webpack/lib/dependencies/HarmonyCompatibilityDependency.js

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/

"use strict";

const InitFragment = require("../InitFragment");
const NullDependency = require("./NullDependency");

/** @typedef {import("webpack-sources").ReplaceSource} ReplaceSource */
/** @typedef {import("../Dependency")} Dependency */
/** @typedef {import("../DependencyTemplate").DependencyTemplateContext} DependencyTemplateContext */
/** @typedef {import("../Module")} Module */

class HarmonyCompatibilityDependency extends NullDependency {
	get type() {
		return "harmony export header";
	}
}

HarmonyCompatibilityDependency.Template = class HarmonyExportDependencyTemplate 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, templateContext) {
		// no-op
	}

	/**
	 * @param {Dependency} dependency the dependency for which the template should be applied
	 * @param {DependencyTemplateContext} templateContext the template context
	 * @returns {InitFragment[]|null} the init fragments
	 */
	getInitFragments(dependency, { module, runtimeTemplate, moduleGraph }) {
		const usedExports = moduleGraph.getUsedExports(module);
		if (usedExports === true || usedExports === null) {
			const content = runtimeTemplate.defineEsModuleFlagStatement({
				exportsArgument: module.exportsArgument
			});
			return [
				new InitFragment(
					content,
					InitFragment.STAGE_HARMONY_EXPORTS,
					0,
					"harmony compatibility"
				)
			];
		} else {
			return null;
		}
	}
};

module.exports = HarmonyCompatibilityDependency;