test.html

<!DOCTYPE html>
<script src="node_modules/moment/moment.js"></script>
<script>
  function require() {
    return moment;
  }
</script>
<script src="frozen-moment.js"></script>
<script>
  function printToDOM(/* ...arguments */) {
    var str = '';
    for (var i = 0; i < arguments.length; i++) {
      str += '  ' + arguments[i];
    }
    document.body.innerHTML = document.body.innerHTML + '<p>' + str + '</p>';
  }
  function wrapConsole(methodName) {
    var oldConsole = console[methodName];
    console[methodName] = function (firstArgument) {
      if (oldConsole && oldConsole.apply) {
        oldConsole.apply(this, arguments);
      }
      printToDOM.apply(this, arguments);
    };
  }
  wrapConsole('error');
  wrapConsole('log');
  window.onerror = function (err) {
    printToDOM('test failed, see console for details');
  };
</script>
<body>
  <p>Running tests...</p>

  <script src="test.js"></script>
</body>