fix(tests): replace runpytest_subprocess with runpytest

changelog.d/1275.downstream.rst

@@ -0,0 +1 @@
+Tests are run in the same pytest process, instead of spawning a subprocess with `pytest.Pytester.runpytest_subprocess`. This prevents the test suite from accidentally using a system installation of pytest-asyncio, which could result in test errors.

tests/hypothesis/test_base.py

@@ -27,7 +27,7 @@ async def test_mark_inner(n):
             """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict", "-W default")
+    result = pytester.runpytest("--asyncio-mode=strict", "-W default")
     result.assert_outcomes(passed=1)
 
 

tests/markers/test_class_scope.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import asyncio
+import sys
 from textwrap import dedent
 
 import pytest
@@ -143,8 +144,15 @@ async def test_does_not_use_custom_event_loop_policy():
             """
         )
     )
-    result = pytester.runpytest("--asyncio-mode=strict")
-    result.assert_outcomes(passed=2)
+    pytest_args = ["--asyncio-mode=strict"]
+    if sys.version_info >= (3, 14):
+        pytest_args.extend(["-W", "default"])
+    result = pytester.runpytest(*pytest_args)
+    if sys.version_info >= (3, 14):
+        result.assert_outcomes(passed=2, warnings=3)
+        result.stdout.fnmatch_lines("*DefaultEventLoopPolicy*")
+    else:
+        result.assert_outcomes(passed=2)
 
 
 def test_asyncio_mark_respects_parametrized_loop_policies(
@@ -175,8 +183,15 @@ async def test_parametrized_loop(self, request):
             """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict")
-    result.assert_outcomes(passed=2)
+    pytest_args = ["--asyncio-mode=strict"]
+    if sys.version_info >= (3, 14):
+        pytest_args.extend(["-W", "default"])
+    result = pytester.runpytest(*pytest_args)
+    if sys.version_info >= (3, 14):
+        result.assert_outcomes(passed=2, warnings=2)
+        result.stdout.fnmatch_lines("*DefaultEventLoopPolicy*")
+    else:
+        result.assert_outcomes(passed=2)
 
 
 def test_asyncio_mark_provides_class_scoped_loop_to_fixtures(
@@ -205,7 +220,7 @@ async def test_runs_is_same_loop_as_fixture(self, my_fixture):
             """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict")
+    result = pytester.runpytest("--asyncio-mode=strict")
     result.assert_outcomes(passed=1)
 
 
@@ -293,5 +308,5 @@ async def test_anything(self):
             """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict")
+    result = pytester.runpytest("--asyncio-mode=strict")
     result.assert_outcomes(warnings=0, passed=1)

tests/markers/test_function_scope.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import sys
 from textwrap import dedent
 
 from pytest import Pytester
@@ -87,7 +88,7 @@ async def test_warns():
             """
         )
     )
-    result = pytester.runpytest("--asyncio-mode=strict", "--assert=plain")
+    result = pytester.runpytest("--asyncio-mode=strict", "-W", "default")
     result.assert_outcomes(passed=1, warnings=1)
     result.stdout.fnmatch_lines("*DeprecationWarning*")
 
@@ -119,8 +120,15 @@ async def test_uses_custom_event_loop_policy():
             """
         ),
     )
-    result = pytester.runpytest("--asyncio-mode=strict")
-    result.assert_outcomes(passed=1)
+    pytest_args = ["--asyncio-mode=strict"]
+    if sys.version_info >= (3, 14):
+        pytest_args.extend(["-W", "default"])
+    result = pytester.runpytest(*pytest_args)
+    if sys.version_info >= (3, 14):
+        result.assert_outcomes(passed=1, warnings=2)
+        result.stdout.fnmatch_lines("*DefaultEventLoopPolicy*")
+    else:
+        result.assert_outcomes(passed=1)
 
 
 def test_asyncio_mark_respects_parametrized_loop_policies(
@@ -157,8 +165,15 @@ async def test_parametrized_loop():
             """
         )
     )
-    result = pytester.runpytest("--asyncio-mode=strict")
-    result.assert_outcomes(passed=2)
+    pytest_args = ["--asyncio-mode=strict"]
+    if sys.version_info >= (3, 14):
+        pytest_args.extend(["-W", "default"])
+    result = pytester.runpytest(*pytest_args)
+    if sys.version_info >= (3, 14):
+        result.assert_outcomes(passed=2, warnings=3)
+        result.stdout.fnmatch_lines("*DefaultEventLoopPolicy*")
+    else:
+        result.assert_outcomes(passed=2)
 
