webpack/lib/container/ContainerEntryModule.js

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra, Zackary Jackson @ScriptedAlchemy, Marais Rossouw @maraisr
*/

"use strict";

const { OriginalSource } = require("webpack-sources");
const AsyncDependenciesBlock = require("../AsyncDependenciesBlock");
const Module = require("../Module");
const RuntimeGlobals = require("../RuntimeGlobals");
const Template = require("../Template");
const makeSerializable = require("../util/makeSerializable");
const ContainerExposedDependency = require("./ContainerExposedDependency");

/** @typedef {import("../../declarations/WebpackOptions").WebpackOptionsNormalized} WebpackOptions */
/** @typedef {import("../ChunkGraph")} ChunkGraph */
/** @typedef {import("../ChunkGroup")} ChunkGroup */
/** @typedef {import("../Compilation")} Compilation */
/** @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 */
/** @typedef {import("./ContainerEntryDependency")} ContainerEntryDependency */

const SOURCE_TYPES = new Set(["javascript"]);

class ContainerEntryModule extends Module {
	/**
	 * @param {[string, string][]} exposes list of exposed modules
	 */
	constructor(exposes) {
		super("javascript/dynamic", null);
		this.exposes = exposes;
	}

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

	/**
	 * @returns {string} a unique identifier of the module
	 */
	identifier() {
		return `container entry ${JSON.stringify(this.exposes)}`;
	}

	/**
	 * @param {RequestShortener} requestShortener the request shortener
	 * @returns {string} a user readable identifier of the module
	 */
	readableIdentifier(requestShortener) {
		return `container entry`;
	}

	/**
	 * @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, !this.buildMeta);
	}

	/**
	 * @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) {
		this.buildMeta = {};
		this.buildInfo = {
			strict: true
		};

		this.clearDependenciesAndBlocks();

		const dependencies = [];

		let idx = -1;
		for (const [name, request] of this.exposes) {
			++idx;
			const dep = new ContainerExposedDependency(name, request);
			dep.loc = {
				name,
				index: idx
			};

			dependencies.push(dep);
		}

		for (const dep of dependencies) {
			const block = new AsyncDependenciesBlock(undefined, dep.loc, dep.request);
			block.addDependency(dep);
			this.addBlock(block);
		}

		callback();
	}

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

		for (const block of this.blocks) {
			const {
				dependencies: [dependency]
			} = block;
			const dep = /** @type {ContainerExposedDependency} */ (dependency);
			const name = dep.exposedName;
			const mod = moduleGraph.getModule(dep);
			const request = dep.userRequest;

			let str;

			if (!mod) {
				str = runtimeTemplate.throwMissingModuleErrorBlock({
					request: dep.userRequest
				});
			} else {
				str = `return ${runtimeTemplate.blockPromise({
					block,
					message: "",
					chunkGraph,
					runtimeRequirements
				})}.then(${runtimeTemplate.returningFunction(
					runtimeTemplate.returningFunction(
						runtimeTemplate.moduleRaw({
							module: mod,
							chunkGraph,
							request,
							weak: false,
							runtimeRequirements
						})
					)
				)});`;
			}

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

		const source = Template.asString([
			`var moduleMap = {`,
			Template.indent(getters.join(",\n")),
			"};",
			`var get = ${runtimeTemplate.basicFunction("module", [
				"return (",
				Template.indent([
					`${RuntimeGlobals.hasOwnProperty}(moduleMap, module)`,
					Template.indent([
						"? moduleMap[module]()",
						`: Promise.resolve().then(${runtimeTemplate.basicFunction(
							"",
							'throw new Error("Module " + module + " does not exist in container.");'
						)})`
					])
				]),
				");"
			])};`,
			`var override = ${runtimeTemplate.basicFunction(
				"override",
				`Object.assign(${RuntimeGlobals.overrides}, override);`
			)}`,
			"",
			"// This exports getters to disallow modifications",
			`${RuntimeGlobals.definePropertyGetters}(exports, {`,
			Template.indent([
				`get: ${runtimeTemplate.returningFunction("get")},`,
				`override: ${runtimeTemplate.returningFunction("override")}`
			]),
			"});"
		]);

		sources.set(
			"javascript",
			new OriginalSource(source, "webpack/container-entry")
		);

		return {
			sources,
			runtimeRequirements
		};
	}

	/**
	 * @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;
	}

	serialize(context) {
		const { write } = context;
		write(this.exposes);
		super.serialize(context);
	}

	deserialize(context) {
		const { read } = context;
		this.exposes = read();
		super.deserialize(context);
	}
}

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

module.exports = ContainerEntryModule;