Skip uvloop tests with pypy

tests/conftest.py

@@ -1,19 +1,26 @@
 import pytest
 import asyncio
-import uvloop
+import platform
 
 
 @pytest.fixture(
     params=(
-        asyncio.DefaultEventLoopPolicy(),
-        uvloop.EventLoopPolicy(),
+        "default",
+        "uvloop",
     ),
-    ids=("default", "uvloop"),
 )
 def event_loop_policy(request):
+    if request.param == "default":
+        return asyncio.DefaultEventLoopPolicy()
+    elif request.param == "uvloop":
+        if platform.python_implementation() == "PyPy":
+            pytest.skip("Skip uvloop tests on PyPy.")
+        import uvloop
+
+        return uvloop.EventLoopPolicy()
     return request.param
 
 
 @pytest.fixture
 def is_uvloop(event_loop_policy):
-    return isinstance(event_loop_policy, uvloop.EventLoopPolicy)
+    return not isinstance(event_loop_policy, asyncio.DefaultEventLoopPolicy)