dependency-cruiser/src/utl/extract-root-module-name.cjs

Validate and visualize dependencies. With your rules. JavaScript, TypeScript, CoffeeScript. ES6, CommonJS, AMD.

const LOCAL_MODULE_RE = /^[.]{1,2}($|\/.*)/;
const ABSOLUTE_MODULE_RE = /^\/.*/;

const PACKAGE_RE = "[^/]+";
const SCOPED_PACKAGE_RE = "@[^/]+(/[^/]+)";
const ROOT_MODULE_RE = new RegExp(`^(${SCOPED_PACKAGE_RE}|${PACKAGE_RE})`, "g");

/**
 * returns the module name that likely contains the package.json
 *
 * @param {string} pModuleName module name string as you'd require it
 * @returns {string|undefined} the module name that likely contains the package.json
 */
module.exports = function extractRootModuleName(pModuleName) {
	if (
		LOCAL_MODULE_RE.test(pModuleName) ||
		ABSOLUTE_MODULE_RE.test(pModuleName)
	) {
		return pModuleName;
	} else {
		return (pModuleName.match(ROOT_MODULE_RE) || []).shift();
	}
};