Fix Python 3.7.1 and run more versions in CI (#1076)

.github/workflows/ci.yml

@@ -14,7 +14,11 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10", "3.11-dev"]
+        # We try to test on the earliest available bugfix release of each
+        # Python version, because typing sometimes changed between bugfix releases.
+        # For available versions, see:
+        # https://raw.githubusercontent.com/actions/python-versions/main/versions-manifest.json
+        python-version: ["3.6", "3.6.7", "3.7", "3.7.1", "3.8", "3.8.0", "3.9", "3.9.0", "3.10", "3.10.0", "3.11-dev"]
 
     runs-on: ubuntu-latest
 

typing_extensions/CHANGELOG

@@ -1,3 +1,8 @@
+# Release 4.1.1 (February 13, 2022)
+
+- Fix importing `typing_extensions` on Python 3.7.0 and 3.7.1. Original
+  patch by Nikita Sobolev (@sobolevn).
+
 # Release 4.1.0 (February 12, 2022)
 
 - Runtime support for PEP 646, adding `typing_extensions.TypeVarTuple`

typing_extensions/src/test_typing_extensions.py

@@ -131,7 +131,13 @@ def some(arg: NoReturn) -> NoReturn: ...
         def some_str(arg: 'NoReturn') -> 'typing.NoReturn': ...
 
         expected = {'arg': NoReturn, 'return': NoReturn}
-        for target in [some, some_str]:
+        targets = [some]
+
+        # On 3.7.0 and 3.7.1, https://github.com/python/cpython/pull/10772
+        # wasn't applied yet and NoReturn fails _type_check.
+        if not ((3, 7, 0) <= sys.version_info < (3, 7, 2)):
+            targets.append(some_str)
+        for target in targets:
             with self.subTest(target=target):
                 self.assertEqual(gth(target), expected)
 

typing_extensions/src/typing_extensions.py

@@ -140,26 +140,14 @@ def _collect_type_vars(types, typevar_types=None):
         if (
             isinstance(t, typevar_types) and
             t not in tvars and
-            not isinstance(t, _UnpackAlias)
+            not _is_unpack(t)
         ):
             tvars.append(t)
         if _should_collect_from_parameters(t):
             tvars.extend([t for t in t.__parameters__ if t not in tvars])
     return tuple(tvars)
 
 
-# We have to do some monkey patching to deal with the dual nature of
-# Unpack/TypeVarTuple:
-# - We want Unpack to be a kind of TypeVar so it gets accepted in
-#   Generic[Unpack[Ts]]
-# - We want it to *not* be treated as a TypeVar for the purposes of
-#   counting generic parameters, so that when we subscript a generic,
-#   the runtime doesn't try to substitute the Unpack with the subscripted type.
-if not hasattr(typing, "TypeVarTuple"):
-    typing._collect_type_vars = _collect_type_vars
-    typing._check_generic = _check_generic
-
-
 # 3.6.2+
 if hasattr(typing, 'NoReturn'):
     NoReturn = typing.NoReturn
@@ -2906,3 +2894,15 @@ def decorator(cls_or_fn):
             }
             return cls_or_fn
         return decorator
+
+
+# We have to do some monkey patching to deal with the dual nature of
+# Unpack/TypeVarTuple:
+# - We want Unpack to be a kind of TypeVar so it gets accepted in
+#   Generic[Unpack[Ts]]
+# - We want it to *not* be treated as a TypeVar for the purposes of
+#   counting generic parameters, so that when we subscript a generic,
+#   the runtime doesn't try to substitute the Unpack with the subscripted type.
+if not hasattr(typing, "TypeVarTuple"):
+    typing._collect_type_vars = _collect_type_vars
+    typing._check_generic = _check_generic