Use None instead of mutables in method params defaults

Mutables in the method params defaults might cause errors and
that's why it's anti-pattern in most of the cases and should be
removed.

Change-Id: I8bc284f12ce72082a0482410ec2c20c2fc087a4b
Closes-Bug: #1327473

contrib/extraroute/extraroute/tests/test_extraroute.py

@@ -68,7 +68,8 @@ class NeutronExtraRouteTest(HeatTestCase):
         resource._register_class("OS::Neutron::ExtraRoute",
                                  extraroute.ExtraRoute)
 
-    def create_extraroute(self, t, stack, resource_name, properties={}):
+    def create_extraroute(self, t, stack, resource_name, properties=None):
+        properties = properties or {}
         t['Resources'][resource_name]['Properties'] = properties
         rsrc = extraroute.ExtraRoute(
             resource_name,

contrib/rackspace/rackspace/tests/test_cloud_loadbalancer.py

@@ -51,7 +51,7 @@ class FakeManager(object):
     def find(self, *args, **kwargs):
         pass
 
-    def action(self, item, action_type, body={}):
+    def action(self, item, action_type, body=None):
         pass
 
 

heat/api/aws/utils.py

@@ -106,9 +106,11 @@ def get_param_value(params, key):
         raise exception.HeatMissingParameterError(key)
 
 
-def reformat_dict_keys(keymap={}, inputdict={}):
+def reformat_dict_keys(keymap=None, inputdict=None):
     '''
     Utility function for mapping one dict format to another
     '''
+    keymap = keymap or {}
+    inputdict = inputdict or {}
     return dict([(outk, inputdict[ink]) for ink, outk in keymap.items()
                 if ink in inputdict])

heat/api/cloudwatch/watch.py

@@ -183,13 +183,14 @@ class WatchController(object):
         """
         self._enforce(req, 'ListMetrics')
 
-        def format_metric_data(d, fil={}):
+        def format_metric_data(d, fil=None):
             """
             Reformat engine output into the AWS "Metric" format
             Takes an optional filter dict, which is traversed
             so a metric dict is only returned if all keys match
             the filter dict
             """
+            fil = fil or {}
             dimensions = [
                 {'AlarmName': d[engine_api.WATCH_DATA_ALARM]},
                 {'Timestamp': d[engine_api.WATCH_DATA_TIME]}

heat/api/openstack/v1/actions.py

@@ -34,12 +34,12 @@ class ActionController(object):
         self.rpc_client = rpc_client.EngineClient()
 
     @util.identified_stack
-    def action(self, req, identity, body={}):
+    def action(self, req, identity, body=None):
         """
         Performs a specified action on a stack, the body is expecting to
         contain exactly one item whose key specifies the action
         """
-
+        body = body or {}
         if len(body) < 1:
             raise exc.HTTPBadRequest(_("No action specified"))
 

heat/api/openstack/v1/resources.py

@@ -21,7 +21,8 @@ from heat.rpc import api as engine_api
 from heat.rpc import client as rpc_client
 
 
-def format_resource(req, res, keys=[]):
+def format_resource(req, res, keys=None):
+    keys = keys or []
     include_key = lambda k: k in keys if keys else True
 
     def transform(key, value):

heat/engine/constraints.py

@@ -80,7 +80,7 @@ class Schema(collections.Mapping):
 
     def __init__(self, data_type, description=None,
                  default=None, schema=None,
-                 required=False, constraints=[], label=None):
+                 required=False, constraints=None, label=None):
         self._len = None
         self.label = label
         self.type = data_type
@@ -108,7 +108,7 @@ class Schema(collections.Mapping):
                                                        utype=self.type)
             raise InvalidSchemaError(msg)
 
-        self.constraints = constraints
+        self.constraints = constraints or []
         self.default = default
 
     def validate(self, context=None):

heat/engine/dependencies.py

@@ -160,11 +160,12 @@ class Graph(collections.defaultdict):
 class Dependencies(object):
     '''Helper class for calculating a dependency graph.'''
 
