Code Quality Enforcement Plan

The standards in CODE_QUALITY.md are currently enforced by review plus advisory CI — the Code Quality (advisory) workflow reports findings but never fails a PR. This document is the staged plan to turn the mechanical checks into blocking gates. The phases are ordered so the build is never broken mid-migration.

Current enforcement status

Signal	Status	Notes
Formatting (dotnet format)	✅ Blocking	Codebase normalized to tabs per .editorconfig; build is format-clean.
License-header banner	✅ Blocking	All 473 source files carry the banner.
Analyzer/compiler warnings	✅ Blocking	Library builds warning-clean (CA catalog disabled via AnalysisMode=None; the library enforces its own targeted rules, not the full MS set).
Oversized files (>800 lines)	⚠️ Advisory	26 files remain over the limit; splitting is real refactoring (Phase 4).
Multi-TFM PR matrix	⏳ Planned	Phase 5.

The first three were brought to a clean state and flipped to blocking. File size stays advisory until the remaining files are split.

What's machine-checkable vs review-only

• Machine-checkable (target of this plan): formatting, license headers, compiler/ analyzer warnings, file-size limits, trailing whitespace.
• Review-only (cannot be automated): no magic numbers, no duplication, correct SetCell/SetNarrowCell usage, display-width correctness, UI-thread marshalling, no-breaking-changes. These stay in human review — the PR template checklist exists to prompt them.

Phases

Phase 0 — Baseline ✅ done

• .editorconfig added (tabs, whitespace, analyzers at suggestion severity).
• EnableNETAnalyzers + EnforceCodeStyleInBuild on; AnalysisMode=None so the broad CA catalog doesn't escalate to build warnings.
• code-quality.yml workflow checks formatting / headers / warnings / file size.

Phase 1 — Formatting gate ✅ done

• dotnet format applied across the library (normalized ~194 space-indented files to tabs; whitespace-only, all tests green). Formatting step is now blocking.

Phase 2 — License-header gate ✅ done

• Banner backfilled into the 108 files that lacked it. Header check is now blocking.

Phase 3 — Warning burn-down ✅ done

• Real CS warnings fixed (CS1573 docs; safe analyzer auto-fixes). Public-API CS0067/CS0414 silenced with justification in .editorconfig. CA catalog disabled via AnalysisMode=None. Build is warning-clean and the warning check is blocking.

Phase 4 — File-size gate (remaining)

1. Split the remaining oversized controls into Model / Renderer / InputHandler partials.
2. Make the file-size check blocking.

Phase 5 — Multi-TFM PR matrix (related)

• Build + test across net8.0/net9.0/net10.0 on PRs so a change can't silently break a target framework.

Notes

• Each phase is independently shippable and keeps main green.
• No phase changes public API or runtime behavior — these are build/CI/style only.