rewrote test in a less resource intensive way

Author: wxtim

tests/conftest.py

@@ -208,10 +208,12 @@ def _call(*args, **kwargs):
 @pytest.fixture
 def set_nonexistent_timezone(monkeypatch):
     """Fixture to temporarily set a non-existent time zone."""
-    try:
+    def patch():
         with monkeypatch.context() as mp:
             mp.setenv('TZ', 'XXX-19:17')  # Set to a non-existent time zone
             time.tzset()
-            yield
+
+    try:
+        yield patch
     finally:
         time.tzset()  # Reset to the original time zone after the test

tests/integration/test_workflow_db_mgr.py

@@ -17,6 +17,7 @@
 from datetime import datetime, timedelta
 import pytest
 import sqlite3
+import time
 from typing import TYPE_CHECKING
 
 from cylc.flow import commands
@@ -185,19 +186,21 @@ async def test_time_zone_writing(
     one_conf,
     flow,
     scheduler,
-    run,
-    complete,
-    set_nonexistent_timezone,
+    start,
     db_select,
+    set_nonexistent_timezone
 ):
     """Don't store scheduler startup timezone forever.
 
     https://github.com/cylc/cylc-flow/issues/6701
     """
     wid = flow(one_conf)
     schd = scheduler(wid, paused_start=False, run_mode='live')
-    async with run(schd):
-        await complete(schd, timeout=20)
+    async with start(schd):
+        itask = schd.pool.get_tasks()[0]
+        schd.submit_task_jobs([itask])
+        set_nonexistent_timezone()
+        schd.task_events_mgr.process_message(itask, 'INFO', 'submitted')
 
     # Check the db time_submit (defective) against time_submit_exit
     # which was ok:

tests/unit/test_wallclock.py

@@ -70,5 +70,6 @@ def test_get_current_time_string(set_nonexistent_timezone):
 
     https://github.com/cylc/cylc-flow/issues/6701
     """
+    set_nonexistent_timezone()
     res = get_current_time_string()
     assert res[-6:] == '+19:17'