Add StableObjectJsonFixture and use it in our base test class

This will ensure that our object JSON is stable during unit tests.
Specifically, the changes field, which is listified from a set, which
can vary in order.

Closes-Bug: #1545177
Change-Id: Ib40ca16c41d5422c18f4fc7d658273a8059100ab

1 files changed, 14 insertions, 0 deletions

diff --git a/nova/tests/unit/test_fixtures.py b/nova/tests/unit/test_fixtures.py
index 16b87cea47..f0764fada5 100644
--- a/nova/tests/unit/test_fixtures.py
+++ b/nova/tests/unit/test_fixtures.py
@@ -331,3 +331,17 @@ class TestBannedDBSchemaOperations(testtools.TestCase):
                               table.drop)
             self.assertRaises(exception.DBNotAllowed,
                               table.alter)
+
+
+class TestStableObjectJsonFixture(testtools.TestCase):
+    def test_changes_sort(self):
+        class TestObject(obj_base.NovaObject):
+            def obj_what_changed(self):
+                return ['z', 'a']
+
+        obj = TestObject()
+        self.assertEqual(['z', 'a'],
+                         obj.obj_to_primitive()['nova_object.changes'])
+        with fixtures.StableObjectJsonFixture():
+            self.assertEqual(['a', 'z'],
+                             obj.obj_to_primitive()['nova_object.changes'])