unit-testing - 在 AAA 单元测试语法中混合使用 Assert 和 Act

Question

可以混合 Assert 和 Act 步骤吗？ AAA 更像是指南而不是规则吗？或者我错过了什么？

这是我的测试:

[TestMethod]
public void CancelButtonSelected_DontCancelTwiceThenCancel_DialogCloses()
{
    // Arrange
    IAddAddressForm form = Substitute.For<IAddAddressForm>();
    // Indicate that when Show CancelMessage is called it 
    //  should return cancel twice (saying we want to cancel the cancel)
    //  then it should return ok
    form.ShowCancelMessage().Returns(DialogResult.Cancel, 
         DialogResult.Cancel, DialogResult.OK);

    AddAddressController controller = new AddAddressController(form);
    AddressItem item = TestHelper.CreateAddressBob();

    // Act
    EnterAddressInfo(form, controller, item);
    controller.CancelButtonSelected();
    Assert.IsTrue(form.DialogResult == DialogResult.None);

    controller.CancelButtonSelected();
    Assert.IsTrue(form.DialogResult == DialogResult.None);

    controller.CancelButtonSelected();

    // Assert
    Assert.IsTrue(form.DialogResult == DialogResult.Cancel);
}

所以我调用了一个方法 3 次。每次通话后，我想确保我们没有真正取消对话。然后在第三次调用时，对话应该被取消。

这是 AAA 语法/样式的“合法”使用吗？

Answer 1

AAA 是使您的单元测试更具可读性的指南。在您提供的示例中，我认为您没有实现该目标。

我认为以下测试使您正在测试的场景更具可读性。

[TestMethod]
public void CancelButtonSelected_ShouldSetDialogResultToNone_WhenFirstCancelButtonIsSelected()
{
    // Arrange
    IAddAddressForm form = ArrangeFormForCancelButtonSelectedTests();
    AddAddressController controller = ArrangeControllerForCancelButtonSelectedTests();

    // Act
    controller.CancelButtonSelected();

    // Assert
    Assert.IsTrue(form.DialogResult == DialogResult.None);
}

[TestMethod]
public void CancelButtonSelected_ShouldSetDialogResultToNone_WhenSecondCancelButtonIsSelected()
{
    // Arrange
    IAddAddressForm form = ArrangeFormForCancelButtonSelectedTests();
    AddAddressController controller = ArrangeControllerForCancelButtonSelectedTests();

    // Act
    controller.CancelButtonSelected();
    controller.CancelButtonSelected();

    // Assert
    Assert.IsTrue(form.DialogResult == DialogResult.None);

}

[TestMethod]
public void CancelButtonSelected_ShouldSetDialogResultToCancel_WhenThirdCancelButtonIsSelected()
{
    // Arrange
    IAddAddressForm form = ArrangeFormForCancelButtonSelectedTests();
    AddAddressController controller = ArrangeControllerForCancelButtonSelectedTests();

    // Act
    controller.CancelButtonSelected();
    controller.CancelButtonSelected();
    controller.CancelButtonSelected();

    // Assert
    Assert.IsTrue(form.DialogResult == DialogResult.Cancel);
}