Index: imaps-frontend/node_modules/webpack/lib/Compiler.js
===================================================================
--- imaps-frontend/node_modules/webpack/lib/Compiler.js	(revision 79a03170cdde4e801d12257ee86723774970427b)
+++ imaps-frontend/node_modules/webpack/lib/Compiler.js	(revision 79a03170cdde4e801d12257ee86723774970427b)
@@ -0,0 +1,1384 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+
+"use strict";
+
+const parseJson = require("json-parse-even-better-errors");
+const asyncLib = require("neo-async");
+const {
+	SyncHook,
+	SyncBailHook,
+	AsyncParallelHook,
+	AsyncSeriesHook
+} = require("tapable");
+const { SizeOnlySource } = require("webpack-sources");
+const webpack = require(".");
+const Cache = require("./Cache");
+const CacheFacade = require("./CacheFacade");
+const ChunkGraph = require("./ChunkGraph");
+const Compilation = require("./Compilation");
+const ConcurrentCompilationError = require("./ConcurrentCompilationError");
+const ContextModuleFactory = require("./ContextModuleFactory");
+const ModuleGraph = require("./ModuleGraph");
+const NormalModuleFactory = require("./NormalModuleFactory");
+const RequestShortener = require("./RequestShortener");
+const ResolverFactory = require("./ResolverFactory");
+const Stats = require("./Stats");
+const Watching = require("./Watching");
+const WebpackError = require("./WebpackError");
+const { Logger } = require("./logging/Logger");
+const { join, dirname, mkdirp } = require("./util/fs");
+const { makePathsRelative } = require("./util/identifier");
+const { isSourceEqual } = require("./util/source");
+
+/** @typedef {import("webpack-sources").Source} Source */
+/** @typedef {import("../declarations/WebpackOptions").EntryNormalized} Entry */
+/** @typedef {import("../declarations/WebpackOptions").OutputNormalized} OutputOptions */
+/** @typedef {import("../declarations/WebpackOptions").WatchOptions} WatchOptions */
+/** @typedef {import("../declarations/WebpackOptions").WebpackOptionsNormalized} WebpackOptions */
+/** @typedef {import("../declarations/WebpackOptions").WebpackPluginInstance} WebpackPluginInstance */
+/** @typedef {import("./Chunk")} Chunk */
+/** @typedef {import("./Compilation").References} References */
+/** @typedef {import("./Dependency")} Dependency */
+/** @typedef {import("./FileSystemInfo").FileSystemInfoEntry} FileSystemInfoEntry */
+/** @typedef {import("./Module")} Module */
+/** @typedef {import("./Module").BuildInfo} BuildInfo */
+/** @typedef {import("./config/target").PlatformTargetProperties} PlatformTargetProperties */
+/** @typedef {import("./logging/createConsoleLogger").LoggingFunction} LoggingFunction */
+/** @typedef {import("./util/fs").IStats} IStats */
+/** @typedef {import("./util/fs").InputFileSystem} InputFileSystem */
+/** @typedef {import("./util/fs").IntermediateFileSystem} IntermediateFileSystem */
+/** @typedef {import("./util/fs").OutputFileSystem} OutputFileSystem */
+/** @typedef {import("./util/fs").WatchFileSystem} WatchFileSystem */
+
+/**
+ * @template {any[]} T
+ * @template V
+ * @typedef {import("./util/WeakTupleMap")<T, V>} WeakTupleMap
+ */
+
+/**
+ * @typedef {object} CompilationParams
+ * @property {NormalModuleFactory} normalModuleFactory
+ * @property {ContextModuleFactory} contextModuleFactory
+ */
+
+/**
+ * @template T
+ * @callback RunCallback
+ * @param {Error | null} err
+ * @param {T=} result
+ */
+
+/**
+ * @template T
+ * @callback Callback
+ * @param {(Error | null)=} err
+ * @param {T=} result
+ */
+
+/**
+ * @callback RunAsChildCallback
+ * @param {Error | null} err
+ * @param {Chunk[]=} entries
+ * @param {Compilation=} compilation
+ */
+
+/**
+ * @typedef {object} AssetEmittedInfo
+ * @property {Buffer} content
+ * @property {Source} source
+ * @property {Compilation} compilation
+ * @property {string} outputPath
+ * @property {string} targetPath
+ */
+
+/** @typedef {{ sizeOnlySource: SizeOnlySource | undefined, writtenTo: Map<string, number> }} CacheEntry */
+/** @typedef {{ path: string, source: Source, size: number | undefined, waiting: ({ cacheEntry: any, file: string }[] | undefined) }} SimilarEntry */
+
+/** @typedef {{ buildInfo: BuildInfo, references: References | undefined, memCache: WeakTupleMap<any, any> }} ModuleMemCachesItem */
+
+/**
+ * @param {string[]} array an array
+ * @returns {boolean} true, if the array is sorted
+ */
+const isSorted = array => {
+	for (let i = 1; i < array.length; i++) {
+		if (array[i - 1] > array[i]) return false;
+	}
+	return true;
+};
+
+/**
+ * @param {{[key: string]: any}} obj an object
+ * @param {string[]} keys the keys of the object
+ * @returns {{[key: string]: any}} the object with properties sorted by property name
+ */
+const sortObject = (obj, keys) => {
+	/** @type {{[key: string]: any}} */
+	const o = {};
+	for (const k of keys.sort()) {
+		o[k] = obj[k];
+	}
+	return o;
+};
+
+/**
+ * @param {string} filename filename
