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,
    },
  },
})