feat: autocommit sample (#172)

* feat: autocommit sample

* remove unused imports

* Remove samples/samples init

* No package-relative imports in samples

* fix check errors, rename test file

* move ResultsChecksum() to test

* use connection.Cursor in patch

* Apply suggestions from code review

Co-authored-by: Chris Kleinknecht <libc@google.com>

* Update samples/samples/autocommit_test.py

Co-authored-by: Chris Kleinknecht <libc@google.com>

* lint fix

Co-authored-by: Chris Kleinknecht <libc@google.com>
Co-authored-by: Alex <7764119+AVaksman@users.noreply.github.com>
Co-authored-by: Ilya Gurov <ilya.faer@mail.ru>
Co-authored-by: larkee <31196561+larkee@users.noreply.github.com>

samples/samples/autocommit.py

@@ -0,0 +1,64 @@
+# Copyright 2020 Google LLC
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+import argparse
+
+from google.cloud.spanner_dbapi import connect
+
+
+def enable_autocommit_mode(instance_id, database_id):
+    """Enables autocommit mode."""
+    # [START spanner_enable_autocommit_mode]
+
+    connection = connect(instance_id, database_id)
+    connection.autocommit = True
+    print("Autocommit mode is enabled.")
+
+    cursor = connection.cursor()
+
+    cursor.execute(
+        """CREATE TABLE Singers (
+                SingerId     INT64 NOT NULL,
+                FirstName    STRING(1024),
+                LastName     STRING(1024),
+                SingerInfo   BYTES(MAX)
+            ) PRIMARY KEY (SingerId)"""
+    )
+
+    cursor.execute(
+        """INSERT INTO Singers (SingerId, FirstName, LastName) VALUES
+            (12, 'Melissa', 'Garcia'),
+            (13, 'Russell', 'Morales'),
+            (14, 'Jacqueline', 'Long'),
+            (15, 'Dylan', 'Shaw')"""
+    )
+
+    cursor.execute("""SELECT * FROM Singers WHERE SingerId = 13""")
+
+    print("SingerId: {}, AlbumId: {}, AlbumTitle: {}".format(*cursor.fetchone()))
+
+    connection.close()
+    # [END spanner_enable_autocommit_mode]
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description=__doc__,
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+    )
+    parser.add_argument("instance_id", help="Your Cloud Spanner instance ID.")
+    parser.add_argument(
+        "--database-id",
+        help="Your Cloud Spanner database ID.",
+        default="example_db",
+    )
+    subparsers = parser.add_subparsers(dest="command")
+    subparsers.add_parser("enable_autocommit_mode", help=enable_autocommit_mode.__doc__)
+    args = parser.parse_args()
+    if args.command == "enable_autocommit_mode":
+        enable_autocommit_mode(args.instance_id, args.database_id)
+    else:
+        print(f"Command {args.command} did not match expected commands.")

samples/samples/autocommit_test.py

@@ -0,0 +1,62 @@
+# Copyright 2020 Google LLC
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+import uuid
+
+from google.cloud import spanner
+from google.cloud.spanner_dbapi import connect
+import mock
+import pytest
+
+import autocommit
+
+
+def unique_instance_id():
+    """Creates a unique id for the database."""
+    return f"test-instance-{uuid.uuid4().hex[:10]}"
+
+
+def unique_database_id():
+    """Creates a unique id for the database."""
+    return f"test-db-{uuid.uuid4().hex[:10]}"
+
+
+INSTANCE_ID = unique_instance_id()
+DATABASE_ID = unique_database_id()
+
+
+@pytest.fixture(scope="module")
+def spanner_instance():
+    spanner_client = spanner.Client()
+    config_name = f"{spanner_client.project_name}/instanceConfigs/regional-us-central1"
+
+    instance = spanner_client.instance(INSTANCE_ID, config_name)
+    op = instance.create()
+    op.result(120)  # block until completion
+    yield instance
+    instance.delete()
+
+
+@pytest.fixture(scope="module")
+def database(spanner_instance):
+    """Creates a temporary database that is removed after testing."""
+    db = spanner_instance.database(DATABASE_ID)
+    db.create()
+    yield db
+    db.drop()
+
+
+def test_enable_autocommit_mode(capsys, database):
+    connection = connect(INSTANCE_ID, DATABASE_ID)
+    cursor = connection.cursor()
+
+    with mock.patch(
+        "google.cloud.spanner_dbapi.connection.Cursor", return_value=cursor,
+    ):
+        autocommit.enable_autocommit_mode(INSTANCE_ID, DATABASE_ID)
+        out, _ = capsys.readouterr()
+        assert "Autocommit mode is enabled." in out
+        assert "SingerId: 13, AlbumId: Russell, AlbumTitle: Morales" in out