+ * @param {string | string[] | undefined} hashes list of hashes
+ * @returns {boolean} true, if the filename contains any hash
+ */
+const includesHash = (filename, hashes) => {
+	if (!hashes) return false;
+	if (Array.isArray(hashes)) {
+		return hashes.some(hash => filename.includes(hash));
+	}
+	return filename.includes(hashes);
+};
+
+class Compiler {
+	/**
+	 * @param {string} context the compilation path
+	 * @param {WebpackOptions} options options
+	 */
+	constructor(context, options = /** @type {WebpackOptions} */ ({})) {
+		this.hooks = Object.freeze({
+			/** @type {SyncHook<[]>} */
+			initialize: new SyncHook([]),
+
+			/** @type {SyncBailHook<[Compilation], boolean | void>} */
+			shouldEmit: new SyncBailHook(["compilation"]),
+			/** @type {AsyncSeriesHook<[Stats]>} */
+			done: new AsyncSeriesHook(["stats"]),
+			/** @type {SyncHook<[Stats]>} */
+			afterDone: new SyncHook(["stats"]),
+			/** @type {AsyncSeriesHook<[]>} */
+			additionalPass: new AsyncSeriesHook([]),
+			/** @type {AsyncSeriesHook<[Compiler]>} */
+			beforeRun: new AsyncSeriesHook(["compiler"]),
+			/** @type {AsyncSeriesHook<[Compiler]>} */
+			run: new AsyncSeriesHook(["compiler"]),
+			/** @type {AsyncSeriesHook<[Compilation]>} */
+			emit: new AsyncSeriesHook(["compilation"]),
+			/** @type {AsyncSeriesHook<[string, AssetEmittedInfo]>} */
+			assetEmitted: new AsyncSeriesHook(["file", "info"]),
+			/** @type {AsyncSeriesHook<[Compilation]>} */
+			afterEmit: new AsyncSeriesHook(["compilation"]),
+
+			/** @type {SyncHook<[Compilation, CompilationParams]>} */
+			thisCompilation: new SyncHook(["compilation", "params"]),
+			/** @type {SyncHook<[Compilation, CompilationParams]>} */
+			compilation: new SyncHook(["compilation", "params"]),
+			/** @type {SyncHook<[NormalModuleFactory]>} */
+			normalModuleFactory: new SyncHook(["normalModuleFactory"]),
+			/** @type {SyncHook<[ContextModuleFactory]>}  */
+			contextModuleFactory: new SyncHook(["contextModuleFactory"]),
+
+			/** @type {AsyncSeriesHook<[CompilationParams]>} */
+			beforeCompile: new AsyncSeriesHook(["params"]),
+			/** @type {SyncHook<[CompilationParams]>} */
+			compile: new SyncHook(["params"]),
+			/** @type {AsyncParallelHook<[Compilation]>} */
+			make: new AsyncParallelHook(["compilation"]),
+			/** @type {AsyncParallelHook<[Compilation]>} */
+			finishMake: new AsyncSeriesHook(["compilation"]),
+			/** @type {AsyncSeriesHook<[Compilation]>} */
+			afterCompile: new AsyncSeriesHook(["compilation"]),
+
+			/** @type {AsyncSeriesHook<[]>} */
+			readRecords: new AsyncSeriesHook([]),
+			/** @type {AsyncSeriesHook<[]>} */
+			emitRecords: new AsyncSeriesHook([]),
+
+			/** @type {AsyncSeriesHook<[Compiler]>} */
+			watchRun: new AsyncSeriesHook(["compiler"]),
+			/** @type {SyncHook<[Error]>} */
+			failed: new SyncHook(["error"]),
+			/** @type {SyncHook<[string | null, number]>} */
+			invalid: new SyncHook(["filename", "changeTime"]),
+			/** @type {SyncHook<[]>} */
+			watchClose: new SyncHook([]),
+			/** @type {AsyncSeriesHook<[]>} */
+			shutdown: new AsyncSeriesHook([]),
+
+			/** @type {SyncBailHook<[string, string, any[] | undefined], true | void>} */
+			infrastructureLog: new SyncBailHook(["origin", "type", "args"]),
+
+			// TODO the following hooks are weirdly located here
+			// TODO move them for webpack 5
+			/** @type {SyncHook<[]>} */
+			environment: new SyncHook([]),
+			/** @type {SyncHook<[]>} */
+			afterEnvironment: new SyncHook([]),
+			/** @type {SyncHook<[Compiler]>} */
+			afterPlugins: new SyncHook(["compiler"]),
+			/** @type {SyncHook<[Compiler]>} */
+			afterResolvers: new SyncHook(["compiler"]),
+			/** @type {SyncBailHook<[string, Entry], boolean | void>} */
+			entryOption: new SyncBailHook(["context", "entry"])
+		});
+
+		this.webpack = webpack;
+
+		/** @type {string | undefined} */
+		this.name = undefined;
+		/** @type {Compilation | undefined} */
+		this.parentCompilation = undefined;
+		/** @type {Compiler} */
+		this.root = this;
+		/** @type {string} */
+		this.outputPath = "";
+		/** @type {Watching | undefined} */
+		this.watching = undefined;
+
+		/** @type {OutputFileSystem | null} */
+		this.outputFileSystem = null;
+		/** @type {IntermediateFileSystem | null} */
+		this.intermediateFileSystem = null;
+		/** @type {InputFileSystem | null} */
+		this.inputFileSystem = null;
+		/** @type {WatchFileSystem | null} */
+		this.watchFileSystem = null;
+
+		/** @type {string|null} */
+		this.recordsInputPath = null;
+		/** @type {string|null} */
+		this.recordsOutputPath = null;
+		/** @type {Record<string, TODO>} */
+		this.records = {};
+		/** @type {Set<string | RegExp>} */
+		this.managedPaths = new Set();
+		/** @type {Set<string | RegExp>} */
+		this.unmanagedPaths = new Set();
+		/** @type {Set<string | RegExp>} */
+		this.immutablePaths = new Set();
+
+		/** @type {ReadonlySet<string> | undefined} */
