Fix type errors in Pyright

src/attr/__init__.pyi

@@ -3,13 +3,11 @@ import sys
 from typing import (
     Any,
     Callable,
-    ClassVar,
     Dict,
     Generic,
     List,
     Mapping,
     Optional,
-    Protocol,
     Sequence,
     Tuple,
     Type,
@@ -26,6 +24,9 @@ from . import setters as setters
 from . import validators as validators
 from ._cmp import cmp_using as cmp_using
 from ._version_info import VersionInfo
+from ._typing_compat import AttrsInstance_
+
+AttrsInstance = AttrsInstance_
 
 if sys.version_info >= (3, 10):
     from typing import TypeGuard
@@ -64,10 +65,6 @@ _FieldTransformer = Callable[
 # _ValidatorType from working when passed in a list or tuple.
 _ValidatorArgType = Union[_ValidatorType[_T], Sequence[_ValidatorType[_T]]]
 
-# A protocol to be able to statically accept an attrs class.
-class AttrsInstance(Protocol):
-    __attrs_attrs__: ClassVar[Any]
-
 # _make --
 
 NOTHING: object

src/attr/_typing_compat.pyi

@@ -0,0 +1,12 @@
+from typing import Any, ClassVar, Protocol
+
+MYPY = False
+
+# A protocol to be able to statically accept an attrs class.
+class AttrsInstance(Protocol):
+    __attrs_attrs__: ClassVar[Any]
+
+if MYPY:
+    AttrsInstance_ = AttrsInstance
+else:
+    AttrsInstance_ = Any

tests/test_pyright.py

@@ -11,6 +11,7 @@
 
 
 _found_pyright = shutil.which("pyright")
+pytestmark = pytest.mark.skipif(not _found_pyright, reason="Requires pyright.")
 
 
 @attr.s(frozen=True)
@@ -19,14 +20,7 @@ class PyrightDiagnostic:
     message = attr.ib()
 
 
-@pytest.mark.skipif(not _found_pyright, reason="Requires pyright.")
-def test_pyright_baseline():
-    """The __dataclass_transform__ decorator allows pyright to determine
-    attrs decorated class types.
-    """
-
-    test_file = os.path.dirname(__file__) + "/dataclass_transform_example.py"
-
+def parse_pyright_output(test_file):
     pyright = subprocess.run(
         ["pyright", "--outputjson", str(test_file)], capture_output=True
     )
@@ -37,6 +31,17 @@ def test_pyright_baseline():
         for d in pyright_result["generalDiagnostics"]
     }
 
+    return diagnostics
+
+
+def test_pyright_baseline():
+    """The __dataclass_transform__ decorator allows pyright to determine
+    attrs decorated class types.
+    """
+    diagnostics = parse_pyright_output(
+        os.path.dirname(__file__) + "/dataclass_transform_example.py"
+    )
+
     # Expected diagnostics as per pyright 1.1.135
     expected_diagnostics = {
         PyrightDiagnostic(
@@ -65,3 +70,28 @@ def test_pyright_baseline():
     }
 
     assert diagnostics == expected_diagnostics
+
+
+def test_pyright_attrsinstance_is_any(tmp_path):
+    """
+    Test that `AttrsInstance` is `Any` under Pyright.
+    """
+    test_pyright_attrsinstance_is_any_path = (
+        tmp_path / "test_pyright_attrsinstance_is_any.py"
+    )
+    test_pyright_attrsinstance_is_any_path.write_text(
+        """\
+import attrs
+
+reveal_type(attrs.AttrsInstance)
+"""
+    )
+
+    diagnostics = parse_pyright_output(test_pyright_attrsinstance_is_any_path)
+    expected_diagnostics = {
+        PyrightDiagnostic(
+            severity="information",
+            message='Type of "attrs.AttrsInstance" is "Any"',
+        ),
+    }
+    assert diagnostics == expected_diagnostics

tox.ini

@@ -93,7 +93,7 @@ commands = towncrier build --version UNRELEASED --draft
 basepython = python3.10
 deps = mypy>=0.902
 commands =
-    mypy src/attrs/__init__.pyi src/attr/__init__.pyi src/attr/_version_info.pyi src/attr/converters.pyi src/attr/exceptions.pyi src/attr/filters.pyi src/attr/setters.pyi src/attr/validators.pyi
+    mypy src/attrs/__init__.pyi src/attr/__init__.pyi src/attr/_typing_compat.pyi src/attr/_version_info.pyi src/attr/converters.pyi src/attr/exceptions.pyi src/attr/filters.pyi src/attr/setters.pyi src/attr/validators.pyi
     mypy tests/typing_example.py