webpack/lib/ProvidePlugin.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 {
	JAVASCRIPT_MODULE_TYPE_AUTO,
	JAVASCRIPT_MODULE_TYPE_DYNAMIC,
	JAVASCRIPT_MODULE_TYPE_ESM
} = require("./ModuleTypeConstants");
const ConstDependency = require("./dependencies/ConstDependency");
const ProvidedDependency = require("./dependencies/ProvidedDependency");
const { approve } = require("./javascript/JavascriptParserHelpers");

/** @typedef {import("../declarations/WebpackOptions").JavascriptParserOptions} JavascriptParserOptions */
/** @typedef {import("./Compiler")} Compiler */
/** @typedef {import("./Dependency").DependencyLocation} DependencyLocation */
/** @typedef {import("./javascript/JavascriptParser")} JavascriptParser */
/** @typedef {import("./javascript/JavascriptParser").Range} Range */

const PLUGIN_NAME = "ProvidePlugin";

class ProvidePlugin {
	/**
	 * Creates an instance of ProvidePlugin.
	 * @param {Record<string, string | string[]>} definitions the provided identifiers
	 */
	constructor(definitions) {
		this.definitions = definitions;
	}

	/**
	 * Applies the plugin by registering its hooks on the compiler.
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		const definitions = this.definitions;
		compiler.hooks.compilation.tap(
			PLUGIN_NAME,
			(compilation, { normalModuleFactory }) => {
				compilation.dependencyTemplates.set(
					ConstDependency,
					new ConstDependency.Template()
				);
				compilation.dependencyFactories.set(
					ProvidedDependency,
					normalModuleFactory
				);
				compilation.dependencyTemplates.set(
					ProvidedDependency,
					new ProvidedDependency.Template()
				);
				/**
				 * Handles the hook callback for this code path.
				 * @param {JavascriptParser} parser the parser
				 * @param {JavascriptParserOptions} parserOptions options
				 * @returns {void}
				 */
				const handler = (parser, parserOptions) => {
					for (const name of Object.keys(definitions)) {
						const request = [
							...(Array.isArray(definitions[name])
								? definitions[name]
								: [definitions[name]])
						];
						const splittedName = name.split(".");
						if (splittedName.length > 0) {
							for (const [i, _] of splittedName.slice(1).entries()) {
								const name = splittedName.slice(0, i + 1).join(".");
								parser.hooks.canRename.for(name).tap(PLUGIN_NAME, approve);
							}
						}

						parser.hooks.expression.for(name).tap(PLUGIN_NAME, (expr) => {
							const nameIdentifier = name.includes(".")
								? `__webpack_provided_${name.replace(/\./g, "_dot_")}`
								: name;
							const dep = new ProvidedDependency(
								request[0],
								nameIdentifier,
								request.slice(1),
								/** @type {Range} */ (expr.range)
							);
							dep.loc = /** @type {DependencyLocation} */ (expr.loc);
							parser.state.module.addDependency(dep);
							return true;
						});

						parser.hooks.call.for(name).tap(PLUGIN_NAME, (expr) => {
							const nameIdentifier = name.includes(".")
								? `__webpack_provided_${name.replace(/\./g, "_dot_")}`
								: name;
							const dep = new ProvidedDependency(
								request[0],
								nameIdentifier,
								request.slice(1),
								/** @type {Range} */ (expr.callee.range)
							);
							dep.loc = /** @type {DependencyLocation} */ (expr.callee.loc);
							parser.state.module.addDependency(dep);
							parser.walkExpressions(expr.arguments);
							return true;
						});
					}
				};
				normalModuleFactory.hooks.parser
					.for(JAVASCRIPT_MODULE_TYPE_AUTO)
					.tap(PLUGIN_NAME, handler);
				normalModuleFactory.hooks.parser
					.for(JAVASCRIPT_MODULE_TYPE_DYNAMIC)
					.tap(PLUGIN_NAME, handler);
				normalModuleFactory.hooks.parser
					.for(JAVASCRIPT_MODULE_TYPE_ESM)
					.tap(PLUGIN_NAME, handler);
			}
		);
	}
}

module.exports = ProvidePlugin;