Flaky Test Report

Test: TestCheckIdleTaskList/Active_adding_task
Package: github.com/uber/cadence/service/matching/tasklist
File: service/matching/tasklist/task_list_manager_test.go:553

Failure

The test intermittently fails with the task list shutting down before a task can be added:

--- FAIL: TestCheckIdleTaskList (0.08s)
    --- FAIL: TestCheckIdleTaskList/Active_adding_task (0.02s)
        task_list_manager_test.go:553:
            Error Trace: /cadence/service/matching/tasklist/task_list_manager_test.go:553
            Error:       Received unexpected error:
                         task list shutting down
            Test:        TestCheckIdleTaskList/Active_adding_task
FAIL    github.com/uber/cadence/service/matching/tasklist   22.942s

Root Cause

The test is timing-sensitive. The task list manager detects an idle condition and shuts down before the test can add a task, causing the task list shutting down error. The log output shows the manager stopped due to 'Task list manager stopping because no recent events' with an interval of 10ms, suggesting the idle timeout is racing with the task addition.

Observed In

• CI run: https://github.com/cadence-workflow/cadence/actions/runs/23808340038/job/69388077323
• PR: docs: Add additional non-determinism rules to workflow guide for agents #7806 (docs-only change, unrelated to this failure)

Suggested Fix

• Ensure the 'active adding task' subtest pre-seeds or immediately adds a task before the idle timer fires, or mocks/controls the idle timer duration to prevent premature shutdown.
• Consider using a longer idle timeout in test setup or explicitly disabling idle timeout for this test scenario.