Add specific optional test

Author: InvincibleRMC

tests/test_pytypes.cpp

@@ -1034,6 +1034,45 @@ TEST_SUBMODULE(pytypes, m) {
     m.attr("defined_PYBIND11_TYPING_H_HAS_STRING_LITERAL") = false;
 #endif
 
+#if defined(PYBIND11_TEST_PTYPES_HAS_OPTIONAL)
+    m.def("generic_T", []() -> void {}, pybind11::detail::typevar_record::from_name("T"));
+
+    m.def(
+        "generic_T_V",
+        []() -> void {},
+        pybind11::detail::typevar_record::from_name("T"),
+        pybind11::detail::typevar_record::from_name("V"));
+
+    m.def(
+        "generic_bound_int",
+        []() -> void {},
+        pybind11::detail::typevar_record::with_bound<int>("T"));
+
+    m.def(
+        "generic_constraints_int_str",
+        []() -> void {},
+        pybind11::detail::typevar_record::with_constraints<py::int_, py::str>("T"));
+
+    m.def(
+        "generic_default_int",
+        []() -> void {},
+        pybind11::detail::typevar_record::with_default<int>("T"));
+
+    m.def(
+        "generic_bound_and_default_int",
+        []() -> void {},
+        pybind11::detail::typevar_record::with_default_and_bound<int, int>("T"));
+
+    m.def(
+        "generic_constraints_and_default",
+        []() -> void {},
+        pybind11::detail::typevar_record::
+            with_default_and_constraints<py::str, py::typing::List<int>, py::str>("T"));
+    m.attr("defined_PYBIND11_TEST_PTYPES_HAS_OPTIONAL") = true;
+#else
+    m.attr("defined_PYBIND11_TEST_PTYPES_HAS_OPTIONAL") = false;
+#endif
+
 #if defined(PYBIND11_TEST_PYTYPES_HAS_RANGES)
 
     // test_tuple_ranges

tests/test_pytypes.py

@@ -1085,6 +1085,38 @@ def test_literal(doc):
     )
 
 
+@pytest.mark.skipif(
+    not m.defined_PYBIND11_TEST_PTYPES_HAS_OPTIONAL,
+    reason="use of optional feature not available.",
+)
+def test_generic(doc):
+    assert doc(m.generic_T) == "generic_T[T]() -> None"
+
+    assert (
+        doc(m.generic_bound_int) == "generic_bound_int[T: typing.SupportsInt]() -> None"
+    )
+
+    assert (
+        doc(m.generic_constraints_int_str)
+        == "generic_constraints_int_str[T: (typing.SupportsInt, str)]() -> None"
+    )
+
+    assert (
+        doc(m.generic_default_int)
+        == "generic_default_int[T = typing.SupportsInt]() -> None"
+    )
+
+    assert (
+        doc(m.generic_bound_and_default_int)
+        == "generic_bound_and_default_int[T: typing.SupportsInt = typing.SupportsInt]() -> None"
+    )
+
+    assert (
+        doc(m.generic_constraints_and_default)
+        == "generic_constraints_and_default[T: (list[typing.SupportsInt], str) = str]() -> None"
+    )
+
+
 @pytest.mark.skipif(
     not m.defined_PYBIND11_TYPING_H_HAS_STRING_LITERAL,
     reason="C++20 non-type template args feature not available.",