feat: User provided client (#311)

* chore: auto-release

* feat:pass client object direcrly

* read me

* read me

* read me

* changes

Author: asthamohta

README.rst

@@ -76,6 +76,15 @@ on this step in a dialect prefix part:
    # for SQLAlchemy 1.4:
    spanner+spanner:///projects/project-id/instances/instance-id/databases/database-id
 
+To pass your custom client object directly to be be used, create engine as following:
+
+.. code:: python
+
+    engine = create_engine(
+        "spanner+spanner:///projects/project-id/instances/instance-id/databases/database-id",
+        connect_args={'client': spanner.Client(project="project-id")}
+    )
+
 Create a table
 ~~~~~~~~~~~~~~
 

test/_helpers.py

@@ -71,6 +71,10 @@ def use_test_ot_exporter():
     _TEST_OT_PROVIDER_INITIALIZED = True
 
 
+def get_project():
+    return PROJECT
+
+
 class OpenTelemetryBase(fixtures.TestBase):
     @classmethod
     def setup_class(cls):

test/test_suite_13.py

@@ -24,7 +24,7 @@
 import time
 from unittest import mock
 
-from google.cloud.spanner_v1 import RequestOptions
+from google.cloud.spanner_v1 import RequestOptions, Client
 
 import sqlalchemy
 from sqlalchemy import create_engine
@@ -120,7 +120,7 @@
     UnicodeVarcharTest as _UnicodeVarcharTest,
     UnicodeTextTest as _UnicodeTextTest,
 )
-from test._helpers import get_db_url
+from test._helpers import get_db_url, get_project
 
 config.test_schema = ""
 
@@ -1961,3 +1961,30 @@ def test_round_trip_none_as_json_null(self):
     )
     def test_round_trip_none_as_sql_null(self):
         pass
+
+
+class CreateEngineWithClientObjectTest(fixtures.TestBase):
+    def test_create_engine_w_valid_client_object(self):
+        """
+        SPANNER TEST:
+
+        Check that we can connect to SqlAlchemy
+        by passing custom Client object.
+        """
+        client = Client(project=get_project())
+        engine = create_engine(get_db_url(), connect_args={"client": client})
+        with engine.connect() as connection:
+            assert connection.connection.instance._client == client
+
+    def test_create_engine_w_invalid_client_object(self):
+        """
+        SPANNER TEST:
+
+        Check that if project id in url and custom Client
+        Object passed to enginer mismatch, error is thrown.
+        """
+        client = Client(project="project_id")
+        engine = create_engine(get_db_url(), connect_args={"client": client})
+
+        with pytest.raises(ValueError):
+            engine.connect()

test/test_suite_14.py

@@ -24,7 +24,7 @@
 import time
 from unittest import mock
 
-from google.cloud.spanner_v1 import RequestOptions
+from google.cloud.spanner_v1 import RequestOptions, Client
 
 import sqlalchemy
 from sqlalchemy import create_engine
@@ -134,7 +134,7 @@
     UnicodeTextTest as _UnicodeTextTest,
     _UnicodeFixture as __UnicodeFixture,
 )
-from test._helpers import get_db_url
+from test._helpers import get_db_url, get_project
 
 config.test_schema = ""
 
@@ -2193,3 +2193,30 @@ def test_request_priority(self):
         engine = create_engine("sqlite:///database")
         with engine.connect() as connection:
             pass
+
+
+class CreateEngineWithClientObjectTest(fixtures.TestBase):
+    def test_create_engine_w_valid_client_object(self):
+        """
+        SPANNER TEST:
+
+        Check that we can connect to SqlAlchemy
+        by passing custom Client object.
+        """
+        client = Client(project=get_project())
+        engine = create_engine(get_db_url(), connect_args={"client": client})
+        with engine.connect() as connection:
+            assert connection.connection.instance._client == client
+
+    def test_create_engine_w_invalid_client_object(self):
+        """
+        SPANNER TEST:
+
+        Check that if project id in url and custom Client
+        Object passed to enginer mismatch, error is thrown.
+        """
+        client = Client(project="project_id")
+        engine = create_engine(get_db_url(), connect_args={"client": client})
+
+        with pytest.raises(ValueError):
+            engine.connect()