Hmm, I wonder if this test is run directly, will __name__ be `main``? Wouldn't that make the test pass incorrectly? (Throwing this question out there because I'm not too sure myself). Maybe we should be safe and give it a distinct name?

The test is to ensure that ForwardRef with module set is different from ForwardRef with module not set (That was previsously not the case). The actual value of module (or __name__) is not relevant. Under the hood the comparison is None vs str

My bad, thanks for pointing that out. I mistakenly assumed it would grab a default value from the current scope to populate module in things like ClassVar['int'] due to the _type_check/_type_convert function (I'm now shocked that it doesn't and only does that for TypedDict).

Yes, unfortunately the current module is not captured automatically.
The current scope/module is typicallly obtained by get_type_hints because a class knows its module (and so all ForwardRefs in member annotations can be correctly resolved. But each forward Ref does originally not know its module).
However for type aliases this does not work, and there one needs the explicit module.

For example

Json = Union[ List['Json'], Dict[str,'Json'], int, float, bool, None ]

cannot be exported (and expect to work) unless one sets the module for each forward ref.