Merge branch 'develop' into feature-ukwargs

src/mdsynthesis/tests/test_treants.py

@@ -12,7 +12,7 @@
 from datreant.core.tests.test_treants import TestTreant
 
 import MDAnalysis as mda
-from MDAnalysisTests.datafiles import PDB, GRO, XTC
+from MDAnalysisTests.datafiles import PDB, GRO, XTC, PSF
 
 
 class TestSim(TestTreant):
@@ -55,6 +55,25 @@ def test_set_universe(self, treant):
             assert treant.udef.topology == GRO
             assert treant.udef.trajectory == XTC
 
+        def test_set_universe_only_topology(self, treant):
+            """Test setting the Universe to a topology-only universe"""
+            u = mda.Universe(PSF)
+
+            treant.universe = u
+
+            assert treant.universe.filename == PSF
+            assert treant.udef.topology == PSF
+            assert treant.udef.trajectory is None
+
+        def test_set_universe_chainreader(self, treant):
+            """Test setting the Universe to multiple file trajectory (chain)"""
+            u = mda.Universe(GRO, [XTC, XTC])
+
+            treant.universe = u
+
+            assert treant.udef.topology == GRO
+            assert treant.udef.trajectory == [XTC, XTC]
+
         def test_add_univese_typeerror(self, treant):
             """Test checking of what is passed to setter"""
             with pytest.raises(TypeError):

src/mdsynthesis/treants.py

@@ -94,12 +94,12 @@ def universe(self, universe):
                                 type(universe)))
         else:
             self.udef.topology = universe.filename
-            try:
-                traj = universe.trajectory.filename
+            try:  # ChainReader?
+                traj = universe.trajectory.filenames
             except AttributeError:
-                try:
-                    traj = universe.trajectory.filenames
-                except AttributeError:
+                try:  # Reader?
+                    traj = universe.trajectory.filename
+                except AttributeError:  # Only topology
                     traj = None
 
             self.udef.trajectory = traj