Bug: qfcqueue-enqueue-path-lacks-injectable-seams #871

• Work Mode: full-bug

Summary

QfcQueue.EnqueueAsync (0 of 46 lines covered) and QfcQueue.LoadControllersViewersAsync (0 of 24 lines covered) drive a live WinForms TableLayoutPanel, per-row ItemViewer construction, UI idle-call marshalling, and the EmailMoveMonitor hook through private members with no injectable seam, so their control flow cannot be unit-tested without a live Outlook window. Item #678 left its acceptance criterion AC20 unchecked for this reason and issue #727 sub-finding 4 recorded it as a policy gap. The maintainer decision recorded on #727 on 2026-09-11 is that the resolution is a seam, not a coverage exemption.

Environment

• OS/version: Windows 11 Pro 10.0.26200
• Python version: not applicable (C# / .NET Framework 4.8 VSTO add-in, MSTest + Moq)
• Command/flags used: scripts/vscode/Invoke-MSTestWithCoverage.ps1 over QuickFiler.Test.dll; static inspection of QuickFiler/Controllers/QfcQueue.cs and QuickFiler/Controllers/QfcQueue.Enqueue.cs
• Data source or fixture: the committed Cobertura evidence for item Bug: quickfiler-carry-folder-predictor-to-item-controller #678 (PR fix(quickfiler): carry the initialised folder predictor to the item controller (#678) #724), which reports both members at zero covered lines

Steps to Reproduce

1. Search QuickFiler.Test for EnqueueAsync: zero references across QfcQueueTests.cs, QfcQueuePurePathsTests.cs, and QfcQueueCoverageExpansionTests.cs.
2. Read QfcQueue.Enqueue.cs:71-138. EnqueueAsync calls _moveMonitor.HookItem on a field initialised inline to new EmailMoveMonitor() (QfcQueue.cs:42), clones _tlpTemplate through UiIdleCallAsync, and awaits LoadControllersViewersAsync through UiIdleAsyncCallAsync.
3. Read QfcQueue.Enqueue.cs:154-198. LoadControllersViewersAsync calls AddAsync (QfcQueue.cs:264), which constructs a viewer and adds it to the TableLayoutPanel on the UI idle path. Only the item-controller construction that follows is behind a seam (ItemControllerFactory, added by Bug: quickfiler-carry-folder-predictor-to-item-controller #678).
4. Attempt to write an MSTest that exercises either member: construction of the real TableLayoutPanel, the real ItemViewer, and the real EmailMoveMonitor requires a message pump and Outlook COM objects, which unit-test policy prohibits.

Expected Behavior

Both members accept mocks for every boundary they drive, following the injectable-delegate pattern already used for ItemControllerFactory (form 2 of the DI seam guidance in .claude/rules/csharp.md): the move-monitor hook, the template clone and viewer/row construction performed by AddAsync, and the UI idle-call marshalling. Tests then cover the argument-guard branches, the _jobsRunning increment and decrement, the OperationCanceledException and general-exception catch paths, the CollectionChanged raise in finally, the digits computation, and the carrier resolution per row, without a live WinForms viewer or Outlook process. Both members reach the 90% new-code floor as written.

Actual Behavior

Neither member is reachable from a unit test. The production defaults are constructed inline from private fields, so no test can substitute them. Coverage on both members is 0%, and item #678's AC20 remains unchecked.

Logs / Screenshots

• Attached minimal logs or screenshot
• Snippet: item Bug: quickfiler-carry-folder-predictor-to-item-controller #678 review, AC20 recorded PARTIAL (PR fix(quickfiler): carry the initialised folder predictor to the item controller (#678) #724); issue Bug: quickfiler-coverage-filesize-evidence-debt #727 sub-finding 4.

Impact / Severity

• Blocker
• High
• Medium
• Low

Medium: no incorrect production behavior. Two members on the high-confidence display path carry zero test coverage, and every future change to them is unverifiable by the unit suite.

Source

From: docs/features/potential/2026-09-11-qfcqueue-enqueue-path-lacks-injectable-seams.md