chore: replace utcnow() with now(timezone.utc) and fix test collection

- Replaces deprecated datetime.utcnow() with timezone-aware datetime.now(timezone.utc).
- Renames MockCredentials and MockClass to avoid pytest/unittest collection warnings.

Author: aseering

google/cloud/spanner_v1/pool.py

@@ -35,7 +35,8 @@
 
 from google.cloud.spanner_v1.metrics.metrics_capture import MetricsCapture
 
-_NOW = datetime.datetime.utcnow  # unit tests may replace
+def _NOW():
+    return datetime.datetime.now(datetime.timezone.utc)  # unit tests may replace
 
 
 class AbstractSessionPool(object):

google/cloud/spanner_v1/session.py

@@ -16,7 +16,7 @@
 
 from functools import total_ordering
 import time
-from datetime import datetime
+from datetime import datetime, timezone
 from typing import MutableMapping, Optional
 
 from google.api_core.exceptions import Aborted
@@ -80,7 +80,7 @@ def __init__(self, database, labels=None, database_role=None, is_multiplexed=Fal
         self._labels: MutableMapping[str, str] = labels
         self._database_role: Optional[str] = database_role
         self._is_multiplexed: bool = is_multiplexed
-        self._last_use_time: datetime = datetime.utcnow()
+        self._last_use_time: datetime = datetime.now(timezone.utc)
 
     def __lt__(self, other):
         return self._session_id < other._session_id

tests/system/test_dbapi.py

@@ -1482,7 +1482,7 @@ def test_read_only_dml(self):
     def test_staleness(self):
         """Check the DB API `staleness` option."""
 
-        before_insert = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        before_insert = datetime.datetime.now(UTC)
         time.sleep(0.25)
 
         self._cursor.execute(

tests/system/test_session_api.py

@@ -1749,7 +1749,7 @@ def test_snapshot_read_w_various_staleness(sessions_database):
     committed = _set_up_table(sessions_database, row_count)
     all_data_rows = list(_row_data(row_count))
 
-    before_reads = datetime.datetime.utcnow().replace(tzinfo=UTC)
+    before_reads = datetime.datetime.now(UTC)
 
     # Test w/ read timestamp
     with sessions_database.snapshot(read_timestamp=committed) as read_tx:
@@ -1761,7 +1761,7 @@ def test_snapshot_read_w_various_staleness(sessions_database):
         rows = list(min_read_ts.read(sd.TABLE, sd.COLUMNS, sd.ALL))
         sd._check_row_data(rows, all_data_rows)
 
-    staleness = datetime.datetime.utcnow().replace(tzinfo=UTC) - before_reads
+    staleness = datetime.datetime.now(UTC) - before_reads
 
     # Test w/ max staleness
     with sessions_database.snapshot(max_staleness=staleness) as max_staleness:

tests/unit/test__helpers.py

@@ -868,7 +868,7 @@ def test(self):
 
 
 class Test_retry(unittest.TestCase):
-    class test_class:
+    class MockClass:
         def test_fxn(self):
             return True
 
@@ -877,7 +877,7 @@ def test_retry_on_error(self):
         from google.cloud.spanner_v1._helpers import _retry
         import functools
 
-        test_api = mock.create_autospec(self.test_class)
+        test_api = mock.create_autospec(self.MockClass)
         test_api.test_fxn.side_effect = [
             InternalServerError("testing"),
             NotFound("testing"),
@@ -893,7 +893,7 @@ def test_retry_allowed_exceptions(self):
         from google.cloud.spanner_v1._helpers import _retry
         import functools
 
-        test_api = mock.create_autospec(self.test_class)
+        test_api = mock.create_autospec(self.MockClass)
         test_api.test_fxn.side_effect = [
             NotFound("testing"),
             InternalServerError("testing"),
@@ -914,7 +914,7 @@ def test_retry_count(self):
         from google.cloud.spanner_v1._helpers import _retry
         import functools
 
-        test_api = mock.create_autospec(self.test_class)
+        test_api = mock.create_autospec(self.MockClass)
         test_api.test_fxn.side_effect = [
             InternalServerError("testing"),
             InternalServerError("testing"),
@@ -930,7 +930,7 @@ def test_check_rst_stream_error(self):
         from google.cloud.spanner_v1._helpers import _retry, _check_rst_stream_error
         import functools
 
-        test_api = mock.create_autospec(self.test_class)
+        test_api = mock.create_autospec(self.MockClass)
         test_api.test_fxn.side_effect = [
             InternalServerError("Received unexpected EOS on DATA frame from server"),
             InternalServerError("RST_STREAM"),
@@ -951,7 +951,7 @@ def test_retry_on_aborted_exception_with_success_after_first_aborted_retry(self)
         from google.cloud.spanner_v1._helpers import _retry_on_aborted_exception
         import functools
 