-    def __init__(self, edges=[]):
+    def __init__(self, edges=None):
         '''
         Initialise, optionally with a list of edges, in the form of
         (requirer, required) tuples.
         '''
+        edges = edges or []
         self._graph = Graph()
         for e in edges:
             self += e

heat/engine/parameters.py

@@ -54,7 +54,7 @@ class Schema(constr.Schema):
     )
 
     def __init__(self, data_type, description=None, default=None, schema=None,
-                 constraints=[], hidden=False, label=None):
+                 constraints=None, hidden=False, label=None):
         super(Schema, self).__init__(data_type=data_type,
                                      description=description,
                                      default=default,
@@ -403,11 +403,13 @@ class Parameters(collections.Mapping):
         'AWS::StackId', 'AWS::StackName', 'AWS::Region'
     )
 
-    def __init__(self, stack_identifier, tmpl, user_params={}):
+    def __init__(self, stack_identifier, tmpl, user_params=None):
         '''
         Create the parameter container for a stack from the stack name and
         template, optionally setting the user-supplied parameter values.
         '''
+        user_params = user_params or {}
+
         def user_parameter(schema_item):
             name, schema = schema_item
             return Parameter(name, schema,

heat/engine/properties.py

@@ -50,7 +50,7 @@ class Schema(constr.Schema):
 
     def __init__(self, data_type, description=None,
                  default=None, schema=None,
-                 required=False, constraints=[],
+                 required=False, constraints=None,
                  implemented=True,
                  update_allowed=False,
                  support_status=support.SupportStatus()):

heat/engine/resource.py

@@ -264,12 +264,13 @@ class Resource(object):
         return identifier.ResourceIdentifier(resource_name=self.name,
                                              **self.stack.identifier())
 
-    def parsed_template(self, section=None, default={}):
+    def parsed_template(self, section=None, default=None):
         '''
         Return the parsed template data for the resource. May be limited to
         only one section of the data, in which case a default value may also
         be supplied.
         '''
+        default = default or {}
         if section is None:
             template = self.t
         else:

heat/engine/resources/autoscaling.py

@@ -386,7 +386,7 @@ class InstanceGroup(stack_resource.StackResource):
             # nodes.
             self._lb_reload()
 
-    def _lb_reload(self, exclude=[]):
+    def _lb_reload(self, exclude=None):
         '''
         Notify the LoadBalancer to reload its config to include
         the changes in instances we have just made.
@@ -394,6 +394,7 @@ class InstanceGroup(stack_resource.StackResource):
         This must be done after activation (instance in ACTIVE state),
         otherwise the instances' IP addresses may not be available.
         '''
+        exclude = exclude or []
         if self.properties[self.LOAD_BALANCER_NAMES]:
             id_list = [inst.FnGetRefId() for inst in self.get_instances()
                        if inst.FnGetRefId() not in exclude]

heat/engine/rsrc_defn.py

@@ -36,7 +36,7 @@ class ResourceDefinitionCore(object):
     )
 
     def __init__(self, name, resource_type, properties=None, metadata=None,
-                 depends=[], deletion_policy=None, update_policy=None,
+                 depends=None, deletion_policy=None, update_policy=None,
                  description=''):
         """
         Initialise with the parsed definition of a resource.
@@ -53,7 +53,7 @@ class ResourceDefinitionCore(object):
         :param update_policy: A dictionary of supplied update policies
         :param description: A string describing the resource
         """
-
+        depends = depends or []
         self.name = name
         self.resource_type = resource_type
         self.description = description

heat/engine/watchrule.py

@@ -48,7 +48,7 @@ class WatchRule(object):
     updated_at = timestamp.Timestamp(db_api.watch_rule_get, 'updated_at')
 
     def __init__(self, context, watch_name, rule, stack_id=None,
-                 state=NODATA, wid=None, watch_data=[],
+                 state=NODATA, wid=None, watch_data=None,
                  last_evaluated=timeutils.utcnow()):
         self.context = context
         self.now = timeutils.utcnow()
@@ -63,7 +63,7 @@ class WatchRule(object):
             period = int(rule['period'])
         self.timeperiod = datetime.timedelta(seconds=period)
         self.id = wid
-        self.watch_data = watch_data
+        self.watch_data = watch_data or []
         self.last_evaluated = last_evaluated
 
