											new WebpackError(
												"SplitChunksPlugin\n" +
													`Cache group "${cacheGroup.key}" conflicts with existing chunk.\n` +
													`Both have the same name "${name}" and existing chunk is not a parent of the selected modules.\n` +
													"Use a different name for the cache group or make sure that the existing chunk is a parent (e. g. via dependOn).\n" +
													'HINT: You can omit "name" to automatically create a name.\n' +
													"BREAKING CHANGE: webpack < 5 used to allow to use an entrypoint as splitChunk. " +
													"This is no longer allowed when the entrypoint is not a parent of the selected modules.\n" +
													"Remove this entrypoint and add modules to cache group's 'test' instead. " +
													"If you need modules to be evaluated on startup, add them to the existing entrypoints (make them arrays). " +
													"See migration guide of more info."
											)
										);
									}
									return;
								}
							}
						}
						// Create key for maps
						// When it has a name we use the name as key
						// Otherwise we create the key from chunks and cache group key
						// This automatically merges equal names
						const key =
							cacheGroup.key +
							(name ? ` name:${name}` : ` chunks:${selectedChunks.debugId}`);
						// Add module to maps
						let info = chunksInfoMap.get(key);
						if (info === undefined) {
							chunksInfoMap.set(
								key,
								(info = {
									modules: new SortableSet(
										undefined,
										compareModulesByIdentifier
									),
									cacheGroup,
									cacheGroupIndex,
									name,
									sizes: {},
									chunks: ChunkCombination.empty,
									reuseableChunks: new Set(),
									chunkCombinations: new Set()
								})
							);
						}
						const oldSize = info.modules.size;
						info.modules.add(module);
						if (info.modules.size !== oldSize) {
							for (const type of module.getSourceTypes()) {
								info.sizes[type] = (info.sizes[type] || 0) + module.size(type);
							}
						}
						const oldChunksKeysSize = info.chunkCombinations.size;
						info.chunkCombinations.add(selectedChunks);
						if (oldChunksKeysSize !== info.chunkCombinations.size) {
							info.chunks = info.chunks.withAll(selectedChunks);
						}
					};

					const context = {
						moduleGraph,
						chunkGraph
					};

					logger.timeEnd("prepare");

					logger.time("modules");

					// Walk through all modules
					for (const module of compilation.modules) {
						// Get cache group
						let cacheGroups = this.options.getCacheGroups(module, context);
						if (!Array.isArray(cacheGroups) || cacheGroups.length === 0) {
							continue;
						}

						const chunkCombination =
							chunkGraph.getModuleChunkCombination(module);

						let cacheGroupIndex = 0;
						for (const cacheGroupSource of cacheGroups) {
							const cacheGroup = this._getCacheGroup(cacheGroupSource);

							// Break if minimum number of chunks is not reached
							if (chunkCombination.size < cacheGroup.minChunks) continue;

							/** @type {Iterable<ChunkCombination>} */
							let combs;
							if (cacheGroup.usedExports) {
								// fill the groupedByExportsMap
								getExportsChunkCombinationsInGraph();
								/** @type {Set<ChunkCombination>} */
								const set = new Set();
								const groupedByUsedExports = groupedByExportsMap.get(module);
								for (const chunkCombination of groupedByUsedExports) {
									const preSelectedChunks = getSelectedChunks(
										chunkCombination,
										cacheGroup.chunksFilter
									);
									// Break if minimum number of chunks is not reached
									if (preSelectedChunks.size < cacheGroup.minChunks) continue;

									for (const comb of getExportsCombinations(preSelectedChunks))
										set.add(comb);
								}
								combs = set;
							} else {
								const preSelectedChunks = getSelectedChunks(
									chunkCombination,
									cacheGroup.chunksFilter
								);
								// Break if minimum number of chunks is not reached
								if (preSelectedChunks.size < cacheGroup.minChunks) continue;

								combs = getCombinations(preSelectedChunks);
							}
							// For all combination of chunk selection
							for (const selectedChunks of combs) {
								// Break if minimum number of chunks is not reached
								const count = chunkCombination.size;
								if (count < cacheGroup.minChunks) continue;

								addModuleToChunksInfoMap(
									cacheGroup,
									cacheGroupIndex,
									selectedChunks,
									module
								);
							}
							cacheGroupIndex++;
						}
					}

					logger.timeEnd("modules");

					logger.time("queue");

					/**
					 * @param {ChunksInfoItem} info entry
					 * @param {string[]} sourceTypes source types to be removed
					 */
					const removeModulesWithSourceType = (info, sourceTypes) => {
						for (const module of info.modules) {
							const types = module.getSourceTypes();
							if (sourceTypes.some(type => types.has(type))) {
								info.modules.delete(module);
								for (const type of types) {
									info.sizes[type] -= module.size(type);
								}
							}
						}
					};

