swarmbucket: allow overriding config

appengine/cr-buildbucket/swarming/test/swarmingcfg_test.py

 
 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from components import config as config_component
 from testing_utils import testing
 
 from proto import project_config_pb2
 from test import config_test
@@ skipping 168 matching lines @@
         common_dimensions=['pool:default'],
         common_recipe=Swarming.Recipe(
             repository='https://x.com',
             name='foo',
             properties=['a:b', 'x:y'],
         ),
         builders=[
           Swarming.Builder(name='debug'),
           Swarming.Builder(
               name='release',
-              recipe=Swarming.Recipe(properties=['a:c'], properties_j=['x:']),
+              recipe=Swarming.Recipe(
+                  properties=['a:c'],
+                  properties_j=['x:null']),
           ),
         ],
     )
     self.cfg_test(cfg, [])
 
   def test_common_recipe_bad(self):
     cfg = Swarming(
         hostname='chromium-swarm.appspot.com',
         common_dimensions=['pool:default'],
         common_recipe=Swarming.Recipe(
             name='foo',
             properties=['a'],
         ),
         builders=[
           Swarming.Builder(name='debug'),
         ],
     )
     self.cfg_test(cfg, [
       'builder_defaults: recipe: properties #1: does not have colon',
     ])