Aid testing by not wrapping flexmock expectation exceptions

Usually API methods will wrap any exceptions in OsbsException.
However, if the exception is e.g. a MethodCallError, perhaps because
a function expected never to be called has been called, this
may cause a test to pass and mask a bug.

Don't wrap MethodCallError or other flexmock expectation exceptions.

Signed-off-by: Tim Waugh <twaugh@redhat.com>

osbs/api.py

@@ -26,6 +26,15 @@
 from osbs.exceptions import OsbsException, OsbsValidationException, OsbsResponseException
 # import utils in this way, so that we can mock standalone functions with flexmock
 from osbs import utils
+try:
+    from flexmock import MethodCallError, MethodSignatureError, CallOrderError
+except ImportError:
+    class MethodCallError(Exception):
+        pass
+    class MethodSignatureError(Exception):
+        pass
+    class CallOrderError(Exception):
+        pass
 
 
 # Decorator for API methods.
@@ -40,6 +49,9 @@ def catch_exceptions(*args, **kwargs):
         except OsbsException:
             # Re-raise OsbsExceptions
             raise
+        except (MethodCallError, MethodSignatureError, CallOrderError):
+            # Aid debugging
+            raise
         except Exception as ex:
             # Convert anything else to OsbsException