Don't crash when partial types are used in inherited attribute #6766
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| @@ -2689,3 +2689,13 @@ reveal_type(x) # E: Revealed type is 'builtins.list[Any]' | |||
| reveal_type(y) # E: Revealed type is 'builtins.dict[Any, Any]' | |||
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| [builtins fixtures/dict.pyi] | |||
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| [case testInheritedAttributeNoStrictOptional] | |||
| # flags: --no-strict-optional | |||
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I would also add a test case with --strict-optional as well (to avoid regressions).
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| class B(A): | ||
| x = None | ||
| x = '' |
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Could you please also add a test where this causes an incompatible override error (an int)?
test-data/unit/check-inference.test
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| class B(A): | ||
| x = None | ||
| x = '' | ||
| reveal_type(x) # E: Revealed type is 'builtins.str' |
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No new line at the end of file.
| @@ -1833,6 +1833,11 @@ def check_assignment(self, lvalue: Lvalue, rvalue: Expression, infer_lvalue_type | |||
| # Try to infer a partial type. No need to check the return value, as | |||
| # an error will be reported elsewhere. | |||
| self.infer_partial_type(lvalue_type.var, lvalue, rvalue_type) | |||
| # Handle PartialType's super type checking here, after it's resolved. | |||
| if (isinstance(lvalue, RefExpr) and | |||
| self.check_compatibility_all_supers(lvalue, lvalue_type, rvalue)): | |||
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The exception you added above removes the check for all kinds of partial types, while this only re-adds the check for partial None types. I don't say it is necessarily wrong, but I would at least add test cases with partial list and dict types (e.g. with an empty list in subclass that is subsequently gets an .append()).
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Yes, you are right. I will change the code, actually.
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Are you going to add the tests with an empty list in the subclass?
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I don't think I should add them anymore, because now I make the exception for only None partial types.
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But there may be a similar crash (or a regression later), I think it is better to have one in any case.
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I tried this on both master and this branch, it didn't give an error:
class A:
x = ['a', 'b']
class B(A):
x = []
x.append(2)I think it should give an error, but I could not be sure. What do you think? @ilevkivskyi
…n#6766) Fixes python#4552 by deferring the compatibility check.
Fix #4552.