Function make

packages/effect/src/FileSystem.ts:686–762

(
  impl: Omit<FileSystem, typeof TypeId | "exists" | "readFileString" | "stream" | "sink" | "writeFileString">
)

 * @since 4.0.0
 */
export const make = (
  impl: Omit<FileSystem, typeof TypeId | "exists" | "readFileString" | "stream" | "sink" | "writeFileString">
): FileSystem =>
  FileSystem.of({
    ...impl,
    [TypeId]: TypeId,
    exists: (path) =>
      pipe(
        impl.access(path),
        Effect.as(true),
        Effect.catchTag(
          "PlatformError",
          (e) => e.reason._tag === "NotFound" ? Effect.succeed(false) : Effect.fail(e)
        )
      ),
    readFileString: (path, encoding) =>
      Effect.flatMap(impl.readFile(path), (_) =>
        Effect.try({
          try: () => new TextDecoder(encoding).decode(_),
          catch: (cause) =>
            badArgument({
              module: "FileSystem",
              method: "readFileString",
              description: "invalid encoding",
              cause
            })
        })),
    stream: Effect.fnUntraced(function*(path, options) {
      const file = yield* impl.open(path, { flag: "r" })
      if (options?.offset) {
        yield* file.seek(options.offset, "start")
      }
      const bytesToRead = options?.bytesToRead !== undefined ? Size(options.bytesToRead) : undefined
      let totalBytesRead = BigInt(0)
      const chunkSize = Size(options?.chunkSize ?? 64 * 1024)
      const readChunk = file.readAlloc(chunkSize)
      return Stream.fromPull(Effect.succeed(
        Effect.flatMap(
          Effect.suspend((): Pull.Pull<Option.Option<Uint8Array>, PlatformError> => {
            if (bytesToRead !== undefined && bytesToRead <= totalBytesRead) {
              return Cause.done()
            }
            return bytesToRead !== undefined && (bytesToRead - totalBytesRead) < chunkSize
              ? file.readAlloc(bytesToRead - totalBytesRead)
              : readChunk
          }),
          Option.match({
            onNone: () => Cause.done(),
            onSome: (buf) => {
              totalBytesRead += BigInt(buf.length)
              return Effect.succeed(Arr.of(buf))
            }
          })
        )
      ))
    }, Stream.unwrap),
    sink: (path, options) =>
      pipe(