Adding _DEFAULTS stubs in all tests that use it.

Introduces
- concept of `implicit` for `_DefaultsContainer`.
- testing module for datastore for patching

Verified all test cases that would accidentally rely on _DEFAULTS implicit
behavior by using a custom `_DefaultsContainer` that raises when the
instance is implicit.

Main delta for the custom properties:

diff --git a/gcloud/datastore/_implicit_environ.py b/gcloud/datastore/_implicit_environ.py
index 3afc954..1d38562 100644
--- a/gcloud/datastore/_implicit_environ.py
+++ b/gcloud/datastore/_implicit_environ.py
@@ -38,9 +38,37 @@ class _DefaultsContainer(object):
     :param dataset_id: Persistent implied dataset ID from environment.
     """

-    def __init__(self, connection=None, dataset_id=None):
-        self.connection = connection
-        self.dataset_id = dataset_id
+    class FooError(Exception):
+        pass
+
+    @Property
+    def dataset_id(self):
+        if self.implicit:
+            raise self.FooError
+        return self._dataset_id
+
+    @dataset_id.setter
+    def dataset_id(self, value):
+        if self.implicit:
+            raise self.FooError
+        self._dataset_id = value
+
+    @Property
+    def connection(self):
+        if self.implicit:
+            raise self.FooError
+        return self._connection
+
+    @connection.setter
+    def connection(self, value):
+        if self.implicit:
+            raise self.FooError
+        self._connection = value
+
+    def __init__(self, connection=None, dataset_id=None, implicit=False):
+        self.implicit = implicit
+        self._connection = connection
+        self._dataset_id = dataset_id

 def app_engine_id():

gcloud/datastore/_implicit_environ.py

@@ -38,7 +38,8 @@ class _DefaultsContainer(object):
     :param dataset_id: Persistent implied dataset ID from environment.
     """
 
-    def __init__(self, connection=None, dataset_id=None):
+    def __init__(self, connection=None, dataset_id=None, implicit=False):
+        self.implicit = implicit
         self.connection = connection
         self.dataset_id = dataset_id
 
@@ -107,4 +108,4 @@ def get_default_dataset_id():
     return _DEFAULTS.dataset_id
 
 
-_DEFAULTS = _DefaultsContainer()
+_DEFAULTS = _DefaultsContainer(implicit=True)

gcloud/datastore/_testing.py

@@ -0,0 +1,33 @@
+# Copyright 2014 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Shared datastore testing utilities."""
+
+from gcloud._testing import _Monkey
+from gcloud.datastore import _implicit_environ
+from gcloud.datastore._implicit_environ import _DefaultsContainer
+
+
+def _monkey_defaults(*args, **kwargs):
+    mock_defaults = _DefaultsContainer(*args, **kwargs)
+    return _Monkey(_implicit_environ, _DEFAULTS=mock_defaults)
+
+
+def _setup_defaults(test_case):
+    test_case._replaced_defaults = _implicit_environ._DEFAULTS
+    _implicit_environ._DEFAULTS = _DefaultsContainer()
+
+
+def _tear_down_defaults(test_case):
+    _implicit_environ._DEFAULTS = test_case._replaced_defaults

gcloud/datastore/test___init__.py

@@ -18,14 +18,12 @@
 class Test_set_default_dataset_id(unittest2.TestCase):
 
     def setUp(self):
-        from gcloud.datastore import _implicit_environ
-        self._replaced_defaults = _implicit_environ._DEFAULTS
-        _implicit_environ._DEFAULTS = _implicit_environ._DefaultsContainer(
-            None, None)
+        from gcloud.datastore._testing import _setup_defaults
+        _setup_defaults(self)
 
     def tearDown(self):
-        from gcloud.datastore import _implicit_environ
-        _implicit_environ._DEFAULTS = self._replaced_defaults
+        from gcloud.datastore._testing import _tear_down_defaults
+        _tear_down_defaults(self)
 
     def _callFUT(self, dataset_id=None):
         from gcloud.datastore import set_default_dataset_id
@@ -280,14 +278,12 @@ def test_set_implicit_three_env_appengine_and_compute(self):
 class Test_set_default_connection(unittest2.TestCase):
 
     def setUp(self):
-        from gcloud.datastore import _implicit_environ
-        self._replaced_defaults = _implicit_environ._DEFAULTS
-        _implicit_environ._DEFAULTS = _implicit_environ._DefaultsContainer(
-            None, None)
+        from gcloud.datastore._testing import _setup_defaults
+        _setup_defaults(self)
 
     def tearDown(self):
-        from gcloud.datastore import _implicit_environ
-        _implicit_environ._DEFAULTS = self._replaced_defaults
+        from gcloud.datastore._testing import _tear_down_defaults
+        _tear_down_defaults(self)
 
     def _callFUT(self, connection=None):
         from gcloud.datastore import set_default_connection

gcloud/datastore/test__implicit_environ.py

@@ -17,6 +17,14 @@
 
 class Test_get_default_connection(unittest2.TestCase):
 
