A central location for catching throwables of JUnit tests? - selenium

Question

I would like to catch any throwable during a Selenium test e.g. in order to make a screenshot. The only solution I could come up with for now is to separately surround the test steps with a try and catch block in every test method as following:
#Test
public void testYouTubeVideo() throws Throwable {
try {
// My test steps go here
} catch (Throwable t) {
captureScreenshots();
throw t;
}
}
I'm sure there is a better solution for this. I would like a higher, more centralized location for this try-catch-makeScreenshot routine, so that my test would be able to include just the test steps again. Any ideas would be greatly appreciated.

Answer 1

You need to declare a TestRule, probably a TestWatcher or if you want to define the rules more explicitly, ExternalResource. This would look something like:
public class WatchmanTest {
#Rule
public TestRule watchman= new TestWatcher() {
#Override
protected void failed(Description d) {
// take screenshot here
}
};
#Test
public void fails() {
fail();
}
#Test
public void succeeds() {
}
}
The TestWatcher anonymous class can of course be factored out, and just referenced from the test classes.

Answer 2

I solved a similar problem using Spring's AOP. In summary:
Declare the selenium object as a bean
Add an aspect using
#AfterThrowing
The aspect can take the screenshot and save it to a
file with a semirandom generated name.
The aspect also rethrows the exception, with the exception message including the filename so you can look at it afterwards.
I found it more helpful to save the HTML of the page due to flakiness of grabbing screenshots.