I'm utterly convinced of both the need for, and the benefits of testing during the development process. My argument is entirely aimed at the methodology and tools being advocated and used.
As for the slides, I got as far as page 12 and 13 and just stopped reading:
No! Redundancy is redundant.
I'll put that another way. It costs time. And time is money. Redundant effort is therefore, wasted money.
Rubbish! Of course there are stupid tests.
Testing that perl can load a module and converting the result into a 0.05% change in a statistic is stupid. When left to it's own devices, perl will report a failure to load a module with a concise and accurately informative warning message...and stop. Preventing that stop is pointless. Every subsequent test of that module is, by definition, going to fail.
When testing tools or suites are more complex and laborious than the code under test; when they prevent or inhibit you from using simple tools (like print/warn/perl -de1), they become a burden rather than a help.
In the car industry (in which I grew up), there are many ways of testing (for example) the diameter of a hole in a piece of sheet metal. You might use a lasar micrometer. You might a set of inner calipers and a set of slip gauges.
The favoured test tool? A simple, tapered shaft with a handle and clearly marked, upper and lower bounds. You simply poke it in the hole and if it passes the lower bound and stops before the upper, the hole is within tolorance. It is simple to operate, Is extremely robust in use. And takes no time at all to use. It's easy to use, so it gets used.
The Occam's Razor of test tools. I seem to think that Andy has an appreciation for OZ. He should consider applying it in this case also.
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