block39.ts

beforeEach(() => {
  TasksApi.addTask = jest.fn();
});

it("adds tasks if they cannot be found", async () => {
  const context = mockContext(undefined);
  const taskTitle = "title";
  const task = new Task(taskTitle);
  TasksApi.addTask.mockReturnValueOnce(
    Promise.resolve(task)
  );

  await actions.addTask(context, {
    type: Actions.AddTask,
    title: taskTitle
  });

  expect(context.commit).toHaveBeenCalledWith({
    type:  Mutations.AddTaskSucceeded,
    task
  });
});