+    def setUp(self):
+        from gcloud.datastore._testing import _setup_defaults
+        _setup_defaults(self)
+
+    def tearDown(self):
+        from gcloud.datastore._testing import _tear_down_defaults
+        _tear_down_defaults(self)
+
     def _callFUT(self):
         from gcloud.datastore._implicit_environ import get_default_connection
         return get_default_connection()
@@ -25,17 +33,23 @@ def test_default(self):
         self.assertEqual(self._callFUT(), None)
 
     def test_preset(self):
-        from gcloud._testing import _Monkey
-        from gcloud.datastore import _implicit_environ
+        from gcloud.datastore._testing import _monkey_defaults
 
         SENTINEL = object()
-        MOCK_DEFAULTS = _implicit_environ._DefaultsContainer(SENTINEL, None)
-        with _Monkey(_implicit_environ, _DEFAULTS=MOCK_DEFAULTS):
+        with _monkey_defaults(connection=SENTINEL):
             self.assertEqual(self._callFUT(), SENTINEL)
 
 
 class Test_get_default_dataset_id(unittest2.TestCase):
 
+    def setUp(self):
+        from gcloud.datastore._testing import _setup_defaults
+        _setup_defaults(self)
+
+    def tearDown(self):
+        from gcloud.datastore._testing import _tear_down_defaults
+        _tear_down_defaults(self)
+
     def _callFUT(self):
         from gcloud.datastore._implicit_environ import get_default_dataset_id
         return get_default_dataset_id()
@@ -44,10 +58,8 @@ def test_default(self):
         self.assertEqual(self._callFUT(), None)
 
     def test_preset(self):
-        from gcloud._testing import _Monkey
-        from gcloud.datastore import _implicit_environ
+        from gcloud.datastore._testing import _monkey_defaults
 
         SENTINEL = object()
-        MOCK_DEFAULTS = _implicit_environ._DefaultsContainer(None, SENTINEL)
-        with _Monkey(_implicit_environ, _DEFAULTS=MOCK_DEFAULTS):
+        with _monkey_defaults(dataset_id=SENTINEL):
             self.assertEqual(self._callFUT(), SENTINEL)

gcloud/datastore/test_api.py

@@ -26,10 +26,8 @@ def _callFUT(self, passed=_MARKER, first_key=None):
         return _require_dataset_id(dataset_id=passed, first_key=first_key)
 
     def _monkey(self, dataset_id):
-        from gcloud.datastore import _implicit_environ
-        from gcloud._testing import _Monkey
-        MOCK_DEFAULTS = _implicit_environ._DefaultsContainer(None, dataset_id)
-        return _Monkey(_implicit_environ, _DEFAULTS=MOCK_DEFAULTS)
+        from gcloud.datastore._testing import _monkey_defaults
+        return _monkey_defaults(dataset_id=dataset_id)
 
     def test_implicit_unset_wo_keys(self):
         with self._monkey(None):
@@ -121,10 +119,8 @@ def _callFUT(self, passed=_MARKER):
         return _require_connection(passed)
 
     def _monkey(self, connection):
-        from gcloud.datastore import _implicit_environ
-        from gcloud._testing import _Monkey
-        MOCK_DEFAULTS = _implicit_environ._DefaultsContainer(connection, None)
-        return _Monkey(_implicit_environ, _DEFAULTS=MOCK_DEFAULTS)
+        from gcloud.datastore._testing import _monkey_defaults
+        return _monkey_defaults(connection=connection)
 
     def test_implicit_unset(self):
         with self._monkey(None):
@@ -164,6 +160,14 @@ def test_implicit_set_passed_explicitly(self):
 
 class Test_get_function(unittest2.TestCase):
 
+    def setUp(self):
+        from gcloud.datastore._testing import _setup_defaults
+        _setup_defaults(self)
+
+    def tearDown(self):
+        from gcloud.datastore._testing import _tear_down_defaults
+        _tear_down_defaults(self)
+
     def _callFUT(self, keys, missing=None, deferred=None,
                  connection=None, dataset_id=None):
         from gcloud.datastore.api import get
@@ -455,10 +459,9 @@ def test_hit_multiple_keys_different_dataset(self):
                           dataset_id=DATASET_ID1)
 
     def test_implicit_wo_transaction(self):
-        from gcloud.datastore import _implicit_environ
+        from gcloud.datastore._testing import _monkey_defaults
         from gcloud.datastore.key import Key
         from gcloud.datastore.test_connection import _Connection
-        from gcloud._testing import _Monkey
 
