SplitChunksPlugin.js 29.8 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968
/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
"use strict";

const crypto = require("crypto");
const SortableSet = require("../util/SortableSet");
const GraphHelpers = require("../GraphHelpers");
const { isSubset } = require("../util/SetHelpers");
const deterministicGrouping = require("../util/deterministicGrouping");
const MinMaxSizeWarning = require("./MinMaxSizeWarning");
const contextify = require("../util/identifier").contextify;

/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("../Chunk")} Chunk */
/** @typedef {import("../Module")} Module */
/** @typedef {import("../util/deterministicGrouping").Options<Module>} DeterministicGroupingOptionsForModule */
/** @typedef {import("../util/deterministicGrouping").GroupedItems<Module>} DeterministicGroupingGroupedItemsForModule */

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

const hashFilename = name => {
	return crypto
		.createHash("md4")
		.update(name)
		.digest("hex")
		.slice(0, 8);
};

const sortByIdentifier = (a, b) => {
	if (a.identifier() > b.identifier()) return 1;
	if (a.identifier() < b.identifier()) return -1;
	return 0;
};

const getRequests = chunk => {
	let requests = 0;
	for (const chunkGroup of chunk.groupsIterable) {
		requests = Math.max(requests, chunkGroup.chunks.length);
	}
	return requests;
};

const getModulesSize = modules => {
	let sum = 0;
	for (const m of modules) {
		sum += m.size();
	}
	return sum;
};

/**
 * @template T
 * @param {Set<T>} a set
 * @param {Set<T>} b other set
 * @returns {boolean} true if at least one item of a is in b
 */
const isOverlap = (a, b) => {
	for (const item of a) {
		if (b.has(item)) return true;
	}
	return false;
};

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 = a.size * (a.chunks.size - 1);
	const bSizeReduce = b.size * (b.chunks.size - 1);
	const diffSizeReduce = aSizeReduce - bSizeReduce;
	if (diffSizeReduce) return diffSizeReduce;
	// 4. by cache group index
	const indexDiff = a.cacheGroupIndex - b.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();
	const aI = modulesA[Symbol.iterator]();
	const bI = modulesB[Symbol.iterator]();
	// eslint-disable-next-line no-constant-condition
	while (true) {
		const aItem = aI.next();
		const bItem = bI.next();
		if (aItem.done) return 0;
		const aModuleIdentifier = aItem.value.identifier();
		const bModuleIdentifier = bItem.value.identifier();
		if (aModuleIdentifier > bModuleIdentifier) return -1;
		if (aModuleIdentifier < bModuleIdentifier) return 1;
	}
};

const compareNumbers = (a, b) => a - b;

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

module.exports = class SplitChunksPlugin {
	constructor(options) {
		this.options = SplitChunksPlugin.normalizeOptions(options);
	}

	static normalizeOptions(options = {}) {
		return {
			chunksFilter: SplitChunksPlugin.normalizeChunksFilter(
				options.chunks || "all"
			),
			minSize: options.minSize || 0,
			enforceSizeThreshold: options.enforceSizeThreshold || 0,
			maxSize: options.maxSize || 0,
			minChunks: options.minChunks || 1,
			maxAsyncRequests: options.maxAsyncRequests || 1,
			maxInitialRequests: options.maxInitialRequests || 1,
			hidePathInfo: options.hidePathInfo || false,
			filename: options.filename || undefined,
			getCacheGroups: SplitChunksPlugin.normalizeCacheGroups({
				cacheGroups: options.cacheGroups,
				name: options.name,
				automaticNameDelimiter: options.automaticNameDelimiter,
				automaticNameMaxLength: options.automaticNameMaxLength
			}),
			automaticNameDelimiter: options.automaticNameDelimiter,
			automaticNameMaxLength: options.automaticNameMaxLength || 109,
			fallbackCacheGroup: SplitChunksPlugin.normalizeFallbackCacheGroup(
				options.fallbackCacheGroup || {},
				options
			)
		};
	}

