Unit Testing for an Absolute Beginner - I'm using Ruby

I've realised that I really do need to get started on the behaviours and patterns related to unit testing in general and with ruby specifically, as I can then migrate that knowledge to other languages. Are there any really good examples on how to get started? Th开发者_如何学运维e problem I have is that with the current systems I'm using and working on it seems like getting started with Unit testing is insurmountable.

I've never built a single unit test for operational code other than trying the same fifteen or so online tutorials that show you ruby's core classes seem to function fine. I need to know how to build these tests for my own systems and the mentality of what to look for and test for.

What good tutorials are online that show you how to do more than just test that an assert_true is true and the opposite is false? Even if they're not for ruby, what must-read and must experiment unit testing guide should I read or go over? Preferably one with a step by step tutorial.

Stuff like using these unit tests in actual existing models and frameworks and what to actually test for? I'm still trying to get my head around the testing mentality and I keep getting sidetracked by the different elements. No one's really specifically outlined what mentality you need to approach unit testing with, as all of those who have written guides or tutorials seem to have internalised the logic with which you approach the system.

Any help would be really appreciated.

Technically it's BDD, but I would recommend The RSpec Book because it does a good job of explaining concepts and has extended tutorials. The second section of the book covers Cucumber, so it will teach you that as well.

I know this is a perl tutorial, but I think it's really good for the approach/philosophy: cromatic's and Michael G Schwern's Test::Tutorial pdf. It's the first tutorial I read that said to make your tests fail first, and there's lots of other good tips.

It's really easy to get sidetracked and drawn into details such as code coverage tools like rcov and even more detailed tools such as heckle, flog, flay. These tools are great and they track down bugs but they should be secondary to unit tests being related to design and documentation.

I feel this sums it up - From the agile TDD page

• "The act of writing a unit test is more an act of design than of verification."
• "It is also more an act of documentation than of verification"