Allow passing explicit connection to '_PropertyMixin.{reload,patch}'.

See #825.

gcloud/storage/_helpers.py

@@ -52,12 +52,20 @@ def __init__(self, name=None):
         self._properties = {}
         self._changes = set()
 
-    def reload(self):
-        """Reload properties from Cloud Storage."""
+    def reload(self, connection=None):
+        """Reload properties from Cloud Storage.
+
+        :type connection: :class:`gcloud.storage.connection.Connection`
+        :param connection: An explicit connection to use for the API request.
+                           If not passed, use the connection assigned to
+                           the object in its constructor.
+        """
+        if connection is None:
+            connection = self.connection
         # Pass only '?projection=noAcl' here because 'acl' and related
         # are handled via custom endpoints.
         query_params = {'projection': 'noAcl'}
-        api_response = self.connection.api_request(
+        api_response = connection.api_request(
             method='GET', path=self.path, query_params=query_params)
         self._set_properties(api_response)
 
@@ -89,16 +97,23 @@ def _set_properties(self, value):
         # If the values are reset, the changes must as well.
         self._changes = set()
 
-    def patch(self):
+    def patch(self, connection=None):
         """Sends all changed properties in a PATCH request.
 
         Updates the ``_properties`` with the response from the backend.
+
+        :type connection: :class:`gcloud.storage.connection.Connection`
+        :param connection: An explicit connection to use for the API request.
+                           If not passed, use the connection assigned to
+                           the object in its constructor.
         """
+        if connection is None:
+            connection = self.connection
         # Pass '?projection=full' here because 'PATCH' documented not
         # to work properly w/ 'noAcl'.
         update_properties = dict((key, self._properties[key])
                                  for key in self._changes)
-        api_response = self.connection.api_request(
+        api_response = connection.api_request(
             method='PATCH', path=self.path, data=update_properties,
             query_params={'projection': 'full'})
         self._set_properties(api_response)

gcloud/storage/test__helpers.py

@@ -61,6 +61,21 @@ def test_reload(self):
         # Make sure changes get reset by reload.
         self.assertEqual(derived._changes, set())
 
+    def test_reload_w_explicit_connection(self):
+        connection = _Connection({'foo': 'Foo'})
+        derived = self._derivedClass(None, '/path')()
+        # Make sure changes is not a set, so we can observe a change.
+        derived._changes = object()
+        derived.reload(connection)
+        self.assertEqual(derived._properties, {'foo': 'Foo'})
+        kw = connection._requested
+        self.assertEqual(len(kw), 1)
+        self.assertEqual(kw[0]['method'], 'GET')
+        self.assertEqual(kw[0]['path'], '/path')
+        self.assertEqual(kw[0]['query_params'], {'projection': 'noAcl'})
+        # Make sure changes get reset by reload.
+        self.assertEqual(derived._changes, set())
+
     def test__patch_property(self):
         derived = self._derivedClass()()
         derived._patch_property('foo', 'Foo')
@@ -86,6 +101,26 @@ def test_patch(self):
         # Make sure changes get reset by patch().
         self.assertEqual(derived._changes, set())
 
+    def test_patch_w_explicit_connection(self):
+        connection = _Connection({'foo': 'Foo'})
+        derived = self._derivedClass(None, '/path')()
+        # Make sure changes is non-empty, so we can observe a change.
+        BAR = object()
+        BAZ = object()
+        derived._properties = {'bar': BAR, 'baz': BAZ}
+        derived._changes = set(['bar'])  # Ignore baz.
+        derived.patch(connection)
+        self.assertEqual(derived._properties, {'foo': 'Foo'})
+        kw = connection._requested
+        self.assertEqual(len(kw), 1)
+        self.assertEqual(kw[0]['method'], 'PATCH')
+        self.assertEqual(kw[0]['path'], '/path')
+        self.assertEqual(kw[0]['query_params'], {'projection': 'full'})
+        # Since changes does not include `baz`, we don't see it sent.
+        self.assertEqual(kw[0]['data'], {'bar': BAR})
+        # Make sure changes get reset by patch().
+        self.assertEqual(derived._changes, set())
+
 
 class Test__scalar_property(unittest2.TestCase):