fix: [382] not starting another event loop

ward/_utilities.py

@@ -1,6 +1,8 @@
+import asyncio
 import collections
 import inspect
 from pathlib import Path
+import sys
 from typing import Any, Callable, Dict, Hashable, Iterable, List, Optional, TypeVar
 
 
@@ -43,3 +45,15 @@ def group_by(items: Iterable[T], key: Callable[[T], H]) -> Dict[H, List[T]]:
     for item in items:
         groups[key(item)].append(item)
     return dict(groups)
+
+def get_current_event_loop() -> asyncio.AbstractEventLoop:
+    if sys.version_info < (3, 10):
+        loop = asyncio.get_event_loop()
+    else:
+        try:
+            loop = asyncio.get_running_loop()
+        except RuntimeError:
+            loop = asyncio.new_event_loop()
+
+        asyncio.set_event_loop(loop)
+    return loop

ward/fixtures.py

@@ -1,4 +1,3 @@
-import asyncio
 import inspect
 from contextlib import ExitStack, redirect_stderr, redirect_stdout, suppress
 from dataclasses import dataclass
@@ -7,6 +6,7 @@
 from pathlib import Path
 from typing import Any, AsyncGenerator, Callable, Generator, List, Optional, Union, cast
 
+from ward._utilities import get_current_event_loop
 from ward.models import CollectionMetadata, Scope
 
 __all__ = ["fixture", "using", "Fixture", "TeardownResult"]
@@ -137,7 +137,7 @@ def teardown(self, capture_output: bool) -> "TeardownResult":
                     next(cast(Generator, self.gen))
                 elif self.is_async_generator_fixture and self.gen:
                     awaitable = cast(AsyncGenerator, self.gen).__anext__()
-                    asyncio.run(awaitable)
+                    get_current_event_loop().run_until_complete(awaitable)
         except Exception as e:
             # Note that with StopIterations being suppressed, we have an issue
             # that if a StopIteration occurs in fixture teardown code, it will

ward/testing.py

@@ -1,4 +1,3 @@
-import asyncio
 import collections
 import functools
 import inspect
@@ -31,7 +30,7 @@
     _Timer,
     is_test_module_name,
 )
-from ward._utilities import get_absolute_path
+from ward._utilities import get_absolute_path, get_current_event_loop
 from ward.fixtures import Fixture
 from ward.models import CollectionMetadata, Marker, Scope, SkipMarker, XfailMarker
 
@@ -197,7 +196,7 @@ def run(self, cache: FixtureCache, dry_run=False) -> "TestResult":  # noqa: C901
                 self.format_description(resolved_args)
                 if self.is_async_test:
                     coro = self.fn(**resolved_args)
-                    asyncio.run(coro)
+                    get_current_event_loop().run_until_complete(coro)
                 else:
                     self.fn(**resolved_args)
             except FixtureError as e:
@@ -628,9 +627,9 @@ def _resolve_single_arg(
             elif fixture.is_async_generator_fixture:
                 fixture.gen = arg(**args_to_inject)
                 awaitable = fixture.gen.__anext__()  # type: ignore[union-attr]
-                fixture.resolved_val = asyncio.run(awaitable)
+                fixture.resolved_val = get_current_event_loop().run_until_complete(awaitable)
             elif fixture.is_coroutine_fixture:
-                fixture.resolved_val = asyncio.run(arg(**args_to_inject))
+                fixture.resolved_val = get_current_event_loop().run_until_complete(arg(**args_to_inject))
             else:
                 fixture.resolved_val = arg(**args_to_inject)
         except (Exception, SystemExit) as e: