public async Task DeleteAllTodos_Should_ReturnOk()
{
// Arrange
var adapterMock = new Mock <ITodoAdapter>();
var loggerMock = new Mock <ILogger <TodoController> >();
var testTodos = GetTestTodos();
int countTodosBeforeDelete = testTodos.Count;
adapterMock.Setup(x => x.DeleteAllTodos())
.Callback(() => testTodos.Clear());
var controller = new TodoController(adapterMock.Object, loggerMock.Object);
// Act
var result = await controller.DeleteAllTodos();
// Assert
var actionResult = Assert.IsAssignableFrom <IActionResult>(result);
Assert.IsAssignableFrom <OkResult>(actionResult);
Assert.Equal(2, countTodosBeforeDelete);
Assert.Empty(testTodos);
}