test(spanner): upgrade Spanner sample instance fixtures to session scope

Previously, standard and multi-region Spanner instance fixtures in
conftest.py were module-scoped, meaning a brand-new Spanner instance
was created and destroyed for every single test file, adding massive
execution time (~2 minutes per file) in CI/CD runs.

This change upgrades the instance and config fixtures to session scope.
To prevent ScopeMismatch exceptions, the dependencies on module-scoped
sample_name are replaced with a generic shared-samples label. This
allows the test suite to reuse a single shared Spanner instance,
dramatically optimizing test execution times.

Author: sakthivelmanii

packages/google-cloud-spanner/samples/samples/archived/backup_snippet_test.py

@@ -18,12 +18,6 @@
 from google.api_core.exceptions import DeadlineExceeded
 from test_utils.retry import RetryErrors
 
-
-@pytest.fixture(scope="module")
-def sample_name():
-    return "backup"
-
-
 def unique_database_id():
     """Creates a unique id for the database."""
     return f"test-db-{uuid.uuid4().hex[:10]}"

packages/google-cloud-spanner/samples/samples/archived/pg_samples_test.py

@@ -45,11 +45,6 @@
 retry_429 = RetryErrors(exceptions.ResourceExhausted, delay=15)
 
 
-@pytest.fixture(scope="module")
-def sample_name():
-    return "pg_snippets"
-
-
 @pytest.fixture(scope="module")
 def database_dialect():
     """Spanner dialect to be used for this sample.

packages/google-cloud-spanner/samples/samples/archived/samples_test.py

@@ -53,11 +53,6 @@
 retry_429 = RetryErrors(exceptions.ResourceExhausted, delay=15)
 
 
-@pytest.fixture(scope="module")
-def sample_name():
-    return "snippets"
-
-
 @pytest.fixture(scope="module")
 def database_dialect():
     """Spanner dialect to be used for this sample.

packages/google-cloud-spanner/samples/samples/autocommit_test.py

@@ -11,11 +11,6 @@
 import autocommit
 
 
-@pytest.fixture(scope="module")
-def sample_name():
-    return "autocommit"
-
-
 @RetryErrors(exception=Aborted, max_tries=2)
 def test_enable_autocommit_mode(capsys, instance_id, sample_database):
     # Delete table if it exists for retry attempts.

packages/google-cloud-spanner/samples/samples/backup_sample_test.py

@@ -20,11 +20,6 @@
 import backup_sample
 
 
-@pytest.fixture(scope="module")
-def sample_name():
-    return "backup"
-
-
 def unique_database_id():
     """Creates a unique id for the database."""
     return f"test-db-{uuid.uuid4().hex[:10]}"

packages/google-cloud-spanner/samples/samples/backup_schedule_samples_test.py

@@ -22,11 +22,6 @@
 __INCREMENTAL_BACKUP_SCHEDULE_ID = "incremental-backup-schedule"
 
 
-@pytest.fixture(scope="module")
-def sample_name():
-    return "backup_schedule"
-
-
 @pytest.fixture(scope="module")
 def database_id():
     return f"test-db-{uuid.uuid4().hex[:10]}"

packages/google-cloud-spanner/samples/samples/conftest.py

@@ -33,17 +33,6 @@
     (exceptions.ResourceExhausted, exceptions.FailedPrecondition), max_tries=6, delay=15
 )
 
-
-@pytest.fixture(scope="module")
-def sample_name():
-    """Sample testcase modules must define this fixture.
-
-    The name is used to label the instance created by the sample, to
-    aid in debugging leaked instances.
-    """
-    raise NotImplementedError("Define 'sample_name' fixture in sample test driver")
-
-
 @pytest.fixture(scope="module")
 def database_dialect():
     """Database dialect to be used for this sample.
@@ -99,31 +88,31 @@ def cleanup_old_instances(spanner_client):
                 scrub_instance_ignore_not_found(inst)
 
