Pre-Conditions, Post-Conditions & Unit Tests

Recently I wrote a class for program flow-graphs. Writing unit tests, it turned out, required more effort than the unit tests that I had written for other classes .

I was aware that when writing functions one must document the pre-conditions and the post-conditions. These I implemented as asserts. I usually felt that these were adequate. But when it came to the program flow-graph methods, the set of asserts was turning up to be just too messy

As I mentioned, the development of unit tests was turning out to be more difficult. The program flow-graph object to be used for the test had to be decided. What it would be transformed to was to be worked out. I found myself putting these down, in the test case file, as a file comment block. While doing that, I realized I was effectively specifying Pre-Conditions and Post-Conditions. I was saying, "Given this program graph object as the input, some set of attributes should change, and some set of attributes should remain invariant".

Light-Bulb event: Unit tests are statements of Pre-Conditions and Post-conditions.

What about asserts? I now regard these as micro unit tests that are embedded in the code.

PS: I hope to be more frequent in my posts in 2014:-)
Happy New Year.

Documenting Tests

Scientists formulate and carry out tests and record results to verify theories about nature. Software persons formulate and carry out tests to verify their theory that a given piece of software does what it is meant to do, or not do.

Should not tests be documented like experiments?