Take screenshot on test failure + exceptions

Question

Does any of you know possible solution for taking screenshots on test failures and exceptions?

I've added following code in TearDown() but as a result it also makes screenshots on passed tests, so it is not the best solution:

DateTime time = DateTime.Now;
string dateToday = "_date_" + time.ToString("yyyy-MM-dd") + "_time_" + time.ToString("HH-mm-ss");
Screenshot screenshot = ((ITakesScreenshot)driver).GetScreenshot();
screenshot.SaveAsFile((settings.filePathForScreenShots + "Exception" + dateToday + ".png"), System.Drawing.Imaging.ImageFormat.Png);

I've already found that idea: http://yizeng.me/2014/02/08/take-a-screenshot-on-exception-with-selenium-csharp-eventfiringwebdriver/, to use WebDriverExceptionEventArgs, but for some reasons it makes also some random screenshots without any reasonable explanation.

Other ideas I found are for Java and not for NUnit which I use with Selenium, so they are pretty useless.

Answer 1

If you put the screenshot logic in your TearDown method it will be called after each test finishes, no matter if it succeeded or failed.

I use a base class that has a function which wraps the tests and catches all exceptions. When a test fails the exception is caught and a screenshot is taken.

I use this base class for all my Selenium tests and it looks something like this:

public class PageTestBase
{
    protected IWebDriver Driver;

    protected void UITest(Action action)
    {
        try
        {
            action();
        }
        catch (Exception ex)
        {
            var screenshot = Driver.TakeScreenshot();

            var filePath = "<some appropriate file path goes here>";

            screenshot.SaveAsFile(filePath, ImageFormat.Png);

            // This would be a good place to log the exception message and
            // save together with the screenshot

            throw;
        }
    }
}

The test classes then look like this:

[TestFixture]
public class FooBarTests : PageTestBase
{
    // Make sure to initialize the driver in the constructor or SetUp method,
    // depending on your preferences

    [Test]
    public void Some_test_name_goes_here()
    {
        UITest(() =>
        {
            // Do your test steps here, including asserts etc.
            // Any exceptions will be caught by the base class
            // and screenshots will be taken
        });
    }

    [TearDown]
    public void TearDown()
    {
        // Close and dispose the driver
    }
}