webpack/lib/dependencies/ImportDependency.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
*/

"use strict";

const Dependency = require("../Dependency");
const makeSerializable = require("../util/makeSerializable");
const ModuleDependency = require("./ModuleDependency");

/** @typedef {import("webpack-sources").ReplaceSource} ReplaceSource */
/** @typedef {import("../AsyncDependenciesBlock")} AsyncDependenciesBlock */
/** @typedef {import("../Dependency").ReferencedExport} ReferencedExport */
/** @typedef {import("../DependencyTemplate").DependencyTemplateContext} DependencyTemplateContext */
/** @typedef {import("../Module")} Module */
/** @typedef {import("../Module").BuildMeta} BuildMeta */
/** @typedef {import("../ModuleGraph")} ModuleGraph */
/** @typedef {import("../javascript/JavascriptParser").ImportAttributes} ImportAttributes */
/** @typedef {import("../javascript/JavascriptParser").Range} Range */
/** @typedef {import("../serialization/ObjectMiddleware").ObjectDeserializerContext} ObjectDeserializerContext */
/** @typedef {import("../serialization/ObjectMiddleware").ObjectSerializerContext} ObjectSerializerContext */
/** @typedef {import("../util/runtime").RuntimeSpec} RuntimeSpec */

class ImportDependency extends ModuleDependency {
	/**
	 * @param {string} request the request
	 * @param {Range} range expression range
	 * @param {(string[][] | null)=} referencedExports list of referenced exports
	 * @param {ImportAttributes=} attributes import attributes
	 */
	constructor(request, range, referencedExports, attributes) {
		super(request);
		this.range = range;
		this.referencedExports = referencedExports;
		this.assertions = attributes;
	}

	get type() {
		return "import()";
	}

	get category() {
		return "esm";
	}

	/**
	 * Returns list of exports referenced by this dependency
	 * @param {ModuleGraph} moduleGraph module graph
	 * @param {RuntimeSpec} runtime the runtime for which the module is analysed
	 * @returns {(string[] | ReferencedExport)[]} referenced exports
	 */
	getReferencedExports(moduleGraph, runtime) {
		if (!this.referencedExports) return Dependency.EXPORTS_OBJECT_REFERENCED;
		const refs = [];
		for (const referencedExport of this.referencedExports) {
			if (referencedExport[0] === "default") {
				const selfModule =
					/** @type {Module} */
					(moduleGraph.getParentModule(this));
				const importedModule =
					/** @type {Module} */
					(moduleGraph.getModule(this));
				const exportsType = importedModule.getExportsType(
					moduleGraph,
					/** @type {BuildMeta} */
					(selfModule.buildMeta).strictHarmonyModule
				);
				if (
					exportsType === "default-only" ||
					exportsType === "default-with-named"
				) {
					return Dependency.EXPORTS_OBJECT_REFERENCED;
				}
			}
			refs.push({
				name: referencedExport,
				canMangle: false
			});
		}
		return refs;
	}

	/**
	 * @param {ObjectSerializerContext} context context
	 */
	serialize(context) {
		context.write(this.range);
		context.write(this.referencedExports);
		context.write(this.assertions);
		super.serialize(context);
	}

	/**
	 * @param {ObjectDeserializerContext} context context
	 */
	deserialize(context) {
		this.range = context.read();
		this.referencedExports = context.read();
		this.assertions = context.read();
		super.deserialize(context);
	}
}

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

ImportDependency.Template = class ImportDependencyTemplate extends (
	ModuleDependency.Template
) {
	/**
	 * @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,
		{ runtimeTemplate, module, moduleGraph, chunkGraph, runtimeRequirements }
	) {
		const dep = /** @type {ImportDependency} */ (dependency);
		const block = /** @type {AsyncDependenciesBlock} */ (
			moduleGraph.getParentBlock(dep)
		);
		const content = runtimeTemplate.moduleNamespacePromise({
			chunkGraph,
			block: block,
			module: /** @type {Module} */ (moduleGraph.getModule(dep)),
			request: dep.request,
			strict: /** @type {BuildMeta} */ (module.buildMeta).strictHarmonyModule,
			message: "import()",
			runtimeRequirements
		});

		source.replace(dep.range[0], dep.range[1] - 1, content);
	}
};

module.exports = ImportDependency;