Function loadAndTransform

packages/vite/src/node/server/transformRequest.ts:237–444

(
  environment: DevEnvironment,
  id: string,
  url: string,
  options: TransformOptionsInternal,
  timestamp: number,
  mod?: EnvironmentModuleNode,
  resolved?: PartialResolvedId,
)

}

async function loadAndTransform(
  environment: DevEnvironment,
  id: string,
  url: string,
  options: TransformOptionsInternal,
  timestamp: number,
  mod?: EnvironmentModuleNode,
  resolved?: PartialResolvedId,
) {
  const { config, pluginContainer, logger } = environment
  const prettyUrl =
    debugLoad || debugTransform ? prettifyUrl(url, config.root) : class="st">''

  const moduleGraph = environment.moduleGraph

  if (
    !options.skipFsCheck &&
    id[0] !== class="st">'\0' &&
    isServerAccessDeniedForTransform(config, id)
  ) {
    const err: any = new Error(`Denied ID ${id}`)
    err.code = ERR_DENIED_ID
    err.id = id
    throw err
  }

  let code: string | null = null
  let map: SourceDescription[class="st">'map'] = null
  let moduleType: ModuleType | undefined

  class="cm">// load
  const loadStart = debugLoad ? performance.now() : 0
  const loadResult = await pluginContainer.load(id)

  if (loadResult == null) {
    const file = cleanUrl(id)

    class="cm">// try fallback loading it from fs as string
    class="cm">// if the file is a binary, there should be a plugin that already loaded it
    class="cm">// as string
    class="cm">// only try the fallback if access is allowed, skip for out of root url
    class="cm">// like /service-worker.js or /api/users
    if (
      options.skipFsCheck ||
      isFileLoadingAllowed(environment.getTopLevelConfig(), slash(file))
    ) {
      try {
        code = await fsp.readFile(file, class="st">'utf-8')
        debugLoad?.(`${timeFrom(loadStart)} [fs] ${prettyUrl}`)
      } catch (e) {
        if (e.code !== class="st">'ENOENT' && e.code !== class="st">'EISDIR') {
          throw e
        }
      }
      if (code != null && environment.pluginContainer.watcher) {
        ensureWatchedFile(
          environment.pluginContainer.watcher,
          file,