The code to unit test the created Todo is shown as follows:

    @Test
    public void createTodo() throws Exception {
     Todo mockTodo = new Todo(CREATED_TODO_ID, "Jack", 
     "Learn Spring MVC", new Date(), false);
     String todo = "{"user":"Jack","desc":"Learn Spring MVC",     
     "done":false}";

    when(service.addTodo(anyString(), anyString(),   
    isNull(),anyBoolean()))
    .thenReturn(mockTodo);

   mvc
    .perform(MockMvcRequestBuilders.post("/users/Jack/todos")
    .content(todo)
    .contentType(MediaType.APPLICATION_JSON)
    )
    .andExpect(status().isCreated())
    .andExpect(
      header().string("location",containsString("/users/Jack/todos/"
     + CREATED_TODO_ID)));
   }

A few important things to note are as follows:

• String todo = "{"user":"Jack","desc":"Learn Spring MVC","done":false}": The Todo content to post to the create todo service.
• when(service.addTodo(anyString(), anyString(), isNull(), anyBoolean())).thenReturn(mockTodo): Mocks the service to return a dummy todo.
• MockMvcRequestBuilders.post("/users/Jack/todos").content(todo).contentType(MediaType.APPLICATION_JSON)): Creates a POST to a given URI with the given content type.
• andExpect(status().isCreated()): Expects that the status is created.
• andExpect(header().string("location",containsString("/users/Jack/todos/" + CREATED_TODO_ID))): Expects that the header contains location with the URI of created resource.