session-history/ohm/0022/SESSION-0022.1-TRANSCRIPT-2026-05-28T12-04--2026-05-28T12-28.md

Session 0022.1 — Transcript

Parent: SESSION-0022.0-TRANSCRIPT-…md Date: 2026-05-28 Goal: implement roadmap #26 (optional use-case field) as rfc-app v0.22.0 feature code Outcome: Shipped to branch feature/v0.22.0-usecase-field (commit 7c6c906). Optional proposed_use_case field added to propose-RFC + propose-PR surfaces end-to-end. Backend 336 passed (332 baseline + 4 new), frontend build green.

Pre-session state

• Worktree /Users/benstull/git/rfc-app-v0.22.0-usecase, branch feature/v0.22.0-usecase-field based on main @ 2ac20b1 (Merge feature/v0.21.0-ux-polish).
• migrations 001–020 present (no 016 — gap predates this work). 021 reserved for me.
• Baseline: 332 backend tests.

Turn-by-turn arc

1. Explored the propose surfaces. Key finding: the roadmap's mental model doesn't match the architecture. The roadmap names "the rfcs table" and "the PR-metadata table" for a new column, but:
   • The propose-RFC "Why is this RFC needed?" field is named pitch (frontend ProposeModal.jsx + ProposeBody.pitch in api.py), serialized into the RFC entry body and the Gitea PR description. Truth is Gitea, not a DB row.
   • The propose-PR surface (PRModal.jsx + OpenPRBody in api_prs.py) has a single free-text description field — that IS the "why is this change needed" the roadmap refers to. Also Gitea-truth.
   • cached_rfcs / cached_prs (002_cache.sql) are caches, rebuilt from Gitea by cache.py's reconciler. The write path is endpoint → Gitea → reconcile. Since cache.py (which I may NOT edit) doesn't carry a proposed_use_case field, a cache column alone would always read NULL after a propose/open.
2. Decision: added the nullable cache columns per the roadmap's literal shape (migration 021), AND a dedicated canonical, reconcile-proof side table proposed_use_cases (scope ∈ {'rfc','pr'}, keyed by pr_number, UNIQUE(scope,pr_number)) that my endpoint code writes directly and the read endpoints query. The side table is the true source read at view time; cache columns are mirrored for parity / future reconciler use. This keeps everything inside my file ownership (no cache.py/db.py/entry.py edits).
3. Backend wiring:
   • ProposeBody + OpenPRBody gain proposed_use_case: str | None = Field(default=None, max_length=8000) (8000 matches the existing PR description bound; pitch is unbounded but 8000 is generous).
   • propose_rfc (api.py ~line 700) writes the side-table row + mirrors onto cached_prs after cache.refresh_meta_pulls, only when the stripped value is non-empty (blank/whitespace == "left blank", no row).
   • open_pr (api_prs.py, after _refresh_after_pr_write) does the same for scope 'pr'.
   • Reads: _proposal_use_case helper feeds list_proposals + get_proposal; get_rfc looks up by slug (latest 'rfc' row, since the idea PR closes on merge); _pr_use_case (module fn) feeds get_pr.
4. Frontend: api.js (proposeRFC, openPR send proposed_use_case or null); ProposeModal.jsx + PRModal.jsx add optional textareas below the existing required fields with "(optional)" labels and field-help; ProposalView.jsx, RFCView.jsx (main view only), PRView.jsx render with muted italic "left blank" treatment when null. Reused existing classes (entry-body, field-help, pr-description) + inline component-scoped styles only — no App.css/index.css/tokens.css edits.
5. Tests: 4 new tests in test_proposed_use_case_vertical.py reusing FakeGitea/seed helpers. All green on first run. Full suite 336 passed.
6. Frontend build initially failed on missing VITE_APP_NAME (deployment overlay var, not in the worktree) — re-ran npm run build with VITE_APP_NAME/VITE_BETA_CONTACT set inline; built clean. No .env committed.

Cut state

• Branch feature/v0.22.0-usecase-field @ 7c6c906.
• Files changed: backend/app/api.py, backend/app/api_prs.py, frontend/src/api.js, frontend/src/components/{ProposeModal,PRModal,ProposalView,RFCView,PRView}.jsx, + NEW backend/migrations/021_proposed_use_case.sql, + NEW backend/tests/test_proposed_use_case_vertical.py.
• Migration number: 021.
• Backend: 336 passed (332 baseline + 4 new). Frontend: build green.

What the driver needs to know

• CHANGELOG Upgrade steps: proposal: none — additive nullable column + new side table, migration 021 auto-applies on deploy (run_migrations globs migrations/*.sql).
• CHANGELOG entry summary: "#26: Optional 'What will you be using this for?' capture on the propose-RFC and propose-PR surfaces. New optional proposed_use_case free-text field alongside the existing required justification on both modals; persisted, returned, and displayed (with a muted 'left blank' treatment when absent). New migration 021; new canonical proposed_use_cases table."
• api.py regions I edited (merge-overlap awareness vs 0022.2):
  • ProposeBody class (~line 49).
  • propose_rfc endpoint — the block right after await cache.refresh_meta_pulls(...) / before return {"pr_number": ...} (~line 707).
  • list_proposals + get_proposal (~lines 566–640): added _proposal_use_case nested helper + a proposed_use_case key in each return.
  • get_rfc (~line 558): changed return _serialize_rfc(row) into a payload + slug lookup.
  • I did NOT touch _serialize_rfc / _entry_payload / _serialize_rfc list-builder (the catalog list_rfcs loop is untouched).
• api_prs.py: OpenPRBody (~line 42), open_pr (post-refresh block), get_pr return dict (added one key), new module-level _pr_use_case before _pr_capabilities.
• Architectural note for the driver: the roadmap's "rfcs table / PR-metadata table column" framing was reconciled against the real Gitea-truth + cache-mirror architecture by adding a dedicated proposed_use_cases canonical table (the durable source) plus the literal cache columns. If a future change teaches cache.py's reconciler to carry the field, the cache columns are ready; until then the side table is authoritative. No cache.py/db.py edits were needed or made.

§19.2 candidates surfaced

• none. (Possible future: teach the reconciler to round-trip propose-time metadata through a Gitea trailer so the cache columns become self-sufficient and the side table can be retired — but that's speculative and out of scope.)