add-feature

Add a feature

Follow these steps in order. Look at an existing feature first — src/app/(app)/generate/ is the reference implementation of this shape.

1. Spec it

Copy specs/TEMPLATE.md to specs/NNN-short-name.md and fill it in (problem, solution, out-of-scope, data changes, test plan). Two paragraphs beat zero. Show the user before writing code.

2. Data (only if the spec says so)

If the feature needs schema changes, stop and run /db-migration. Schema changes require asking the user first.

3. Server action

Create src/app/(app)/<feature>/actions.ts:

• "use server" at the top.
• First line of every action: re-check the session via the helper in src/lib/auth/ — never rely on middleware alone. Throw/redirect if absent.
• Validate all input with a Zod schema. Parse, don't cast.
• Mutations that touch credits go through src/lib/credits/ only.
• Return typed results; revalidatePath what the mutation changed.

4. Page

Create src/app/(app)/<feature>/page.tsx:

• Server Component. Fetch data directly (Drizzle), no client fetching.
• Re-check the session server-side, same as the action.
• "use client" only for leaf components that need interactivity (forms, toggles) — keep them small, pass data down from the RSC.
• UI per DESIGN.md: existing shadcn primitives from src/components/ui/, ledger rows for lists, mono for numbers/labels, no new colors.

5. Navigation

Add the page to the sidebar nav in the app shell component (one entry: lucide icon + label).

6. Test

Write a Vitest file next to the logic you added (*.test.ts):

• Cover the action's happy path, invalid input (Zod rejection), and the unauthenticated case.
• If credits are involved, assert the ledger invariant still holds (balance cache === sum of transactions).

7. Done means done

pnpm typecheck && pnpm lint && pnpm test all green. Walk the feature once in the browser (pnpm dev).