     @classmethod

heat/rpc/client.py

@@ -403,7 +403,10 @@ class EngineClient(object):
                                              config_id=config_id))
 
     def create_software_config(self, cnxt, group, name, config,
-                               inputs=[], outputs=[], options={}):
+                               inputs=None, outputs=None, options=None):
+        inputs = inputs or []
+        outputs = outputs or []
+        options = options or {}
         return self.call(cnxt, self.make_msg('create_software_config',
                                              group=group,
                                              name=name,
@@ -429,9 +432,10 @@ class EngineClient(object):
                                              deployment_id=deployment_id))
 
     def create_software_deployment(self, cnxt, server_id, config_id=None,
-                                   input_values={}, action='INIT',
+                                   input_values=None, action='INIT',
                                    status='COMPLETE', status_reason='',
                                    stack_user_project_id=None):
+        input_values = input_values or {}
         return self.call(cnxt, self.make_msg(
             'create_software_deployment',
             server_id=server_id,

heat/tests/test_api_cfn_v1.py

@@ -61,8 +61,9 @@ class CfnStackControllerTest(HeatTestCase):
                                                        'deny_stack_user.json')
         self.addCleanup(self.m.VerifyAll)
 
-    def _dummy_GET_request(self, params={}):
+    def _dummy_GET_request(self, params=None):
         # Mangle the params dict into a query string
+        params = params or {}
         qs = "&".join(["=".join([k, str(params[k])]) for k in params])
         environ = {'REQUEST_METHOD': 'GET', 'QUERY_STRING': qs}
         req = Request(environ)

heat/tests/test_api_cloudwatch.py

@@ -31,8 +31,9 @@ class WatchControllerTest(HeatTestCase):
     the endpoint processing API requests after they are routed
     '''
 
-    def _dummy_GET_request(self, params={}):
+    def _dummy_GET_request(self, params=None):
         # Mangle the params dict into a query string
+        params = params or {}
         qs = "&".join(["=".join([k, str(params[k])]) for k in params])
         environ = {'REQUEST_METHOD': 'GET', 'QUERY_STRING': qs}
         req = Request(environ)

heat/tests/test_api_ec2token.py

@@ -33,8 +33,10 @@ class Ec2TokenTest(HeatTestCase):
         super(Ec2TokenTest, self).setUp()
         self.m.StubOutWithMock(requests, 'post')
 
-    def _dummy_GET_request(self, params={}, environ={}):
+    def _dummy_GET_request(self, params=None, environ=None):
         # Mangle the params dict into a query string
+        params = params or {}
+        environ = environ or {}
         qs = "&".join(["=".join([k, str(params[k])]) for k in params])
         environ.update({'REQUEST_METHOD': 'GET', 'QUERY_STRING': qs})
         req = Request(environ)
@@ -179,9 +181,12 @@ class Ec2TokenTest(HeatTestCase):
         ec2 = ec2token.EC2Token(app='xyz', conf={})
         self.assertEqual('xyz', ec2.__call__(dummy_req))
 
-    def _stub_http_connection(self, headers={}, params={}, response=None,
+    def _stub_http_connection(self, headers=None, params=None, response=None,
                               req_url='http://123:5000/v2.0/ec2tokens'):
 
+        headers = headers or {}
+        params = params or {}
+
         class DummyHTTPResponse(object):
             text = response
 

heat/tests/test_api_openstack_v1.py

@@ -2612,7 +2612,9 @@ class EventControllerTest(ControllerTest, HeatTestCase):
 
 class RoutesTest(HeatTestCase):
 
