...and that is why you fail

On the weekend I helped my brother setup a new antenna for his house. Now sure we bought a brand new length of co-ax cable, mast-amp, splitter, connectors and only slightly used (my old) antenna. when I had mounted the antenna and run the first length of cable down from it through the roof, instead of wiring it up straight to the splitter, I first took the whole length, put (temporarily) a connector on the other end and tried it out by hooking it up to his tv. Sure enough only 2 of the 5 channels worked! Lucky I thought, not having yet used the splitter, I now only had 1,2,3, 4!! components to test: antenna, cable, amp, connectors. Yep, even though I thought I was being clever by doing some testing - I was already too late! and infact was trying to test which 1 or more of 4 different components had failed.
To cut a longish story sort, I ended up doing a quick bypass of the masthead amp (which in this case happened to be the most complex component in the system) by virtue of sitting on the roof and holding the 2 pieces of coax together and sure enough the tv started getting all the channels. Now as usual, it was a bit of a painful lesson as it meant I wasted hours and ended up having to climbup onto the roof and ceiling space mutliple times, when of course I could easily have done a unit test of the amp while safely on the ground.
So why didn't I test the amp to start with? Well it was made by someelse who should know what they are doing and I just *assumed* that they tested it thoroughly before giving it to us.
After that, what I ended up doing was testing as much as possible each run of co-ax that I put in, because since even though the components (coax, connectors) were quite simple and not likely to fail, my use of them (I dont do cable runs for a living) was prone to error so deserved testing. But what if I had been unlikly with the cable and had got a batch with a break in it? Well I had my multi-meter with me, so I could easily have done a continuity test as well but of course I didn't since as I said I didn't think about testing all the components individually at the start, but rather half way through, by which time it was even too late to be able to test some components like the cable in isolation.

The moral of this story: version 1.6.1 Helma now comes with the jala unit testing framework out of the box and unless you want to spend a lot of times climbing up and down ladders, I suggest we all start using it.