bpo-46333: include module in ForwardRef.__repr__ (#31283)

The module parameter carries semantic information about the forward ref.
Show to the user that forward refs with same argument but different
module are different.

Co-authored-by: Andreas Hangauer <[email protected]>
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>

Author: 3 people

Lib/test/test_typing.py

@@ -2862,6 +2862,8 @@ def fun(x: a):
 
     def test_forward_repr(self):
         self.assertEqual(repr(List['int']), "typing.List[ForwardRef('int')]")
+        self.assertEqual(repr(List[ForwardRef('int', module='mod')]), 
+                         "typing.List[ForwardRef('int', module='mod')]")	
 
     def test_union_forward(self):
 

Lib/typing.py

@@ -779,7 +779,11 @@ def __ror__(self, other):
         return Union[other, self]
 
     def __repr__(self):
-        return f'ForwardRef({self.__forward_arg__!r})'
+        if self.__forward_module__ is None:
+            module_repr = ''
+        else:
+            module_repr = f', module={self.__forward_module__!r}'
+        return f'ForwardRef({self.__forward_arg__!r}{module_repr})'
 
 class _TypeVarLike:
     """Mixin for TypeVar-like types (TypeVar and ParamSpec)."""

Misc/NEWS.d/next/Library/2022-02-11-20-01-49.bpo-46333.PMTBY9.rst

@@ -0,0 +1,3 @@
+The :meth:`__repr__` method of :class:`typing.ForwardRef` now
+includes the ``module`` parameter of :class:`typing.ForwardRef`
+when it is set.