					/**
					 * @param {ChunksInfoItem} info entry
					 * @returns {boolean} true, if entry become empty
					 */
					const removeMinSizeViolatingModules = info => {
						if (!info.cacheGroup._validateSize) return false;
						const violatingSizes = getViolatingMinSizes(
							info.sizes,
							info.cacheGroup.minSize
						);
						if (violatingSizes === undefined) return false;
						removeModulesWithSourceType(info, violatingSizes);
						return info.modules.size === 0;
					};

					// Filter items were size < minSize
					for (const [key, info] of chunksInfoMap) {
						if (removeMinSizeViolatingModules(info)) {
							chunksInfoMap.delete(key);
						}
					}

					/**
					 * @typedef {Object} MaxSizeQueueItem
					 * @property {SplitChunksSizes} minSize
					 * @property {SplitChunksSizes} maxAsyncSize
					 * @property {SplitChunksSizes} maxInitialSize
					 * @property {string} automaticNameDelimiter
					 * @property {string[]} keys
					 */

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

					while (chunksInfoMap.size > 0) {
						// Find best matching entry
						let bestEntryKey;
						let bestEntry;
						for (const pair of chunksInfoMap) {
							const key = pair[0];
							const info = pair[1];
							if (
								bestEntry === undefined ||
								compareEntries(bestEntry, info) < 0
							) {
								bestEntry = info;
								bestEntryKey = key;
							}
						}

						const item = bestEntry;
						chunksInfoMap.delete(bestEntryKey);

						let chunkName = item.name;
						// Variable for the new chunk (lazy created)
						/** @type {Chunk} */
						let newChunk;
						// When no chunk name, check if we can reuse a chunk instead of creating a new one
						let isExistingChunk = false;
						let isReusedWithAllModules = false;
						if (chunkName) {
							const chunkByName = compilation.namedChunks.get(chunkName);
							if (chunkByName !== undefined) {
								newChunk = chunkByName;
								const newChunks = item.chunks.without(newChunk);
								isExistingChunk = newChunks !== item.chunks;
								if (isExistingChunk) item.chunks = newChunks;
							}
						} else if (item.cacheGroup.reuseExistingChunk) {
							outer: for (const chunk of item.chunks.chunksIterable) {
								if (
									chunkGraph.getNumberOfChunkModules(chunk) !==
									item.modules.size
								) {
									continue;
								}
								if (
									item.chunks.size > 1 &&
									chunkGraph.getNumberOfEntryModules(chunk) > 0
								) {
									continue;
								}
								for (const module of item.modules) {
									if (!chunkGraph.isModuleInChunk(module, chunk)) {
										continue outer;
									}
								}
								if (!newChunk || !newChunk.name) {
									newChunk = chunk;
								} else if (
									chunk.name &&
									chunk.name.length < newChunk.name.length
								) {
									newChunk = chunk;
								} else if (
									chunk.name &&
									chunk.name.length === newChunk.name.length &&
									chunk.name < newChunk.name
								) {
									newChunk = chunk;
								}
							}
							if (newChunk) {
								item.chunks = item.chunks.without(newChunk);
								chunkName = undefined;
								isExistingChunk = true;
								isReusedWithAllModules = true;
							}
						}

						const enforced =
							item.cacheGroup._conditionalEnforce &&
							checkMinSize(item.sizes, item.cacheGroup.enforceSizeThreshold);

						let usedChunks = item.chunks;

						// Check if maxRequests condition can be fulfilled
						if (
							!enforced &&
							(Number.isFinite(item.cacheGroup.maxInitialRequests) ||
								Number.isFinite(item.cacheGroup.maxAsyncRequests))
						) {
							for (const chunk of usedChunks.chunksIterable) {
								// respect max requests
								const maxRequests = chunk.isOnlyInitial()
									? item.cacheGroup.maxInitialRequests
									: chunk.canBeInitial()
									? Math.min(
											item.cacheGroup.maxInitialRequests,
											item.cacheGroup.maxAsyncRequests
									  )
									: item.cacheGroup.maxAsyncRequests;
								if (
									isFinite(maxRequests) &&
									getRequests(chunk) >= maxRequests
								) {
									usedChunks = usedChunks.without(chunk);
								}
							}
						}

						outer: for (const chunk of usedChunks.chunksIterable) {
							for (const module of item.modules) {
								if (chunkGraph.isModuleInChunk(module, chunk)) continue outer;
							}
							usedChunks = usedChunks.without(chunk);
						}

