Added some relay tests.

tests/relay/test_relay.py

@@ -0,0 +1,41 @@
+from pytest import raises
+
+import graphene
+from graphene import relay
+
+
+class OtherNode(relay.Node):
+    name = graphene.StringField()
+
+    @classmethod
+    def get_node(cls, id):
+        pass
+
+
+def test_field_no_contributed_raises_error():
+    with raises(Exception) as excinfo:
+        class Part(relay.Node):
+            x = graphene.StringField()
+
+    assert 'get_node' in str(excinfo.value)
+
+
+def test_node_should_have_connection():
+    assert OtherNode.connection
+
+
+def test_node_should_have_id_field():
+    assert 'id' in OtherNode._meta.fields_map
+
+
+def test_field_no_contributed_raises_error():
+    with raises(Exception) as excinfo:
+        class Ship(graphene.ObjectType):
+            name = graphene.StringField()
+
+
+        class Faction(relay.Node):
+            name = graphene.StringField()
+            ships = relay.ConnectionField(Ship)
+
+    assert 'same type_name' in str(excinfo.value)