<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
</head>
<body>
  <script src="https://wzrd.in/standalone/expect@22.4.3"></script>
  <script src="script.jsx"></script>
</body>
</html>
/*
 * Open the console to see
 * that the tests have passed.
 */

const toggleTodo = (todo) => {
  return {
    ...todo,
    completed: !todo.completed
  };
};

const testToggleTodo = () => {
  const todoBefore = {
    id: 0,
    text: 'Learn Redux',
    completed: false
  };
  const todoAfter = {
    id: 0,
    text: 'Learn Redux',
    completed: true
  };
  
  deepFreeze(todoBefore);
  
  expect(
    toggleTodo(todoBefore)
  ).toEqual(todoAfter);
};

testToggleTodo();
console.log('All tests passed.') || displayInPreview('All tests passed.');



// display in plunker preview
function displayInPreview(string) {
  var newDiv = document.createElement("div"); 
  var newContent = document.createTextNode(string); 
  newDiv.appendChild(newContent);
  document.body.appendChild(newDiv)
}

// Function exported from deep-freeze lib
function deepFreeze (o) {
  if (o===Object(o)) {
    Object.isFrozen(o) || Object.freeze(o)
    Object.getOwnPropertyNames(o).forEach(function (prop) {
      prop==='constructor'||deepFreeze(o[prop])
    })
  }
  return o
}