Add initial gevent tests

Author: SmileyChris

tests/test_gevent.py

@@ -0,0 +1,38 @@
+try:
+    from unittest import mock
+except ImportError:
+    import mock
+
+from graphql_ws.gevent import GeventConnectionContext, GeventSubscriptionServer
+
+
+class TestConnectionContext:
+    def test_receive(self):
+        ws = mock.Mock()
+        connection_context = GeventConnectionContext(ws=ws)
+        connection_context.receive()
+        ws.receive.assert_called()
+
+    def test_send(self):
+        ws = mock.Mock()
+        ws.closed = False
+        connection_context = GeventConnectionContext(ws=ws)
+        connection_context.send("test")
+        ws.send.assert_called_with("test")
+
+    def test_send_closed(self):
+        ws = mock.Mock()
+        ws.closed = True
+        connection_context = GeventConnectionContext(ws=ws)
+        connection_context.send("test")
+        assert not ws.send.called
+
+    def test_close(self):
+        ws = mock.Mock()
+        connection_context = GeventConnectionContext(ws=ws)
+        connection_context.close(123)
+        ws.close.assert_called_with(123)
+
+
+def test_subscription_server_smoke():
+    GeventSubscriptionServer(schema=None)