webpack/lib/container/ContainerEntryModule.js

Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports 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, Zackary Jackson @ScriptedAlchemy, Marais Rossouw @maraisr
*/

"use strict";

const { OriginalSource, RawSource } = require("webpack-sources");
const AsyncDependenciesBlock = require("../AsyncDependenciesBlock");
const Module = require("../Module");
const {
	JAVASCRIPT_TYPE,
	JAVASCRIPT_TYPES
} = require("../ModuleSourceTypeConstants");
const { JAVASCRIPT_MODULE_TYPE_DYNAMIC } = require("../ModuleTypeConstants");
const RuntimeGlobals = require("../RuntimeGlobals");
const Template = require("../Template");
const StaticExportsDependency = require("../dependencies/StaticExportsDependency");
const makeSerializable = require("../util/makeSerializable");
const ContainerExposedDependency = require("./ContainerExposedDependency");

/** @typedef {import("../config/defaults").WebpackOptionsNormalizedWithDefaults} WebpackOptions */
/** @typedef {import("../Compilation")} Compilation */
/** @typedef {import("../Module").BuildCallback} BuildCallback */
/** @typedef {import("../Module").CodeGenerationContext} CodeGenerationContext */
/** @typedef {import("../Module").CodeGenerationResult} CodeGenerationResult */
/** @typedef {import("../Module").LibIdentOptions} LibIdentOptions */
/** @typedef {import("../Module").LibIdent} LibIdent */
/** @typedef {import("../Module").NeedBuildCallback} NeedBuildCallback */
/** @typedef {import("../Module").NeedBuildContext} NeedBuildContext */
/** @typedef {import("../Module").Sources} Sources */
/** @typedef {import("../Module").SourceTypes} SourceTypes */
/** @typedef {import("../RequestShortener")} RequestShortener */
/** @typedef {import("../ResolverFactory").ResolverWithOptions} ResolverWithOptions */
/** @typedef {import("../serialization/ObjectMiddleware").ObjectDeserializerContext} ObjectDeserializerContext */
/** @typedef {import("../serialization/ObjectMiddleware").ObjectSerializerContext} ObjectSerializerContext */
/** @typedef {import("../util/fs").InputFileSystem} InputFileSystem */

/**
 * Defines the expose options type used by this module.
 * @typedef {object} ExposeOptions
 * @property {string[]} import requests to exposed modules (last one is exported)
 * @property {string} name custom chunk name for the exposed module
 */

/** @typedef {[string, ExposeOptions][]} ExposesList */

class ContainerEntryModule extends Module {
	/**
	 * Creates an instance of ContainerEntryModule.
	 * @param {string} name container entry name
	 * @param {ExposesList} exposes list of exposed modules
	 * @param {string} shareScope name of the share scope
	 */
	constructor(name, exposes, shareScope) {
		super(JAVASCRIPT_MODULE_TYPE_DYNAMIC, null);
		/** @type {string} */
		this._name = name;
		/** @type {ExposesList} */
		this._exposes = exposes;
		/** @type {string} */
		this._shareScope = shareScope;
	}

	/**
	 * Returns the source types this module can generate.
	 * @returns {SourceTypes} types available (do not mutate)
	 */
	getSourceTypes() {
		return JAVASCRIPT_TYPES;
	}

	/**
	 * Returns the unique identifier used to reference this module.
	 * @returns {string} a unique identifier of the module
	 */
	identifier() {
		return `container entry (${this._shareScope}) ${JSON.stringify(
			this._exposes
		)}`;
	}

	/**
	 * Returns a human-readable identifier for this module.
	 * @param {RequestShortener} requestShortener the request shortener
	 * @returns {string} a user readable identifier of the module
	 */
	readableIdentifier(requestShortener) {
		return "container entry";
	}

	/**
	 * Gets the library identifier.
	 * @param {LibIdentOptions} options options
	 * @returns {LibIdent | null} an identifier for library inclusion
	 */
	libIdent(options) {
		return `${this.layer ? `(${this.layer})/` : ""}webpack/container/entry/${
			this._name
		}`;
	}

	/**
	 * Checks whether the module needs to be rebuilt for the current build state.
	 * @param {NeedBuildContext} context context info
	 * @param {NeedBuildCallback} callback callback function, returns true, if the module needs a rebuild
	 * @returns {void}
	 */
	needBuild(context, callback) {
		return callback(null, !this.buildMeta);
	}