 
 def test_asyncio_mark_provides_function_scoped_loop_to_fixtures(

tests/markers/test_invalid_arguments.py

@@ -8,6 +8,7 @@
 def test_no_error_when_scope_passed_as_sole_keyword_argument(
     pytester: pytest.Pytester,
 ):
+    pytester.makeini("[pytest]\nasyncio_default_fixture_loop_scope = function")
     pytester.makepyfile(
         dedent(
             """\
@@ -19,14 +20,15 @@ async def test_anything():
             """
         )
     )
-    result = pytester.runpytest_subprocess()
+    result = pytester.runpytest("--assert=plain")
     result.assert_outcomes(passed=1)
     result.stdout.no_fnmatch_line("*ValueError*")
 
 
 def test_error_when_scope_passed_as_positional_argument(
     pytester: pytest.Pytester,
 ):
+    pytester.makeini("[pytest]\nasyncio_default_fixture_loop_scope = function")
     pytester.makepyfile(
         dedent(
             """\
@@ -38,7 +40,7 @@ async def test_anything():
             """
         )
     )
-    result = pytester.runpytest_subprocess()
+    result = pytester.runpytest("--assert=plain")
     result.assert_outcomes(errors=1)
     result.stdout.fnmatch_lines(
         ["*ValueError: mark.asyncio accepts only a keyword argument*"]
@@ -48,6 +50,7 @@ async def test_anything():
 def test_error_when_wrong_keyword_argument_is_passed(
     pytester: pytest.Pytester,
 ):
+    pytester.makeini("[pytest]\nasyncio_default_fixture_loop_scope = function")
     pytester.makepyfile(
         dedent(
             """\
@@ -59,7 +62,7 @@ async def test_anything():
             """
         )
     )
-    result = pytester.runpytest_subprocess()
+    result = pytester.runpytest("--assert=plain")
     result.assert_outcomes(errors=1)
     result.stdout.fnmatch_lines(
         ["*ValueError: mark.asyncio accepts only a keyword argument 'loop_scope'*"]
@@ -69,6 +72,7 @@ async def test_anything():
 def test_error_when_additional_keyword_arguments_are_passed(
     pytester: pytest.Pytester,
 ):
+    pytester.makeini("[pytest]\nasyncio_default_fixture_loop_scope = function")
     pytester.makepyfile(
         dedent(
             """\
@@ -80,7 +84,7 @@ async def test_anything():
             """
         )
     )
-    result = pytester.runpytest_subprocess()
+    result = pytester.runpytest("--assert=plain")
     result.assert_outcomes(errors=1)
     result.stdout.fnmatch_lines(
         ["*ValueError: mark.asyncio accepts only a keyword argument*"]

tests/markers/test_module_scope.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import sys
 from textwrap import dedent
 
 from pytest import Pytester
@@ -87,8 +88,15 @@ async def test_does_not_use_custom_event_loop_policy():
             """
         ),
     )
-    result = pytester.runpytest("--asyncio-mode=strict")
-    result.assert_outcomes(passed=2)
+    pytest_args = ["--asyncio-mode=strict"]
+    if sys.version_info >= (3, 14):
+        pytest_args.extend(["-W", "default"])
+    result = pytester.runpytest(*pytest_args)
+    if sys.version_info >= (3, 14):
+        result.assert_outcomes(passed=2, warnings=3)
+        result.stdout.fnmatch_lines("*DefaultEventLoopPolicy*")
+    else:
+        result.assert_outcomes(passed=2)
 
 
 def test_asyncio_mark_respects_parametrized_loop_policies(
@@ -119,8 +127,15 @@ async def test_parametrized_loop():
             """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict")
-    result.assert_outcomes(passed=2)
+    pytest_args = ["--asyncio-mode=strict"]
+    if sys.version_info >= (3, 14):
+        pytest_args.extend(["-W", "default"])
+    result = pytester.runpytest(*pytest_args)
+    if sys.version_info >= (3, 14):
+        result.assert_outcomes(passed=2, warnings=2)
+        result.stdout.fnmatch_lines("*DefaultEventLoopPolicy*")
+    else:
+        result.assert_outcomes(passed=2)
 
 
 def test_asyncio_mark_provides_module_scoped_loop_to_fixtures(
@@ -150,7 +165,7 @@ async def test_runs_is_same_loop_as_fixture(my_fixture):
             """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict")
+    result = pytester.runpytest("--asyncio-mode=strict")
     result.assert_outcomes(passed=1)
 
