Integration tests: close DB on scheduler() fixture teardown

tests/integration/conftest.py

@@ -18,12 +18,11 @@
 import asyncio
 from functools import partial
 from pathlib import Path
+import pytest
 import re
 from shutil import rmtree
 from typing import List, TYPE_CHECKING
 
-import pytest
-
 from cylc.flow.cfgspec.glbl_cfg import glbl_cfg
 from cylc.flow.pathutil import get_workflow_run_dir
 from cylc.flow.wallclock import get_current_time_string
@@ -139,14 +138,24 @@ def flow(run_dir, test_dir):
 
 @pytest.fixture(scope='module')
 def mod_scheduler():
-    """Return a scheduler object for a flow."""
-    return _make_scheduler
+    """Return a Scheduler object for a flow.
+
+    Usage: see scheduler() below
+    """
+    with _make_scheduler() as _scheduler:
+        yield _scheduler
 
 
 @pytest.fixture
 def scheduler():
-    """Return a scheduler object for a flow."""
-    return _make_scheduler
+    """Return a Scheduler object for a flow.
+
+    Args:
+        reg (str): Workflow name.
+        **opts (Any): Options to be passed to the Scheduler.
+    """
+    with _make_scheduler() as _scheduler:
+        yield _scheduler
 
 
 @pytest.fixture(scope='module')

tests/integration/utils/flow_tools.py

@@ -23,11 +23,11 @@
 
 import asyncio
 from async_timeout import timeout
-from async_generator import asynccontextmanager
+from contextlib import asynccontextmanager, contextmanager
 import logging
 from pathlib import Path
 import pytest
-from typing import Optional
+from typing import Any, Optional
 from uuid import uuid1
 
 from cylc.flow import CYLC_LOG
@@ -54,13 +54,24 @@ def _make_flow(run_dir, test_dir, conf, name=None):
     return reg
 
 
-def _make_scheduler(reg, **opts):
+@contextmanager
+def _make_scheduler():
     """Return a scheduler object for a flow registration."""
-    # This allows paused_start to be overriden:
-    opts = {'paused_start': True, **opts}
-    options = RunOptions(**opts)
-    # create workflow
-    return Scheduler(reg, options)
+    schd: Scheduler = None  # type: ignore
+
+    def __make_scheduler(reg: str, **opts: Any) -> Scheduler:
+        # This allows paused_start to be overriden:
+        opts = {'paused_start': True, **opts}
+        options = RunOptions(**opts)
+        # create workflow
+        nonlocal schd
+        schd = Scheduler(reg, options)
+        return schd
+
+    yield __make_scheduler
+    # Teardown
+    if hasattr(schd, 'workflow_db_mgr'):
+        schd.workflow_db_mgr.on_workflow_shutdown()
 
 
 @asynccontextmanager