Handle morphs that are not dicts (By failing)

2 files changed, 6 insertions, 3 deletions

diff --git a/morphlib/morph2.py b/morphlib/morph2.py
index a32ecbb9..ae720cfb 100644
--- a/morphlib/morph2.py
+++ b/morphlib/morph2.py
@@ -77,6 +77,8 @@ class Morphology(object):
 
         if data is None:
             raise morphlib.YAMLError("Morphology is empty")
+        if type(data) not in [dict, OrderedDict]:
+            raise morphlib.YAMLError("Morphology did not parse as a dict")
 
         self._set_defaults()
         self._validate_children()
diff --git a/morphlib/morph2_tests.py b/morphlib/morph2_tests.py
index a2c44753..61e1744b 100644
--- a/morphlib/morph2_tests.py
+++ b/morphlib/morph2_tests.py
@@ -164,11 +164,12 @@ class MorphologyTests(unittest.TestCase):
 
     ## Validation tests
 
-    def test_morphology_must_not_be_empty(self):
-        # Causes crashes if not handled, because code expecting a dict gets
-        # None instead.
+    def test_not_empty(self):
         self.assertRaises(morphlib.YAMLError, Morphology, '')
 
+    def test_is_dict(self):
+        self.assertRaises(morphlib.YAMLError, Morphology, 'foo')
+
     def test_makes_max_jobs_be_an_integer(self):
         m = Morphology('''
             {