	static normalizeName({
		name,
		automaticNameDelimiter,
		automaticNamePrefix,
		automaticNameMaxLength
	}) {
		if (name === true) {
			/** @type {WeakMap<Chunk[], Record<string, string>>} */
			const cache = new WeakMap();
			const fn = (module, chunks, cacheGroup) => {
				let cacheEntry = cache.get(chunks);
				if (cacheEntry === undefined) {
					cacheEntry = {};
					cache.set(chunks, cacheEntry);
				} else if (cacheGroup in cacheEntry) {
					return cacheEntry[cacheGroup];
				}
				const names = chunks.map(c => c.name);
				if (!names.every(Boolean)) {
					cacheEntry[cacheGroup] = undefined;
					return;
				}
				names.sort();
				const prefix =
					typeof automaticNamePrefix === "string"
						? automaticNamePrefix
						: cacheGroup;
				const namePrefix = prefix ? prefix + automaticNameDelimiter : "";
				let name = namePrefix + names.join(automaticNameDelimiter);
				// Filenames and paths can't be too long otherwise an
				// ENAMETOOLONG error is raised. If the generated name if too
				// long, it is truncated and a hash is appended. The limit has
				// been set to 109 to prevent `[name].[chunkhash].[ext]` from
				// generating a 256+ character string.
				if (name.length > automaticNameMaxLength) {
					const hashedFilename = hashFilename(name);
					const sliceLength =
						automaticNameMaxLength -
						(automaticNameDelimiter.length + hashedFilename.length);
					name =
						name.slice(0, sliceLength) +
						automaticNameDelimiter +
						hashedFilename;
				}
				cacheEntry[cacheGroup] = name;
				return name;
			};
			return fn;
		}
		if (typeof name === "string") {
			const fn = () => {
				return name;
			};
			return fn;
		}
		if (typeof name === "function") return name;
	}

	static 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;
	}

	static normalizeFallbackCacheGroup(
		{
			minSize = undefined,
			maxSize = undefined,
			automaticNameDelimiter = undefined
		},
		{
			minSize: defaultMinSize = undefined,
			maxSize: defaultMaxSize = undefined,
			automaticNameDelimiter: defaultAutomaticNameDelimiter = undefined
		}
	) {
		return {
			minSize: typeof minSize === "number" ? minSize : defaultMinSize || 0,
			maxSize: typeof maxSize === "number" ? maxSize : defaultMaxSize || 0,
			automaticNameDelimiter:
				automaticNameDelimiter || defaultAutomaticNameDelimiter || "~"
		};
	}

	static normalizeCacheGroups({
		cacheGroups,
		name,
		automaticNameDelimiter,
		automaticNameMaxLength
	}) {
		if (typeof cacheGroups === "function") {
			// TODO webpack 5 remove this
			if (cacheGroups.length !== 1) {
				return module => cacheGroups(module, module.getChunks());
			}
			return cacheGroups;
		}
		if (cacheGroups && typeof cacheGroups === "object") {
			const fn = module => {
				let results;
				for (const key of Object.keys(cacheGroups)) {
					let option = cacheGroups[key];
					if (option === false) continue;
					if (option instanceof RegExp || typeof option === "string") {
						option = {
							test: option
						};
					}
					if (typeof option === "function") {
						let result = option(module);
						if (result) {
							if (results === undefined) results = [];
							for (const r of Array.isArray(result) ? result : [result]) {
								const result = Object.assign({ key }, r);
								if (result.name) result.getName = () => result.name;
								if (result.chunks) {
									result.chunksFilter = SplitChunksPlugin.normalizeChunksFilter(
										result.chunks
									);
								}
								results.push(result);
							}
						}
					} else if (SplitChunksPlugin.checkTest(option.test, module)) {
						if (results === undefined) results = [];
						results.push({
							key: key,
							priority: option.priority,
							getName:
								SplitChunksPlugin.normalizeName({
									name: option.name || name,
									automaticNameDelimiter:
										typeof option.automaticNameDelimiter === "string"
											? option.automaticNameDelimiter
											: automaticNameDelimiter,
									automaticNamePrefix: option.automaticNamePrefix,
									automaticNameMaxLength:
										option.automaticNameMaxLength || automaticNameMaxLength
								}) || (() => {}),
							chunksFilter: SplitChunksPlugin.normalizeChunksFilter(
								option.chunks
							),
							enforce: option.enforce,
							minSize: option.minSize,
							enforceSizeThreshold: option.enforceSizeThreshold,
							maxSize: option.maxSize,
							minChunks: option.minChunks,
							maxAsyncRequests: option.maxAsyncRequests,
							maxInitialRequests: option.maxInitialRequests,
							filename: option.filename,
							reuseExistingChunk: option.reuseExistingChunk
						});
					}
				}
				return results;
			};
			return fn;
		}
		const fn = () => {};
		return fn;
	}

