The `**/src_archive/**` exclusion patterns seem to have to do with
trying to exclude archived source files from being picked up for the
extractor while running the test itself. However it seems that directory
is not being used any more by `codeql` (which uses a `src` directory
instead).
A `*.testproj` exclusion pattern will work in a more robust way, by
excluding any file inside the database being built.
I'm beginning to realise why I didn't do the `toString` overriding way
back when. Thankfully, now that all of our tests are in the same place,
this is actually not a terrible ordeal.
These were causing `git` to behave strangely, leaving files that were
impossible to reset. In the future we should probably generate these
problematic test files on the fly, so that they don't have to exist in
the repo, but in the short run, it's easier to just remove them so as to
not block other users of the repo.
