get test coverage

[moritz-gross]

after praising the tests today, I was thinking about how I haven't run any test coverage yet ;)

Somehow, this seems more involved for Rust than I thought it would be.
In IntellJ and PyCharm, there are IDE-integrations that immediately let you do it.
RustRover (what a name) doesn't seem to have that (yet).

I managed to get something running with grcov, which generates a report in target/coverage/html/index.html that looks like this:

• Do you already have workflow for test coverage?
• If not, what do you think about this option?
• I'm not sure if this will work on Windows nicely
• If we want to document this workflow, should we add it to the README? It does not have any technical guidance like this so far.
• Do we want to create a CONTRIBUTING.md for more technical information instead and add this (and some more basics) to it? I think this would be a good idea if there'll be more new people coming

Edit: I think I figured out how to do it with my IDE, but I think it's still a good idea to have a Rust-only way to do this

[NSoiffer]

I like the idea of code coverage -- I never spent the time looking for such a tool. I don't think it should go in a readme, but rather when there is some developer documentation (I thought there was something minimal in docs/developers.html, but there isn't). It would be good to have it run as part of a check in, although it seems excessive to run it for every push. Maybe a job that runs once per week but also could be triggered manually? The results could be put on github pages and the (non-existent) documentation can point to it. Is that something you know how to do?

I am actually surprised that the coverage is as high as it is. It's too bad it can't figure out coverage for the YAML rules. I guess that could be a long term project for someone.

If there is a way to exclude main.rs from the coverage tests, you should do that. It is a file that I use for testing/debugging because it is easy to do tests while adding something or looking at a bug. I have an alias for env RUST_LOG=DEBUG cargo run |& less for debugging to make things particularly easy.

[moritz-gross]

I added it to the testing-section of helpers.md for now.
should be fine to run it manually I think.
Yes, main.rs should be excluded if the results are automatically evaluated, but for now I just ignored that part.
Coverage of the YAMLs is a good idea, but doesn't sound straightforward.

I think it makes sense to split helpers.md and developers.md. Can I just create it in the docs folder or is there more setup needed for that? The page should be used for https://talkingcatsw.github.io/ I assume?