	static checkTest(test, module) {
		if (test === undefined) return true;
		if (typeof test === "function") {
			if (test.length !== 1) {
				return test(module, module.getChunks());
			}
			return test(module);
		}
		if (typeof test === "boolean") return test;
		if (typeof test === "string") {
			if (
				module.nameForCondition &&
				module.nameForCondition().startsWith(test)
			) {
				return true;
			}
			for (const chunk of module.chunksIterable) {
				if (chunk.name && chunk.name.startsWith(test)) {
					return true;
				}
			}
			return false;
		}
		if (test instanceof RegExp) {
			if (module.nameForCondition && test.test(module.nameForCondition())) {
				return true;
			}
			for (const chunk of module.chunksIterable) {
				if (chunk.name && test.test(chunk.name)) {
					return true;
				}
			}
			return false;
		}
		return false;
	}

	/**
	 * @param {Compiler} compiler webpack compiler
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.thisCompilation.tap("SplitChunksPlugin", compilation => {
			let alreadyOptimized = false;
			compilation.hooks.unseal.tap("SplitChunksPlugin", () => {
				alreadyOptimized = false;
			});
			compilation.hooks.optimizeChunksAdvanced.tap(
				"SplitChunksPlugin",
				chunks => {
					if (alreadyOptimized) return;
					alreadyOptimized = true;
					// Give each selected chunk an index (to create strings from chunks)
					const indexMap = new Map();
					let index = 1;
					for (const chunk of chunks) {
						indexMap.set(chunk, index++);
					}
					const getKey = chunks => {
						return Array.from(chunks, c => indexMap.get(c))
							.sort(compareNumbers)
							.join();
					};
					/** @type {Map<string, Set<Chunk>>} */
					const chunkSetsInGraph = new Map();
					for (const module of compilation.modules) {
						const chunksKey = getKey(module.chunksIterable);
						if (!chunkSetsInGraph.has(chunksKey)) {
							chunkSetsInGraph.set(chunksKey, new Set(module.chunksIterable));
						}
					}

					// group these set of chunks by count
					// to allow to check less sets via isSubset
					// (only smaller sets can be subset)
					/** @type {Map<number, Array<Set<Chunk>>>} */
					const chunkSetsByCount = new Map();
					for (const chunksSet of chunkSetsInGraph.values()) {
						const count = chunksSet.size;
						let array = chunkSetsByCount.get(count);
						if (array === undefined) {
							array = [];
							chunkSetsByCount.set(count, array);
						}
						array.push(chunksSet);
					}

					// Create a list of possible combinations
					const combinationsCache = new Map(); // Map<string, Set<Chunk>[]>

					const getCombinations = key => {
						const chunksSet = chunkSetsInGraph.get(key);
						var array = [chunksSet];
						if (chunksSet.size > 1) {
							for (const [count, setArray] of chunkSetsByCount) {
								// "equal" is not needed because they would have been merge in the first step
								if (count < chunksSet.size) {
									for (const set of setArray) {
										if (isSubset(chunksSet, set)) {
											array.push(set);
										}
									}
								}
							}
						}
						return array;
					};

					/**
					 * @typedef {Object} SelectedChunksResult
					 * @property {Chunk[]} chunks the list of chunks
					 * @property {string} key a key of the list
					 */

