Improve traceback for case missing an attribute

src/zinolib/ritz.py

@@ -276,8 +276,12 @@ def __getattr__(self, name):
         elif "downtime" == name:
             return self.get_downtime()
         else:
-            self.__getattribute__(name)
-            # raise AttributeError("%s instance of type %s has no attribute '%s'" % (self.__class__, self._attrs["type"], name))
+            try:
+                self.__getattribute__(name)
+            except AttributeError as e:
+                msg = "%s of type %s has no attribute '%s'"
+                typename = self._attrs.get("type", "UNKNOWN")
+                raise AttributeError(msg % (self, typename, name))
         return self
 
     def __getitem__(self, key):

tests/test_ritz.py

@@ -0,0 +1,29 @@
+import unittest
+
+from zinolib.ritz import Case
+
+
+class CaseTest(unittest.TestCase):
+    class FakeZino:
+        def __init__(self, attrs=None):
+            if attrs:
+                self.attrs = attrs
+            else:
+                self.attrs = {}
+
+        def get_attributes(self, caseid):
+            return self.attrs
+
+    def test_golden_path_attribute_access(self):
+        zino = self.FakeZino({'foo': 'bar'})
+        case = Case(zino, 1)
+        self.assertTrue(case._attrs)
+        self.assertEqual(case.foo, 'bar')
+
+    def test_accessing_missing_attribute_should_fail_with_extra_info(self):
+        zino = self.FakeZino({'foo': 'bar'})
+        case = Case(zino, 1)
+        expected_msg = "<class 'zinolib.ritz.Case'>(1) of type UNKNOWN has no attribute 'xux'"
+        with self.assertRaises(AttributeError) as cm:
+            case.xux
+        self.assertEqual(cm.exception.args[0], expected_msg)