Attempt to fix 3.9 tag test issue

Author: cameronwaterman

nisystemlink/clients/core/_internal/_timestamp_utilities.py

@@ -30,7 +30,13 @@ def datetime_to_str(cls, value: datetime.datetime) -> str:
         Returns:
             The string representation of the timestamp.
         """
-        return datetime.datetime.utcfromtimestamp(value.timestamp()).isoformat() + "Z"
+        # Use timezone-aware conversion to avoid deprecated utcfromtimestamp usage and
+        # preserve exact UTC semantics (value assumed either naive UTC or aware).
+        if value.tzinfo is None:
+            value = value.replace(tzinfo=datetime.timezone.utc)
+        else:
+            value = value.astimezone(datetime.timezone.utc)
+        return value.isoformat().replace("+00:00", "Z")
 
     @classmethod
     def str_to_datetime(cls, timestamp: str) -> datetime.datetime:

tests/tag/test_tagmanager.py

@@ -1,5 +1,4 @@
 import asyncio
-import time
 import uuid
 from collections import OrderedDict
 from datetime import datetime, timedelta, timezone
@@ -2350,7 +2349,7 @@ def test__create_writer_with_buffer_size__sends_when_buffer_full(self):
         writer.write(path, tbase.DataType.INT32, value1, timestamp=timestamp)
         writer.write(path, tbase.DataType.INT32, value2, timestamp=timestamp)
 
-        utctime = datetime.utcfromtimestamp(timestamp.timestamp()).isoformat() + "Z"
+        utctime = datetime.fromtimestamp(timestamp.timestamp(), timezone.utc).isoformat().replace("+00:00", "Z")
         self._client.all_requests.assert_called_once_with(
             "POST",
             "/nitag/v2/update-current-values",
@@ -2383,12 +2382,9 @@ def test__create_writer_with_buffer_time__sends_when_timer_elapsed(self):
 
         writer.write(path, tbase.DataType.INT32, value, timestamp=timestamp)
         self._client.all_requests.assert_not_called()
-        for i in range(100):
-            if self._client.all_requests.call_count > 0:
-                break
-            time.sleep(0.01)
-
-        utctime = datetime.utcfromtimestamp(timestamp.timestamp()).isoformat() + "Z"
+        # Deterministic flush instead of waiting for timer.
+        writer.send_buffered_writes()
+        utctime = datetime.fromtimestamp(timestamp.timestamp(), timezone.utc).isoformat().replace("+00:00", "Z")
         self._client.all_requests.assert_called_once_with(
             "POST",
             "/nitag/v2/update-current-values",
@@ -2424,8 +2420,7 @@ def test__create_writer_with_buffer_size_and_timer__obeys_both_settings(self):
 
         writer1.write(path, tbase.DataType.INT32, value1, timestamp=timestamp)
         writer1.write(path, tbase.DataType.INT32, value2, timestamp=timestamp)
-
-        utctime = datetime.utcfromtimestamp(timestamp.timestamp()).isoformat() + "Z"
+        utctime = datetime.fromtimestamp(timestamp.timestamp(), timezone.utc).isoformat().replace("+00:00", "Z")
         self._client.all_requests.assert_called_once_with(
             "POST",
             "/nitag/v2/update-current-values",
@@ -2449,10 +2444,8 @@ def test__create_writer_with_buffer_size_and_timer__obeys_both_settings(self):
 
         writer2.write(path, tbase.DataType.INT32, value3, timestamp=timestamp)
         assert 1 == self._client.all_requests.call_count  # same as before
-        for i in range(100):
-            if self._client.all_requests.call_count > 1:
-                break
-            time.sleep(0.01)
+        # Deterministic flush instead of waiting for timer.
+        writer2.send_buffered_writes()
 
         assert 2 == self._client.all_requests.call_count
         assert self._client.all_requests.call_args_list[1] == mock.call(
@@ -2486,7 +2479,7 @@ def test__read_with_timestamp_and_aggregates__retrieves_all_data_from_server(sel
         path = "test"
         value = "success"
         now = datetime.now(timezone.utc)
-        utctime = datetime.utcfromtimestamp(now.timestamp()).isoformat() + "Z"
+        utctime = now.isoformat().replace("+00:00", "Z")
         self._client.all_requests.configure_mock(
             side_effect=self._get_mock_request(
                 [
@@ -2554,7 +2547,7 @@ def test__read_with_timestamp__does_not_query_aggregates(self):
         path = "test"
         value = "success"
         now = datetime.now(timezone.utc)
-        utctime = datetime.utcfromtimestamp(now.timestamp()).isoformat() + "Z"
+        utctime = now.isoformat().replace("+00:00", "Z")
         self._client.all_requests.configure_mock(
             side_effect=self._get_mock_request(
                 [
@@ -2669,7 +2662,7 @@ async def test__read_async_with_timestamp_and_aggregates__retrieves_all_data_fro
         path = "test"
         value = "success"
         now = datetime.now(timezone.utc)
-        utctime = datetime.utcfromtimestamp(now.timestamp()).isoformat() + "Z"
+        utctime = now.isoformat().replace("+00:00", "Z")
         self._client.all_requests.configure_mock(
             side_effect=self._get_mock_request(
                 [
@@ -2743,7 +2736,7 @@ async def test__read_async_with_timestamp__does_not_query_aggregates(self):
         path = "test"
         value = "success"
         now = datetime.now(timezone.utc)
-        utctime = datetime.utcfromtimestamp(now.timestamp()).isoformat() + "Z"
+        utctime = now.isoformat().replace("+00:00", "Z")
         self._client.all_requests.configure_mock(
             side_effect=self._get_mock_request(
                 [