+		this.modifiedFiles = undefined;
+		/** @type {ReadonlySet<string> | undefined} */
+		this.removedFiles = undefined;
+		/** @type {ReadonlyMap<string, FileSystemInfoEntry | "ignore" | null> | undefined} */
+		this.fileTimestamps = undefined;
+		/** @type {ReadonlyMap<string, FileSystemInfoEntry | "ignore" | null> | undefined} */
+		this.contextTimestamps = undefined;
+		/** @type {number | undefined} */
+		this.fsStartTime = undefined;
+
+		/** @type {ResolverFactory} */
+		this.resolverFactory = new ResolverFactory();
+
+		/** @type {LoggingFunction | undefined} */
+		this.infrastructureLogger = undefined;
+
+		/** @type {Readonly<PlatformTargetProperties>} */
+		this.platform = {
+			web: null,
+			browser: null,
+			webworker: null,
+			node: null,
+			nwjs: null,
+			electron: null
+		};
+
+		this.options = options;
+
+		this.context = context;
+
+		this.requestShortener = new RequestShortener(context, this.root);
+
+		this.cache = new Cache();
+
+		/** @type {Map<Module, ModuleMemCachesItem> | undefined} */
+		this.moduleMemCaches = undefined;
+
+		this.compilerPath = "";
+
+		/** @type {boolean} */
+		this.running = false;
+
+		/** @type {boolean} */
+		this.idle = false;
+
+		/** @type {boolean} */
+		this.watchMode = false;
+
+		this._backCompat = this.options.experiments.backCompat !== false;
+
+		/** @type {Compilation | undefined} */
+		this._lastCompilation = undefined;
+		/** @type {NormalModuleFactory | undefined} */
+		this._lastNormalModuleFactory = undefined;
+
+		/**
+		 * @private
+		 * @type {WeakMap<Source, CacheEntry>}
+		 */
+		this._assetEmittingSourceCache = new WeakMap();
+		/**
+		 * @private
+		 * @type {Map<string, number>}
+		 */
+		this._assetEmittingWrittenFiles = new Map();
+		/**
+		 * @private
+		 * @type {Set<string>}
+		 */
+		this._assetEmittingPreviousFiles = new Set();
+	}
+
+	/**
+	 * @param {string} name cache name
+	 * @returns {CacheFacade} the cache facade instance
+	 */
+	getCache(name) {
+		return new CacheFacade(
+			this.cache,
+			`${this.compilerPath}${name}`,
+			this.options.output.hashFunction
+		);
+	}
+
+	/**
+	 * @param {string | (function(): string)} name name of the logger, or function called once to get the logger name
+	 * @returns {Logger} a logger with that name
+	 */
+	getInfrastructureLogger(name) {
+		if (!name) {
+			throw new TypeError(
+				"Compiler.getInfrastructureLogger(name) called without a name"
+			);
+		}
+		return new Logger(
+			(type, args) => {
+				if (typeof name === "function") {
+					name = name();
+					if (!name) {
+						throw new TypeError(
+							"Compiler.getInfrastructureLogger(name) called with a function not returning a name"
+						);
+					}
+				}
+				if (
+					this.hooks.infrastructureLog.call(name, type, args) === undefined &&
+					this.infrastructureLogger !== undefined
+				) {
+					this.infrastructureLogger(name, type, args);
+				}
+			},
+			childName => {
+				if (typeof name === "function") {
+					if (typeof childName === "function") {
+						return this.getInfrastructureLogger(() => {
+							if (typeof name === "function") {
+								name = name();
+								if (!name) {
+									throw new TypeError(
+										"Compiler.getInfrastructureLogger(name) called with a function not returning a name"
+									);
+								}
+							}
+							if (typeof childName === "function") {
+								childName = childName();
+								if (!childName) {
+									throw new TypeError(
+										"Logger.getChildLogger(name) called with a function not returning a name"
+									);
+								}
+							}
+							return `${name}/${childName}`;
+						});
+					}
+					return this.getInfrastructureLogger(() => {
+						if (typeof name === "function") {
+							name = name();
+							if (!name) {
+								throw new TypeError(
+									"Compiler.getInfrastructureLogger(name) called with a function not returning a name"
+								);
+							}
+						}
+						return `${name}/${childName}`;
+					});
+				}
+				if (typeof childName === "function") {
+					return this.getInfrastructureLogger(() => {
+						if (typeof childName === "function") {
+							childName = childName();
+							if (!childName) {
+								throw new TypeError(
+									"Logger.getChildLogger(name) called with a function not returning a name"
+								);
+							}
+						}
+						return `${name}/${childName}`;
+					});
+				}
+				return this.getInfrastructureLogger(`${name}/${childName}`);
+			}
+		);
+	}
+
+	// TODO webpack 6: solve this in a better way
+	// e.g. move compilation specific info from Modules into ModuleGraph
+	_cleanupLastCompilation() {
+		if (this._lastCompilation !== undefined) {
+			for (const childCompilation of this._lastCompilation.children) {
+				for (const module of childCompilation.modules) {
+					ChunkGraph.clearChunkGraphForModule(module);
+					ModuleGraph.clearModuleGraphForModule(module);
+					module.cleanupForCache();
+				}
