webpack/lib/dependencies/RequireContextDependencyParserPlugin.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 RequireContextDependency = require("./RequireContextDependency");

module.exports = class RequireContextDependencyParserPlugin {
	apply(parser) {
		parser.hooks.call
			.for("require.context")
			.tap("RequireContextDependencyParserPlugin", expr => {
				let regExp = /^\.\/.*$/;
				let recursive = true;
				let mode = "sync";
				switch (expr.arguments.length) {
					case 4: {
						const modeExpr = parser.evaluateExpression(expr.arguments[3]);
						if (!modeExpr.isString()) return;
						mode = modeExpr.string;
					}
					// falls through
					case 3: {
						const regExpExpr = parser.evaluateExpression(expr.arguments[2]);
						if (!regExpExpr.isRegExp()) return;
						regExp = regExpExpr.regExp;
					}
					// falls through
					case 2: {
						const recursiveExpr = parser.evaluateExpression(expr.arguments[1]);
						if (!recursiveExpr.isBoolean()) return;
						recursive = recursiveExpr.bool;
					}
					// falls through
					case 1: {
						const requestExpr = parser.evaluateExpression(expr.arguments[0]);
						if (!requestExpr.isString()) return;
						const dep = new RequireContextDependency(
							{
								request: requestExpr.string,
								recursive,
								regExp,
								mode,
								category: "commonjs"
							},
							expr.range
						);
						dep.loc = expr.loc;
						dep.optional = !!parser.scope.inTry;
						parser.state.current.addDependency(dep);
						return true;
					}
				}
			});
	}
};