Winforms Automation Extensions

In preparation for my talk next Saturday, I am publishing the code that I use to help drive my WinForms application via NUnit tests. The idea is simple -- instantiate the form and use extension methods on the controls to find the controls and drive from there.

This is a preliminary release. I will update this file as I find more functionality s needed. It turns out that you don't need much (besides some creativity) to automate WinForms UIs. This set of extension methods will help you get started.

Download WAX -- Winforms Automation Extensions

To run your forms in NUnit, you just need create/show it in the setup and close it in the teardown:

[SetUp]
public void SetUp()
{
    _testForm = new FormToTest();
    _testForm.Show();
}

[TearDown]
public void TearDown()
{
    _testForm.Close();
}

Here is an example of finding a button by name, clicking on it and validating that the app changed the text of the label:

[Test]
public void Test_That_Button_Click_Changes_Text()
{
   var button = _testForm.FindByName<Button>("Button1");
   var label = _testForm.FindByName<Label>("Label1");

   button.SimulateClick();

   Assert.That(label.Text, Is.EqualTo("Hello World"));
}

Note that the FindByName method is just a specialization of the Find method. The Find method takes a delegate you can use to find your controls using any method you wish. For instance, say you want to find a control with a known tag:

[Test]
public void Test_Find_With_Custom_Filter()
{
    var l1 = _testForm.Find<Control>(target => (target.Tag as string) == "FindTag");

    Assert.That(l1.Name, Is.EqualTo("ListBox1"));
}

In my experience, driving the controls directly is the easiest way to automate the UI. For instance, if you have a list control that you want to set, you might write code like this:

[Test]
public void Test_Setting_ListBox()
{
    var listBox = _testForm.FindByName<ListBox>("ListBox1");
    listBox.SelectedIndex = 1;

    Assert.That(listBox.SelectedItem.ToString(), Is.EqualTo("The Test"));
}

If you have any questions or thoughts about this code, please contact me. I want to grow this code over time, and feedback is very welcome.