-    def assertRoute(self, mapper, path, method, action, controller, params={}):
+    def assertRoute(self, mapper, path, method, action, controller,
+                    params=None):
+        params = params or {}
         route = mapper.match(path, {'REQUEST_METHOD': method})
         self.assertIsNotNone(route)
         self.assertEqual(action, route['action'])

heat/tests/test_autoscaling.py

@@ -185,7 +185,8 @@ class AutoScalingTest(HeatTestCase):
         instance.Instance.check_delete_complete(
             task).MultipleTimes().AndReturn(True)
 
-    def _stub_suspend(self, cookies=[], with_error=None):
+    def _stub_suspend(self, cookies=None, with_error=None):
+        cookies = cookies or []
         self.m.StubOutWithMock(instance.Instance, 'handle_suspend')
         self.m.StubOutWithMock(instance.Instance, 'check_suspend_complete')
         if with_error:
@@ -200,7 +201,8 @@ class AutoScalingTest(HeatTestCase):
             instance.Instance.check_suspend_complete(
                 cookie).InAnyOrder().AndReturn(True)
 
-    def _stub_resume(self, cookies=[], with_error=None):
+    def _stub_resume(self, cookies=None, with_error=None):
+        cookies = cookies or []
         self.m.StubOutWithMock(instance.Instance, 'handle_resume')
         self.m.StubOutWithMock(instance.Instance, 'check_resume_complete')
         if with_error:

heat/tests/test_engine_service.py

@@ -2622,7 +2622,10 @@ class SoftwareConfigServiceTest(HeatTestCase):
 
     def _create_software_config(
             self, group='Heat::Shell', name='config_mysql', config=None,
-            inputs=[], outputs=[], options={}):
+            inputs=None, outputs=None, options=None):
+        inputs = inputs or []
+        outputs = outputs or []
+        options = options or {}
         return self.engine.create_software_config(
             self.ctx, group, name, config, inputs, outputs, options)
 
@@ -2674,13 +2677,14 @@ class SoftwareConfigServiceTest(HeatTestCase):
                                self.ctx, config_id)
         self.assertEqual(ex.exc_info[0], exception.NotFound)
 
-    def _create_software_deployment(self, config_id=None, input_values={},
+    def _create_software_deployment(self, config_id=None, input_values=None,
                                     action='INIT',
                                     status='COMPLETE', status_reason='',
                                     config_group=None,
                                     server_id=str(uuid.uuid4()),
                                     config_name=None,
                                     stack_user_project_id=None):
+        input_values = input_values or {}
         if config_id is None:
             config = self._create_software_config(group=config_group,
                                                   name=config_name)

heat/tests/test_heatclient.py

@@ -889,8 +889,9 @@ class KeystoneClientTest(HeatTestCase):
                           user_id='duser123', project_id='aproject',
                           credential_id='acredentialid')
 
-    def _stub_uuid(self, values=[]):
+    def _stub_uuid(self, values=None):
         # stub UUID.hex to return the values specified
+        values = values or []
         self.m.StubOutWithMock(uuid, 'uuid4')
         for v in values:
             mock_uuid = self.m.CreateMockAnything()

heat/tests/test_metadata_refresh.py

@@ -136,7 +136,8 @@ class MetadataRefreshTest(HeatTestCase):
 
     # Note tests creating a stack should be decorated with @stack_delete_after
     # to ensure the stack is properly cleaned up
-    def create_stack(self, stack_name='test_stack', params={}):
+    def create_stack(self, stack_name='test_stack', params=None):
+        params = params or {}
         temp = template_format.parse(test_template_metadata)
         template = parser.Template(temp)
         ctx = utils.dummy_context()

heat/tests/test_multi_part.py

@@ -30,7 +30,8 @@ class MultipartMimeTest(HeatTestCase):
         self.ctx = utils.dummy_context()
         self.init_config()
 
-    def init_config(self, parts=[]):
+    def init_config(self, parts=None):
+        parts = parts or []
         stack = parser.Stack(
             self.ctx, 'software_config_test_stack',
             template.Template({

heat/tests/test_neutron.py

@@ -1169,7 +1169,9 @@ class NeutronRouterTest(HeatTestCase):
         self.assertEqual((rsrc.CREATE, rsrc.COMPLETE), rsrc.state)
         return rsrc
 
