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

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

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

	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		const definitions = this.definitions;
		compiler.hooks.compilation.tap(
			"ProvidePlugin",
			(compilation, { normalModuleFactory }) => {
				compilation.dependencyTemplates.set(
					ConstDependency,
					new ConstDependency.Template()
				);
				compilation.dependencyFactories.set(
					ProvidedDependency,
					normalModuleFactory
				);
				compilation.dependencyTemplates.set(
					ProvidedDependency,
					new ProvidedDependency.Template()
				);
				const handler = (parser, parserOptions) => {
					Object.keys(definitions).forEach(name => {
						const request = [].concat(definitions[name]);
						const splittedName = name.split(".");
						if (splittedName.length > 0) {
							splittedName.slice(1).forEach((_, i) => {
								const name = splittedName.slice(0, i + 1).join(".");
								parser.hooks.canRename.for(name).tap("ProvidePlugin", approve);
							});
						}

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

						parser.hooks.call.for(name).tap("ProvidePlugin", expr => {
							const nameIdentifier = name.includes(".")
								? `__webpack_provided_${name.replace(/\./g, "_dot_")}`
								: name;
							const dep = new ProvidedDependency(
								request[0],
								nameIdentifier,
								request.slice(1),
								expr.callee.range
							);
							dep.loc = expr.callee.loc;
							parser.state.module.addDependency(dep);
							parser.walkExpressions(expr.arguments);
							return true;
						});
					});
				};
				normalModuleFactory.hooks.parser
					.for("javascript/auto")
					.tap("ProvidePlugin", handler);
				normalModuleFactory.hooks.parser
					.for("javascript/dynamic")
					.tap("ProvidePlugin", handler);
				normalModuleFactory.hooks.parser
					.for("javascript/esm")
					.tap("ProvidePlugin", handler);
			}
		);
	}
}

module.exports = ProvidePlugin;