# FINAL Report — 03-code-quality-refactoring

**Run name**: `03-code-quality-refactoring`
**Mode**: Automatic (skill discovered scope from full-codebase scan; user confirmed Phase 0 to execute Phases 0-7)
**Input mode**: Automatic (no input file; scope produced by Phase 1)
**Epic**: AZ-350
**Phases executed**: 0, 1, 2, 3, 4 (10 batches, 27 tasks), 5 (inline), 6 (smoke verification), 7 (documentation sync), this report
**Duration**: 2026-05-10 (Phase 0 baseline) → 2026-05-11 (FINAL_report)
**Verdict**: SUCCESS — PASS at every gate, 0 regressions, all 5 Phase-0 ACs met

## What changed in plain English

The refactor swept every C# source file in the production projects (`Api`, `Common`, `DataAccess`, `Services.*`) for code-quality issues and remediated them in 10 small, reviewable batches. Tooling was added so future regressions get caught at PR time. The architecture and HTTP contract did not change.

Concretely:

- **HTTP / DI hardening**: sanitized 5xx responses, strict-by-default CORS, real 501 for stub endpoints, idempotent POST contract for region/route, typed HttpClient for Google Maps.
- **Domain model cleanup**: status & point-type enums replace stringly-typed fields end-to-end; the obsolete `Version` / `MapsVersion` columns are dropped (with a dedupe migration).
- **Algorithmic / structural cleanup**: god-classes decomposed (`RouteProcessingService`, `RouteService.CreateRouteAsync`); shared helpers extracted (`TileCsvWriter`, `TileGridStitcher`, Haversine + filename parser); per-cell O(N) tile lookup replaced with `HashSet`; magic numbers and Earth-geometry constants consolidated to one home each; repository SELECT column lists deduplicated; dead code (FindExistingTileAsync, CalculatePolygonDiagonalDistance, write-only queue counters) removed; unused repo logger fields cleaned up; null logger in DatabaseMigrator fixed; empty catch in tile-coords parser replaced with logging.
- **Tooling**: `.editorconfig`, `Directory.Build.props` with `Microsoft.CodeAnalysis.NetAnalyzers`, Coverlet wired into the test project, `dotnet format` gate as Step 0 of the test script.

## Phase summary

| Phase | Status | Artifact | Notes |
|-------|--------|----------|-------|
| 0 — Baseline | Done | `baseline_metrics.md` | 5 goals + 4 constraints captured; user confirmed execute |
| 1 — Discovery | Done | `discovery/` + `list-of-changes.md` | 27 entries C01..C27, severity-tagged |
| 2 — Analysis | Done | `analysis/research_findings.md`, `analysis/refactoring_roadmap.md` | 4 execution phases; 27 tasks `AZ-3{51..80}` created in tracker |
| 3 — Safety Net | Done | (existing test suite) | Pre-existing 37 unit + 5 smoke kept as the safety net |
| 4 — Execution | Done | 10 batches @ `_docs/03_implementation/batch_15..24_report.md` | Cumulative K=3 reviews after batches 18, 21, 24 — all PASS or PASS_WITH_WARNINGS |
| 5 — Test Sync | Done (inline) | per-batch test files | New tests added per batch; no obsolete tests removed (refactors were behavior-preserving); no broken tests to fix |
| 6 — Verification | Done | `verification_report.md` | Format gate PASS; 200/200 unit; --smoke green; metric table vs baseline shows only improvements |
| 7 — Documentation | Done | `module-layout.md`, `architecture_compliance_baseline.md` (F5 revised), `00_discovery.md` (Updates Since Baseline section), this FINAL_report | F5 baseline doc-drift corrected; tooling additions documented |

## Acceptance criteria (vs Phase 0a)

| AC | Status | Evidence |
|----|--------|----------|
| 1. Code-smell inventory across all production projects | Met | `list-of-changes.md` C01..C27 |
| 2. Inventory consumable by `/implement` (template + tasks) | Met | 27 task files in `_docs/02_tasks/done/` |
| 3. Roadmap ranked by ROI, batches ≤5 points each | Met | `analysis/refactoring_roadmap.md`; tracker rule respected |
| 4. No regression in unit (37→200) or smoke (5→14+) suites | Met | `verification_report.md` §6a |
| 5. Phase 0 gate decision: execute vs Quick Assessment | Met | User chose execute; full Phases 0-7 ran |

## Constraint compliance (vs Phase 0 §Constraints)

| Constraint | Status |
|------------|--------|
| No public HTTP route changes | Met (stub endpoints' 500→501 is a status tightening, not a route change) |
| No DB schema changes other than the explicit AZ-357 migration | Met (Migration 012 only; explicitly listed in scope) |
| No DI-graph reorder that changes startup behavior | Met (smoke run validates both hosted services start and process correctly) |
| Architecture Vision honored | Met (cumulative reviews surfaced 0 new architectural violations; 1 doc-drift Low fixed in Phase 7) |

