I’ve got a bunch of python scripts that I have written over the last eleven years or so. I have published some of them on github here: https://github.com/jpfxgood Probably the most sophisticated is the editor ped (python editor) that I wrote originally back in 2009 and have been working on ever since. Over those years I was pretty busy as a professional programmer and managing software engineers in ever larger groups. I snuck in the work on these scripts when I had the time to focus. A couple of things just didn’t get done as part of that, I never wrote proper tests, and I ignored the looming end of life for Python 2 and the migration to Python 3.
Well, now I have the time so I’ve started on both projects. First I brought the github projects up to date, truth be told I use svn locally because it is what I was used to. After this project github will be the canonical version of these scripts. Then I used the 2to3 script to do the rough conversion to Python 3 into a new temporary subdirectory “2to3out”. The script does a decent job, but it was still a surprise that division suddenly works differently… Also some of the code around reading and writing “utf-8” encoded files need to be tweaked. The differences between byte streams and character streams came up in several places. A few miscellaneous changes to the signatures of imported modules and functions had to be corrected. In general the changes beyond what the script converted were small.
The testing was the real problem. As I went through and manually tested each feature of each script I found a number of bugs, most of those bugs were unrelated to the 2to3 conversion, they were simply things I’d never really tested before. So as I got to the point that I was fixing more and more of these I decided that now was the time to bite the bullet and do penance for my past sins and write a regression test suite for these projects.
I liked pytest in the past, it is simple, doesn’t require any intrusive changes, is flexible, and I’ve used it before. So, after a few minutes reviving the brain cells that used to know about pytest I started on a tests folder and a set of test suites for each module in the scripts. I started with the editor first since it is the most complex. I’ll probably do the backup script after that since the fixtures to test it are going to be interesting to implement.
I’ve got a few cases written already and I do thank my past self for refactoring the editor multiple times over the years to make the internals pretty modular and independent. Apparently they screwed with the regular expression module as well as I’m getting Deprecation warnings for many of my uses of it, sigh, I’ll have to go through and clear those up too.
Here’s the test output so far:
It is a meditative process writing tests for eleven year old code, I get to appreciate the good parts of the code and laugh at the crappy parts again.
More updates as it continues…