Function watch

packages/platform-node-shared/src/internal/fileSystem.ts:581–594

(
  backend: Option.Option<Context.Tag.Service<FileSystem.WatchBackend>>,
  path: string,
  options?: FileSystem.WatchOptions
)

  )

const watch = (
  backend: Option.Option<Context.Tag.Service<FileSystem.WatchBackend>>,
  path: string,
  options?: FileSystem.WatchOptions
) =>
  stat(path).pipe(
    Effect.map((stat) =>
      backend.pipe(
        Option.flatMap((_) => _.register(path, stat, options)),
        Option.getOrElse(() => watchNode(path, options))
      )
    ),
    Stream.unwrap
  )

// == writeFile