Fixed #251: Add docs for testing Generic Consumers (#323)

docs/testing.rst

@@ -62,6 +62,31 @@ and post the square of it to the ``"result"`` channel::
             self.assertEqual(result['value'], 1089)
 
 
+Generic Consumers
+-----------------
+
+You can use ``ChannelTestCase`` to test generic consumers as well. Just pass the message
+object from ``get_next_message`` to the constructor of the class. To test replies to a specific channel,
+use the ``reply_channel`` property on the ``Message`` object. For example::
+
+    from channels import Channel
+    from channels.tests import ChannelTestCase
+
+    from myapp.consumers import MyConsumer
+
+    class MyTests(ChannelTestCase):
+
+        def test_a_thing(self):
+            # Inject a message onto the channel to use in a consumer
+            Channel("input").send({"value": 33})
+            # Run the consumer with the new Message object
+            message = self.get_next_message("input", require=True)
+            MyConsumer(message)
+            # Verify there's a reply and that it's accurate
+            result = self.get_next_message(message.reply_channel.name, require=True)
+            self.assertEqual(result['value'], 1089)
+
+
 Groups
 ------