					/**
					 * @typedef {function(Chunk): boolean} ChunkFilterFunction
					 */

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

					/**
					 * get list and key by applying the filter function to the list
					 * It is cached for performance reasons
					 * @param {Set<Chunk>} chunks list of chunks
					 * @param {ChunkFilterFunction} chunkFilter filter function for chunks
					 * @returns {SelectedChunksResult} list and key
					 */
					const getSelectedChunks = (chunks, chunkFilter) => {
						let entry = selectedChunksCacheByChunksSet.get(chunks);
						if (entry === undefined) {
							entry = new WeakMap();
							selectedChunksCacheByChunksSet.set(chunks, entry);
						}
						/** @type {SelectedChunksResult} */
						let entry2 = entry.get(chunkFilter);
						if (entry2 === undefined) {
							/** @type {Chunk[]} */
							const selectedChunks = [];
							for (const chunk of chunks) {
								if (chunkFilter(chunk)) selectedChunks.push(chunk);
							}
							entry2 = {
								chunks: selectedChunks,
								key: getKey(selectedChunks)
							};
							entry.set(chunkFilter, entry2);
						}
						return entry2;
					};

					/**
					 * @typedef {Object} ChunksInfoItem
					 * @property {SortableSet} modules
					 * @property {TODO} cacheGroup
					 * @property {number} cacheGroupIndex
					 * @property {string} name
					 * @property {number} size
					 * @property {Set<Chunk>} chunks
					 * @property {Set<Chunk>} reuseableChunks
					 * @property {Set<string>} chunksKeys
					 */

					// 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 {TODO} cacheGroup the current cache group
					 * @param {number} cacheGroupIndex the index of the cache group of ordering
					 * @param {Chunk[]} selectedChunks chunks selected for this module
					 * @param {string} selectedChunksKey a key of selectedChunks
					 * @param {Module} module the current module
					 * @returns {void}
					 */
					const addModuleToChunksInfoMap = (
						cacheGroup,
						cacheGroupIndex,
						selectedChunks,
						selectedChunksKey,
						module
					) => {
						// Break if minimum number of chunks is not reached
						if (selectedChunks.length < cacheGroup.minChunks) return;
						// Determine name for split chunk
						const name = cacheGroup.getName(
							module,
							selectedChunks,
							cacheGroup.key
						);
						// Create key for maps
						// When it has a name we use the name as key
						// Elsewise we create the key from chunks and cache group key
						// This automatically merges equal names
						const key =
							cacheGroup.key +
							(name ? ` name:${name}` : ` chunks:${selectedChunksKey}`);
						// Add module to maps
						let info = chunksInfoMap.get(key);
						if (info === undefined) {
							chunksInfoMap.set(
								key,
								(info = {
									modules: new SortableSet(undefined, sortByIdentifier),
									cacheGroup,
									cacheGroupIndex,
									name,
									size: 0,
									chunks: new Set(),
									reuseableChunks: new Set(),
									chunksKeys: new Set()
								})
							);
						}
						info.modules.add(module);
						info.size += module.size();
						if (!info.chunksKeys.has(selectedChunksKey)) {
							info.chunksKeys.add(selectedChunksKey);
							for (const chunk of selectedChunks) {
								info.chunks.add(chunk);
							}
						}
					};

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

						// Prepare some values
						const chunksKey = getKey(module.chunksIterable);
						let combs = combinationsCache.get(chunksKey);
						if (combs === undefined) {
							combs = getCombinations(chunksKey);
							combinationsCache.set(chunksKey, combs);
						}

						let cacheGroupIndex = 0;
						for (const cacheGroupSource of cacheGroups) {
							const minSize =
								cacheGroupSource.minSize !== undefined
									? cacheGroupSource.minSize
									: cacheGroupSource.enforce
									? 0
									: this.options.minSize;
							const enforceSizeThreshold =
								cacheGroupSource.enforceSizeThreshold !== undefined
									? cacheGroupSource.enforceSizeThreshold
									: cacheGroupSource.enforce
									? 0
									: this.options.enforceSizeThreshold;
							const cacheGroup = {
								key: cacheGroupSource.key,
								priority: cacheGroupSource.priority || 0,
								chunksFilter:
									cacheGroupSource.chunksFilter || this.options.chunksFilter,
								minSize,
								minSizeForMaxSize:
									cacheGroupSource.minSize !== undefined
										? cacheGroupSource.minSize
										: this.options.minSize,
								enforceSizeThreshold,
								maxSize:
									cacheGroupSource.maxSize !== undefined
										? cacheGroupSource.maxSize
										: cacheGroupSource.enforce
										? 0
										: this.options.maxSize,
								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,
								filename:
									cacheGroupSource.filename !== undefined
										? cacheGroupSource.filename
										: this.options.filename,
								automaticNameDelimiter:
									cacheGroupSource.automaticNameDelimiter !== undefined
										? cacheGroupSource.automaticNameDelimiter
										: this.options.automaticNameDelimiter,
								reuseExistingChunk: cacheGroupSource.reuseExistingChunk,
								_validateSize: minSize > 0,
								_conditionalEnforce: enforceSizeThreshold > 0
							};
							// For all combination of chunk selection
							for (const chunkCombination of combs) {
								// Break if minimum number of chunks is not reached
								if (chunkCombination.size < cacheGroup.minChunks) continue;
								// Select chunks by configuration
								const {
									chunks: selectedChunks,
									key: selectedChunksKey
								} = getSelectedChunks(
									chunkCombination,
									cacheGroup.chunksFilter
								);

