Added unit test and support for calling getfixturevalue on a synchron…

…ous fixture definition

src/anyio/pytest_plugin.py

@@ -2,7 +2,7 @@
 
 from collections.abc import Iterator
 from contextlib import contextmanager
-from contextvars import Context, copy_context
+from contextvars import Context, ContextVar, copy_context
 from inspect import isasyncgenfunction, iscoroutinefunction
 from typing import Any, Dict, Tuple, cast
 
@@ -15,17 +15,35 @@
 from .abc import TestRunner
 
 _current_runner: TestRunner | None = None
+_current_reentrancy_token = ContextVar[object]("anyio.pytest_plugin.reentrancy_token")
 contextvars_context_key: StashKey[Context] = StashKey()
 _test_context_like_key: StashKey[ContextLike] = StashKey()
 
 
 class _TestContext(ContextLike):
-    """This class manages transmission of sniffio.current_async_library_cvar"""
+    """Manages reentrancy and transmission of sniffio.current_async_library_cvar"""
 
     def __init__(self, context: Context):
         self._context = context
+        self._reentrancy_token = object()
+
+    def _is_already_in_context(self) -> bool:
+        # if context var is not set to the token, we are in another context
+        if _current_reentrancy_token.get(None) is not self._reentrancy_token:
+            return False
+
+        # Token value is the same, but we may be in a copy of self._context
+        test_value = object()
+        reset_reentrancy = _current_reentrancy_token.set(test_value)
+        try:
+            return self._context[_current_reentrancy_token] is test_value
+        finally:
+            _current_reentrancy_token.reset(reset_reentrancy)
 
     def run(self, func: Any, /, *args: Any, **kwargs: Any) -> Any:
+        if self._is_already_in_context():
+            return func(*args, **kwargs)
+
         return self._context.run(
             self._set_context_and_run,
             sniffio.current_async_library_cvar.get(None),
@@ -37,6 +55,7 @@ def run(self, func: Any, /, *args: Any, **kwargs: Any) -> Any:
     def _set_context_and_run(
         self, current_async_library: str | None, func: Any, /, *args: Any, **kwargs: Any
     ) -> Any:
+        reset_reentrancy = _current_reentrancy_token.set(self._reentrancy_token)
         reset_sniffio = None
         if current_async_library is not None:
             reset_sniffio = sniffio.current_async_library_cvar.set(
@@ -46,6 +65,7 @@ def _set_context_and_run(
         try:
             return func(*args, **kwargs)
         finally:
+            _current_reentrancy_token.reset(reset_reentrancy)
             if reset_sniffio is not None:
                 sniffio.current_async_library_cvar.reset(reset_sniffio)
 

tests/test_pytest_plugin.py

@@ -439,3 +439,61 @@ def test_sync_func_sync_then_async_fixture(
 
     result = testdir.runpytest(*pytest_args)
     result.assert_outcomes(passed=4 * len(get_all_backends()))
+
+
+def test_sync_getfixturevalue(testdir: Pytester) -> None:
+    testdir.makepyfile(
+        """
+        from __future__ import annotations
+
+        from contextvars import ContextVar
+
+        import pytest
+
+
+        var = ContextVar("var")
+
+
+        @pytest.fixture
+        def function_fixture():
+            return "function"
+
+
+        @pytest.fixture
+        def generator_fixture():
+            yield "generator"
+
+
+        @pytest.fixture
+        def set_var():
+            value = object()
+            reset = var.set(value)
+            yield value
+            var.reset(reset)
+
+
+        @pytest.mark.parametrize("prefix", ["function", "generator"])
+        def test_getfixturevalue_from_sync(request, prefix):
+            assert request.getfixturevalue(f"{prefix}_fixture") == prefix
+
+
+        @pytest.mark.anyio
+        @pytest.mark.parametrize("prefix", ["function", "generator"])
+        async def test_getfixturevalue_from_async(request, prefix):
+            assert request.getfixturevalue(f"{prefix}_fixture") == prefix
+
+
+        def test_getfixturevalue_with_context_from_sync(request):
+            value = request.getfixturevalue("set_var")
+            assert var.get(None) is value
+
+
+        @pytest.mark.anyio
+        async def test_getfixturevalue_with_context_from_async(request):
+            value = request.getfixturevalue("set_var")
+            assert var.get(None) is value
+        """
+    )
+
+    result = testdir.runpytest(*pytest_args)
+    result.assert_outcomes(passed=3 * len(get_all_backends()) + 3)