-        test_api = mock.create_autospec(self.test_class)
+        test_api = mock.create_autospec(self.MockClass)
         test_api.test_fxn.side_effect = [
             Aborted("aborted exception", errors=("Aborted error")),
             "true",
@@ -970,7 +970,7 @@ def test_retry_on_aborted_exception_with_success_after_three_retries(self):
         from google.cloud.spanner_v1._helpers import _retry_on_aborted_exception
         import functools
 
-        test_api = mock.create_autospec(self.test_class)
+        test_api = mock.create_autospec(self.MockClass)
         # Case where aborted exception is thrown after other generic exceptions
         aborted = Aborted("aborted exception", errors=["Aborted error"])
         test_api.test_fxn.side_effect = [
@@ -994,7 +994,7 @@ def test_retry_on_aborted_exception_raises_aborted_if_deadline_expires(self):
         from google.cloud.spanner_v1._helpers import _retry_on_aborted_exception
         import functools
 
-        test_api = mock.create_autospec(self.test_class)
+        test_api = mock.create_autospec(self.MockClass)
         test_api.test_fxn.side_effect = [
             Aborted("aborted exception", errors=("Aborted error")),
             "true",

tests/unit/test_backup.py

@@ -36,7 +36,7 @@ def _make_timestamp():
         import datetime
         from google.cloud._helpers import UTC
 
-        return datetime.datetime.utcnow().replace(tzinfo=UTC)
+        return datetime.datetime.now(UTC)
 
 
 class TestBackup(_BaseTest):
@@ -357,8 +357,7 @@ def test_create_success(self):
         api.create_backup.return_value = op_future
 
         instance = _Instance(self.INSTANCE_NAME, client=client)
-        version_timestamp = datetime.utcnow() - timedelta(minutes=5)
-        version_timestamp = version_timestamp.replace(tzinfo=timezone.utc)
+        version_timestamp = datetime.now(timezone.utc) - timedelta(minutes=5)
         expire_timestamp = self._make_timestamp()
         encryption_config = {"encryption_type": 3, "kms_key_name": "key_name"}
         backup = self._make_one(

tests/unit/test_batch.py

@@ -238,7 +238,7 @@ def test_commit_grpc_error(self, mock_region):
         return_value="global",
     )
     def test_commit_ok(self, mock_region):
-        now = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        now = datetime.datetime.now(UTC)
         now_pb = _datetime_to_pb_timestamp(now)
         response = CommitResponse(commit_timestamp=now_pb)
         database = _Database()
@@ -321,7 +321,7 @@ def _test_commit_with_options(
         isolation_level=TransactionOptions.IsolationLevel.ISOLATION_LEVEL_UNSPECIFIED,
         read_lock_mode=TransactionOptions.ReadWrite.ReadLockMode.READ_LOCK_MODE_UNSPECIFIED,
     ):
-        now = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        now = datetime.datetime.now(UTC)
         now_pb = _datetime_to_pb_timestamp(now)
         response = CommitResponse(commit_timestamp=now_pb)
         database = _Database()
@@ -513,7 +513,7 @@ def test_commit_w_isolation_level_and_read_lock_mode(self, mock_region):
         return_value="global",
     )
     def test_context_mgr_already_committed(self, mock_region):
-        now = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        now = datetime.datetime.now(UTC)
         database = _Database()
         api = database.spanner_api = _FauxSpannerAPI()
         session = _Session(database)
@@ -531,7 +531,7 @@ def test_context_mgr_already_committed(self, mock_region):
         return_value="global",
     )
     def test_context_mgr_success(self, mock_region):
-        now = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        now = datetime.datetime.now(UTC)
         now_pb = _datetime_to_pb_timestamp(now)
         response = CommitResponse(commit_timestamp=now_pb)
         database = _Database()
@@ -582,7 +582,7 @@ def test_context_mgr_success(self, mock_region):
         return_value="global",
     )
     def test_context_mgr_failure(self, mock_region):
-        now = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        now = datetime.datetime.now(UTC)
         now_pb = _datetime_to_pb_timestamp(now)
         response = CommitResponse(commit_timestamp=now_pb)
         database = _Database()
@@ -671,7 +671,7 @@ def _test_batch_write_with_request_options(
         exclude_txn_from_change_streams=False,
         enable_end_to_end_tracing=False,
     ):
-        now = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        now = datetime.datetime.now(UTC)
         now_pb = _datetime_to_pb_timestamp(now)
         status_pb = Status(code=200)
         response = BatchWriteResponse(

tests/unit/test_database.py

@@ -91,7 +91,7 @@ def _make_timestamp():
         import datetime
         from google.cloud._helpers import UTC
 