## Baseline → Final metrics

Reproduced from `verification_report.md` §6b:

| Metric | Baseline | Final | Status |
|--------|----------|-------|--------|
| Unit tests | 37 | 200 | Improved (+163) |
| Smoke scenarios | 5 | 14+ (added AZ-353, AZ-356, AZ-357, AZ-362, SEC-01..04, CORS) | Improved |
| Format gate | none | `dotnet format whitespace --verify-no-changes` runs as Step 0 | Added |
| Static analyzers | defaults only | `Microsoft.CodeAnalysis.NetAnalyzers` (CA1001, CA1051, CA1816, CA2227 → warning) | Added |
| Coverage tooling | none | Coverlet → `cobertura.xml` per run | Added |
| Editor convention pin | none | `.editorconfig` | Added |
| Earth + tile-pixel constants | duplicated 5+ sites | one source on `GeoUtils` + `MapConfig.DefaultTileSizePixels` | Improved |
| Existing-tile lookup | O(N) per cell × O(grid) cells | O(1) per cell after one O(existingTiles) preprocess | Improved |
| Repo SELECT column duplication | inline per method | one `private const string ColumnList` per repo | Improved |
| Dead methods (unused public) | 2 (FindExistingTileAsync, CalculatePolygonDiagonalDistance) | 0 | Improved |
| Repo logger fields without log calls | 3 unused | 0 (RegionRepository / RouteRepository removed; TileRepository emits slow-query warnings) | Improved |
| Stub endpoints status code | 500 (incorrect) | 501 with ProblemDetails | Improved |
| 5xx response shape | leaked exception details | sanitized ProblemDetails | Improved |
| CORS default | permissive | strict, opt-in for permissive with production warning | Improved |

## Cumulative reviews

| Cum-rev | Batches | Verdict | Findings (Critical / High / Medium / Low) |
|---------|---------|---------|-------------------------------------------|
| #1 | 16-18 | PASS | 0 / 0 / 0 / 0 |
| #2 | 19-21 | PASS_WITH_WARNINGS | 0 / 0 / 0 / 3 |
| #3 | 22-24 | PASS_WITH_WARNINGS | 0 / 0 / 0 / 4 |

All Low findings were either documentation drift, deliberate trade-offs, or pre-existing carry-overs — none introduced by this run.

## Changes summary

27 tracker tasks delivered in 10 implementation batches:

- **Batch 15** (Phase 1 critical fixes): AZ-351, AZ-352, AZ-363, AZ-356, AZ-354, AZ-353
- **Batch 16** (Phase 2 correctness — part 1): AZ-359
- **Batch 17** (Phase 2 correctness — part 2): AZ-357
- **Batch 18** (Phase 2 correctness — part 3, includes folded AZ-360): AZ-362, AZ-364 (folds AZ-360)
- **Batch 19** (Phase 3 structural — part 1): AZ-366, AZ-367, AZ-365
- **Batch 20** (Phase 3 structural — part 2): AZ-368, AZ-369
- **Batch 21** (Phase 3 structural — part 3): AZ-370, AZ-373, AZ-374
- **Batch 22** (Phase 4 tooling): AZ-372
- **Batch 23** (Phase 4 cleanup — part 1): AZ-376, AZ-378, AZ-379, AZ-380
- **Batch 24** (Phase 4 cleanup — part 2): AZ-375, AZ-377

(Batch numbers continue from `02-coupling-refactoring` — that run ended at batch 14.)

## Remaining items

None for the 03 run. All 27 entries C01..C27 are landed, reviewed, tested, and committed. No deferred items.

Recommended follow-ups (out of scope for this run; flag as candidates for a future run if priorities allow):

1. **CA2227 hot-spots** — 4 DTO classes still trigger `CA2227 Change 'Points/Polygons/Tiles' to be read-only`. We elevated CA2227 to warning intentionally; tightening these to `IReadOnlyList` would change the JSON deserialization contract for `CreateRouteRequest`, `GeofencePolygon`, `GetSatelliteTilesResponse`, `RouteResponse`. A one-task ticket can sweep these together with binding-style switch.
2. **CA1816 / xUnit1031 in tests** — two test classes implement `IDisposable` without `GC.SuppressFinalize`, and two `TileServiceTests` use blocking task ops. Cosmetic; a follow-up test-cleanup ticket would remove them.
3. **Cyclomatic-complexity tool** — Phase 0 noted no complexity tool was wired up. The format + analyzers gate covers most issues; a dedicated `dotnet-counters` or NDepend run would be the next tooling step.

## Lessons learned

1. **Documentation can lie.** The architecture compliance baseline F5 entry asserted DataAccess had no Common dependency, when the csproj reference and 5 import sites had been there since the AZ-309 split. Re-verifying the assertion against the actual code during AZ-377 caught the drift. Action: when batches encounter doc-vs-code disagreement, trust the code and surface the doc fix as a follow-up — never silently propagate the wrong assumption.
2. **Tooling additions land best alone.** AZ-372 (the tooling batch) was deliberately one batch by itself, late in the run, because earlier batches would have hit format failures while in flight. Lesson for future runs: schedule format/static-analysis enablement as the **last** Phase-4 batch, not the first.
3. **K=3 cumulative reviews are the right cadence.** Two of the three cumulative reviews caught real items (Low-severity). One (cum-rev #1, batches 16-18) was clean. The K=3 cadence was light enough not to delay, dense enough to catch drift.
4. **`--no-restore` is a foot-gun in unit-only mode.** `scripts/run-tests.sh --unit-only` was running `dotnet test --no-restore` without first running `dotnet restore`, which broke `SixLabors.ImageSharp` resolution in clean containers. Fixed in batch 24 by wrapping the Docker invocation with `sh -c "dotnet restore && dotnet test --no-restore"`. Lesson: never use `--no-restore` unless you control the workspace and know packages are already restored.
5. **Behavior-preserving HashSet swap is the safest perf win in this codebase.** AZ-375 collapsed an O(N²) hot loop to O(N) without behavioral change because tile coordinates at a fixed zoom are integers — the prior tolerance comparison was redundant. Look for similar `Math.Abs(a - b) < tolerance` patterns over keys that are actually quantized; they are usually free wins.

## Sign-off

The 03-code-quality-refactoring run is complete. All artifacts under `_docs/04_refactoring/03-code-quality-refactoring/` are final. Tracker (Jira) reflects 27 tasks in `In Testing` with the AZ-350 epic at parity. Autodev state will advance from refactor Phase 7 to the next existing-code flow step at the user's next `/autodev` invocation.
