I ran into an interesting problem today while trying to write some unit tests for an SDK we’re helping to build at work.  It involved instantiating a third-party library, then running a few tests to be sure that our delegate code was being called as expected.

The problem is that the third party library contained code to instantiate a UIWebView.  At first I was puzzled.  That couldn’t be causing a crash.  I ended up stripping out the actual test and just putting in a line like this:

UIWebView *wv = [[UIWebView alloc] init];

And an exception was thrown.

After Googling around for a while, I came across a Stack Overflow post discussing the behaviour.  It looks like when you’re trying to test UIWebView in a static library, it needs an app target set to run.  I created an empty app, set it as the target, and boom, we had a working unit test.

It’s the things like this that make me realize that I’ll never be done learning.