Update warning when invalid delivery is set

bugsnag/configuration.py

@@ -273,6 +273,25 @@ def delivery(self):
     def delivery(self, value):
         if hasattr(value, 'deliver') and callable(value.deliver):
             self._delivery = value
+
+            # deliver_sessions is _technically_ optional in that if you disable
+            # session tracking it will never be called
+            # this should be made mandatory in the next major release
+            if (
+                hasattr(value, 'deliver_sessions') and
+                callable(value.deliver_sessions)
+            ):
+                parameter_names = value.deliver_sessions.__code__.co_varnames
+
+                if 'options' not in parameter_names:
+                    warnings.warn(
+                        'delivery.deliver_sessions should accept an ' +
+                        '"options" parameter to allow for synchronous ' +
+                        'delivery, sessions may be lost when the process ' +
+                        'exits',
+                        DeprecationWarning
+                    )
+
         else:
             message = ('delivery should implement Delivery interface, got ' +
                        '{0}. This will be an error in a future release.')

tests/test_configuration.py

@@ -195,6 +195,13 @@ class BadDelivery(object):
             def deliv(self, *args, **kwargs):
                 pass
 
+        class OkDelivery:
+            def deliver(self, *args, **kwargs):
+                pass
+
+            def deliver_sessions(self, config, payload):
+                pass
+
         class GoodDelivery(object):
             def deliver(self, *args, **kwargs):
                 pass
@@ -213,6 +220,20 @@ def deliver(self, *args, **kwargs):
             assert len(record) == 1
             assert c.delivery == good
 
+        with pytest.warns(DeprecationWarning) as record:
+            ok = OkDelivery()
+
+            c.configure(delivery=ok)
+
+            assert len(record) == 1
+            assert str(record[0].message) == (
+                'delivery.deliver_sessions should accept an "options" ' +
+                'parameter to allow for synchronous delivery, sessions ' +
+                'may be lost when the process exits'
+            )
+
+            assert c.delivery == ok
+
     def test_validate_hostname(self):
         c = Configuration()
         with pytest.warns(RuntimeWarning) as record: