Tests for ES6 arrow function, passing arrow function as the paramter On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS f(x=>{return x * 25;}, 121) is 25*121 PASS f2((x, y)=>{return x * y;}, 14, 12) is 14*12 PASS successfullyParsed is true TEST COMPLETE