Update typeddicts_class_syntax.py test to use a custom metaclass. - #2327
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rchen152 wants to merge 1 commit into
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Update typeddicts_class_syntax.py test to use a custom metaclass.#2327rchen152 wants to merge 1 commit into
rchen152 wants to merge 1 commit into
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The TypedDict chapter of the spec says: > It is also invalid to specify a custom metaclass. It looks like most type checkers interpret this to mean that the appearance of `metaclass=...` is illegal in a TypedDict definition. Pyrefly interprets this to mean that a non-`type` metaclass is illegal, so a redundant `metaclass=type` is fine. IMO either interpretation is defensible, but the conformance test currently uses `metaclass=type`, which only accommodates the first. This PR changes the test to use a non-`type` metaclass, which is unambiguously an error. This doesn't actually change pyrefly's conformance results because pyrefly has a bug that causes it to emit a different, nonsensical error on the `metaclass=type` line, which was mistakenly taken as pyrefly passing the test. I'm in the process of fixing that bug, which is how I discovered that pyrefly behaves slightly differently from the other checkers here.
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The TypedDict chapter of the spec says (emphasis mine):
It looks like most type checkers interpret this to mean that the appearance of
metaclass=...is illegal in a TypedDict definition.Pyrefly interprets this to mean that a non-
typemetaclass is illegal, so a redundantmetaclass=typeis fine.IMO either interpretation is defensible, but the conformance test currently uses
metaclass=type, which only accommodates the first. This PR changes the test to use a non-typemetaclass, which is unambiguously an error.This doesn't actually change pyrefly's conformance results because pyrefly has a bug that causes it to emit a different, nonsensical error on the
metaclass=typeline, which was mistakenly taken as pyrefly passing the test. I'm in the process of fixing that bug, which is how I discovered that pyrefly behaves slightly differently from the other checkers here.