Retain $ServerOnly templates while HMR is active

[birkskyum]

Summary

When an SSR application uses $ServerOnly on a component's root JSX element, the initial render and hydration succeed, but the first HMR update throws and leaves stale DOM.

babel-plugin-jsx-dom-expressions@0.40.10 now defaults omitServerOnlyTemplates to true. During a client HMR re-evaluation, Solid Refresh calls the component outside the initial hydration pass, but the compiled component only calls getNextElement() and has no retained template.

Because vite-plugin-solid already determines needHmr, could it default omitServerOnlyTemplates to false for client transforms while HMR is active? An explicit user setting should presumably continue to win.

Reproduction

https://github.com/birkskyum/repro-solid-server-only-hmr

git clone https://github.com/birkskyum/repro-solid-server-only-hmr.git
cd repro-solid-server-only-hmr
pnpm install
pnpm dev

1. Open http://localhost:4174.
2. Change edit me! in src/App.tsx and save.

Actual

The DOM does not update, and the HMR evaluation throws:

TypeError: template is not a function
  at getNextElement (.../solid-js/web/dist/dev.js)
  at _$getNextElement (src/App.tsx)
  at HMRComp.createMemo.name [as fn] (@solid-refresh)

Expected

The component hot-updates normally.

Control / proposed direction

The exact same edit succeeds when the compiler option is set explicitly:

solid({
  ssr: true,
  solid: { omitServerOnlyTemplates: false },
})

This appears to be needed only for the client transform when HMR is enabled; server and production transforms can keep omitting the template.

Versions

• solid-js@1.9.15
• vite-plugin-solid@2.11.14
• babel-preset-solid@1.9.15
• babel-plugin-jsx-dom-expressions@0.40.10
• vite@8.2.1

Downstream report: solidjs/solid-start#1930

Relevant dom-expressions change: ryansolid/dom-expressions@3774c79