loadConfigFromBundledFile() — vite Function Reference

Source Code

packages/vite/src/node/config.ts lines 2544–2611

async function loadConfigFromBundledFile(
  fileName: string,
  bundledCode: string,
  isESM: boolean,
): Promise<UserConfigExport> {
  // for esm, before we can register loaders without requiring users to run node
  // with --experimental-loader themselves, we have to do a hack here:
  // write it to disk, load it with native Node ESM, then delete the file.
  if (isESM) {
    // Storing the bundled file in node_modules/ is avoided for Deno
    // because Deno only supports Node.js style modules under node_modules/
    // and configs with `npm:` import statements will fail when executed.
    let nodeModulesDir =
      typeof process.versions.deno === 'string'
        ? undefined
        : findNearestNodeModules(path.dirname(fileName))
    if (nodeModulesDir) {
      try {
        await fsp.mkdir(path.resolve(nodeModulesDir, '.vite-temp/'), {
          recursive: true,
        })
      } catch (e) {
        if (e.code === 'EACCES') {
          // If there is no access permission, a temporary configuration file is created by default.
          nodeModulesDir = undefined
        } else {
          throw e
        }
      }
    }
    const hash = `timestamp-${Date.now()}-${Math.random().toString(16).slice(2)}`
    const tempFileName = nodeModulesDir
      ? path.resolve(
          nodeModulesDir,
          `.vite-temp/${path.basename(fileName)}.${hash}.mjs`,
        )
      : `${fileName}.${hash}.mjs`
    await fsp.writeFile(tempFileName, bundledCode)
    try {
      return (await import(pathToFileURL(tempFileName).href)).default
    } finally {
      fs.unlink(tempFileName, () => {}) // Ignore errors
    }
  }
  // for cjs, we can register a custom loader via `_require.extensions`
  else {
    const extension = path.extname(fileName)
    // We don't use fsp.realpath() here because it has the same behaviour as
    // fs.realpath.native. On some Windows systems, it returns uppercase volume
    // letters (e.g. "C:\") while the Node.js loader uses lowercase volume letters.
    // See https://github.com/vitejs/vite/issues/12923
    const realFileName = await promisifiedRealpath(fileName)
    const loaderExt = extension in _require.extensions ? extension : '.js'
    const defaultLoader = _require.extensions[loaderExt]!
    _require.extensions[loaderExt] = (module: NodeModule, filename: string) => {
      if (filename === realFileName) {
        ;(module as NodeModuleWithCompile)._compile(bundledCode, filename)
      } else {
        defaultLoader(module, filename)
      }
    }
    // clear cache in case of server restart
    delete _require.cache[_require.resolve(fileName)]
    const raw = _require(fileName)
    _require.extensions[loaderExt] = defaultLoader
    return raw.__esModule ? raw.default : raw
  }
}