What is your issue?

Hi,

TLDR: Is there a way to only run relevant CI checks (eg documentation) when a new commit is pushed on a PR's branch?

The following issue is written from a naive user point of view. Indeed I do not know how the CI works on this project. I constated that when updating an existing Pull Request, the whole test battery is re-executed. However, it is a common scenario that someone wants to update only the documentation, for instance. In that case, it might make sense to only retrigger the documentation checks. A little bit like pre-commit that only runs on the updated files. Achieving such a level of granularity is not desirable as even a small code change could make geographically remote tests in the code fail, however, a high-level separation between code and docs for instance, might relieve a little bit the pipelines. This is assuming the code does not depend at all on the code. Maybe other separations exists, but the first I can think of is code vs docs.

Another separation would be to have an "order" / "dependency system" in the pipeline. Eg, A -> B -> C ; if A fails, there is no point into taking resources to compute B as we know for sure the rest will fail. Such a hierarchy might be difficult for the test matrix that is unordered (eg Python Version x OS, on this project it seems to be more or less (3.9, 3.10, 3.11, 3.12) x (Ubuntu, macOS, Windows)

There is also a notion of frequency and execution time: pipelines' stages that are the most empirically likely to fail and the shortest to runshould be ran first, to avoid having them fail due to flakiness and out of bad luck when all the other checks passed before. Such a stage exists: CI / ubuntu-latest py3.10 flaky (it is in the name). Taking that into account, the CI Additional / Mypy stage qualifies for both criteria should be ran before everything else for instance. Indeed, it is static code checking and very likely to fail, something a developer might also run locally before committing / pushing, and only takes one minute to run (compared to several minutes for each of stages of the Python Version x OS matrix). The goal here is to save resources (at the cost of losing the "completeness" of the CI run)