-    def create_router_interface(self, t, stack, resource_name, properties={}):
+    def create_router_interface(self, t, stack, resource_name,
+                                properties=None):
+        properties = properties or {}
         t['Resources'][resource_name]['Properties'] = properties
         resource_defns = stack.t.resource_definitions(stack)
         rsrc = router.RouterInterface(
@@ -1180,7 +1182,8 @@ class NeutronRouterTest(HeatTestCase):
         self.assertEqual((rsrc.CREATE, rsrc.COMPLETE), rsrc.state)
         return rsrc
 
-    def create_gateway_router(self, t, stack, resource_name, properties={}):
+    def create_gateway_router(self, t, stack, resource_name, properties=None):
+        properties = properties or {}
         t['Resources'][resource_name]['Properties'] = properties
         resource_defns = stack.t.resource_definitions(stack)
         rsrc = router.RouterGateway(

heat/tests/test_neutron_security_group.py

@@ -116,7 +116,8 @@ Resources:
         stack.store()
         return stack
 
-    def assertResourceState(self, rsrc, ref_id, metadata={}):
+    def assertResourceState(self, rsrc, ref_id, metadata=None):
+        metadata = metadata or {}
         self.assertIsNone(rsrc.validate())
         self.assertEqual((rsrc.CREATE, rsrc.COMPLETE), rsrc.state)
         self.assertEqual(ref_id, rsrc.FnGetRefId())

heat/tests/test_parameters.py

@@ -361,8 +361,9 @@ params_schema = json.loads('''{
 
 
 class ParametersTest(testtools.TestCase):
-    def new_parameters(self, stack_name, tmpl, user_params={}, stack_id=None,
-                       validate_value=True):
+    def new_parameters(self, stack_name, tmpl, user_params=None,
+                       stack_id=None, validate_value=True):
+        user_params = user_params or {}
         tmpl.update({'HeatTemplateFormatVersion': '2012-12-12'})
         tmpl = template.Template(tmpl)
         params = tmpl.parameters(

heat/tests/test_security_group.py

@@ -156,7 +156,8 @@ Resources:
         stack.store()
         return stack
 
-    def assertResourceState(self, rsrc, ref_id, metadata={}):
+    def assertResourceState(self, rsrc, ref_id, metadata=None):
+        metadata = metadata or {}
         self.assertIsNone(rsrc.validate())
         self.assertEqual((rsrc.CREATE, rsrc.COMPLETE), rsrc.state)
         self.assertEqual(ref_id, rsrc.FnGetRefId())

heat/tests/test_waitcondition.py

@@ -109,8 +109,9 @@ class WaitConditionTest(HeatTestCase):
     # Note tests creating a stack should be decorated with @stack_delete_after
     # to ensure the stack is properly cleaned up
     def create_stack(self, stack_id=None,
-                     template=test_template_waitcondition, params={},
+                     template=test_template_waitcondition, params=None,
                      stub=True):
+        params = params or {}
         temp = template_format.parse(template)
         template = parser.Template(temp)
         ctx = utils.dummy_context(tenant_id='test_tenant')

heat/tests/utils.py

@@ -65,7 +65,8 @@ def reset_dummy_db():
 
 
 def dummy_context(user='test_username', tenant_id='test_tenant_id',
-                  password='password', roles=[], user_id=None):
+                  password='password', roles=None, user_id=None):
+    roles = roles or []
     return context.RequestContext.from_dict({
         'tenant_id': tenant_id,
         'tenant': 'test_tenant',
@@ -79,8 +80,9 @@ def dummy_context(user='test_username', tenant_id='test_tenant_id',
     })
 
 
-def parse_stack(t, params={}, stack_name='test_stack', stack_id=None,
+def parse_stack(t, params=None, stack_name='test_stack', stack_id=None,
                 timeout_mins=None):
+    params = params or {}
     ctx = dummy_context()
     template = parser.Template(t)
     stack = parser.Stack(ctx, stack_name, template,