warn about async def rather than coroutine

Author: graingert

src/_pytest/python.py

@@ -153,13 +153,13 @@ def pytest_configure(config):
 def pytest_pyfunc_call(pyfuncitem):
     testfunction = pyfuncitem.obj
     if iscoroutinefunction(testfunction):
-        msg = "Coroutine functions are not natively supported and have been skipped.\n"
+        msg = "async def functions are not natively supported and have been skipped.\n"
         msg += "You need to install a suitable plugin for your async framework, for example:\n"
         msg += "  - pytest-asyncio\n"
         msg += "  - pytest-trio\n"
         msg += "  - pytest-tornasync"
         warnings.warn(PytestUnhandledCoroutineWarning(msg.format(pyfuncitem.nodeid)))
-        skip(msg="coroutine function and no async plugin installed (see warnings)")
+        skip(msg="async def function and no async plugin installed (see warnings)")
     funcargs = pyfuncitem.funcargs
     testargs = {arg: funcargs[arg] for arg in pyfuncitem._fixtureinfo.argnames}
     testfunction(**testargs)

testing/acceptance_test.py

@@ -1199,11 +1199,11 @@ async def test_2():
         [
             "test_async.py::test_1",
             "test_async.py::test_2",
-            "*Coroutine functions are not natively supported*",
+            "*async def functions are not natively supported*",
             "*2 skipped, 2 warnings in*",
         ]
     )
     # ensure our warning message appears only once
     assert (
-        result.stdout.str().count("Coroutine functions are not natively supported") == 1
+        result.stdout.str().count("async def functions are not natively supported") == 1
     )