webpack/lib/RuntimeModule.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

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

"use strict";

const { RawSource } = require("webpack-sources");
const OriginalSource = require("webpack-sources").OriginalSource;
const Module = require("./Module");

/** @typedef {import("webpack-sources").Source} Source */
/** @typedef {import("../declarations/WebpackOptions").WebpackOptionsNormalized} WebpackOptions */
/** @typedef {import("./Chunk")} Chunk */
/** @typedef {import("./ChunkGraph")} ChunkGraph */
/** @typedef {import("./Compilation")} Compilation */
/** @typedef {import("./Dependency").UpdateHashContext} UpdateHashContext */
/** @typedef {import("./Module").CodeGenerationContext} CodeGenerationContext */
/** @typedef {import("./Module").CodeGenerationResult} CodeGenerationResult */
/** @typedef {import("./Module").NeedBuildContext} NeedBuildContext */
/** @typedef {import("./RequestShortener")} RequestShortener */
/** @typedef {import("./ResolverFactory").ResolverWithOptions} ResolverWithOptions */
/** @typedef {import("./WebpackError")} WebpackError */
/** @typedef {import("./util/Hash")} Hash */
/** @typedef {import("./util/fs").InputFileSystem} InputFileSystem */

const TYPES = new Set(["runtime"]);

class RuntimeModule extends Module {
	/**
	 * @param {string} name a readable name
	 * @param {number=} stage an optional stage
	 */
	constructor(name, stage = 0) {
		super("runtime");
		this.name = name;
		this.stage = stage;
		this.buildMeta = {};
		this.buildInfo = {};
		/** @type {Compilation} */
		this.compilation = undefined;
		/** @type {Chunk} */
		this.chunk = undefined;
		/** @type {ChunkGraph} */
		this.chunkGraph = undefined;
		this.fullHash = false;
		this.dependentHash = false;
		/** @type {string} */
		this._cachedGeneratedCode = undefined;
	}

	/**
	 * @param {Compilation} compilation the compilation
	 * @param {Chunk} chunk the chunk
	 * @param {ChunkGraph} chunkGraph the chunk graph
	 * @returns {void}
	 */
	attach(compilation, chunk, chunkGraph = compilation.chunkGraph) {
		this.compilation = compilation;
		this.chunk = chunk;
		this.chunkGraph = chunkGraph;
	}

	/**
	 * @returns {string} a unique identifier of the module
	 */
	identifier() {
		return `webpack/runtime/${this.name}`;
	}

	/**
	 * @param {RequestShortener} requestShortener the request shortener
	 * @returns {string} a user readable identifier of the module
	 */
	readableIdentifier(requestShortener) {
		return `webpack/runtime/${this.name}`;
	}

	/**
	 * @param {NeedBuildContext} context context info
	 * @param {function(WebpackError=, boolean=): void} callback callback function, returns true, if the module needs a rebuild
	 * @returns {void}
	 */
	needBuild(context, callback) {
		return callback(null, false);
	}

	/**
	 * @param {WebpackOptions} options webpack options
	 * @param {Compilation} compilation the compilation
	 * @param {ResolverWithOptions} resolver the resolver
	 * @param {InputFileSystem} fs the file system
	 * @param {function(WebpackError=): void} callback callback function
	 * @returns {void}
	 */
	build(options, compilation, resolver, fs, callback) {
		// do nothing
		// should not be called as runtime modules are added later to the compilation
		callback();
	}

	/**
	 * @param {Hash} hash the hash used to track dependencies
	 * @param {UpdateHashContext} context context
	 * @returns {void}
	 */
	updateHash(hash, context) {
		hash.update(this.name);
		hash.update(`${this.stage}`);
		try {
			if (this.fullHash || this.dependentHash) {
				// Do not use getGeneratedCode here, because i. e. compilation hash might be not
				// ready at this point. We will cache it later instead.
				hash.update(this.generate());
			} else {
				hash.update(this.getGeneratedCode());
			}
		} catch (err) {
			hash.update(err.message);
		}
		super.updateHash(hash, context);
	}

	/**
	 * @returns {Set<string>} types available (do not mutate)
	 */
	getSourceTypes() {
		return TYPES;
	}

	/**
	 * @param {CodeGenerationContext} context context for code generation
	 * @returns {CodeGenerationResult} result
	 */
	codeGeneration(context) {
		const sources = new Map();
		const generatedCode = this.getGeneratedCode();
		if (generatedCode) {
			sources.set(
				"runtime",
				this.useSourceMap || this.useSimpleSourceMap
					? new OriginalSource(generatedCode, this.identifier())
					: new RawSource(generatedCode)
			);
		}
		return {
			sources,
			runtimeRequirements: null
		};
	}

	/**
	 * @param {string=} type the source type for which the size should be estimated
	 * @returns {number} the estimated size of the module (must be non-zero)
	 */
	size(type) {
		try {
			const source = this.getGeneratedCode();
			return source ? source.length : 0;
		} catch (e) {
			return 0;
		}
	}

	/* istanbul ignore next */
	/**
	 * @abstract
	 * @returns {string} runtime code
	 */
	generate() {
		const AbstractMethodError = require("./AbstractMethodError");
		throw new AbstractMethodError();
	}

	/**
	 * @returns {string} runtime code
	 */
	getGeneratedCode() {
		if (this._cachedGeneratedCode) {
			return this._cachedGeneratedCode;
		}
		return (this._cachedGeneratedCode = this.generate());
	}

	/**
	 * @returns {boolean} true, if the runtime module should get it's own scope
	 */
	shouldIsolate() {
		return true;
	}
}

/**
 * Runtime modules without any dependencies to other runtime modules
 */
RuntimeModule.STAGE_NORMAL = 0;

/**
 * Runtime modules with simple dependencies on other runtime modules
 */
RuntimeModule.STAGE_BASIC = 5;

/**
 * Runtime modules which attach to handlers of other runtime modules
 */
RuntimeModule.STAGE_ATTACH = 10;

/**
 * Runtime modules which trigger actions on bootstrap
 */
RuntimeModule.STAGE_TRIGGER = 20;

module.exports = RuntimeModule;