						// Were some (invalid) chunks removed from usedChunks?
						// => readd all modules to the queue, as things could have been changed
						if (usedChunks !== item.chunks) {
							if (isExistingChunk) usedChunks = usedChunks.with(newChunk);
							if (usedChunks.size >= item.cacheGroup.minChunks) {
								for (const module of item.modules) {
									addModuleToChunksInfoMap(
										item.cacheGroup,
										item.cacheGroupIndex,
										usedChunks,
										module
									);
								}
							}
							continue;
						}

						// Validate minRemainingSize constraint when a single chunk is left over
						if (
							!enforced &&
							item.cacheGroup._validateRemainingSize &&
							usedChunks.size === 1
						) {
							const [chunk] = usedChunks.chunksIterable;
							let chunkSizes = Object.create(null);
							for (const module of chunkGraph.getChunkModulesIterable(chunk)) {
								if (!item.modules.has(module)) {
									for (const type of module.getSourceTypes()) {
										chunkSizes[type] =
											(chunkSizes[type] || 0) + module.size(type);
									}
								}
							}
							const violatingSizes = getViolatingMinSizes(
								chunkSizes,
								item.cacheGroup.minRemainingSize
							);
							if (violatingSizes !== undefined) {
								const oldModulesSize = item.modules.size;
								removeModulesWithSourceType(item, violatingSizes);
								if (
									item.modules.size > 0 &&
									item.modules.size !== oldModulesSize
								) {
									// queue this item again to be processed again
									// without violating modules
									chunksInfoMap.set(bestEntryKey, item);
								}
								continue;
							}
						}

						// Create the new chunk if not reusing one
						if (newChunk === undefined) {
							newChunk = compilation.addChunk(chunkName);
						}
						// Walk through all chunks
						for (const chunk of usedChunks.chunksIterable) {
							// Add graph connections for splitted chunk
							chunk.split(newChunk);
						}

						// Add a note to the chunk
						newChunk.chunkReason =
							(newChunk.chunkReason ? newChunk.chunkReason + ", " : "") +
							(isReusedWithAllModules
								? "reused as split chunk"
								: "split chunk");
						if (item.cacheGroup.key) {
							newChunk.chunkReason += ` (cache group: ${item.cacheGroup.key})`;
						}
						if (chunkName) {
							newChunk.chunkReason += ` (name: ${chunkName})`;
						}
						if (item.cacheGroup.filename) {
							newChunk.filenameTemplate = item.cacheGroup.filename;
						}
						if (item.cacheGroup.idHint) {
							newChunk.idNameHints.add(item.cacheGroup.idHint);
						}
						if (!isReusedWithAllModules) {
							// Add all modules to the new chunk
							for (const module of item.modules) {
								if (!module.chunkCondition(newChunk, compilation)) continue;
								// Add module to new chunk
								chunkGraph.connectChunkAndModule(newChunk, module);
								// Remove module from used chunks
								for (const chunk of usedChunks.chunksIterable) {
									chunkGraph.disconnectChunkAndModule(chunk, module);
								}
							}
						} else {
							// Remove all modules from used chunks
							for (const module of item.modules) {
								for (const chunk of usedChunks.chunksIterable) {
									chunkGraph.disconnectChunkAndModule(chunk, module);
								}
							}
						}

						if (
							Object.keys(item.cacheGroup.maxAsyncSize).length > 0 ||
							Object.keys(item.cacheGroup.maxInitialSize).length > 0
						) {
							const oldMaxSizeSettings = maxSizeQueueMap.get(newChunk);
							maxSizeQueueMap.set(newChunk, {
								minSize: oldMaxSizeSettings
									? combineSizes(
											oldMaxSizeSettings.minSize,
											item.cacheGroup._minSizeForMaxSize,
											Math.max
									  )
									: item.cacheGroup.minSize,
								maxAsyncSize: oldMaxSizeSettings
									? combineSizes(
											oldMaxSizeSettings.maxAsyncSize,
											item.cacheGroup.maxAsyncSize,
											Math.min
									  )
									: item.cacheGroup.maxAsyncSize,
								maxInitialSize: oldMaxSizeSettings
									? combineSizes(
											oldMaxSizeSettings.maxInitialSize,
											item.cacheGroup.maxInitialSize,
											Math.min
									  )
									: item.cacheGroup.maxInitialSize,
								automaticNameDelimiter: item.cacheGroup.automaticNameDelimiter,
								keys: oldMaxSizeSettings
									? oldMaxSizeSettings.keys.concat(item.cacheGroup.key)
									: [item.cacheGroup.key]
							});
						}

