Sharepoint-Toolbox/.planning/RETROSPECTIVE.md

Retrospective

Milestone: v1.0 — MVP

Shipped: 2026-04-07 Phases: 5 | Plans: 36 | Commits: 164 | LOC: 10,071

What Was Built

• Complete C#/WPF rewrite replacing 6,400-line PowerShell monolith
• 10 feature tabs: Permissions, Storage, Search, Duplicates, Transfer, Bulk Members, Bulk Sites, Folder Structure, Templates, Settings
• Multi-tenant MSAL authentication with per-tenant token caching
• CSV and interactive HTML export across all scan features
• Bulk operations with continue-on-error, per-item reporting, retry, and cancellation
• Self-contained 200 MB EXE with full EN/FR localization (199 keys)

What Worked

• Wave 0 scaffold pattern: Creating models, interfaces, and test stubs before implementation gave every phase testable targets from day 1
• FeatureViewModelBase contract: Establishing the async/cancel/progress pattern in Phase 1 meant Phases 2-4 had zero friction adding new features
• BulkOperationRunner abstraction: One shared helper gave consistent error semantics across 4 different bulk operations
• Phase dependency ordering: Foundation → Permissions → Storage → Bulk → Hardening prevented rework
• Atomic commits per task: Each plan produced clear, reviewable commit history

What Was Inefficient

• Phase 03 missing verification: The only phase without a VERIFICATION.md — caught during milestone audit, but should have been produced during execution
• Stale audit notes: Phase 2 verification reported export buttons as hardcoded English, but they were actually already localized by the time of the audit — suggests verification reads code at a point-in-time snapshot that may not reflect later fixes
• Cancel test locale mismatch: The French locale test failure was flagged in Phase 3 plan 08 summary but deferred until post-milestone cleanup — should have been fixed inline

Patterns Established

• Write-then-replace JSON persistence with SemaphoreSlim for thread safety
• TranslationSource singleton with PropertyChanged(string.Empty) for runtime culture switching
• ExecuteQueryRetryHelper for throttle-aware CSOM calls (429/503 detection)
• SharePointPaginationHelper with ListItemCollectionPosition for 5,000+ item lists
• CsvValidationService with auto-delimiter detection (comma/semicolon) and BOM handling
• DataGrid RowStyle DataTrigger for invalid-row visual highlighting

Key Lessons

• Establish shared infrastructure patterns (auth, retry, pagination, progress) in Phase 1 — every subsequent phase benefits
• Test scaffolds (Wave 0) eliminate the "no tests until the end" anti-pattern
• Phase verifications should be mandatory during execution, not optional — catching Phase 03's gap at audit time is late
• Localization tests (key parity + diacritic spot-checks) are cheap and catch real bugs

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Cross-Milestone Trends

Metric	v1.0
Phases	5
Plans	36
LOC	10,071
Tests	134 pass / 22 skip
Timeline	28 days
Commits	164