Fix tests on Python 2.7

glue/core/state_path_patches.txt

@@ -25,3 +25,4 @@ glue_vispy_viewers.common.toolbar.PatchedElementSubsetState -> glue.core.subset.
 glue.plugins.dendro_viewer.qt.viewer_widget.DendroWidget -> glue.plugins.dendro_viewer.qt.DendrogramViewer
 glue.plugins.dendro_viewer.layer_artist.DendroLayerArtist -> glue.plugins.dendro_viewer.layer_artist.DendrogramLayerArtist
 builtins.builtin_function_or_method ->  types.BuiltinFunctionType
+__builtin__.builtin_function_or_method -> types.BuiltinFunctionType

glue/core/tests/test_data_collection.py

@@ -13,12 +13,13 @@
 from ..data_collection import DataCollection
 from ..hub import HubListener
 from ..message import (Message, DataCollectionAddMessage, DataRemoveComponentMessage,
-                       DataCollectionDeleteMessage,
+                       DataCollectionDeleteMessage, DataAddComponentMessage,
                        ComponentsChangedMessage, ExternallyDerivableComponentsChangedMessage)
 from ..exceptions import IncompatibleAttribute
 
 from .test_state import clone
 
+
 class HubLog(HubListener):
 
     def __init__(self):
@@ -30,6 +31,9 @@ def register_to_hub(self, hub):
     def notify(self, message):
         self.messages.append(message)
 
+    def clear(self):
+        self.messages[:] = []
+
 
 class TestDataCollection(object):
 
@@ -159,10 +163,15 @@ def test_catch_data_add_component_message(self):
         self.dc.append(d)
         d.add_component(Component(np.array([1, 2, 3])), id1)
         assert link not in self.dc._link_manager
+        self.log.clear()
         d.add_component(dc, id2)
 
-        msg = self.log.messages[-1]
-        assert isinstance(msg, ComponentsChangedMessage)
+        msgs = sorted(self.log.messages)
+
+        assert isinstance(msgs[0], ComponentsChangedMessage)
+        assert isinstance(msgs[1], DataAddComponentMessage)
+        assert isinstance(msgs[2], ExternallyDerivableComponentsChangedMessage)
+
         assert link in self.dc._link_manager
 
     def test_links_auto_added(self):