qunit_test.js

module("Calculator");

test('calculator can perform basic operations', 2, function() {
  var calc = new Calculator();
  equals (calc.sum(5,10), 15, 'Simple addition');
  equals (calc.multiple(5,5), 25, 'Simple multiplication');
});

test('AJAX addition operation', 2, function() {
  stop(5000); // wait for up to 5 seconds
  var calc = new Calculator();
  calc.sendAjaxOperation('+', {
    value: 10,
    modify_value: 25,
    history: '',
    failureCallback: function() {
      ok(false, 'AJAX request failed');
      start();
    },
    successCallback: function(data) {
      equals (data.value, 35);
      equals (data.history.length, 1);
      start();
    }
  });
});

route.rb

get '/javascript_test/:script' => 'javascript_test#render_test'