Fix mutable defaults in tests

Some test methods have mutables objects as default types. It
potentially can lead to unpredictable errors in tests and it is
considered as bad practice in python. So the patch replaces these
defaults with None and introduces default values in method body.

Change-Id: If523d8ddfb4c176ad2ba81c15858b78bbd89c80b

glance/common/jsonpatchvalidator.py

@@ -34,7 +34,9 @@ class JsonPatchValidatorMixin(object):
     ALLOWED = ["replace", "test", "remove", "add", "copy"]
     PATH_REGEX_COMPILED = re.compile("^/[^/]+(/[^/]+)*$")
 
-    def __init__(self, methods_allowed=["replace", "remove"]):
+    def __init__(self, methods_allowed=None):
+        if methods_allowed is None:
+            methods_allowed = ["replace", "remove"]
         self.schema = self._gen_schema(methods_allowed)
         self.methods_allowed = [m for m in methods_allowed
                                 if m in self.ALLOWED]

glance/db/registry/api.py

@@ -604,8 +604,10 @@ def artifact_get(client, artifact_id,
 
 @_get_client
 def artifact_get_all(client, marker=None, limit=None, sort_key=None,
-                     sort_dir=None, filters={},
+                     sort_dir=None, filters=None,
                      show_level=artifacts.Showlevel.NONE, session=None):
+    if filters is None:
+        filters = {}
     return client.artifact_create(marker, limit, sort_key,
                                   sort_dir, filters, show_level)
 

glance/tests/functional/artifacts/test_artifacts.py

@@ -235,7 +235,10 @@ paste.filter_factory = glance.tests.utils:FakeAuthMiddleware.factory
         return response.text
 
     def _check_artifact_post(self, url, data, status=201,
-                             headers={'Content-Type': 'application/json'}):
+                             headers=None):
+        if headers is None:
+            headers = {'Content-Type': 'application/json'}
+
         return self._check_artifact_method("post", url, data, status=status,
                                            headers=headers)
 

glance/tests/unit/test_cache_middleware.py

@@ -29,7 +29,9 @@ from glance.tests.unit import utils as unit_test_utils
 
 
 class ImageStub(object):
-    def __init__(self, image_id, extra_properties={}, visibility='private'):
+    def __init__(self, image_id, extra_properties=None, visibility='private'):
+        if extra_properties is None:
+            extra_properties = {}
         self.image_id = image_id
         self.visibility = visibility
         self.status = 'active'

glance/tests/unit/test_jsonpatchmixin.py

@@ -19,7 +19,10 @@ import glance.tests.utils as utils
 
 
 class TestValidator(jpv.JsonPatchValidatorMixin):
-    def __init__(self, methods_allowed=["replace", "add"]):
+    def __init__(self, methods_allowed=None):
+        if methods_allowed is None:
+            methods_allowed = ["replace", "add"]
+
         super(TestValidator, self).__init__(methods_allowed)
 
 

glance/tests/unit/utils.py

@@ -64,7 +64,10 @@ def sort_url_by_qs_keys(url):
 
 
 def get_fake_request(path='', method='POST', is_admin=False, user=USER1,
-                     roles=['member'], tenant=TENANT1):
+                     roles=None, tenant=TENANT1):
+    if roles is None:
+            roles = ['member']
+
     req = wsgi.Request.blank(path)
     req.method = method
 

glance/tests/unit/v2/test_image_actions_resource.py

@@ -71,8 +71,11 @@ class TestImageActionsController(base.IsolatedUnitTest):
         self.controller.gateway.store_utils = self.store_utils
         store.create_stores()
 
-    def _get_fake_context(self, user=USER1, tenant=TENANT1, roles=['member'],
+    def _get_fake_context(self, user=USER1, tenant=TENANT1, roles=None,
                           is_admin=False):
+        if roles is None:
+            roles = ['member']
+
         kwargs = {
             'user': user,
             'tenant': tenant,