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

					// Filter items were size < minSize
					for (const pair of chunksInfoMap) {
						const info = pair[1];
						if (
							info.cacheGroup._validateSize &&
							info.size < info.cacheGroup.minSize
						) {
							chunksInfoMap.delete(pair[0]);
						}
					}

					/** @type {Map<Chunk, {minSize: number, maxSize: number, automaticNameDelimiter: string, keys: string[]}>} */
					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) {
								bestEntry = info;
								bestEntryKey = key;
							} else if (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 isReused = false;
						if (item.cacheGroup.reuseExistingChunk) {
							outer: for (const chunk of item.chunks) {
								if (chunk.getNumberOfModules() !== item.modules.size) continue;
								if (chunk.hasEntryModule()) continue;
								for (const module of item.modules) {
									if (!chunk.containsModule(module)) 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;
								}
								chunkName = undefined;
								isReused = true;
							}
						}
						// Check if maxRequests condition can be fulfilled

						const selectedChunks = Array.from(item.chunks).filter(chunk => {
							// skip if we address ourself
							return (
								(!chunkName || chunk.name !== chunkName) && chunk !== newChunk
							);
						});

						const enforced =
							item.cacheGroup._conditionalEnforce &&
							item.size >= item.cacheGroup.enforceSizeThreshold;

						// Skip when no chunk selected
						if (selectedChunks.length === 0) continue;

						const usedChunks = new Set(selectedChunks);

						// Check if maxRequests condition can be fulfilled
						if (
							!enforced &&
							(Number.isFinite(item.cacheGroup.maxInitialRequests) ||
								Number.isFinite(item.cacheGroup.maxAsyncRequests))
						) {
							for (const chunk of usedChunks) {
								// 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.delete(chunk);
								}
							}
						}

						outer: for (const chunk of usedChunks) {
							for (const module of item.modules) {
								if (chunk.containsModule(module)) continue outer;
							}
							usedChunks.delete(chunk);
						}

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

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

						// Add a note to the chunk
						newChunk.chunkReason = isReused
							? "reused as split chunk"
							: "split chunk";
						if (item.cacheGroup.key) {
							newChunk.chunkReason += ` (cache group: ${item.cacheGroup.key})`;
						}
						if (chunkName) {
							newChunk.chunkReason += ` (name: ${chunkName})`;
							// If the chosen name is already an entry point we remove the entry point
							const entrypoint = compilation.entrypoints.get(chunkName);
							if (entrypoint) {
								compilation.entrypoints.delete(chunkName);
								entrypoint.remove();
								newChunk.entryModule = undefined;
							}
						}
						if (item.cacheGroup.filename) {
							if (!newChunk.isOnlyInitial()) {
								throw new Error(
									"SplitChunksPlugin: You are trying to set a filename for a chunk which is (also) loaded on demand. " +
										"The runtime can only handle loading of chunks which match the chunkFilename schema. " +
										"Using a custom filename would fail at runtime. " +
										`(cache group: ${item.cacheGroup.key})`
								);
							}
							newChunk.filenameTemplate = item.cacheGroup.filename;
						}
						if (!isReused) {
							// Add all modules to the new chunk
							for (const module of item.modules) {
								if (typeof module.chunkCondition === "function") {
									if (!module.chunkCondition(newChunk)) continue;
								}
								// Add module to new chunk
								GraphHelpers.connectChunkAndModule(newChunk, module);
								// Remove module from used chunks
								for (const chunk of usedChunks) {
									chunk.removeModule(module);
									module.rewriteChunkInReasons(chunk, [newChunk]);
								}
							}
						} else {
							// Remove all modules from used chunks
							for (const module of item.modules) {
								for (const chunk of usedChunks) {
									chunk.removeModule(module);
									module.rewriteChunkInReasons(chunk, [newChunk]);
								}
							}
						}

