Add missing transforms to 'google.cloud.firestore' shim. (#8481)

Add a unit test that asserts the shim stays in sync with
'google.cloud.firestore_v1'.

Closes #8173.

firestore/google/cloud/firestore.py

@@ -16,6 +16,8 @@
 
 
 from google.cloud.firestore_v1 import __version__
+from google.cloud.firestore_v1 import ArrayRemove
+from google.cloud.firestore_v1 import ArrayUnion
 from google.cloud.firestore_v1 import Client
 from google.cloud.firestore_v1 import CollectionReference
 from google.cloud.firestore_v1 import DELETE_FIELD
@@ -24,7 +26,10 @@
 from google.cloud.firestore_v1 import enums
 from google.cloud.firestore_v1 import ExistsOption
 from google.cloud.firestore_v1 import GeoPoint
+from google.cloud.firestore_v1 import Increment
 from google.cloud.firestore_v1 import LastUpdateOption
+from google.cloud.firestore_v1 import Maximum
+from google.cloud.firestore_v1 import Minimum
 from google.cloud.firestore_v1 import Query
 from google.cloud.firestore_v1 import ReadAfterWriteError
 from google.cloud.firestore_v1 import SERVER_TIMESTAMP
@@ -38,6 +43,8 @@
 
 __all__ = [
     "__version__",
+    "ArrayRemove",
+    "ArrayUnion",
     "Client",
     "CollectionReference",
     "DELETE_FIELD",
@@ -46,7 +53,10 @@
     "enums",
     "ExistsOption",
     "GeoPoint",
+    "Increment",
     "LastUpdateOption",
+    "Maximum",
+    "Minimum",
     "Query",
     "ReadAfterWriteError",
     "SERVER_TIMESTAMP",

firestore/tests/unit/test_firestore_shim.py

@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -*-
+# Copyright 2017 Google LLC 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.
+
+import unittest
+
+
+class TestFirestoreShim(unittest.TestCase):
+    def test_shim_matches_firestore_v1(self):
+        from google.cloud import firestore
+        from google.cloud import firestore_v1
+
+        self.assertEqual(firestore.__all__, firestore_v1.__all__)
+
+        for name in firestore.__all__:
+            found = getattr(firestore, name)
+            expected = getattr(firestore_v1, name)
+            self.assertIs(found, expected)