-        return datetime.datetime.utcnow().replace(tzinfo=UTC)
+        return datetime.datetime.now(UTC)
 
     @staticmethod
     def _make_duration(seconds=1, microseconds=0):
@@ -1580,7 +1580,7 @@ def test_snapshot_w_read_timestamp_and_multi_use(self):
         from google.cloud.spanner_v1.database import SnapshotCheckout
         from google.cloud.spanner_v1.snapshot import Snapshot
 
-        now = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        now = datetime.datetime.now(UTC)
         client = _Client()
         instance = _Instance(self.INSTANCE_NAME, client=client)
         pool = _Pool()
@@ -2155,7 +2155,7 @@ def test_context_mgr_success(self):
         from google.cloud._helpers import _datetime_to_pb_timestamp
         from google.cloud.spanner_v1.batch import Batch
 
-        now = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        now = datetime.datetime.now(UTC)
         now_pb = _datetime_to_pb_timestamp(now)
         response = CommitResponse(commit_timestamp=now_pb)
         database = _Database(self.DATABASE_NAME)
@@ -2206,7 +2206,7 @@ def test_context_mgr_w_commit_stats_success(self):
         from google.cloud._helpers import _datetime_to_pb_timestamp
         from google.cloud.spanner_v1.batch import Batch
 
-        now = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        now = datetime.datetime.now(UTC)
         now_pb = _datetime_to_pb_timestamp(now)
         commit_stats = CommitResponse.CommitStats(mutation_count=4)
         response = CommitResponse(commit_timestamp=now_pb, commit_stats=commit_stats)
@@ -2358,7 +2358,7 @@ def test_ctor_w_read_timestamp_and_multi_use(self):
         from google.cloud._helpers import UTC
         from google.cloud.spanner_v1.snapshot import Snapshot
 
-        now = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        now = datetime.datetime.now(UTC)
         database = _Database(self.DATABASE_NAME)
         session = _Session(database)
         pool = database._pool = _Pool()
@@ -3358,7 +3358,7 @@ def test_context_mgr_success(self):
         from google.cloud.spanner_v1.batch import MutationGroups
         from google.rpc.status_pb2 import Status
 
-        now = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        now = datetime.datetime.now(UTC)
         now_pb = _datetime_to_pb_timestamp(now)
         status_pb = Status(code=200)
         response = BatchWriteResponse(

tests/unit/test_instance.py

@@ -680,7 +680,7 @@ def test_backup_factory_explicit(self):
         instance = self._make_one(self.INSTANCE_ID, client, self.CONFIG_NAME)
         BACKUP_ID = "backup-id"
         DATABASE_NAME = "database-name"
-        timestamp = datetime.datetime.utcnow().replace(tzinfo=UTC)
+        timestamp = datetime.datetime.now(UTC)
         encryption_config = CreateBackupEncryptionConfig(
             encryption_type=CreateBackupEncryptionConfig.EncryptionType.CUSTOMER_MANAGED_ENCRYPTION,
             kms_key_name="kms_key_name",

tests/unit/test_metrics.py

@@ -1,4 +1,4 @@
-# Copyright 2025 Google LLC
+# Copyright 2025 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -31,7 +31,7 @@
 # pytest.importorskip("opentelemetry.semconv.attributes.otel_attributes")
 
 
-class TestCredentials(Credentials):
+class MockCredentials(Credentials):
     @property
     def expired(self):
         return False
@@ -60,12 +60,23 @@ def patched_client(monkeypatch):
     if SpannerMetricsTracerFactory._metrics_tracer_factory is not None:
         SpannerMetricsTracerFactory._metrics_tracer_factory = None
 
-    client = Client(
-        project="test",
-        credentials=TestCredentials(),
-        # client_options={"api_endpoint": "none"}
-    )
-    yield client
+    # Reset the global flag to ensure metrics initialization runs
+    from google.cloud.spanner_v1 import client as client_module
+
+    client_module._metrics_monitor_initialized = False
+
+    with patch(
+        "google.cloud.spanner_v1.metrics.metrics_exporter.MetricServiceClient"
+    ), patch(
+        "google.cloud.spanner_v1.metrics.metrics_exporter.CloudMonitoringMetricsExporter"
+    ), patch(
+        "opentelemetry.sdk.metrics.export.PeriodicExportingMetricReader"
+    ):
+        client = Client(
+            project="test",
+            credentials=MockCredentials(),
+        )
+        yield client
 
     # Resetting
     metrics.set_meter_provider(metrics.NoOpMeterProvider())