Add mypy config; run mypy in CI #286
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| @@ -81,3 +83,23 @@ find = {} # Scanning implicit namespaces is active by default | |||
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| [tool.setuptools.dynamic] | |||
| version = {attr = "pyperformance.__version__"} | |||
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| [tool.mypy] | |||
| python_version = "3.7" | |||
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It's generally a good idea to run mypy on the lowest Python version you support; this means it will flag if you accidentally use a feature that only exists in a newer Python version
| [tool.mypy] | ||
| python_version = "3.7" | ||
| pretty = true | ||
| enable_error_code = "ignore-without-code" |
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This means that mypy will emit an error if you do a bare # type: ignore without a specific error code (e.g. you should use # type: ignore[import] to suppress mypy's import-related errors)
| python_version = "3.7" | ||
| pretty = true | ||
| enable_error_code = "ignore-without-code" | ||
| disallow_any_generics = true |
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This means that mypy will forbid using, for example, list or typing.List as an annotation. You should use list[int] or typing.List[int] instead, which gives the type checker much more information to work with.
| [[tool.mypy.overrides]] | ||
| module = "pyperf" | ||
| ignore_missing_imports = true |
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pyperf doesn't have type annotations, so without this section, mypy would emit an error at every location pyperf was imported, which was quite annoying.
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In case it's useful, this is the gradient of options I recommend: https://mypy.readthedocs.io/en/latest/existing_code.html#introduce-stricter-options
In particular, I'd add strict_equality=True and as you already know, work asap to getting check_untyped_defs=True passing.
Thanks! My basic plan here is:
So I'm slightly loathe to add any stricter settings right now that could flag pre-existing errors in the code, rather than errors related to the type annotations I'm adding (I'd rather deal with that category of errors in stage 3). But |
| pretty = true | ||
| enable_error_code = "ignore-without-code" | ||
| disallow_any_generics = true | ||
| strict_concatenate = true |
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I doubt we'll be making much use of typing.Concatenate in pyperformance, but this is one of the stricter settings that mypy offers which can be easily enabled from the get-go, so we may as well enable it now
Work towards #282.
Adding type hints without validating them with a type checker is a bad idea, because the type hints can quickly go out of date with the source code they're describing. This PR adds some configuration for mypy, and a job to run mypy in CI.
Mypy is run on the
pyperformance/directory, butpyperformance/data-files/andpyperformance/tests/are excluded from being typechecked. I've only enabled a few of the stricter settings for now, so that we can take advantage of "gradual typing" -- mypy will only emit errors on functions that have type annotations. It will assume all functions that don't have type annotations are meant to be ignored by the type checker.