Allow any subtype of typing.Mapping[str, Any] to be passed in as kwargs.
#3604
Conversation
test-data/unit/check-kwargs.test
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| @@ -280,12 +280,22 @@ reveal_type(formatter.__call__) # E: Revealed type is 'def (message: builtins.s | |||
| [builtins fixtures/bool.pyi] | |||
| [out] | |||
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| [case testPassingMappingForKeywordVarArg] | |||
| from typing import Mapping | |||
| def f( **kwargs: 'A') -> None: pass | |||
mypy/messages.py
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| if isinstance(typ, Instance): | ||
| suffix = ', not {}'.format(typ.type.fullname()) | ||
| self.fail( | ||
| 'Argument after ** must be a subtype of Mapping{}'.format(suffix), |
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I would just say must be a mapping (with small m), not must be a subtype of Mapping.
test-data/unit/check-kwargs.test
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| f(**m) | ||
| class A: pass | ||
| [builtins fixtures/dict.pyi] | ||
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Maybe add a test with a custom subclass of Mapping?
mypy/messages.py
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| context) | ||
| suffix = '' | ||
| if isinstance(typ, Instance): | ||
| suffix = ', not {}'.format(typ.type.fullname()) |
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I'm not sure calling typ.type.fullname() is the best option.
In order to be consistent with other error messages, I would use self.format(typ) instead of typ.type.fullname().
test-data/unit/fixtures/args.pyi
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| class dict(Generic[T, S]): pass | ||
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| class dict(Iterable[T], Mapping[T, S], Generic[T, S]): | ||
| pass |
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nit: it seems like all other fixtures have pass on the same line as the class declaration. I would try to be consistent.
mypy/messages.py
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| context) | ||
| suffix = '' | ||
| if isinstance(typ, Instance): | ||
| suffix = ', not {}'.format(typ) |
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Sorry, what I meant was:
', not {}'.format(self.format(typ))
This would make the user message more user friendly:
Argument after ** must be a mapping, not A instead of Argument after ** must be a mapping, not __main__.A
This fixes #3595