+				for (const chunk of childCompilation.chunks) {
+					ChunkGraph.clearChunkGraphForChunk(chunk);
+				}
+			}
+
+			for (const module of this._lastCompilation.modules) {
+				ChunkGraph.clearChunkGraphForModule(module);
+				ModuleGraph.clearModuleGraphForModule(module);
+				module.cleanupForCache();
+			}
+			for (const chunk of this._lastCompilation.chunks) {
+				ChunkGraph.clearChunkGraphForChunk(chunk);
+			}
+			this._lastCompilation = undefined;
+		}
+	}
+
+	// TODO webpack 6: solve this in a better way
+	_cleanupLastNormalModuleFactory() {
+		if (this._lastNormalModuleFactory !== undefined) {
+			this._lastNormalModuleFactory.cleanupForCache();
+			this._lastNormalModuleFactory = undefined;
+		}
+	}
+
+	/**
+	 * @param {WatchOptions} watchOptions the watcher's options
+	 * @param {RunCallback<Stats>} handler signals when the call finishes
+	 * @returns {Watching} a compiler watcher
+	 */
+	watch(watchOptions, handler) {
+		if (this.running) {
+			return handler(new ConcurrentCompilationError());
+		}
+
+		this.running = true;
+		this.watchMode = true;
+		this.watching = new Watching(this, watchOptions, handler);
+		return this.watching;
+	}
+
+	/**
+	 * @param {RunCallback<Stats>} callback signals when the call finishes
+	 * @returns {void}
+	 */
+	run(callback) {
+		if (this.running) {
+			return callback(new ConcurrentCompilationError());
+		}
+
+		/** @type {Logger | undefined} */
+		let logger;
+
+		/**
+		 * @param {Error | null} err error
+		 * @param {Stats=} stats stats
+		 */
+		const finalCallback = (err, stats) => {
+			if (logger) logger.time("beginIdle");
+			this.idle = true;
+			this.cache.beginIdle();
+			this.idle = true;
+			if (logger) logger.timeEnd("beginIdle");
+			this.running = false;
+			if (err) {
+				this.hooks.failed.call(err);
+			}
+			if (callback !== undefined) callback(err, stats);
+			this.hooks.afterDone.call(/** @type {Stats} */ (stats));
+		};
+
+		const startTime = Date.now();
+
+		this.running = true;
+
+		/**
+		 * @param {Error | null} err error
+		 * @param {Compilation=} _compilation compilation
+		 * @returns {void}
+		 */
+		const onCompiled = (err, _compilation) => {
+			if (err) return finalCallback(err);
+
+			const compilation = /** @type {Compilation} */ (_compilation);
+
+			if (this.hooks.shouldEmit.call(compilation) === false) {
+				compilation.startTime = startTime;
+				compilation.endTime = Date.now();
+				const stats = new Stats(compilation);
+				this.hooks.done.callAsync(stats, err => {
+					if (err) return finalCallback(err);
+					return finalCallback(null, stats);
+				});
+				return;
+			}
+
+			process.nextTick(() => {
+				logger = compilation.getLogger("webpack.Compiler");
+				logger.time("emitAssets");
+				this.emitAssets(compilation, err => {
+					/** @type {Logger} */
+					(logger).timeEnd("emitAssets");
+					if (err) return finalCallback(err);
+
+					if (compilation.hooks.needAdditionalPass.call()) {
+						compilation.needAdditionalPass = true;
+
+						compilation.startTime = startTime;
+						compilation.endTime = Date.now();
+						/** @type {Logger} */
+						(logger).time("done hook");
+						const stats = new Stats(compilation);
+						this.hooks.done.callAsync(stats, err => {
+							/** @type {Logger} */
+							(logger).timeEnd("done hook");
+							if (err) return finalCallback(err);
+
+							this.hooks.additionalPass.callAsync(err => {
+								if (err) return finalCallback(err);
+								this.compile(onCompiled);
+							});
+						});
+						return;
+					}
+
+					/** @type {Logger} */
+					(logger).time("emitRecords");
+					this.emitRecords(err => {
+						/** @type {Logger} */
+						(logger).timeEnd("emitRecords");
+						if (err) return finalCallback(err);
+
+						compilation.startTime = startTime;
+						compilation.endTime = Date.now();
+						/** @type {Logger} */
+						(logger).time("done hook");
+						const stats = new Stats(compilation);
+						this.hooks.done.callAsync(stats, err => {
+							/** @type {Logger} */
+							(logger).timeEnd("done hook");
+							if (err) return finalCallback(err);
+							this.cache.storeBuildDependencies(
+								compilation.buildDependencies,
+								err => {
+									if (err) return finalCallback(err);
+									return finalCallback(null, stats);
+								}
+							);
+						});
+					});
+				});
+			});
+		};
+
+		const run = () => {
+			this.hooks.beforeRun.callAsync(this, err => {
+				if (err) return finalCallback(err);
+
+				this.hooks.run.callAsync(this, err => {
+					if (err) return finalCallback(err);
+
+					this.readRecords(err => {
+						if (err) return finalCallback(err);
+
+						this.compile(onCompiled);
+					});
+				});
+			});
+		};
+
+		if (this.idle) {
+			this.cache.endIdle(err => {
+				if (err) return finalCallback(err);
+
+				this.idle = false;
+				run();
+			});
+		} else {
+			run();
+		}
+	}
+
+	/**
+	 * @param {RunAsChildCallback} callback signals when the call finishes
+	 * @returns {void}
+	 */
+	runAsChild(callback) {
+		const startTime = Date.now();
+
+		/**
+		 * @param {Error | null} err error
+		 * @param {Chunk[]=} entries entries
+		 * @param {Compilation=} compilation compilation
+		 */
+		const finalCallback = (err, entries, compilation) => {
+			try {
+				callback(err, entries, compilation);
+			} catch (runAsChildErr) {
+				const err = new WebpackError(
+					`compiler.runAsChild callback error: ${runAsChildErr}`
+				);
+				err.details = /** @type {Error} */ (runAsChildErr).stack;
+				/** @type {Compilation} */
+				(this.parentCompilation).errors.push(err);
+			}
+		};
+
+		this.compile((err, _compilation) => {
+			if (err) return finalCallback(err);
+
+			const compilation = /** @type {Compilation} */ (_compilation);
+			const parentCompilation = /** @type {Compilation} */ (
+				this.parentCompilation
+			);
+
+			parentCompilation.children.push(compilation);
+
+			for (const { name, source, info } of compilation.getAssets()) {
+				parentCompilation.emitAsset(name, source, info);
+			}
+
+			/** @type {Chunk[]} */
+			const entries = [];
+
+			for (const ep of compilation.entrypoints.values()) {
+				entries.push(...ep.chunks);
+			}
+
+			compilation.startTime = startTime;
+			compilation.endTime = Date.now();
+
+			return finalCallback(null, entries, compilation);
+		});
+	}
+
+	purgeInputFileSystem() {
+		if (this.inputFileSystem && this.inputFileSystem.purge) {
+			this.inputFileSystem.purge();
+		}
+	}
+
+	/**
+	 * @param {Compilation} compilation the compilation
+	 * @param {Callback<void>} callback signals when the assets are emitted
+	 * @returns {void}
+	 */
+	emitAssets(compilation, callback) {
+		/** @type {string} */
+		let outputPath;
+
+		/**
+		 * @param {Error=} err error
+		 * @returns {void}
+		 */
+		const emitFiles = err => {
+			if (err) return callback(err);
+
+			const assets = compilation.getAssets();
+			compilation.assets = { ...compilation.assets };
+			/** @type {Map<string, SimilarEntry>} */
+			const caseInsensitiveMap = new Map();
+			/** @type {Set<string>} */
+			const allTargetPaths = new Set();
+			asyncLib.forEachLimit(
+				assets,
+				15,
+				({ name: file, source, info }, callback) => {
+					let targetFile = file;
+					let immutable = info.immutable;
+					const queryStringIdx = targetFile.indexOf("?");
+					if (queryStringIdx >= 0) {
+						targetFile = targetFile.slice(0, queryStringIdx);
+						// We may remove the hash, which is in the query string
+						// So we recheck if the file is immutable
+						// This doesn't cover all cases, but immutable is only a performance optimization anyway
+						immutable =
+							immutable &&
+							(includesHash(targetFile, info.contenthash) ||
+								includesHash(targetFile, info.chunkhash) ||
+								includesHash(targetFile, info.modulehash) ||
+								includesHash(targetFile, info.fullhash));
+					}
+
+					/**
+					 * @param {Error=} err error
+					 * @returns {void}
+					 */
+					const writeOut = err => {
+						if (err) return callback(err);
+						const targetPath = join(
+							/** @type {OutputFileSystem} */
+							(this.outputFileSystem),
+							outputPath,
+							targetFile
+						);
+						allTargetPaths.add(targetPath);
+
+						// check if the target file has already been written by this Compiler
+						const targetFileGeneration =
+							this._assetEmittingWrittenFiles.get(targetPath);
+
+						// create an cache entry for this Source if not already existing
+						let cacheEntry = this._assetEmittingSourceCache.get(source);
+						if (cacheEntry === undefined) {
+							cacheEntry = {
+								sizeOnlySource: undefined,
+								writtenTo: new Map()
+							};
+							this._assetEmittingSourceCache.set(source, cacheEntry);
+						}
+
+						/** @type {SimilarEntry | undefined} */
+						let similarEntry;
+
+						const checkSimilarFile = () => {
+							const caseInsensitiveTargetPath = targetPath.toLowerCase();
+							similarEntry = caseInsensitiveMap.get(caseInsensitiveTargetPath);
+							if (similarEntry !== undefined) {
+								const { path: other, source: otherSource } = similarEntry;
+								if (isSourceEqual(otherSource, source)) {
+									// Size may or may not be available at this point.
+									// If it's not available add to "waiting" list and it will be updated once available
+									if (similarEntry.size !== undefined) {
+										updateWithReplacementSource(similarEntry.size);
+									} else {
+										if (!similarEntry.waiting) similarEntry.waiting = [];
+										similarEntry.waiting.push({ file, cacheEntry });
+									}
+									alreadyWritten();
+								} else {
+									const err =
+										new WebpackError(`Prevent writing to file that only differs in casing or query string from already written file.
+This will lead to a race-condition and corrupted files on case-insensitive file systems.
+${targetPath}
+${other}`);
+									err.file = file;
+									callback(err);
+								}
+								return true;
+							}
+							caseInsensitiveMap.set(
+								caseInsensitiveTargetPath,
+								(similarEntry = /** @type {SimilarEntry} */ ({
+									path: targetPath,
+									source,
+									size: undefined,
+									waiting: undefined
+								}))
+							);
+							return false;
+						};
+
+						/**
+						 * get the binary (Buffer) content from the Source
+						 * @returns {Buffer} content for the source
+						 */
+						const getContent = () => {
+							if (typeof source.buffer === "function") {
+								return source.buffer();
+							}
+							const bufferOrString = source.source();
+							if (Buffer.isBuffer(bufferOrString)) {
+								return bufferOrString;
+							}
+							return Buffer.from(bufferOrString, "utf8");
+						};
+
+						const alreadyWritten = () => {
+							// cache the information that the Source has been already been written to that location
+							if (targetFileGeneration === undefined) {
+								const newGeneration = 1;
+								this._assetEmittingWrittenFiles.set(targetPath, newGeneration);
+								/** @type {CacheEntry} */
+								(cacheEntry).writtenTo.set(targetPath, newGeneration);
+							} else {
+								/** @type {CacheEntry} */
+								(cacheEntry).writtenTo.set(targetPath, targetFileGeneration);
+							}
+							callback();
+						};
+
+						/**
+						 * Write the file to output file system
+						 * @param {Buffer} content content to be written
+						 * @returns {void}
+						 */
+						const doWrite = content => {
+							/** @type {OutputFileSystem} */
+							(this.outputFileSystem).writeFile(targetPath, content, err => {
+								if (err) return callback(err);
+
+								// information marker that the asset has been emitted
+								compilation.emittedAssets.add(file);
+
+								// cache the information that the Source has been written to that location
+								const newGeneration =
+									targetFileGeneration === undefined
+										? 1
+										: targetFileGeneration + 1;
+								/** @type {CacheEntry} */
+								(cacheEntry).writtenTo.set(targetPath, newGeneration);
+								this._assetEmittingWrittenFiles.set(targetPath, newGeneration);
+								this.hooks.assetEmitted.callAsync(
+									file,
+									{
+										content,
+										source,
+										outputPath,
+										compilation,
+										targetPath
+									},
+									callback
+								);
+							});
+						};
+
+						/**
+						 * @param {number} size size
+						 */
+						const updateWithReplacementSource = size => {
+							updateFileWithReplacementSource(
+								file,
+								/** @type {CacheEntry} */ (cacheEntry),
+								size
+							);
+							/** @type {SimilarEntry} */
+							(similarEntry).size = size;
+							if (
+								/** @type {SimilarEntry} */ (similarEntry).waiting !== undefined
+							) {
+								for (const { file, cacheEntry } of /** @type {SimilarEntry} */ (
+									similarEntry
+								).waiting) {
+									updateFileWithReplacementSource(file, cacheEntry, size);
+								}
+							}
+						};
+
+						/**
+						 * @param {string} file file
+						 * @param {CacheEntry} cacheEntry cache entry
+						 * @param {number} size size
+						 */
+						const updateFileWithReplacementSource = (
+							file,
+							cacheEntry,
+							size
+						) => {
+							// Create a replacement resource which only allows to ask for size
+							// This allows to GC all memory allocated by the Source
+							// (expect when the Source is stored in any other cache)
+							if (!cacheEntry.sizeOnlySource) {
+								cacheEntry.sizeOnlySource = new SizeOnlySource(size);
+							}
+							compilation.updateAsset(file, cacheEntry.sizeOnlySource, {
+								size
+							});
+						};
+
+						/**
+						 * @param {IStats} stats stats
+						 * @returns {void}
+						 */
+						const processExistingFile = stats => {
+							// skip emitting if it's already there and an immutable file
+							if (immutable) {
+								updateWithReplacementSource(/** @type {number} */ (stats.size));
+								return alreadyWritten();
+							}
+
+							const content = getContent();
+
+							updateWithReplacementSource(content.length);
+
+							// if it exists and content on disk matches content
+							// skip writing the same content again
+							// (to keep mtime and don't trigger watchers)
+							// for a fast negative match file size is compared first
+							if (content.length === stats.size) {
+								compilation.comparedForEmitAssets.add(file);
+								return /** @type {OutputFileSystem} */ (
+									this.outputFileSystem
+								).readFile(targetPath, (err, existingContent) => {
+									if (
+										err ||
+										!content.equals(/** @type {Buffer} */ (existingContent))
+									) {
+										return doWrite(content);
+									}
+									return alreadyWritten();
+								});
+							}
+
+							return doWrite(content);
+						};
+
+						const processMissingFile = () => {
+							const content = getContent();
+
+							updateWithReplacementSource(content.length);
+
+							return doWrite(content);
+						};
+
+						// if the target file has already been written
+						if (targetFileGeneration !== undefined) {
+							// check if the Source has been written to this target file
+							const writtenGeneration = /** @type {CacheEntry} */ (
+								cacheEntry
+							).writtenTo.get(targetPath);
+							if (writtenGeneration === targetFileGeneration) {
+								// if yes, we may skip writing the file
+								// if it's already there
+								// (we assume one doesn't modify files while the Compiler is running, other then removing them)
+
+								if (this._assetEmittingPreviousFiles.has(targetPath)) {
+									const sizeOnlySource = /** @type {SizeOnlySource} */ (
+										/** @type {CacheEntry} */ (cacheEntry).sizeOnlySource
+									);
+
+									// We assume that assets from the last compilation say intact on disk (they are not removed)
+									compilation.updateAsset(file, sizeOnlySource, {
+										size: sizeOnlySource.size()
+									});
+
+									return callback();
+								}
+								// Settings immutable will make it accept file content without comparing when file exist
+								immutable = true;
+							} else if (!immutable) {
+								if (checkSimilarFile()) return;
+								// We wrote to this file before which has very likely a different content
+								// skip comparing and assume content is different for performance
+								// This case happens often during watch mode.
+								return processMissingFile();
+							}
+						}
+
+						if (checkSimilarFile()) return;
+						if (this.options.output.compareBeforeEmit) {
+							/** @type {OutputFileSystem} */
+							(this.outputFileSystem).stat(targetPath, (err, stats) => {
+								const exists = !err && /** @type {IStats} */ (stats).isFile();
+
+								if (exists) {
+									processExistingFile(/** @type {IStats} */ (stats));
+								} else {
+									processMissingFile();
+								}
+							});
+						} else {
+							processMissingFile();
+						}
+					};
+
+					if (/\/|\\/.test(targetFile)) {
+						const fs = /** @type {OutputFileSystem} */ (this.outputFileSystem);
+						const dir = dirname(fs, join(fs, outputPath, targetFile));
+						mkdirp(fs, dir, writeOut);
+					} else {
+						writeOut();
+					}
+				},
+				err => {
+					// Clear map to free up memory
+					caseInsensitiveMap.clear();
+					if (err) {
+						this._assetEmittingPreviousFiles.clear();
+						return callback(err);
+					}
+
+					this._assetEmittingPreviousFiles = allTargetPaths;
+
+					this.hooks.afterEmit.callAsync(compilation, err => {
+						if (err) return callback(err);
+
+						return callback();
+					});
+				}
+			);
+		};
+
+		this.hooks.emit.callAsync(compilation, err => {
+			if (err) return callback(err);
+			outputPath = compilation.getPath(this.outputPath, {});
+			mkdirp(
+				/** @type {OutputFileSystem} */ (this.outputFileSystem),
+				outputPath,
+				emitFiles
+			);
+		});
+	}
+
+	/**
+	 * @param {Callback<void>} callback signals when the call finishes
+	 * @returns {void}
+	 */
+	emitRecords(callback) {
+		if (this.hooks.emitRecords.isUsed()) {
+			if (this.recordsOutputPath) {
+				asyncLib.parallel(
+					[
+						cb => this.hooks.emitRecords.callAsync(cb),
+						this._emitRecords.bind(this)
+					],
+					err => callback(err)
+				);
+			} else {
+				this.hooks.emitRecords.callAsync(callback);
+			}
+		} else if (this.recordsOutputPath) {
+			this._emitRecords(callback);
+		} else {
+			callback();
+		}
+	}
+
+	/**
+	 * @param {Callback<void>} callback signals when the call finishes
+	 * @returns {void}
+	 */
+	_emitRecords(callback) {
+		const writeFile = () => {
+			/** @type {OutputFileSystem} */
+			(this.outputFileSystem).writeFile(
+				/** @type {string} */ (this.recordsOutputPath),
+				JSON.stringify(
+					this.records,
+					(n, value) => {
+						if (
+							typeof value === "object" &&
+							value !== null &&
+							!Array.isArray(value)
+						) {
+							const keys = Object.keys(value);
+							if (!isSorted(keys)) {
+								return sortObject(value, keys);
+							}
+						}
+						return value;
+					},
+					2
+				),
+				callback
+			);
+		};
+
+		const recordsOutputPathDirectory = dirname(
+			/** @type {OutputFileSystem} */ (this.outputFileSystem),
+			/** @type {string} */ (this.recordsOutputPath)
+		);
+		if (!recordsOutputPathDirectory) {
+			return writeFile();
+		}
+		mkdirp(
+			/** @type {OutputFileSystem} */ (this.outputFileSystem),
+			recordsOutputPathDirectory,
+			err => {
+				if (err) return callback(err);
+				writeFile();
+			}
+		);
+	}
+
+	/**
+	 * @param {Callback<void>} callback signals when the call finishes
+	 * @returns {void}
+	 */
+	readRecords(callback) {
+		if (this.hooks.readRecords.isUsed()) {
+			if (this.recordsInputPath) {
+				asyncLib.parallel(
+					[
+						cb => this.hooks.readRecords.callAsync(cb),
+						this._readRecords.bind(this)
+					],
+					err => callback(err)
+				);
+			} else {
+				this.records = {};
+				this.hooks.readRecords.callAsync(callback);
+			}
+		} else if (this.recordsInputPath) {
+			this._readRecords(callback);
+		} else {
+			this.records = {};
+			callback();
+		}
+	}
+
+	/**
+	 * @param {Callback<void>} callback signals when the call finishes
+	 * @returns {void}
+	 */
+	_readRecords(callback) {
+		if (!this.recordsInputPath) {
+			this.records = {};
+			return callback();
+		}
+		/** @type {InputFileSystem} */
+		(this.inputFileSystem).stat(this.recordsInputPath, err => {
+			// It doesn't exist
+			// We can ignore this.
+			if (err) return callback();
+
+			/** @type {InputFileSystem} */
+			(this.inputFileSystem).readFile(
+				/** @type {string} */ (this.recordsInputPath),
+				(err, content) => {
+					if (err) return callback(err);
+
+					try {
+						this.records = parseJson(
+							/** @type {Buffer} */ (content).toString("utf-8")
+						);
+					} catch (parseErr) {
+						return callback(
+							new Error(
+								`Cannot parse records: ${/** @type {Error} */ (parseErr).message}`
+							)
+						);
+					}
+
+					return callback();
+				}
+			);
+		});
+	}
+
+	/**
+	 * @param {Compilation} compilation the compilation
+	 * @param {string} compilerName the compiler's name
+	 * @param {number} compilerIndex the compiler's index
+	 * @param {Partial<OutputOptions>=} outputOptions the output options
+	 * @param {WebpackPluginInstance[]=} plugins the plugins to apply
+	 * @returns {Compiler} a child compiler
+	 */
+	createChildCompiler(
+		compilation,
+		compilerName,
+		compilerIndex,
+		outputOptions,
+		plugins
+	) {
+		const childCompiler = new Compiler(this.context, {
+			...this.options,
+			output: {
+				...this.options.output,
+				...outputOptions
+			}
+		});
+		childCompiler.name = compilerName;
+		childCompiler.outputPath = this.outputPath;
+		childCompiler.inputFileSystem = this.inputFileSystem;
+		childCompiler.outputFileSystem = null;
+		childCompiler.resolverFactory = this.resolverFactory;
+		childCompiler.modifiedFiles = this.modifiedFiles;
