webpack/test/helpers/supportDefaultAssignment.js

module.exports = function supportDefaultAssignment() {
	try {
		var E = eval("class E { toString() { return 'default' } }")
		var f1 = eval("(function f1({a, b = E}) {return new b().toString();})")
		return f1({a: "test"}) === "default" ;
	} catch(e) {
		return false;
	}
};