fix(mountsync): preserve scoped write path case

[khaliqgant]

Summary

• preserve the case of the path segment in scopeGrantsWrite
• keep plane:resource:action matching case-insensitive
• add a regression for uppercase file and CamelCase directory write scopes

Fixes #231.

Context

The Tier-2 production scoped-writeback harness exposed that mountsync lowercased the full write scope before comparing its path segment to the case-preserved remote path. Narrow write scopes over real repo paths such as README.md, LAYOUT.md, or CamelCase directories could therefore deny the member's own in-scope writeback.

ClaudeGateB also audited the Cloud TS read-side matcher: it already preserves scope path case and only lowercases non-path scope metadata. This change restores Go write-side parity with the already-correct read-side semantics.

Verification

• RED anchor: go test ./internal/mountsync -run TestScopeGrantsWritePreservesPathCase -count=1 failed on origin/main before this fix
• go test ./internal/mountsync -run 'TestScopeGrantsWritePreservesPathCase|TestCanWritePathWithRelayauthScopes|TestCanWritePathWithShortScopes' -count=1
• go test ./internal/mountsync -run 'TestScopeGrantsWritePreservesPathCase' -count=1
• go test ./internal/mountsync -count=1

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 87739075-83d6-4e8e-91f8-50e19291f76a

📥 Commits

Reviewing files that changed from the base of the PR and between dbbd973 and 544b8b9.

📒 Files selected for processing (2)

• internal/mountsync/syncer.go
• internal/mountsync/syncer_test.go

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📝 Walkthrough

Walkthrough

scopeGrantsWrite is enhanced to normalize scope input by trimming whitespace and applying case-insensitive matching to scope segments. Short-form scopes and long-form plane/resource/action components are now matched case-insensitively while preserving path case, with a new test validating this behavior.

Changes

Scope Normalization and Case-Insensitive Matching

Layer / File(s)	Summary
Scope input normalization and case-insensitive segment matching internal/mountsync/syncer.go, internal/mountsync/syncer_test.go	Short-form scope comparisons (fs:write, fs:manage) now use EqualFold for case-insensitive matching after trimming input. Long-form scopes trim and lowercase the plane, res, and act segments before validation. New test TestScopeGrantsWritePreservesPathCase validates that path case is preserved while plane/resource/action components are treated case-insensitively.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related issues

• mountsync scoped write paths fail when path segment contains uppercase #231: Directly addresses the same bug in scopeGrantsWrite regarding path case preservation and case-insensitive plane/resource/action matching, including regression test coverage.

Possibly related PRs

• AgentWorkforce/relayfile#227: Adds tier-1 scoped syncer tests validating relayfile:fs:write/* grant parsing and write-scope filtering, which exercises the same scope-evaluation logic now enhanced with case/whitespace normalization.

Poem

🐰 Whitespace trims and cases fold,
Short-form scopes now warm and bold,
Plane and resource, action too,
Normalized to match on cue,
Paths keep their case pristine and true!

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: preserving path case in scoped write matching, which is the core fix addressed in the PR.
Description check	✅ Passed	The description clearly explains the changes, context, and verification steps related to the case-preservation fix in scopeGrantsWrite.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch codex/canwrite-path-case

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[gemini-code-assist]

Code Review

This pull request modifies scopeGrantsWrite in internal/mountsync/syncer.go to preserve the case of the path segment in scopes, making path authorization case-sensitive while keeping the plane, resource, and action segments case-insensitive. It also adds corresponding unit tests in internal/mountsync/syncer_test.go to verify this behavior. There are no review comments, so I have no feedback to provide.

[github-actions]

Relayfile Eval Review

Run: .relayfile/evals/runs/2026-06-01T07-22-05-061Z-HEAD-provider
Mode: provider
Git SHA: 176df1d

Passed: 4 | Needs human: 0 | Reviewable: 0 | Missing output: 0 | Failed: 0 | Skipped: 0

Human Review Cases

No reviewable human-review cases captured Relayfile output.

[cubic-dev-ai]

No issues found across 2 files

_{Re-trigger cubic}

[agent-relay-code]

Reviewed PR #232 and made one scoped fix: internal/mountsync/syncer_test.go now delegates canWritePathForScope to the production scopeGrantsWrite matcher, preventing parser drift around SplitN, fs:manage, and case-insensitive scope segments.

I checked the local bot-review artifacts; they were stale or already resolved and included files outside this PR’s actual surface. I did not run Go tests because go/gofmt are not installed in this environment.

[agent-relay-code]

✅ pr-reviewer applied fixes — committed and pushed 009cfb6 to this PR. The notes below describe what changed.

Reviewed PR #232 and made one scoped fix: internal/mountsync/syncer_test.go now delegates canWritePathForScope to the production scopeGrantsWrite matcher, preventing parser drift around SplitN, fs:manage, and case-insensitive scope segments.

I checked the local bot-review artifacts; they were stale or already resolved and included files outside this PR’s actual surface. I did not run Go tests because go/gofmt are not installed in this environment.

[agent-relay-code]

✅ pr-reviewer applied fixes — committed and pushed 009cfb6 to this PR. The notes below describe what changed.

Reviewed PR #232 and made one scoped fix: internal/mountsync/syncer_test.go now delegates canWritePathForScope to the production scopeGrantsWrite matcher, preventing parser drift around SplitN, fs:manage, and case-insensitive scope segments.

I checked the local bot-review artifacts; they were stale or already resolved and included files outside this PR’s actual surface. I did not run Go tests because go/gofmt are not installed in this environment.