         DATASET_ID = 'DATASET'
         KIND = 'Kind'
@@ -473,9 +476,8 @@ def test_implicit_wo_transaction(self):
         CUSTOM_CONNECTION = _Connection(entity_pb)
 
         key = Key(KIND, ID, dataset_id=DATASET_ID)
-        MOCK_DEFAULTS = _implicit_environ._DefaultsContainer(CUSTOM_CONNECTION,
-                                                             DATASET_ID)
-        with _Monkey(_implicit_environ, _DEFAULTS=MOCK_DEFAULTS):
+        with _monkey_defaults(connection=CUSTOM_CONNECTION,
+                              dataset_id=DATASET_ID):
             result, = self._callFUT([key])
 
         expected_called_with = {
@@ -566,6 +568,14 @@ def test_max_loops(self):
 
 class Test_put_function(unittest2.TestCase):
 
+    def setUp(self):
+        from gcloud.datastore._testing import _setup_defaults
+        _setup_defaults(self)
+
+    def tearDown(self):
+        from gcloud.datastore._testing import _tear_down_defaults
+        _tear_down_defaults(self)
+
     def _callFUT(self, entities, connection=None, dataset_id=None):
         from gcloud.datastore.api import put
         return put(entities, connection=connection, dataset_id=dataset_id)
@@ -668,8 +678,7 @@ def test_existing_batch_w_completed_key(self):
         self.assertEqual(len(CURR_BATCH.mutation.delete), 0)
 
     def test_implicit_connection(self):
-        from gcloud._testing import _Monkey
-        from gcloud.datastore import _implicit_environ
+        from gcloud.datastore._testing import _monkey_defaults
         from gcloud.datastore.test_batch import _Connection
         from gcloud.datastore.test_batch import _Entity
         from gcloud.datastore.test_batch import _Key
@@ -680,8 +689,7 @@ def test_implicit_connection(self):
         entity = _Entity(foo=u'bar')
         key = entity.key = _Key(_DATASET)
 
-        MOCK_DEFAULTS = _implicit_environ._DefaultsContainer(connection, None)
-        with _Monkey(_implicit_environ, _DEFAULTS=MOCK_DEFAULTS):
+        with _monkey_defaults(connection=connection):
             # Set up Batch on stack so we can check it is used.
             with _NoCommitBatch(_DATASET, connection) as CURR_BATCH:
                 result = self._callFUT([entity])
@@ -700,6 +708,14 @@ def test_implicit_connection(self):
 
 class Test_delete_function(unittest2.TestCase):
 
+    def setUp(self):
+        from gcloud.datastore._testing import _setup_defaults
+        _setup_defaults(self)
+
+    def tearDown(self):
+        from gcloud.datastore._testing import _tear_down_defaults
+        _tear_down_defaults(self)
+
     def _callFUT(self, keys, connection=None, dataset_id=None):
         from gcloud.datastore.api import delete
         return delete(keys, connection=connection, dataset_id=dataset_id)
@@ -761,8 +777,7 @@ def test_no_batch(self):
         self.assertEqual(list(mutation.delete), [key.to_protobuf()])
 
     def test_wo_batch_w_key_different_than_default_dataset_id(self):
-        from gcloud._testing import _Monkey
-        from gcloud.datastore import _implicit_environ
+        from gcloud.datastore._testing import _monkey_defaults
         from gcloud.datastore.test_batch import _Connection
         from gcloud.datastore.test_batch import _Key
 
@@ -772,9 +787,8 @@ def test_wo_batch_w_key_different_than_default_dataset_id(self):
         connection = _Connection()
         key = _Key(_DATASET)
 
-        MOCK_DEFAULTS = _implicit_environ._DefaultsContainer(connection,
-                                                             _DEFAULT_DATASET)
-        with _Monkey(_implicit_environ, _DEFAULTS=MOCK_DEFAULTS):
+        with _monkey_defaults(connection=connection,
+                              dataset_id=_DEFAULT_DATASET):
             result = self._callFUT([key])
         self.assertEqual(result, None)
         self.assertEqual(len(connection._committed), 1)
@@ -825,8 +839,7 @@ def test_w_existing_transaction(self):
         self.assertEqual(len(connection._committed), 0)
 
     def test_implicit_connection_and_dataset_id(self):
-        from gcloud._testing import _Monkey
-        from gcloud.datastore import _implicit_environ
+        from gcloud.datastore._testing import _monkey_defaults
         from gcloud.datastore.test_batch import _Connection
         from gcloud.datastore.test_batch import _Key
 
@@ -835,9 +848,7 @@ def test_implicit_connection_and_dataset_id(self):
         connection = _Connection()
         key = _Key(_DATASET)
 
