react-doctor/server-dedup-props

Pass the source array once and derive the projection on the client — passing both doubles RSC serialization bytes

• Category: Server
• Severity: warn
• Source: oxlint-plugin-react-doctor
• Framework: global
• Enabled when: always

Validation prompt

Use this to decide whether a fired diagnostic is real or a false positive.

Rule walks the attributes on a single JSXOpeningElement: it maps identifier-valued props by their identifier name, then reports any other prop whose value is a .toSorted(), .toReversed(), .filter(), .map(), or .slice() call chained off that same root identifier. Both projections then serialize across the RSC wire. Skip when the projection differs enough that client-side re-derivation would duplicate non-trivial server logic.

Fix prompt

Use this once validation confirms the diagnostic is real.

Send the source array once and derive the projection on the client with useMemo, or pre-derive on the server and drop the source prop entirely. Doubling the RSC payload to save a one-line client transform is rarely worth it. See https://react.dev/reference/rsc/use-client#serializable-types

Related rules

More Server rules from the rules reference:

• react-doctor/server-fetch-without-revalidate: Pass `{ next: { revalidate: <seconds> } }` (or `cache: "no-store"` / `next: { tags: [...] }`) so stale cached data doesn't silently persist
• react-doctor/server-hoist-static-io: Hoist the read to module scope: `const FONT_DATA = await fetch(new URL('./fonts/Inter.ttf', import.meta.url)).then(r => r.arrayBuffer())` runs once at module load
• react-doctor/server-no-mutable-module-state: Move per-request data into the action body, headers/cookies, or a request-scope (React.cache, AsyncLocalStorage). Module-scope `let`/`var` is shared across requests.
• react-doctor/server-sequential-independent-await: Wrap independent awaits in `Promise.all([...])` so they race instead of waterfalling — second call doesn't depend on the first
• react-doctor/server-after-nonblocking: `import { after } from 'next/server'` then wrap: `after(() => analytics.track(...))` — response isn't blocked