 
-@pytest.fixture(scope="module")
+@pytest.fixture(scope="session")
 def instance_id():
     """Unique id for the instance used in samples."""
     return f"test-instance-{uuid.uuid4().hex[:10]}"
 
 
-@pytest.fixture(scope="module")
+@pytest.fixture(scope="session")
 def multi_region_instance_id():
     """Unique id for the multi-region instance used in samples."""
     return f"multi-instance-{uuid.uuid4().hex[:10]}"
 
 
-@pytest.fixture(scope="module")
+@pytest.fixture(scope="session")
 def instance_config(spanner_client):
     return "{}/instanceConfigs/{}".format(
         spanner_client.project_name, "regional-us-central1"
     )
 
 
-@pytest.fixture(scope="module")
+@pytest.fixture(scope="session")
 def multi_region_instance_config(spanner_client):
     return "{}/instanceConfigs/{}".format(spanner_client.project_name, "nam3")
 
 
-@pytest.fixture(scope="module")
+@pytest.fixture(scope="session")
 def proto_descriptor_file():
     import os
 
@@ -134,13 +123,12 @@ def proto_descriptor_file():
     file.close()
 
 
-@pytest.fixture(scope="module")
+@pytest.fixture(scope="session")
 def sample_instance(
     spanner_client,
     cleanup_old_instances,
     instance_id,
     instance_config,
-    sample_name,
 ):
     operation = spanner_client.instance_admin_api.create_instance(
         parent=spanner_client.project_name,
@@ -151,7 +139,7 @@ def sample_instance(
             node_count=1,
             labels={
                 "cloud_spanner_samples": "true",
-                "sample_name": sample_name,
+                "sample_name": "shared-samples",
                 "created": str(int(time.time())),
             },
             edition=spanner_instance_admin.Instance.Edition.ENTERPRISE_PLUS,  # Optional
@@ -170,20 +158,19 @@ def sample_instance(
     scrub_instance_ignore_not_found(sample_instance)
 
 
-@pytest.fixture(scope="module")
+@pytest.fixture(scope="session")
 def multi_region_instance(
     spanner_client,
     cleanup_old_instances,
     multi_region_instance_id,
     multi_region_instance_config,
-    sample_name,
 ):
     multi_region_instance = spanner_client.instance(
         multi_region_instance_id,
         multi_region_instance_config,
         labels={
             "cloud_spanner_samples": "true",
-            "sample_name": sample_name,
+            "sample_name": "shared-samples",
             "created": str(int(time.time())),
         },
     )
@@ -205,7 +192,7 @@ def database_id():
 
     Sample testcase modules can override as needed.
     """
-    return "my-database-id"
+    return f"my-db-{uuid.uuid4().hex[:10]}"
 
 
 @pytest.fixture(scope="module")

packages/google-cloud-spanner/samples/samples/graph_snippets_test.py

@@ -80,12 +80,6 @@
                     LABEL Transfers)
 """
 
-
-@pytest.fixture(scope="module")
-def sample_name():
-    return "snippets"
-
-
 @pytest.fixture(scope="module")
 def database_dialect():
     """Spanner dialect to be used for this sample.

packages/google-cloud-spanner/samples/samples/pg_snippets_test.py

@@ -46,11 +46,6 @@
 retry_429 = RetryErrors(exceptions.ResourceExhausted, delay=15)
 
 
-@pytest.fixture(scope="module")
-def sample_name():
-    return "pg_snippets"
-
-
 @pytest.fixture(scope="module")
 def database_dialect():
     """Spanner dialect to be used for this sample.

packages/google-cloud-spanner/samples/samples/quickstart_test.py

@@ -17,11 +17,6 @@
 import quickstart
 
 
-@pytest.fixture(scope="module")
-def sample_name():
-    return "quickstart"
-
-
 def test_quickstart(capsys, instance_id, sample_database):
     quickstart.run_quickstart(instance_id, sample_database.database_id)
     out, _ = capsys.readouterr()