python static code analysis

[AlexanderLanin]

Random concrete example tested with 4 type checkers (an almost bug from eclipse-csi/otterdog#605).

Note: that this might be an unfair comparison, as we would never learn of bugs that mypy has prevented, which the others do not catch.

Code

The code in question forgets to call pull_request as a method.

result = await provider.pull_request.merge_pull_request(
    blueprint.id.org_id, blueprint.id.repo_name, f"{blueprint.remediation_pr}", merge_method
)

Should have been:

result = await provider.pull_request(
    blueprint.id.org_id, blueprint.id.repo_name, f"{blueprint.remediation_pr}", merge_method
).merge_pull_request()

As a secondary bug, merge_method can technically be undefined:

if repo.allow_merge_commit is True:
    merge_method = "merge"
if repo.allow_squash_merge is True:
    merge_method = "squash"
if repo.allow_rebase_merge is True:
    merge_method = "rebase"

Analyzers

Basedpypright - catches both bugs ✅

Pyright - catches both bugs ✅

Mypy - All I can get is a generic warning on Any. This is rather generic and useless. ❌

Ty - only the second part about merge_method being unbound ❌

Conclusion

basedpyright remains the best type checker today. mypy does not catch critical problems. ty is not ready.

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@MaximilianSoerenPollak and all other python programmers :-)

[MaximilianSoerenPollak]

Appreciate the short investigation.

Seems like a clear choice for now