Enable React Compiler for Portal (lazy-ref → useState)

[mattcosta7]

Closes #

Enable React Compiler for Portal

Note

Depends on / based on the migration foundation PR (base branch react-compiler-migrate-all-prep). Diff shown here is Portal-only.

Portal was on the React Compiler unsupportedPatterns allowlist because it read/wrote a ref during render (two react-hooks/refs disables) to lazily create its container <div>. This replaces that with the canonical useState lazy-initializer, which obeys the Rules of React, then removes Portal from the allowlist so it's compiled.

- const elementRef = React.useRef<HTMLDivElement | null>(null)
- // eslint-disable-next-line react-hooks/refs
- if (!elementRef.current) { ... elementRef.current = div }
- // eslint-disable-next-line react-hooks/refs
- const element = elementRef.current
+ const [element] = React.useState<HTMLDivElement>(() => { ...; return div })

Net −3 lines, no behavior change (the container is still created once and reused; SSR profile is identical since the original also created the element during render).

Validation

• eslint src/Portal/Portal.tsx passes with no react-hooks/refs disables.
• Portal test suite passes compiled (9/9).

Rollout

• Patch release

Merge checklist

• Added/updated tests (existing suite runs compiled)
• Changes are SSR compatible

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🦋 Changeset detected

Latest commit: 806aa6a

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@primer/react	Minor

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[github-actions]

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[primer]

🤖 Lint issues have been automatically fixed and committed to this PR.