todos.js

  var todoList = [
    { 'completed': false, 'name': 'thing 1' },
    { 'completed': true,  'name': 'thing 2' },
  ]
  
  function addTaskToList(list, task){
    // Add `task` to `list`
    list.push(task);
  }
  
  function removeTaskFromList(list, task){
    // Remove `task` from `list`...
      // 0. enumerate steps to remove something...
  }
  
  function strikeoutTaskOnList(list, task){
    // "Strikeout" `task` on `list`...
  }
  
  /** -- Start Testing here... -- **/
  assert.deepEqual(todoList, [
    "thing 1",
    "thing 2",
  ]);
  
  var thing1 = todoList[0];
  
  // Mark "thing 1" as "completed"...
  thing1.completed = true;
  
  addTaskToList(todoList, 'thing 3');
  
  assert.deepEqual(todoList, [
    "thing 1",
    "thing 2",
    "thing 3",
  ]);
  
  strikeoutTaskOnList(todoList, 'thing 2');
  
  assert.deepEqual(todoList, [
    "thing 1",
    "thing 2",
    "thing 3",
  ]);

  removeTaskFromList(todoList, 'thing 2');
  
  assert.deepEqual(todoList, [
    "thing 1",
    "thing 3",
  ]);