Differentiating factor with my competitors

Jon showed me how to apply many of the concepts about unit testing to iOS. It was the one thing I needed in order to use it everywhere. Jon is one of the few who knows the stuff and knows how to explain it. My customers value my knowledge about testing and it is always a differentiating factor with my competitors. I owe a lot of it to Jon.

Jorge D. Ortiz-Fuentes Instructor & Consultant

How to Write Clean Code

safety harness

Unit Testing

A robust suite of unit tests acts as a safety harness, giving you courage to make bold changes. But there’s an art to making tests that give you useful information, while keeping the tests themselves readable & maintainable.



Unit tests written after production code are hard to write, and may only confirm your biases. Test Driven Development shapes production code in response to tests, in an evolutionary manner. The secret sauce? Continuous Refactoring.



We can’t just bang code together and expect it to be testable. Testability must be designed in. That design brings other benefits, making it easier to modify the code. The ultimate goal? Drive down your cost of change.

Discover the Quality Coding Blog


Unit test success

Thank you so much for these awesome screencasts and tips!! I have used your techniques to unit test view controller and XIBs and UIAlertViews successfully :-)

Amit Rao

The single biggest influence

Jon approaches software as a craftsman. In my years as a professional, learning from Jon has probably been the single biggest influence on the way I write software today.

Rick Van Voorden
iPhone Developer