Wrong optimization suggestion for react-best-practices #5.4

[grundmanise]

5.4 Extract Default Non-primitive Parameter Value from Memoized Component to Constant

Gives an example where memo should fail. But that's not the case – memo doesn't compare inner component arguments; it compares incoming props. Therefore, the rule and example provided are misleading and don't cause performance issues.

This will memo just fine:

const UserAvatar = memo(function UserAvatar({ onClick = () => {} }: { onClick?: () => void }) {
  // ...
})

// Used without optional onClick
<UserAvatar />

Link: https://github.com/vercel-labs/agent-skills/blob/main/skills/react-best-practices/AGENTS.md#54-extract-default-non-primitive-parameter-value-from-memoized-component-to-constant