webpack/lib/dependencies/HarmonyExportSpecifierDependency.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support 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 makeSerializable = require("../util/makeSerializable");
const HarmonyExportInitFragment = require("./HarmonyExportInitFragment");
const NullDependency = require("./NullDependency");

/** @typedef {import("webpack-sources").ReplaceSource} ReplaceSource */
/** @typedef {import("../Dependency")} Dependency */
/** @typedef {import("../Dependency").ExportsSpec} ExportsSpec */
/** @typedef {import("../DependencyTemplate").DependencyTemplateContext} DependencyTemplateContext */
/** @typedef {import("../ModuleGraph")} ModuleGraph */
/** @typedef {import("../ModuleGraphConnection").ConnectionState} ConnectionState */

class HarmonyExportSpecifierDependency extends NullDependency {
	constructor(id, name) {
		super();
		this.id = id;
		this.name = name;
	}

	get type() {
		return "harmony export specifier";
	}

	/**
	 * Returns the exported names
	 * @param {ModuleGraph} moduleGraph module graph
	 * @returns {ExportsSpec | undefined} export names
	 */
	getExports(moduleGraph) {
		return {
			exports: [this.name],
			priority: 1,
			terminalBinding: true,
			dependencies: undefined
		};
	}

	/**
	 * @param {ModuleGraph} moduleGraph the module graph
	 * @returns {ConnectionState} how this dependency connects the module to referencing modules
	 */
	getModuleEvaluationSideEffectsState(moduleGraph) {
		return false;
	}

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

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

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

HarmonyExportSpecifierDependency.Template = class HarmonyExportSpecifierDependencyTemplate extends (
	NullDependency.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,
		{ module, moduleGraph, initFragments, runtime, concatenationScope }
	) {
		const dep = /** @type {HarmonyExportSpecifierDependency} */ (dependency);
		if (concatenationScope) {
			concatenationScope.registerExport(dep.name, dep.id);
			return;
		}
		const used = moduleGraph
			.getExportsInfo(module)
			.getUsedName(dep.name, runtime);
		if (!used) {
			const set = new Set();
			set.add(dep.name || "namespace");
			initFragments.push(
				new HarmonyExportInitFragment(module.exportsArgument, undefined, set)
			);
			return;
		}

		const map = new Map();
		map.set(used, `/* binding */ ${dep.id}`);
		initFragments.push(
			new HarmonyExportInitFragment(module.exportsArgument, map, undefined)
		);
	}
};

module.exports = HarmonyExportSpecifierDependency;