 
@@ -298,5 +313,5 @@ async def test_anything():
             """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict")
+    result = pytester.runpytest("--asyncio-mode=strict")
     result.assert_outcomes(warnings=0, passed=1)

tests/markers/test_package_scope.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import sys
 from textwrap import dedent
 
 from pytest import Pytester
@@ -127,8 +128,15 @@ async def test_also_uses_custom_event_loop_policy():
             """
         ),
     )
-    result = pytester.runpytest("--asyncio-mode=strict")
-    result.assert_outcomes(passed=2)
+    pytest_args = ["--asyncio-mode=strict"]
+    if sys.version_info >= (3, 14):
+        pytest_args.extend(["-W", "default"])
+    result = pytester.runpytest(*pytest_args)
+    if sys.version_info >= (3, 14):
+        result.assert_outcomes(passed=2, warnings=3)
+        result.stdout.fnmatch_lines("*DefaultEventLoopPolicy*")
+    else:
+        result.assert_outcomes(passed=2)
 
 
 def test_asyncio_mark_respects_parametrized_loop_policies(
@@ -160,8 +168,15 @@ async def test_parametrized_loop():
             """
         ),
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict")
-    result.assert_outcomes(passed=2)
+    pytest_args = ["--asyncio-mode=strict"]
+    if sys.version_info >= (3, 14):
+        pytest_args.extend(["-W", "default"])
+    result = pytester.runpytest(*pytest_args)
+    if sys.version_info >= (3, 14):
+        result.assert_outcomes(passed=2, warnings=2)
+        result.stdout.fnmatch_lines("*DefaultEventLoopPolicy*")
+    else:
+        result.assert_outcomes(passed=2)
 
 
 def test_asyncio_mark_provides_package_scoped_loop_to_fixtures(
@@ -207,7 +222,7 @@ async def test_runs_in_same_loop_as_fixture(my_fixture):
             """
         ),
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict")
+    result = pytester.runpytest("--asyncio-mode=strict")
     result.assert_outcomes(passed=1)
 
 

tests/markers/test_session_scope.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import sys
 from textwrap import dedent
 
 from pytest import Pytester
@@ -128,8 +129,15 @@ async def test_also_uses_custom_event_loop_policy():
             """
         ),
     )
-    result = pytester.runpytest("--asyncio-mode=strict")
-    result.assert_outcomes(passed=2)
+    pytest_args = ["--asyncio-mode=strict"]
+    if sys.version_info >= (3, 14):
+        pytest_args.extend(["-W", "default"])
+    result = pytester.runpytest(*pytest_args)
+    if sys.version_info >= (3, 14):
+        result.assert_outcomes(passed=2, warnings=3)
+        result.stdout.fnmatch_lines("*DefaultEventLoopPolicy*")
+    else:
+        result.assert_outcomes(passed=2)
 
 
 def test_asyncio_mark_respects_parametrized_loop_policies(
@@ -161,8 +169,15 @@ async def test_parametrized_loop():
             """
         ),
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict")
-    result.assert_outcomes(passed=2)
+    pytest_args = ["--asyncio-mode=strict"]
+    if sys.version_info >= (3, 14):
+        pytest_args.extend(["-W", "default"])
+    result = pytester.runpytest(*pytest_args)
+    if sys.version_info >= (3, 14):
+        result.assert_outcomes(passed=2, warnings=2)
+        result.stdout.fnmatch_lines("*DefaultEventLoopPolicy*")
+    else:
+        result.assert_outcomes(passed=2)
 
 
 def test_asyncio_mark_provides_session_scoped_loop_to_fixtures(
@@ -212,7 +227,7 @@ async def test_runs_in_same_loop_as_fixture(my_fixture):
             """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict")
+    result = pytester.runpytest("--asyncio-mode=strict")
     result.assert_outcomes(passed=1)
 
 
@@ -423,5 +438,5 @@ async def test_anything():
             """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict")
+    result = pytester.runpytest("--asyncio-mode=strict")
     result.assert_outcomes(warnings=0, passed=1)

tests/modes/test_strict_mode.py

@@ -94,7 +94,7 @@ async def test_anything():
         """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict", "-W default")
+    result = pytester.runpytest("--asyncio-mode=strict", "-W default", "--assert=plain")
     if pytest_version >= (8, 4, 0):
         result.assert_outcomes(failed=1, skipped=0, warnings=0)
     else:
@@ -119,7 +119,7 @@ async def test_anything(any_fixture):
         """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict", "-W default")
+    result = pytester.runpytest("--asyncio-mode=strict", "-W default", "--assert=plain")
 
     if pytest_version >= (8, 4, 0):
         result.assert_outcomes(failed=1, skipped=0, warnings=2)
@@ -155,7 +155,7 @@ async def test_anything(any_fixture):
         """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict", "-W default")
+    result = pytester.runpytest("--asyncio-mode=strict", "-W default", "--assert=plain")
     if pytest_version >= (8, 4, 0):
         result.assert_outcomes(passed=1, failed=0, skipped=0, warnings=2)
     else:
@@ -202,7 +202,7 @@ async def test_anything(any_fixture):
         """
         )
     )
-    result = pytester.runpytest_subprocess("--asyncio-mode=strict", "-W default")
+    result = pytester.runpytest("--asyncio-mode=strict", "-W default", "--assert=plain")
     if pytest_version >= (8, 4, 0):
         result.assert_outcomes(passed=1, warnings=2)
     else: