Testing DELETE /todos/:id

In this section, you're going to write some test cases that verify our delete route works as expected. Now, before we get into that, what we're going to do is make one quick change to the delete route to make it match our other routes. Our other routes return an object and on that object, the response body, we have a todo property, and we did the same thing for the todos call. On the response body we have the todos property and that stores the array. For the delete request, we never did that.

What I'm going to do is send back an object as the response body, where the todo property equals the todo that got deleted, although we'll just use that ES6 syntax to send that back:

Todo.findByIdAndRemove(id).then((todo) => {
   if(!todo) {
         return res.status(404).send();
   }
   res.send({todo});
}).catch((e) => {
   res.status(400).send();
});

With this in place, we can now go ahead and write some test cases that verify the delete route works as expected, and...