webpack/lib/dependencies/CommonJsPlugin.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("./ConstDependency");
const CommonJsRequireDependency = require("./CommonJsRequireDependency");
const CommonJsRequireContextDependency = require("./CommonJsRequireContextDependency");
const RequireResolveDependency = require("./RequireResolveDependency");
const RequireResolveContextDependency = require("./RequireResolveContextDependency");
const RequireResolveHeaderDependency = require("./RequireResolveHeaderDependency");
const RequireHeaderDependency = require("./RequireHeaderDependency");

const NullFactory = require("../NullFactory");

const RequireResolveDependencyParserPlugin = require("./RequireResolveDependencyParserPlugin");
const CommonJsRequireDependencyParserPlugin = require("./CommonJsRequireDependencyParserPlugin");

const ParserHelpers = require("../ParserHelpers");

class CommonJsPlugin {
	constructor(options) {
		this.options = options;
	}

	apply(compiler) {
		const options = this.options;
		compiler.hooks.compilation.tap(
			"CommonJsPlugin",
			(compilation, { contextModuleFactory, normalModuleFactory }) => {
				compilation.dependencyFactories.set(
					CommonJsRequireDependency,
					normalModuleFactory
				);
				compilation.dependencyTemplates.set(
					CommonJsRequireDependency,
					new CommonJsRequireDependency.Template()
				);

				compilation.dependencyFactories.set(
					CommonJsRequireContextDependency,
					contextModuleFactory
				);
				compilation.dependencyTemplates.set(
					CommonJsRequireContextDependency,
					new CommonJsRequireContextDependency.Template()
				);

				compilation.dependencyFactories.set(
					RequireResolveDependency,
					normalModuleFactory
				);
				compilation.dependencyTemplates.set(
					RequireResolveDependency,
					new RequireResolveDependency.Template()
				);

				compilation.dependencyFactories.set(
					RequireResolveContextDependency,
					contextModuleFactory
				);
				compilation.dependencyTemplates.set(
					RequireResolveContextDependency,
					new RequireResolveContextDependency.Template()
				);

				compilation.dependencyFactories.set(
					RequireResolveHeaderDependency,
					new NullFactory()
				);
				compilation.dependencyTemplates.set(
					RequireResolveHeaderDependency,
					new RequireResolveHeaderDependency.Template()
				);

				compilation.dependencyFactories.set(
					RequireHeaderDependency,
					new NullFactory()
				);
				compilation.dependencyTemplates.set(
					RequireHeaderDependency,
					new RequireHeaderDependency.Template()
				);

				const handler = (parser, parserOptions) => {
					if (parserOptions.commonjs !== undefined && !parserOptions.commonjs)
						return;

					const requireExpressions = [
						"require",
						"require.resolve",
						"require.resolveWeak"
					];
					for (let expression of requireExpressions) {
						parser.hooks.typeof
							.for(expression)
							.tap(
								"CommonJsPlugin",
								ParserHelpers.toConstantDependency(
									parser,
									JSON.stringify("function")
								)
							);
						parser.hooks.evaluateTypeof
							.for(expression)
							.tap(
								"CommonJsPlugin",
								ParserHelpers.evaluateToString("function")
							);
						parser.hooks.evaluateIdentifier
							.for(expression)
							.tap(
								"CommonJsPlugin",
								ParserHelpers.evaluateToIdentifier(expression, true)
							);
					}

					parser.hooks.evaluateTypeof
						.for("module")
						.tap("CommonJsPlugin", ParserHelpers.evaluateToString("object"));
					parser.hooks.assign.for("require").tap("CommonJsPlugin", expr => {
						// to not leak to global "require", we need to define a local require here.
						const dep = new ConstDependency("var require;", 0);
						dep.loc = expr.loc;
						parser.state.current.addDependency(dep);
						parser.scope.definitions.add("require");
						return true;
					});
					parser.hooks.canRename
						.for("require")
						.tap("CommonJsPlugin", () => true);
					parser.hooks.rename.for("require").tap("CommonJsPlugin", expr => {
						// define the require variable. It's still undefined, but not "not defined".
						const dep = new ConstDependency("var require;", 0);
						dep.loc = expr.loc;
						parser.state.current.addDependency(dep);
						return false;
					});
					parser.hooks.typeof.for("module").tap("CommonJsPlugin", () => true);
					parser.hooks.evaluateTypeof
						.for("exports")
						.tap("CommonJsPlugin", ParserHelpers.evaluateToString("object"));

					new CommonJsRequireDependencyParserPlugin(options).apply(parser);
					new RequireResolveDependencyParserPlugin(options).apply(parser);
				};

				normalModuleFactory.hooks.parser
					.for("javascript/auto")
					.tap("CommonJsPlugin", handler);
				normalModuleFactory.hooks.parser
					.for("javascript/dynamic")
					.tap("CommonJsPlugin", handler);
			}
		);
	}
}
module.exports = CommonJsPlugin;