prepare tests and disable warnings for asyncio unittest cases

shoehorn unittest async results into python test result interpretation

changelog

changelog/6924.bugfix.rst

@@ -0,0 +1 @@
+Ensure a ``unittest.IsolatedAsyncioTestCase`` is actually awaited.

src/_pytest/python.py

@@ -175,15 +175,33 @@ def async_warn(nodeid: str) -> None:
 @hookimpl(trylast=True)
 def pytest_pyfunc_call(pyfuncitem: "Function"):
     testfunction = pyfuncitem.obj
-    if iscoroutinefunction(testfunction) or (
-        sys.version_info >= (3, 6) and inspect.isasyncgenfunction(testfunction)
-    ):
+
+    try:
+        # ignoring type as the import is  invalid in py37  and mypy thinks its a error
+        from unittest import IsolatedAsyncioTestCase  # type: ignore
+    except ImportError:
+        async_ok_in_stdlib = False
+    else:
+        async_ok_in_stdlib = isinstance(
+            getattr(testfunction, "__self__", None), IsolatedAsyncioTestCase
+        )
+
+    if (
+        iscoroutinefunction(testfunction)
+        or (sys.version_info >= (3, 6) and inspect.isasyncgenfunction(testfunction))
+    ) and not async_ok_in_stdlib:
         async_warn(pyfuncitem.nodeid)
     funcargs = pyfuncitem.funcargs
     testargs = {arg: funcargs[arg] for arg in pyfuncitem._fixtureinfo.argnames}
     result = testfunction(**testargs)
     if hasattr(result, "__await__") or hasattr(result, "__aiter__"):
-        async_warn(pyfuncitem.nodeid)
+        if async_ok_in_stdlib:
+            # todo: investigate moving this to the unittest plugin
+            #       by a test call result hook
+            testcase = testfunction.__self__
+            testcase._callMaybeAsync(lambda: result)
+        else:
+            async_warn(pyfuncitem.nodeid)
     return True
 
 

testing/example_scripts/pytest.ini

@@ -0,0 +1,2 @@
+[pytest]
+# dummy pytest.ini to ease direct running of example scripts

testing/example_scripts/unittest/test_unittest_asyncio.py

@@ -0,0 +1,15 @@
+from unittest import IsolatedAsyncioTestCase  # type: ignore
+
+
+class AsyncArguments(IsolatedAsyncioTestCase):
+    async def test_something_async(self):
+        async def addition(x, y):
+            return x + y
+
+        self.assertEqual(await addition(2, 2), 4)
+
+    async def test_something_async_fails(self):
+        async def addition(x, y):
+            return x + y
+
+        self.assertEqual(await addition(2, 2), 3)

testing/test_unittest.py

@@ -1129,3 +1129,11 @@ def test_trace(testdir, monkeypatch):
     result = testdir.runpytest("--trace", str(p1))
     assert len(calls) == 2
     assert result.ret == 0
+
+
+def test_async_support(testdir):
+    pytest.importorskip("unittest.async_case")
+
+    testdir.copy_example("unittest/test_unittest_asyncio.py")
+    reprec = testdir.inline_run()
+    reprec.assertoutcome(failed=1, passed=1)