+		childCompiler.removedFiles = this.removedFiles;
+		childCompiler.fileTimestamps = this.fileTimestamps;
+		childCompiler.contextTimestamps = this.contextTimestamps;
+		childCompiler.fsStartTime = this.fsStartTime;
+		childCompiler.cache = this.cache;
+		childCompiler.compilerPath = `${this.compilerPath}${compilerName}|${compilerIndex}|`;
+		childCompiler._backCompat = this._backCompat;
+
+		const relativeCompilerName = makePathsRelative(
+			this.context,
+			compilerName,
+			this.root
+		);
+		if (!this.records[relativeCompilerName]) {
+			this.records[relativeCompilerName] = [];
+		}
+		if (this.records[relativeCompilerName][compilerIndex]) {
+			childCompiler.records = this.records[relativeCompilerName][compilerIndex];
+		} else {
+			this.records[relativeCompilerName].push((childCompiler.records = {}));
+		}
+
+		childCompiler.parentCompilation = compilation;
+		childCompiler.root = this.root;
+		if (Array.isArray(plugins)) {
+			for (const plugin of plugins) {
+				if (plugin) {
+					plugin.apply(childCompiler);
+				}
+			}
+		}
+		for (const name in this.hooks) {
+			if (
+				![
+					"make",
+					"compile",
+					"emit",
+					"afterEmit",
+					"invalid",
+					"done",
+					"thisCompilation"
+				].includes(name) &&
+				childCompiler.hooks[/** @type {keyof Compiler["hooks"]} */ (name)]
+			) {
+				childCompiler.hooks[
+					/** @type {keyof Compiler["hooks"]} */
+					(name)
+				].taps =
+					this.hooks[
+						/** @type {keyof Compiler["hooks"]} */
+						(name)
+					].taps.slice();
+			}
+		}
+
+		compilation.hooks.childCompiler.call(
+			childCompiler,
+			compilerName,
+			compilerIndex
+		);
+
+		return childCompiler;
+	}
+
+	isChild() {
+		return Boolean(this.parentCompilation);
+	}
+
+	/**
+	 * @param {CompilationParams} params the compilation parameters
+	 * @returns {Compilation} compilation
+	 */
+	createCompilation(params) {
+		this._cleanupLastCompilation();
+		return (this._lastCompilation = new Compilation(this, params));
+	}
+
+	/**
+	 * @param {CompilationParams} params the compilation parameters
+	 * @returns {Compilation} the created compilation
+	 */
+	newCompilation(params) {
+		const compilation = this.createCompilation(params);
+		compilation.name = this.name;
+		compilation.records = this.records;
+		this.hooks.thisCompilation.call(compilation, params);
+		this.hooks.compilation.call(compilation, params);
+		return compilation;
+	}
+
+	createNormalModuleFactory() {
+		this._cleanupLastNormalModuleFactory();
+		const normalModuleFactory = new NormalModuleFactory({
+			context: this.options.context,
+			fs: /** @type {InputFileSystem} */ (this.inputFileSystem),
+			resolverFactory: this.resolverFactory,
+			options: this.options.module,
+			associatedObjectForCache: this.root,
+			layers: this.options.experiments.layers
+		});
+		this._lastNormalModuleFactory = normalModuleFactory;
+		this.hooks.normalModuleFactory.call(normalModuleFactory);
+		return normalModuleFactory;
+	}
+
+	createContextModuleFactory() {
+		const contextModuleFactory = new ContextModuleFactory(this.resolverFactory);
+		this.hooks.contextModuleFactory.call(contextModuleFactory);
+		return contextModuleFactory;
+	}
+
+	newCompilationParams() {
+		const params = {
+			normalModuleFactory: this.createNormalModuleFactory(),
+			contextModuleFactory: this.createContextModuleFactory()
+		};
+		return params;
+	}
+
+	/**
+	 * @param {RunCallback<Compilation>} callback signals when the compilation finishes
+	 * @returns {void}
+	 */
+	compile(callback) {
+		const params = this.newCompilationParams();
+		this.hooks.beforeCompile.callAsync(params, err => {
+			if (err) return callback(err);
+
+			this.hooks.compile.call(params);
+
+			const compilation = this.newCompilation(params);
+
+			const logger = compilation.getLogger("webpack.Compiler");
+
+			logger.time("make hook");
+			this.hooks.make.callAsync(compilation, err => {
+				logger.timeEnd("make hook");
+				if (err) return callback(err);
+
+				logger.time("finish make hook");
+				this.hooks.finishMake.callAsync(compilation, err => {
+					logger.timeEnd("finish make hook");
+					if (err) return callback(err);
+
+					process.nextTick(() => {
+						logger.time("finish compilation");
+						compilation.finish(err => {
+							logger.timeEnd("finish compilation");
+							if (err) return callback(err);
+
+							logger.time("seal compilation");
+							compilation.seal(err => {
+								logger.timeEnd("seal compilation");
+								if (err) return callback(err);
+
+								logger.time("afterCompile hook");
+								this.hooks.afterCompile.callAsync(compilation, err => {
+									logger.timeEnd("afterCompile hook");
+									if (err) return callback(err);
+
+									return callback(null, compilation);
+								});
+							});
+						});
+					});
+				});
+			});
+		});
+	}
+
+	/**
+	 * @param {RunCallback<void>} callback signals when the compiler closes
+	 * @returns {void}
+	 */
+	close(callback) {
+		if (this.watching) {
+			// When there is still an active watching, close this first
+			this.watching.close(err => {
+				this.close(callback);
+			});
+			return;
+		}
+		this.hooks.shutdown.callAsync(err => {
+			if (err) return callback(err);
+			// Get rid of reference to last compilation to avoid leaking memory
+			// We can't run this._cleanupLastCompilation() as the Stats to this compilation
+			// might be still in use. We try to get rid of the reference to the cache instead.
+			this._lastCompilation = undefined;
+			this._lastNormalModuleFactory = undefined;
+			this.cache.shutdown(callback);
+		});
+	}
+}
+
+module.exports = Compiler;
