[sheremet-va]

TODO

• remove ws injection on rolldown side https://github.com/rolldown/rolldown/blob/d7f919c18980e6b4a26d06bd071d7cf14cf810a7/crates/rolldown_plugin_hmr/src/hmr_plugin.rs
• remove const __require = createRequire() in rolldown (somewhere)
• remove ws dependency from the playground

I am exploring how full bundle mode can be supported in SSR. At the moment the goal is to support environments.ssr.runner.import and environment.fetchModule. Module graph, transformRequest, pluginContainer are out of scope of this PR, but they will be revisited later.

Known quirks (to discuss)

• url in runner.import(url) is not resolved with resolveId like it is done usually. Instead it accepts:
  • Absolute URL to the bundled entry point specified in rolldownOptions.input
  • Relative URL (relative to root) to the bundled entry point
  • The chunk name
  • Relative URL to the bundled entry point starting with / (/entry-point.js vs ./entry-point.js)
  • The url must be an actual filename or a URL with the extension at the end
• import.meta.url, import.meta.filename and import.meta.dirname reference "would be" (or "virtual") files, these are the URLs that would exist if vite kept the bundle on the file system. Doing something like readFileSync(import.meta.filename) will throw an error because the file does not exist on disk
  • For example for the build configuration like { ourDir: './dist' }, the filename would be something like <root>/dist/asset/chunk-1.js

To enable full bundle mode in SSR, add this to the config:

export default defineConfig({
  environments: {
    ssr: {
      isBundled: true,
    },
  },
})

[jamesopstad]

Very excited to see the beginnings of this!

[RomanHotsiy]

Hi @sheremet-va 🙌 , thanks again fo this work!

I finally tried the branch on a real SSR app (Hono + React streaming SSR through environments.ssr.runner:

• ~1.6k modules-
• noExternal: true
• module runners in child processes

and it is mainly working!
Page edits went from a 1.1 s graph re-evaluation to a 22 ms patch.

There are a few issues found by Claude which we verified and fixed on our side to make it work.

• fetchBundledModule re-runs ssrTransform on the whole chunk for every runner.import() (the runner always invokes fetchModule; cached is ignored) — ~450 ms per request on a 10 MB chunk.
• A build error is sent as an error payload through the server runner transport, which throws and exits the process; full-reload is rejected the same way.
• reloadPending is never re-armed for the module runner after a program reload, so later pushes are dropped.
• Dynamic imports return the stale chunk namespace after a patch; regionId is only set for config entries.
  runner.import() of a module's own virtual import.meta.url throws "Entrypoint … was not defined".
• On 8.3.1, rolldown patches call rolldown_runtime.payloadDelivered, which the runner's runtime lacks, so every patch fell back to a program reload.