webpack/lib/ExportPropertyMainTemplatePlugin.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 { ConcatSource } = require("webpack-sources");

/** @typedef {import("./Compilation")} Compilation */

/**
 * @param {string[]} accessor the accessor to convert to path
 * @returns {string} the path
 */
const accessorToObjectAccess = accessor => {
	return accessor.map(a => `[${JSON.stringify(a)}]`).join("");
};

class ExportPropertyMainTemplatePlugin {
	/**
	 * @param {string|string[]} property the name of the property to export
	 */
	constructor(property) {
		this.property = property;
	}

	/**
	 * @param {Compilation} compilation the compilation instance
	 * @returns {void}
	 */
	apply(compilation) {
		const { mainTemplate, chunkTemplate } = compilation;

		const onRenderWithEntry = (source, chunk, hash) => {
			const postfix = `${accessorToObjectAccess([].concat(this.property))}`;
			return new ConcatSource(source, postfix);
		};

		for (const template of [mainTemplate, chunkTemplate]) {
			template.hooks.renderWithEntry.tap(
				"ExportPropertyMainTemplatePlugin",
				onRenderWithEntry
			);
		}

		mainTemplate.hooks.hash.tap("ExportPropertyMainTemplatePlugin", hash => {
			hash.update("export property");
			hash.update(`${this.property}`);
		});
	}
}

module.exports = ExportPropertyMainTemplatePlugin;