[mizchi]

The current Solid island implementation calls render() instead of hydrate().

It clears the server HTML and replaces the DOM, discarding input entered before activation. This PR uses hydrate() with a matching SSR root for each island instance.

What this PR changes

• Assign each island instance a unique renderId, scope its SSR hydration keys to that root, and store the ID in data-solid-render-id. The existing SSR serializer and Suspense state are retained, and the parent hydration context is restored in finally.
• Use the same FrontmatterContext.Provider tree on the server and client, then call hydrate() with the stored ID without clearing the element.
• Allow a delayed island to hydrate after another island handles an event. Solid 1.x sets document-wide completion flags on the first delegated event, so the adapter resets those flags before hydrating the next island.

The island import syntax and hydration scheduling API are unchanged.

Decisions for review

The implementation accesses Solid 1.x's sharedConfig.context, sharedConfig.done and globalThis._$HY.done. The latter two writes prevent a later hydrate() from falling back to client rendering after a click in an earlier island. This dependency on Solid's internal hydration state needs review, especially for other asynchronous hydration scenarios. Local verification used Solid 1.9.17.

Testing

The pre-fix DOM-reuse regression failed: both the button and input were replaced, and the input value was lost. The new browser suite passes all 6 cases across Vite dev and a production build/preview:

• Repeated islands and an island layout retain the original button/input nodes, input values, label associations and frontmatter; counter state remains independent.
• Two visible islands hydrate in reverse order after an earlier island handles a click.
• An async resource inside Suspense retains its resolved SSR DOM and remains interactive.

vp run build:all, vp run check, vp lint, and the formatter check for the two changed files passed.

The full suite is not green locally: 13,895 passed, 18 failed, 27 skipped. The same 18 failures reproduced after restoring and rebuilding the base adapter at 83799305bbe4 and rerunning the three affected test files.

Validation commands and existing failures

vp test run packages/solid/test/integration/island-hydration.test.ts
vp run build:all
vp run check
vp lint
vp fmt --check packages/solid/src/plugin-islands.ts packages/solid/test/integration/island-hydration.test.ts
vp run test
vp test run

The failures are in:

• packages/void/test/integration/init-install.test.ts: 3 failures.
• packages/void/test/unit/init.test.ts: 14 failures.
• packages/void/test/unit/nitro.test.ts: 1 failure.

The changed-file selection also completed: 10,598 passed, the same 18 failed, and 27 skipped. Live Cloudflare deployment credentials were unset during both suite runs.

Searched issues and PRs in all states for solid hydrate and hydration Solid; no matching report or fix was found.

AI disclosure

I used OpenAI Codex to implement the fix, write the regression tests, and prepare this PR description. The verification commands above were run locally.

[Brooooooklyn]

@codex review

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-19T07:15:51.035053Z	7219ea3	Manual request

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 7219ea39cc

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[Brooooooklyn]

Merge activity

• Oct 19, 8:00 AM UTC: A user started a stack merge that includes this pull request via Graphite.
• Oct 19, 8:00 AM UTC: Graphite couldn't merge this PR because it failed for an unknown reason (Fast-forward merges are not supported for forked repositories. Please create a branch in the target repository in order to merge).