						// remove all modules from other entries and update size
						for (const [key, info] of chunksInfoMap) {
							if (info.chunks.hasSharedChunks(usedChunks)) {
								// update modules and total size
								// may remove it from the map when < minSize
								let updated = false;
								for (const module of item.modules) {
									if (info.modules.has(module)) {
										// remove module
										info.modules.delete(module);
										// update size
										for (const key of module.getSourceTypes()) {
											info.sizes[key] -= module.size(key);
										}
										updated = true;
									}
								}
								if (updated) {
									if (info.modules.size === 0) {
										chunksInfoMap.delete(key);
										continue;
									}
									if (removeMinSizeViolatingModules(info)) {
										chunksInfoMap.delete(key);
										continue;
									}
								}
							}
						}
					}

					logger.timeEnd("queue");

					logger.time("maxSize");

					/** @type {Set<string>} */
					const incorrectMinMaxSizeSet = new Set();

					const { outputOptions } = compilation;

					// Make sure that maxSize is fulfilled
					for (const chunk of Array.from(compilation.chunks)) {
						const chunkConfig = maxSizeQueueMap.get(chunk);
						const {
							minSize,
							maxAsyncSize,
							maxInitialSize,
							automaticNameDelimiter
						} = chunkConfig || this.options.fallbackCacheGroup;
						/** @type {SplitChunksSizes} */
						let maxSize;
						if (chunk.isOnlyInitial()) {
							maxSize = maxInitialSize;
						} else if (chunk.canBeInitial()) {
							maxSize = combineSizes(maxAsyncSize, maxInitialSize, Math.min);
						} else {
							maxSize = maxAsyncSize;
						}
						if (Object.keys(maxSize).length === 0) {
							continue;
						}
						for (const key of Object.keys(maxSize)) {
							const maxSizeValue = maxSize[key];
							const minSizeValue = minSize[key];
							if (
								typeof minSizeValue === "number" &&
								minSizeValue > maxSizeValue
							) {
								const keys = chunkConfig && chunkConfig.keys;
								const warningKey = `${
									keys && keys.join()
								} ${minSizeValue} ${maxSizeValue}`;
								if (!incorrectMinMaxSizeSet.has(warningKey)) {
									incorrectMinMaxSizeSet.add(warningKey);
									compilation.warnings.push(
										new MinMaxSizeWarning(keys, minSizeValue, maxSizeValue)
									);
								}
							}
						}
						const results = deterministicGroupingForModules({
							minSize,
							maxSize: mapObject(maxSize, (value, key) => {
								const minSizeValue = minSize[key];
								return typeof minSizeValue === "number"
									? Math.max(value, minSizeValue)
									: value;
							}),
							items: chunkGraph.getChunkModulesIterable(chunk),
							getKey(module) {
								const cache = getKeyCache.get(module);
								if (cache !== undefined) return cache;
								const ident = cachedMakePathsRelative(module.identifier());
								const nameForCondition =
									module.nameForCondition && module.nameForCondition();
								const name = nameForCondition
									? cachedMakePathsRelative(nameForCondition)
									: ident.replace(/^.*!|\?[^?!]*$/g, "");
								const fullKey =
									name +
									automaticNameDelimiter +
									hashFilename(ident, outputOptions);
								const key = requestToId(fullKey);
								getKeyCache.set(module, key);
								return key;
							},
							getSize(module) {
								const size = Object.create(null);
								for (const key of module.getSourceTypes()) {
									size[key] = module.size(key);
								}
								return size;
							}
						});
						if (results.length <= 1) {
							continue;
						}
						for (let i = 0; i < results.length; i++) {
							const group = results[i];
							const key = this.options.hidePathInfo
								? hashFilename(group.key, outputOptions)
								: group.key;
							let name = chunk.name
								? chunk.name + automaticNameDelimiter + key
								: null;
							if (name && name.length > 100) {
								name =
									name.slice(0, 100) +
									automaticNameDelimiter +
									hashFilename(name, outputOptions);
							}
							if (i !== results.length - 1) {
								const newPart = compilation.addChunk(name);
								chunk.split(newPart);
								newPart.chunkReason = chunk.chunkReason;
								// Add all modules to the new chunk
								for (const module of group.items) {
									if (!module.chunkCondition(newPart, compilation)) {
										continue;
									}
									// Add module to new chunk
									chunkGraph.connectChunkAndModule(newPart, module);
									// Remove module from used chunks
									chunkGraph.disconnectChunkAndModule(chunk, module);
								}
							} else {
								// change the chunk to be a part
								chunk.name = name;
							}
						}
					}
					logger.timeEnd("maxSize");
				}
			);
		});
	}
};