	/**
	 * Builds the module using the provided compilation context.
	 * @param {WebpackOptions} options webpack options
	 * @param {Compilation} compilation the compilation
	 * @param {ResolverWithOptions} resolver the resolver
	 * @param {InputFileSystem} fs the file system
	 * @param {BuildCallback} callback callback function
	 * @returns {void}
	 */
	build(options, compilation, resolver, fs, callback) {
		this.buildMeta = {};
		this.buildInfo = {
			strict: true,
			topLevelDeclarations: new Set(["moduleMap", "get", "init"])
		};
		this.buildMeta.exportsType = "namespace";

		this.clearDependenciesAndBlocks();

		for (const [name, options] of this._exposes) {
			const block = new AsyncDependenciesBlock(
				{
					name: options.name
				},
				{ name },
				options.import[options.import.length - 1]
			);
			let idx = 0;
			for (const request of options.import) {
				const dep = new ContainerExposedDependency(name, request);
				dep.loc = {
					name,
					index: idx++
				};

				block.addDependency(dep);
			}
			this.addBlock(block);
		}
		this.addDependency(new StaticExportsDependency(["get", "init"], false));

		callback();
	}

	/**
	 * Generates code and runtime requirements for this module.
	 * @param {CodeGenerationContext} context context for code generation
	 * @returns {CodeGenerationResult} result
	 */
	codeGeneration({ moduleGraph, chunkGraph, runtimeTemplate }) {
		/** @type {Sources} */
		const sources = new Map();
		const runtimeRequirements = new Set([
			RuntimeGlobals.definePropertyGetters,
			RuntimeGlobals.hasOwnProperty,
			RuntimeGlobals.exports
		]);
		/** @type {string[]} */
		const getters = [];

		for (const block of this.blocks) {
			const { dependencies } = block;

			const modules = dependencies.map((dependency) => {
				const dep = /** @type {ContainerExposedDependency} */ (dependency);
				return {
					name: dep.exposedName,
					module: moduleGraph.getModule(dep),
					request: dep.userRequest
				};
			});

			/** @type {string} */
			let str;

			if (modules.some((m) => !m.module)) {
				str = runtimeTemplate.throwMissingModuleErrorBlock({
					request: modules.map((m) => m.request).join(", ")
				});
			} else {
				str = `return ${runtimeTemplate.blockPromise({
					block,
					message: "",
					chunkGraph,
					runtimeRequirements
				})}.then(${runtimeTemplate.returningFunction(
					runtimeTemplate.returningFunction(
						`(${modules
							.map(({ module, request }) =>
								runtimeTemplate.moduleRaw({
									module,
									chunkGraph,
									request,
									weak: false,
									runtimeRequirements
								})
							)
							.join(", ")})`
					)
				)});`;
			}

			getters.push(
				`${JSON.stringify(modules[0].name)}: ${runtimeTemplate.basicFunction(
					"",
					str
				)}`
			);
		}

		const source = Template.asString([
			"var moduleMap = {",
			Template.indent(getters.join(",\n")),
			"};",
			`var get = ${runtimeTemplate.basicFunction("module, getScope", [
				`${RuntimeGlobals.currentRemoteGetScope} = getScope;`,
				// reusing the getScope variable to avoid creating a new var (and module is also used later)
				"getScope = (",
				Template.indent([
					`${RuntimeGlobals.hasOwnProperty}(moduleMap, module)`,
					Template.indent([
						"? moduleMap[module]()",
						`: Promise.resolve().then(${runtimeTemplate.basicFunction(
							"",
							"throw new Error('Module \"' + module + '\" does not exist in container.');"
						)})`
					])
				]),
				");",
				`${RuntimeGlobals.currentRemoteGetScope} = undefined;`,
				"return getScope;"
			])};`,
			`var init = ${runtimeTemplate.basicFunction("shareScope, initScope", [
				`if (!${RuntimeGlobals.shareScopeMap}) return;`,
				`var name = ${JSON.stringify(this._shareScope)}`,
				`var oldScope = ${RuntimeGlobals.shareScopeMap}[name];`,
				'if(oldScope && oldScope !== shareScope) throw new Error("Container initialization failed as it has already been initialized with a different share scope");',
				`${RuntimeGlobals.shareScopeMap}[name] = shareScope;`,
				`return ${RuntimeGlobals.initializeSharing}(name, initScope);`
			])};`,
			"",
			"// This exports getters to disallow modifications",
			`${RuntimeGlobals.definePropertyGetters}(exports, {`,
			Template.indent([
				`get: ${runtimeTemplate.returningFunction("get")},`,
				`init: ${runtimeTemplate.returningFunction("init")}`
			]),
			"});"
		]);

		sources.set(
			JAVASCRIPT_TYPE,
			this.useSourceMap || this.useSimpleSourceMap
				? new OriginalSource(source, "webpack/container-entry")
				: new RawSource(source)
		);

		return {
			sources,
			runtimeRequirements
		};
	}

	/**
	 * Returns the estimated size for the requested source type.
	 * @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) {
		return 42;
	}

	/**
	 * Serializes this instance into the provided serializer context.
	 * @param {ObjectSerializerContext} context context
	 */
	serialize(context) {
		const { write } = context;
		write(this._name);
		write(this._exposes);
		write(this._shareScope);
		super.serialize(context);
	}

	/**
	 * Restores this instance from the provided deserializer context.
	 * @param {ObjectDeserializerContext} context context
	 * @returns {ContainerEntryModule} deserialized container entry module
	 */
	static deserialize(context) {
		const { read } = context;
		const obj = new ContainerEntryModule(read(), read(), read());
		obj.deserialize(context);
		return obj;
	}
}

makeSerializable(
	ContainerEntryModule,
	"webpack/lib/container/ContainerEntryModule"
);

module.exports = ContainerEntryModule;