						if (item.cacheGroup.maxSize > 0) {
							const oldMaxSizeSettings = maxSizeQueueMap.get(newChunk);
							maxSizeQueueMap.set(newChunk, {
								minSize: Math.max(
									oldMaxSizeSettings ? oldMaxSizeSettings.minSize : 0,
									item.cacheGroup.minSizeForMaxSize
								),
								maxSize: Math.min(
									oldMaxSizeSettings ? oldMaxSizeSettings.maxSize : Infinity,
									item.cacheGroup.maxSize
								),
								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 (isOverlap(info.chunks, usedChunks)) {
								// update modules and total size
								// may remove it from the map when < minSize
								const oldSize = info.modules.size;
								for (const module of item.modules) {
									info.modules.delete(module);
								}
								if (info.modules.size !== oldSize) {
									if (info.modules.size === 0) {
										chunksInfoMap.delete(key);
										continue;
									}
									info.size = getModulesSize(info.modules);
									if (
										info.cacheGroup._validateSize &&
										info.size < info.cacheGroup.minSize
									) {
										chunksInfoMap.delete(key);
									}
									if (info.modules.size === 0) {
										chunksInfoMap.delete(key);
									}
								}
							}
						}
					}

					const incorrectMinMaxSizeSet = new Set();

					// Make sure that maxSize is fulfilled
					for (const chunk of compilation.chunks.slice()) {
						const { minSize, maxSize, automaticNameDelimiter, keys } =
							maxSizeQueueMap.get(chunk) || this.options.fallbackCacheGroup;
						if (!maxSize) continue;
						if (minSize > maxSize) {
							const warningKey = `${keys && keys.join()} ${minSize} ${maxSize}`;
							if (!incorrectMinMaxSizeSet.has(warningKey)) {
								incorrectMinMaxSizeSet.add(warningKey);
								compilation.warnings.push(
									new MinMaxSizeWarning(keys, minSize, maxSize)
								);
							}
						}
						const results = deterministicGroupingForModules({
							maxSize: Math.max(minSize, maxSize),
							minSize,
							items: chunk.modulesIterable,
							getKey(module) {
								const ident = contextify(
									compilation.options.context,
									module.identifier()
								);
								const name = module.nameForCondition
									? contextify(
											compilation.options.context,
											module.nameForCondition()
									  )
									: ident.replace(/^.*!|\?[^?!]*$/g, "");
								const fullKey =
									name + automaticNameDelimiter + hashFilename(ident);
								return fullKey.replace(/[\\/?]/g, "_");
							},
							getSize(module) {
								return module.size();
							}
						});
						results.sort((a, b) => {
							if (a.key < b.key) return -1;
							if (a.key > b.key) return 1;
							return 0;
						});
						for (let i = 0; i < results.length; i++) {
							const group = results[i];
							const key = this.options.hidePathInfo
								? hashFilename(group.key)
								: group.key;
							let name = chunk.name
								? chunk.name + automaticNameDelimiter + key
								: null;
							if (name && name.length > 100) {
								name =
									name.slice(0, 100) +
									automaticNameDelimiter +
									hashFilename(name);
							}
							let newPart;
							if (i !== results.length - 1) {
								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 (typeof module.chunkCondition === "function") {
										if (!module.chunkCondition(newPart)) continue;
									}
									// Add module to new chunk
									GraphHelpers.connectChunkAndModule(newPart, module);
									// Remove module from used chunks
									chunk.removeModule(module);
									module.rewriteChunkInReasons(chunk, [newPart]);
								}
							} else {
								// change the chunk to be a part
								newPart = chunk;
								chunk.name = name;
							}
						}
					}
				}
			);
		});
	}
};