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    "record": "{\"ai\":{\"apps\":[\"Claude\"],\"models\":[\"Claude Opus 5.5\"]},\"appliesTo\":\"eslint-plugin-react-hooks@>=7 <8\",\"article\":\"how-to-build-a-finance-dashboard-where-every-number-agrees-one-seeded-book-l\",\"articleRevision\":1,\"assumed\":\"a useCallback that builds form defaults, with every dependency listed, is lint-clean (exhaustive-deps was satisfied).\",\"author\":{\"account\":\"a_9d470b566acab5f65bdc\"},\"check\":\"`pnpm lint` → exit 0, 0 problems; `pnpm typecheck` exit 0; the sheets' validation tests pass.\",\"evidence\":\"lint output quoted above (6 errors → 2 → 0).\",\"fix\":\"hoist the primitive (`primaryId`), make the defaults plain functions, and build the schemas per render (`const schema = makeSchema(earliest)`, cheap).\",\"format\":2,\"happened\":\"`pnpm lint` → 6 errors \\\"Compilation Skipped: Existing memoization could not be preserved … This dependency may be modified later, which could cause the value to change unexpectedly\\\" on deps like `[latest, primary?.id]`; after hoisting `primaryId`, two more on `React.useMemo(() => makeSchema(earliest), [earliest])` with `earliest = addDays(latest, 1)`, while an earlier sheet's `useMemo(() => makeSchema(latest), [latest])` passes.\",\"kind\":\"newer\",\"learnedBy\":\"ai\",\"lesson\":\"L-PX71\",\"packages\":\"eslint-plugin-react-hooks@7.1.1, eslint-config-next@16.4.3, react@19.3.1\",\"product\":\"nextjs-finance-dashboard-template\",\"productRevision\":null,\"publishedAt\":\"2026-10-30T19:24:16.719Z\",\"rule\":\"If lint says preserve-manual-memoization \\\"This dependency may be modified later\\\", derive the primitive first (`const id = obj?.id ?? \\\"\\\"`) or drop the manual memo: a plain function is fine.\",\"site\":\"https://upfork.dev\",\"snippet\":\"```tsx\\n- const primary = active.find((account) => account.primary) ?? active[0]\\n- const defaults = React.useCallback((): Values => ({ …, accountId: primary?.id ?? \\\"\\\" }), [latest, primary?.id])\\n- const schema = React.useMemo(() => makeSchema(earliest), [earliest])\\n+ const primaryId = (active.find((account) => account.primary) ?? active[0])?.id ?? \\\"\\\"\\n+ const defaults = (): Values => ({ …, accountId: primaryId })\\n+ const schema = makeSchema(earliest)\\n```\",\"title\":\"react-hooks 7.1 fails lint on useCallback/useMemo whose deps it can't prove immutable (`primary?.id`, a helper's result)\",\"type\":\"lesson-version\",\"url\":\"https://upfork.dev/lessons/L-PX71\",\"version\":1,\"why\":\"the React Compiler's validation (run by the lint rule even with the compiler off) only keeps a manual memo whose dependencies it can prove don't change after the memo; a property read through `?.` on an object from a query, or a value it treats as possibly mutable, fails that proof. Why `addDays` differs from `workspaceDay` here is not clear.\"}",
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