-        MOCK_DEFAULTS = _implicit_environ._DefaultsContainer(connection,
-                                                             _DATASET)
-        with _Monkey(_implicit_environ, _DEFAULTS=MOCK_DEFAULTS):
+        with _monkey_defaults(connection=connection, dataset_id=_DATASET):
             # Set up Batch on stack so we can check it is used.
             with _NoCommitBatch(_DATASET, connection) as CURR_BATCH:
                 result = self._callFUT([key])
@@ -875,32 +886,28 @@ def test_w_explicit_connection(self):
         self.assertEqual(len(CONNECTION._called_key_pbs), NUM_IDS)
 
     def test_w_implicit_connection(self):
-        from gcloud.datastore import _implicit_environ
+        from gcloud.datastore._testing import _monkey_defaults
         from gcloud.datastore.key import Key
         from gcloud.datastore.test_connection import _Connection
-        from gcloud._testing import _Monkey
 
         CUSTOM_CONNECTION = _Connection()
         NUM_IDS = 2
-        MOCK_DEFAULTS = _implicit_environ._DefaultsContainer(CUSTOM_CONNECTION,
-                                                             'DATASET')
-        with _Monkey(_implicit_environ, _DEFAULTS=MOCK_DEFAULTS):
+        with _monkey_defaults(connection=CUSTOM_CONNECTION,
+                              dataset_id='DATASET'):
             INCOMPLETE_KEY = Key('KIND')
             result = self._callFUT(INCOMPLETE_KEY, NUM_IDS)
 
         # Check the IDs returned.
         self.assertEqual([key.id for key in result], list(range(NUM_IDS)))
 
     def test_with_already_completed_key(self):
-        from gcloud.datastore import _implicit_environ
+        from gcloud.datastore._testing import _monkey_defaults
         from gcloud.datastore.key import Key
         from gcloud.datastore.test_connection import _Connection
-        from gcloud._testing import _Monkey
 
         CUSTOM_CONNECTION = _Connection()
-        MOCK_DEFAULTS = _implicit_environ._DefaultsContainer(CUSTOM_CONNECTION,
-                                                             'DATASET')
-        with _Monkey(_implicit_environ, _DEFAULTS=MOCK_DEFAULTS):
+        with _monkey_defaults(connection=CUSTOM_CONNECTION,
+                              dataset_id='DATASET'):
             COMPLETE_KEY = Key('KIND', 1234)
             self.assertRaises(ValueError, self._callFUT,
                               COMPLETE_KEY, 2)

gcloud/datastore/test_batch.py

@@ -27,11 +27,9 @@ def _makeOne(self, dataset_id=None, connection=None):
                                       connection=connection)
 
     def test_ctor_missing_required(self):
-        from gcloud._testing import _Monkey
-        from gcloud.datastore import _implicit_environ
+        from gcloud.datastore._testing import _monkey_defaults
 
-        MOCK_DEFAULTS = _implicit_environ._DefaultsContainer(None, None)
-        with _Monkey(_implicit_environ, _DEFAULTS=MOCK_DEFAULTS):
+        with _monkey_defaults():
             self.assertRaises(ValueError, self._makeOne)
             self.assertRaises(ValueError, self._makeOne, dataset_id=object())
             self.assertRaises(ValueError, self._makeOne, connection=object())
@@ -48,15 +46,12 @@ def test_ctor_explicit(self):
         self.assertEqual(batch._auto_id_entities, [])
 
     def test_ctor_implicit(self):
-        from gcloud._testing import _Monkey
-        from gcloud.datastore import _implicit_environ
+        from gcloud.datastore._testing import _monkey_defaults
         from gcloud.datastore._datastore_v1_pb2 import Mutation
         _DATASET = 'DATASET'
         CONNECTION = _Connection()
 
-        MOCK_DEFAULTS = _implicit_environ._DefaultsContainer(CONNECTION,
-                                                             _DATASET)
-        with _Monkey(_implicit_environ, _DEFAULTS=MOCK_DEFAULTS):
+        with _monkey_defaults(connection=CONNECTION, dataset_id=_DATASET):
             batch = self._makeOne()
 
         self.assertEqual(batch.dataset_id, _DATASET)

gcloud/datastore/test_entity.py

@@ -22,14 +22,12 @@
 class TestEntity(unittest2.TestCase):
 
     def setUp(self):
-        from gcloud.datastore import _implicit_environ
-        self._replaced_defaults = _implicit_environ._DEFAULTS
-        _implicit_environ._DEFAULTS = _implicit_environ._DefaultsContainer(
-            None, None)
+        from gcloud.datastore._testing import _setup_defaults
+        _setup_defaults(self)
 
     def tearDown(self):
-        from gcloud.datastore import _implicit_environ
-        _implicit_environ._DEFAULTS = self._replaced_defaults
+        from gcloud.datastore._testing import _tear_down_defaults
+        _tear_down_defaults(self)
 
     def _getTargetClass(self):
         from gcloud.datastore.entity import Entity