Don't be afraid of the big bad stack trace

It's surprising how many people are intimidated by stack traces. A reaction that I regularly see when a stack trace appears on screen is panic!

"Oh my god! Something has gone wrong! There are hundreds of lines of text talking about code I don't recognize and I can't take it all in; what do I do?"

The first thing to do is to relax; stack traces have a lot of information but they are actually really friendly and helpful things. Let's modify our project to produce a stack trace and work through it. We are going to make a small change to the getDriver() method in DriverFactory to force it to always return null by using this code:

    public static WebDriver getDriver() { 
        return null; 
    } 

This is going to make sure that we never return a driver object, something that we would expect to cause errors. Let's run our tests again, but make sure that Maven displays a stack trace by using the -e switch:

mvn clean verify -e

This time, you should see a...