Module.js

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

const util = require("util");

const DependenciesBlock = require("./DependenciesBlock");
const ModuleReason = require("./ModuleReason");
const SortableSet = require("./util/SortableSet");
const Template = require("./Template");

/** @typedef {import("./Chunk")} Chunk */
/** @typedef {import("./RequestShortener")} RequestShortener */
/** @typedef {import("./WebpackError")} WebpackError */
/** @typedef {import("./util/createHash").Hash} Hash */

const EMPTY_RESOLVE_OPTIONS = {};

let debugId = 1000;

const sortById = (a, b) => {
	return a.id - b.id;
};

const sortByDebugId = (a, b) => {
	return a.debugId - b.debugId;
};

/** @typedef {(requestShortener: RequestShortener) => string} OptimizationBailoutFunction */

class Module extends DependenciesBlock {
	constructor(type, context = null) {
		super();
		/** @type {string} */
		this.type = type;
		/** @type {string} */
		this.context = context;

		// Unique Id
		/** @type {number} */
		this.debugId = debugId++;

		// Hash
		/** @type {string} */
		this.hash = undefined;
		/** @type {string} */
		this.renderedHash = undefined;

		// Info from Factory
		/** @type {TODO} */
		this.resolveOptions = EMPTY_RESOLVE_OPTIONS;
		/** @type {object} */
		this.factoryMeta = {};

		// Info from Build
		/** @type {WebpackError[]} */
		this.warnings = [];
		/** @type {WebpackError[]} */
		this.errors = [];
		/** @type {object} */
		this.buildMeta = undefined;
		/** @type {object} */
		this.buildInfo = undefined;

		// Graph (per Compilation)
		/** @type {ModuleReason[]} */
		this.reasons = [];
		/** @type {SortableSet<Chunk>} */
		this._chunks = new SortableSet(undefined, sortById);

		// Info from Compilation (per Compilation)
		/** @type {number|string} */
		this.id = null;
		/** @type {number} */
		this.index = null;
		/** @type {number} */
		this.index2 = null;
		/** @type {number} */
		this.depth = null;
		/** @type {Module} */
		this.issuer = null;
		/** @type {undefined | object} */
		this.profile = undefined;
		/** @type {boolean} */
		this.prefetched = false;
		/** @type {boolean} */
		this.built = false;

		// Info from Optimization (per Compilation)
		/** @type {null | boolean} */
		this.used = null;
		/** @type {false | true | string[]} */
		this.usedExports = null;
		/** @type {(string | OptimizationBailoutFunction)[]} */
		this.optimizationBailout = [];

		// delayed operations
		/** @type {undefined | {oldChunk: Chunk, newChunks: Chunk[]}[] } */
		this._rewriteChunkInReasons = undefined;

		/** @type {boolean} */
		this.useSourceMap = false;

		// info from build
		this._source = null;
	}

	get exportsArgument() {
		return (this.buildInfo && this.buildInfo.exportsArgument) || "exports";
	}

	get moduleArgument() {
		return (this.buildInfo && this.buildInfo.moduleArgument) || "module";
	}

	disconnect() {
		this.hash = undefined;
		this.renderedHash = undefined;

		this.reasons.length = 0;
		this._rewriteChunkInReasons = undefined;
		this._chunks.clear();

		this.id = null;
		this.index = null;
		this.index2 = null;
		this.depth = null;
		this.issuer = null;
		this.profile = undefined;
		this.prefetched = false;
		this.built = false;

		this.used = null;
		this.usedExports = null;
		this.optimizationBailout.length = 0;
		super.disconnect();
	}

	unseal() {
		this.id = null;
		this.index = null;
		this.index2 = null;
		this.depth = null;
		this._chunks.clear();
		super.unseal();
	}

	setChunks(chunks) {
		this._chunks = new SortableSet(chunks, sortById);
	}

	addChunk(chunk) {
		if (this._chunks.has(chunk)) return false;
		this._chunks.add(chunk);
		return true;
	}

	removeChunk(chunk) {
		if (this._chunks.delete(chunk)) {
			chunk.removeModule(this);
			return true;
		}
		return false;
	}

	isInChunk(chunk) {
		return this._chunks.has(chunk);
	}

	isEntryModule() {
		for (const chunk of this._chunks) {
			if (chunk.entryModule === this) return true;
		}
		return false;
	}

	get optional() {
		return (
			this.reasons.length > 0 &&
			this.reasons.every(r => r.dependency && r.dependency.optional)
		);
	}

	/**
	 * @returns {Chunk[]} all chunks which contain the module
	 */
	getChunks() {
		return Array.from(this._chunks);
	}

	getNumberOfChunks() {
		return this._chunks.size;
	}

	get chunksIterable() {
		return this._chunks;
	}

	hasEqualsChunks(otherModule) {
		if (this._chunks.size !== otherModule._chunks.size) return false;
		this._chunks.sortWith(sortByDebugId);
		otherModule._chunks.sortWith(sortByDebugId);
		const a = this._chunks[Symbol.iterator]();
		const b = otherModule._chunks[Symbol.iterator]();
		// eslint-disable-next-line no-constant-condition
		while (true) {
			const aItem = a.next();
			const bItem = b.next();
			if (aItem.done) return true;
			if (aItem.value !== bItem.value) return false;
		}
	}

	addReason(module, dependency, explanation) {
		this.reasons.push(new ModuleReason(module, dependency, explanation));
	}

	removeReason(module, dependency) {
		for (let i = 0; i < this.reasons.length; i++) {
			let r = this.reasons[i];
			if (r.module === module && r.dependency === dependency) {
				this.reasons.splice(i, 1);
				return true;
			}
		}
		return false;
	}

	hasReasonForChunk(chunk) {
		if (this._rewriteChunkInReasons) {
			for (const operation of this._rewriteChunkInReasons) {
				this._doRewriteChunkInReasons(operation.oldChunk, operation.newChunks);
			}
			this._rewriteChunkInReasons = undefined;
		}
		for (let i = 0; i < this.reasons.length; i++) {
			if (this.reasons[i].hasChunk(chunk)) return true;
		}
		return false;
	}

	hasReasons() {
		return this.reasons.length > 0;
	}

	rewriteChunkInReasons(oldChunk, newChunks) {
		// This is expensive. Delay operation until we really need the data
		if (this._rewriteChunkInReasons === undefined) {
			this._rewriteChunkInReasons = [];
		}
		this._rewriteChunkInReasons.push({
			oldChunk,
			newChunks
		});
	}

	_doRewriteChunkInReasons(oldChunk, newChunks) {
		for (let i = 0; i < this.reasons.length; i++) {
			this.reasons[i].rewriteChunks(oldChunk, newChunks);
		}
	}

	/**
	 * @param {string=} exportName the name of the export
	 * @returns {boolean|string} false if the export isn't used, true if no exportName is provided and the module is used, or the name to access it if the export is used
	 */
	isUsed(exportName) {
		if (!exportName) return this.used !== false;
		if (this.used === null || this.usedExports === null) return exportName;
		if (!this.used) return false;
		if (!this.usedExports) return false;
		if (this.usedExports === true) return exportName;
		let idx = this.usedExports.indexOf(exportName);
		if (idx < 0) return false;

		// Mangle export name if possible
		if (this.isProvided(exportName)) {
			if (this.buildMeta.exportsType === "namespace") {
				return Template.numberToIdentifer(idx);
			}
			if (
				this.buildMeta.exportsType === "named" &&
				!this.usedExports.includes("default")
			) {
				return Template.numberToIdentifer(idx);
			}
		}
		return exportName;
	}

	isProvided(exportName) {
		if (!Array.isArray(this.buildMeta.providedExports)) return null;
		return this.buildMeta.providedExports.includes(exportName);
	}

	toString() {
		return `Module[${this.id || this.debugId}]`;
	}

	needRebuild(fileTimestamps, contextTimestamps) {
		return true;
	}

	/**
	 * @param {Hash} hash the hash used to track dependencies
	 * @returns {void}
	 */
	updateHash(hash) {
		hash.update(`${this.id}`);
		hash.update(JSON.stringify(this.usedExports));
		super.updateHash(hash);
	}

	sortItems(sortChunks) {
		super.sortItems();
		if (sortChunks) this._chunks.sort();
		this.reasons.sort((a, b) => {
			if (a.module === b.module) return 0;
			if (!a.module) return -1;
			if (!b.module) return 1;
			return sortById(a.module, b.module);
		});
		if (Array.isArray(this.usedExports)) {
			this.usedExports.sort();
		}
	}

	unbuild() {
		this.dependencies.length = 0;
		this.blocks.length = 0;
		this.variables.length = 0;
		this.buildMeta = undefined;
		this.buildInfo = undefined;
		this.disconnect();
	}

	get arguments() {
		throw new Error("Module.arguments was removed, there is no replacement.");
	}

	set arguments(value) {
		throw new Error("Module.arguments was removed, there is no replacement.");
	}
}

// TODO remove in webpack 5
Object.defineProperty(Module.prototype, "forEachChunk", {
	configurable: false,
	value: util.deprecate(
		/**
		 * @deprecated
		 * @param {function(any, any, Set<any>): void} fn callback function
		 * @returns {void}
		 * @this {Module}
		 */
		function(fn) {
			this._chunks.forEach(fn);
		},
		"Module.forEachChunk: Use for(const chunk of module.chunksIterable) instead"
	)
});

// TODO remove in webpack 5
Object.defineProperty(Module.prototype, "mapChunks", {
	configurable: false,
	value: util.deprecate(
		/**
		 * @deprecated
		 * @param {function(any, any): void} fn Mapper function
		 * @returns {Array<TODO>} Array of chunks mapped
		 * @this {Module}
		 */
		function(fn) {
			return Array.from(this._chunks, fn);
		},
		"Module.mapChunks: Use Array.from(module.chunksIterable, fn) instead"
	)
});

// TODO remove in webpack 5
Object.defineProperty(Module.prototype, "entry", {
	configurable: false,
	get() {
		throw new Error("Module.entry was removed. Use Chunk.entryModule");
	},
	set() {
		throw new Error("Module.entry was removed. Use Chunk.entryModule");
	}
});

// TODO remove in webpack 5
Object.defineProperty(Module.prototype, "meta", {
	configurable: false,
	get: util.deprecate(
		/**
		 * @deprecated
		 * @returns {void}
		 * @this {Module}
		 */
		function() {
			return this.buildMeta;
		},
		"Module.meta was renamed to Module.buildMeta"
	),
	set: util.deprecate(
		/**
		 * @deprecated
		 * @param {TODO} value Value
		 * @returns {void}
		 * @this {Module}
		 */
		function(value) {
			this.buildMeta = value;
		},
		"Module.meta was renamed to Module.buildMeta"
	)
});

/** @type {function(): string} */
Module.prototype.identifier = null;

/** @type {function(RequestShortener): string} */
Module.prototype.readableIdentifier = null;

Module.prototype.build = null;
Module.prototype.source = null;
Module.prototype.size = null;
Module.prototype.nameForCondition = null;
/** @type {null | function(Chunk): boolean} */
Module.prototype.chunkCondition = null;
Module.prototype.updateCacheModule = null;

module.exports = Module;