Mixing Assert and Act in AAA unit testing syntax

Question

Is it OK to mix Assert and Act steps? Is AAA more of a guideline than a rule? Or am I missing something?

Here is my test:

[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);
}

So I call a method 3 times. After each call, I want to make sure that we did not really cancel the dialog. Then on the third call, the dialog should be canceled.

Is this "legal" use of AAA syntax/styling?

Answer 1

AAA is just a guideline to make your unit tests more readable. It is perfectly OK to deviate if you have a good reason to do so. You used whitespaces and comments to separate the different phases in code to some extent, which is good. In such cases it may also be helpful to add comments explaining the story you are testing.