Make DBPersistence.data setter in sycn with getter + tests

redash/models/__init__.py

@@ -232,19 +232,23 @@ class DataSourceGroup(db.Model):
     __tablename__ = "data_source_groups"
 
 
+DESERIALIZED_DATA_ATTR = '_deserialized_data'
+
 class DBPersistence(object):
     @property
     def data(self):
         if self._data is None:
             return None
-
-        if not hasattr(self, '_deserialized_data'):
-            self._deserialized_data = json_loads(self._data)
+        
+        if not hasattr(self, DESERIALIZED_DATA_ATTR):
+            setattr(self, DESERIALIZED_DATA_ATTR, json_loads(self._data))
 
         return self._deserialized_data
 
     @data.setter
     def data(self, data):
+        if hasattr(self, DESERIALIZED_DATA_ATTR):
+            delattr(self, DESERIALIZED_DATA_ATTR)
         self._data = data
 
 

tests/models/test_query_results.py

@@ -1,9 +1,12 @@
 #encoding: utf8
 import datetime
 
+from unittest import TestCase
 from tests import BaseTestCase
+from mock import patch
 
 from redash import models
+from redash.models import DBPersistence
 from redash.utils import utcnow, json_dumps
 
 
@@ -66,4 +69,23 @@ def test_store_result_does_not_modify_query_update_at(self):
 
         models.QueryResult.store_result(query.org_id, query.data_source, query.query_hash, query.query_text, "", 0, utcnow())
 
-        self.assertEqual(original_updated_at, query.updated_at)
+        self.assertEqual(original_updated_at, query.updated_at)
+
+
+class TestDBPersistence(TestCase):
+    def test_updating_data_removes_cached_result(self):
+        p = DBPersistence()
+        p.data = '{"test": 1}'
+        self.assertDictEqual(p.data, {"test": 1})
+        p.data = '{"test": 2}'
+        self.assertDictEqual(p.data, {"test": 2})
+
+    @patch('redash.models.json_loads')
+    def test_calls_json_loads_only_once(self, json_loads_patch):
+        json_loads_patch.return_value = '1'
+        p = DBPersistence()
+        json_data = '{"test": 1}'
+        p.data = json_data
+        a = p.data
+        b = p.data
+        json_loads_patch.assert_called_once_with(json_data)