📄 ImportDependency.js
/home/palash/git/site/node_modules/webpack/lib/dependencies/ImportDependency.js
Language: js • Lines: 177
/*
	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 { ImportPhaseUtils } = require("./ImportPhase");
const ModuleDependency = require("./ModuleDependency");

/** @typedef {import("webpack-sources").ReplaceSource} ReplaceSource */
/** @typedef {import("../AsyncDependenciesBlock")} AsyncDependenciesBlock */
/** @typedef {import("../Dependency").RawReferencedExports} RawReferencedExports */
/** @typedef {import("../Dependency").ReferencedExports} ReferencedExports */
/** @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 */
/** @typedef {import("./ImportPhase").ImportPhaseType} ImportPhaseType */

class ImportDependency extends ModuleDependency {
	/**
	 * Creates an instance of ImportDependency.
	 * @param {string} request the request
	 * @param {Range} range expression range
	 * @param {RawReferencedExports | null} referencedExports list of referenced exports
	 * @param {ImportPhaseType} phase import phase
	 * @param {ImportAttributes=} attributes import attributes
	 */
	constructor(request, range, referencedExports, phase, attributes) {
		super(request);
		this.range = range;
		this.referencedExports = referencedExports;
		this.phase = phase;
		this.attributes = attributes;
	}

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

	get category() {
		return "esm";
	}

	/**
	 * Returns an identifier to merge equal requests.
	 * @returns {string | null} an identifier to merge equal requests
	 */
	getResourceIdentifier() {
		let str = super.getResourceIdentifier();
		// We specifically use this check to avoid writing the default (`evaluation` or `0`) value and save memory
		if (this.phase) {
			str += `|phase${ImportPhaseUtils.stringify(this.phase)}`;
		}
		if (this.attributes) {
			str += `|attributes${JSON.stringify(this.attributes)}`;
		}
		return str;
	}

	/**
	 * 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 {ReferencedExports} referenced exports
	 */
	getReferencedExports(moduleGraph, runtime) {
		if (!this.referencedExports) return Dependency.EXPORTS_OBJECT_REFERENCED;
		/** @type {ReferencedExports} */
		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;
	}

	/**
	 * Serializes this instance into the provided serializer context.
	 * @param {ObjectSerializerContext} context context
	 */
	serialize(context) {
		context.write(this.range);
		context.write(this.referencedExports);
		context.write(this.phase);
		context.write(this.attributes);
		super.serialize(context);
	}

	/**
	 * Restores this instance from the provided deserializer context.
	 * @param {ObjectDeserializerContext} context context
	 */
	deserialize(context) {
		this.range = context.read();
		this.referencedExports = context.read();
		this.phase = context.read();
		this.attributes = context.read();
		super.deserialize(context);
	}
}

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

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

		// For source phase imports, unwrap the default export
		// import.source() should return the source directly, not a namespace
		if (ImportPhaseUtils.isSource(dep.phase)) {
			content = `${content}.then(${runtimeTemplate.returningFunction(
				'm["default"]',
				"m"
			)})`;
		}

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

module.exports = ImportDependency;