Function resolveRolldownOptions

packages/vite/src/node/build.ts:586–808

(
  environment: Environment,
  chunkMetadataMap: ChunkMetadataMap,
)

}

export function resolveRolldownOptions(
  environment: Environment,
  chunkMetadataMap: ChunkMetadataMap,
): RolldownOptions {
  const { root, packageCache, base, build: options } = environment.config
  const libOptions = options.lib
  const { logger } = environment
  const ssr = environment.config.consumer === 'server'

  const resolve = (p: string) => path.resolve(root, p)
  const input = libOptions
    ? options.rolldownOptions.input ||
      (typeof libOptions.entry === 'string'
        ? resolve(libOptions.entry)
        : Array.isArray(libOptions.entry)
          ? libOptions.entry.map(resolve)
          : Object.fromEntries(
              Object.entries(libOptions.entry).map(([alias, file]) => [
                alias,
                resolve(file),
              ]),
            ))
    : typeof options.ssr === 'string'
      ? resolve(options.ssr)
      : options.rolldownOptions.input || resolve('index.html')

  if (ssr && typeof input === 'string' && input.endsWith('.html')) {
    throw new Error(
      `rolldownOptions.input should not be an html file when building for SSR. ` +
        `Please specify a dedicated SSR entry.`,
    )
  }
  if (options.cssCodeSplit === false) {
    const inputs =
      typeof input === 'string'
        ? [input]
        : Array.isArray(input)
          ? input
          : Object.values(input)
    if (inputs.some((input) => input.endsWith('.css'))) {
      throw new Error(
        `When "build.cssCodeSplit: false" is set, "rolldownOptions.input" should not include CSS files.`,
      )
    }
  }

  const outDir = resolve(options.outDir)

  // inject environment and ssr arg to plugin load/transform hooks
  const plugins = environment.plugins.map((p) =>
    injectEnvironmentToHooks(environment, chunkMetadataMap, p),
  )

  const rolldownOptions: RolldownOptions = {
    preserveEntrySignatures: ssr
      ? 'allow-extension'
      : libOptions
        ? 'strict'