Bug: filesystem-wrapper-tests-open-repository-solution-file

[drmoisan]

• Work Mode: minor-audit

Summary

Several UtilitiesCS.Test file-system wrapper tests locate the repository root at run time and open or enumerate the real TaskMaster.sln. This is the same defect class that #931 (PR #939) fixed in FileInfoWrapper_Tests: the outcome of a unit test depends on repository layout and on whether another process holds the solution file open.

Environment

• OS/version: Windows 11 (local) and windows-latest (CI)
• Python version: n/a (C# / MSTest, .NET Framework 4.8)
• Command/flags used: Invoke-MSTestWithCoverage.ps1 (parallel run, Workers=0, Scope=ClassLevel)
• Data source or fixture: the repository's own TaskMaster.sln

Steps to Reproduce

1. Hold TaskMaster.sln open with a share mode that excludes readers (for example a resident MSBuild node or an IDE).
2. Run UtilitiesCS.Test with the standard coverage route.
3. Alternatively, run the test assembly from a location whose ancestors contain no TaskMaster.sln.

Expected Behavior

The wrapper tests verify wrapper delegation through test-owned fixtures or mocks, independent of repository layout and of other processes.

Actual Behavior

• UtilitiesCS.Test/HelperClasses/PhysicalFileSystemAdapters_Tests.cs walks up to the repository root (line ~361), builds a FileInfo over TaskMaster.sln (line ~376), asserts it is enumerated (lines 110-129), and swallows IOException in places, which hides the contention instead of removing it.
• UtilitiesCS.Test/HelperClasses/DirectoryInfoWrapper_Tests.cs asserts that TaskMaster.sln is enumerated from the repository root (lines 60 and 79, root walk at line ~381).

Logs / Screenshots

• Attached minimal logs or screenshot
• Snippet: see the PR test(931): remove scheduler and file-handle dependence from breadcrumb thread-affinity and FileInfoWrapper tests #939 body, section Follow-ups, items 1 and 2.

Impact / Severity

• Blocker
• High
• Medium
• Low

Source

From: docs/features/potential/2026-09-29-filesystem-wrapper-tests-open-repository-solution-file.md

[drmoisan]

Restoring sections dropped by the promotion tooling.

Suspected Cause / Notes

A unit test depends on environment state it does not control, which is the root cause recorded for #931 (PR #939). Other root-walk sites to triage under the same fix:

• TaskMaster.Test/Ribbon/RibbonControllerTests.cs:429
• TaskMaster.Test/Bootstrap/FSharpCoreHintPathAlignmentTests.cs:27
• UtilitiesCS.Test/EmailIntelligence/SortEmail_Tests.cs:405

Some of these may legitimately read repository files, for example build-configuration alignment tests. Classify each one before changing it.

Source: docs/features/active/2026-09-28-tests-depend-on-uncontrolled-environment-931/evidence/qa-gates/p4-t13-follow-up-handoff.2026-09-29T09-46.md.

Proposed Fix / Validation Ideas

• Reuse the Bug: tests-depend-on-uncontrolled-environment #931 pattern: exercise delegation through the internal IFileInfo/IDirectoryInfo seams with Moq, or through a test-owned stream opened with FileShare.ReadWrite. Use no temporary files.
• Remove the IOException swallowing in PhysicalFileSystemAdapters_Tests.
• Negative control: show that each rewritten test fails against a deliberately broken wrapper.

[drmoisan]

Delivered by PR 955 (merge commit 039cf77), parallel run bugs-2026-09-28. All 8 acceptance criteria in issue.md are checked off (AC8 amended per coordinator ruling to the per-file no-regression rule, with a dated note); all seven checks green on head b95a061 (run 36740921329) before merge. Follow-ups are filed separately by the run coordinator.