webpack/lib/dependencies/ExternalModuleDependency.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 Ivan Kopeykin @vankop
*/

"use strict";

const makeSerializable = require("../util/makeSerializable");
const CachedConstDependency = require("./CachedConstDependency");
const ExternalModuleInitFragment = require("./ExternalModuleInitFragment");

/** @typedef {import("webpack-sources").ReplaceSource} ReplaceSource */
/** @typedef {import("../Dependency")} Dependency */
/** @typedef {import("../DependencyTemplate").DependencyTemplateContext} DependencyTemplateContext */
/** @typedef {import("../javascript/JavascriptParser").Range} Range */
/** @typedef {import("../dependencies/ExternalModuleInitFragment").ArrayImportSpecifiers} ArrayImportSpecifiers */
/** @typedef {import("../serialization/ObjectMiddleware").ObjectDeserializerContext} ObjectDeserializerContext */
/** @typedef {import("../serialization/ObjectMiddleware").ObjectSerializerContext} ObjectSerializerContext */

class ExternalModuleDependency extends CachedConstDependency {
	/**
	 * Creates an instance of ExternalModuleDependency.
	 * @param {string} module module
	 * @param {ArrayImportSpecifiers} importSpecifiers import specifiers
	 * @param {string | undefined} defaultImport default import
	 * @param {string} expression expression
	 * @param {Range | null} range range
	 * @param {string} identifier identifier
	 * @param {number=} place place where we inject the expression
	 */
	constructor(
		module,
		importSpecifiers,
		defaultImport,
		expression,
		range,
		identifier,
		place = CachedConstDependency.PLACE_MODULE
	) {
		super(expression, range, identifier, place);

		this.importedModule = module;
		this.specifiers = importSpecifiers;
		this.default = defaultImport;
	}

	/**
	 * Create hash update.
	 * @returns {string} hash update
	 */
	_createHashUpdate() {
		return `${this.importedModule}${JSON.stringify(this.specifiers)}${
			this.default || "null"
		}${super._createHashUpdate()}`;
	}

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

	/**
	 * Restores this instance from the provided deserializer context.
	 * @param {ObjectDeserializerContext} context context
	 */
	deserialize(context) {
		super.deserialize(context);
		const { read } = context;
		this.importedModule = read();
		this.specifiers = read();
		this.default = read();
	}
}

makeSerializable(
	ExternalModuleDependency,
	"webpack/lib/dependencies/ExternalModuleDependency"
);

ExternalModuleDependency.Template = class ExternalModuleDependencyTemplate extends (
	CachedConstDependency.Template
) {
	/**
	 * Applies the plugin by registering its hooks on the compiler.
	 * @param {Dependency} dependency the dependency for which the template should be applied
	 * @param {ReplaceSource} source the current replace source which can be modified
	 * @param {DependencyTemplateContext} templateContext the context object
	 * @returns {void}
	 */
	apply(dependency, source, templateContext) {
		super.apply(dependency, source, templateContext);
		const dep = /** @type {ExternalModuleDependency} */ (dependency);
		const { chunkInitFragments, runtimeTemplate } = templateContext;

		chunkInitFragments.push(
			new ExternalModuleInitFragment(
				`${runtimeTemplate.supportNodePrefixForCoreModules() ? "node:" : ""}${
					dep.importedModule
				}`,
				dep.specifiers,
				dep.default
			)
		);
	}
};

module.exports = ExternalModuleDependency;