Fix crash when calling type[Any] from dict.get() #20586
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byteforge38
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test-data/unit/check-classes.test
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| # Regression test for https://github.com/python/mypy/issues/20585 | ||
| from typing import Any | ||
| op: type[Any] | ||
| reveal_type({0: object}.get(0, op)()) # N: Revealed type is "builtins.object" |
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I would have expected Any, not object. Is there a way to reproduce the crash without relying on .get()? And did you verify this line crashed without the fix? Our fixture may be simpler than the actual typeshed stubs for dict.get.
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I added two unit tests to mypy/test/testtypes.py, and yes, I was able to reproduce that crash
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According to mypy_primer, this change doesn't affect type check results on a corpus of open source code. ✅ |
A5rocks
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I don't like the object return but it sounds like that will need some special casing :/
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Fixes #20585
When a callable has
type[Any]as its return type (e.g., fromdict.get(key, type[Any])), calling it would crash withAssertionError: isinstance(ret, Instance).The issue was in
is_type_obj()which returnedTruefortype[Any]becausetypeis a metaclass andAnyTypeisn'tUninhabitedType. However,type_object()then failed because it expects anInstance, notAnyType.The fix excludes
AnyTypefromis_type_obj()since we can't determine a concrete type object when the return type isAny.Contribution by Gittensor, see my contribution statistics at https://gittensor.io/miners/details?githubId=4217675