Class T

tests/test_typing.py:46–59

@pytest.mark.mypy_testing
def mypy_decorator_typing() -> None:
    class T(HasTraits):
        foo = Unicode("").tag(config=True)

        @default("foo")
        def _default_foo(self) -> str:
            return "hi"

        @observe("foo")
        def _foo_observer(self, change: t.Any) -> bool:
            return True

        @validate("foo")
        def _foo_validate(self, commit: t.Any) -> bool:
            return True

    t = T()
    reveal_type(t.foo)  # R: builtins.str