pytest: typecheck with pyrefly (#5898)

Helps to ensure the generated type stubs are compatible with it

Author: Tpt

.github/workflows/ci.yml

@@ -793,9 +793,14 @@ jobs:
       - run: python -m pip install --upgrade pip && pip install nox[uv]
       - run: nox -s test-introspection
 
-  mypy-pytests:
+  pytests-type-checking:
     needs: [fmt]
     runs-on: ubuntu-latest
+    strategy:
+      # If one platform fails, allow the rest to keep testing if `CI-no-fail-fast` label is present
+      fail-fast: ${{ !contains(github.event.pull_request.labels.*.name, 'CI-no-fail-fast') }}
+      matrix:
+        checker: [mypy, pyrefly]
     steps:
       - uses: actions/checkout@v6.0.2
       - uses: dtolnay/rust-toolchain@stable
@@ -805,7 +810,7 @@ jobs:
         with:
           python-version: "3.14"
       - run: python -m pip install --upgrade pip && pip install nox[uv]
-      - run: nox -s mypy
+      - run: nox -s ${{matrix.checker}}
         working-directory: pytests
 
   conclusion:

pytests/noxfile.py

@@ -1,3 +1,4 @@
+from collections.abc import Iterable
 import shutil
 from pathlib import Path
 
@@ -41,19 +42,29 @@ def bench(session: nox.Session):
 
 @nox.session
 def mypy(session: nox.Session):
+    type_checker(
+        session,
+        ("python", "-m", "mypy", "tests"),
+    )
+    # TODO: enable stubtest session.run_always("python", "-m", "mypy.stubtest", "pyo3_pytests")
+
+
+@nox.session
+def pyrefly(session: nox.Session):
+    type_checker(
+        session,
+        ("python", "-m", "pyrefly", "check", "tests"),
+    )
+
+
+def type_checker(session: nox.Session, command: Iterable[str]):
     session.env["MATURIN_PEP517_ARGS"] = "--profile=dev"
     try:
         # We move the stubs where maturin is expecting them to be
         shutil.copytree("stubs", "pyo3_pytests")
         (Path("pyo3_pytests") / "py.typed").touch()
         session.install(".[dev]")
 
-        session.run_always(
-            "python",
-            "-m",
-            "mypy",
-            "tests",
-        )
-        # TODO: enable stubtest when previously listed errors will be fixed session.run_always("python", "-m", "mypy.stubtest", "pyo3_pytests")
+        session.run_always(*command)
     finally:
         shutil.rmtree("pyo3_pytests")

pytests/pyproject.toml

@@ -22,6 +22,7 @@ classifiers = [
 dev = [
     "hypothesis>=3.55",
     "mypy~=1.0",
+    "pyrefly~=0.57.0",
     "pytest-asyncio>=0.21,<2",
     "pytest-benchmark>=3.4",
     "pytest>=7",

pytests/src/awaitable.rs

@@ -44,6 +44,22 @@ pub mod awaitable {
                 _ => Ok(py.None()),
             }
         }
+
+        fn send(&mut self, value: Bound<'_, PyAny>) -> PyResult<Py<PyAny>> {
+            self.__next__(value.py())
+        }
+
+        #[pyo3(signature = (value, _a = None, _b = None))]
+        fn throw(
+            &mut self,
+            value: Bound<'_, PyAny>,
+            _a: Option<Bound<'_, PyAny>>,
+            _b: Option<Bound<'_, PyAny>>,
+        ) -> PyResult<Py<PyAny>> {
+            self.__next__(value.py())
+        }
+
+        fn close(&self) {}
     }
 
     #[pyclass]
@@ -80,5 +96,24 @@ pub mod awaitable {
                 _ => Ok(pyself),
             }
         }
+
+        fn send<'py>(
+            pyself: PyRefMut<'py, Self>,
+            _value: Bound<'py, PyAny>,
+        ) -> PyResult<PyRefMut<'py, Self>> {
+            Self::__next__(pyself)
+        }
+
+        #[pyo3(signature = (_value, _a = None, _b = None))]
+        fn throw<'py>(
+            pyself: PyRefMut<'py, Self>,
+            _value: Bound<'py, PyAny>,
+            _a: Option<Bound<'py, PyAny>>,
+            _b: Option<Bound<'py, PyAny>>,
+        ) -> PyResult<PyRefMut<'py, Self>> {
+            Self::__next__(pyself)
+        }
+
+        fn close(&self) {}
     }
 }

pytests/stubs/awaitable.pyi

@@ -10,10 +10,20 @@ class FutureAwaitable:
     def _asyncio_future_blocking(self, /) -> bool: ...
     @_asyncio_future_blocking.setter
     def _asyncio_future_blocking(self, /, value: bool) -> None: ...
+    def close(self, /) -> None: ...
+    def send(self, /, _value: Any) -> FutureAwaitable: ...
+    def throw(
+        self, /, _value: Any, _a: Any | None = None, _b: Any | None = None
+    ) -> FutureAwaitable: ...
 
 @final
 class IterAwaitable:
     def __await__(self, /) -> IterAwaitable: ...
     def __iter__(self, /) -> IterAwaitable: ...
     def __new__(cls, /, result: Any) -> IterAwaitable: ...
     def __next__(self, /) -> Any: ...
+    def close(self, /) -> None: ...
+    def send(self, /, value: Any) -> Any: ...
+    def throw(
+        self, /, value: Any, _a: Any | None = None, _b: Any | None = None
+    ) -> Any: ...

pytests/tests/test_datetime.py

@@ -107,7 +107,7 @@ def test_date_from_timestamp(d):
             rdt.date_from_timestamp(ts)
         assert str(exc_info.value) == str(pdt_fail)
     else:
-        assert rdt.date_from_timestamp(int(ts)) == expected
+        assert rdt.date_from_timestamp(ts) == expected
 
 
 @pytest.mark.parametrize(
@@ -233,7 +233,7 @@ def test_invalid_datetime_fails():
 
 def test_datetime_typeerror():
     with pytest.raises(TypeError):
-        rdt.make_datetime("2011", 1, 1, 0, 0, 0, 0)
+        rdt.make_datetime("2011", 1, 1, 0, 0, 0, 0)  # type: ignore[bad-argument-type]
 
 
 @given(dt=st.datetimes(MIN_DATETIME, MAX_DATETIME))

pytests/tests/test_misc.py

@@ -1,4 +1,4 @@
-import importlib
+import importlib.util
 import platform
 import sys
 
@@ -22,6 +22,8 @@ def test_issue_219():
 )
 def test_multiple_imports_same_interpreter_ok():
     spec = importlib.util.find_spec("pyo3_pytests.pyo3_pytests")
+    assert spec is not None
+    assert spec.loader is not None
 
     module = importlib.util.module_from_spec(spec)
     spec.loader.exec_module(module)

pytests/tests/test_path.py

@@ -31,7 +31,7 @@ def test_take_invalid_pathlike():
 
 def test_take_invalid():
     with pytest.raises(TypeError):
-        assert rpath.take_pathbuf(3)
+        assert rpath.take_pathbuf(3)  # type: ignore[bad-argument-type]
 
 
 class PathLike:

pytests/tests/test_pyclasses.py

@@ -150,7 +150,7 @@ def test_dict():
     d = ClassWithDict()
     assert d.__dict__ == {}
 
-    d.foo = 42
+    d.foo = 42  # type: ignore[missing-attribute]
     assert d.__dict__ == {"foo": 42}