var with, withOut nErr
	with.n, with.err = io.Copy(discard, NewReader(nil))
	withOut.n, withOut.err = io.Copy(discard, justReader{NewReader(nil)})
	if with != withOut {
		t.Errorf("behavior differs: with = %#v; without: %#v", with, withOut)
	}
}

// tests that Len is affected by reads, but Size is not.
func TestReaderLenSize(t *testing.T) {
	r := NewReader([]byte("abc"))
	io.CopyN(io.Discard, r, 1)
	if r.Len() != 2 {

	bf := bufio.NewReader(r)
	switch f := detect(bf); f {
	case formatGzip:
		gz, err := gzip.NewReader(bf)
		if err != nil {
			return err
		}
		defer gz.Close()
		r = gz
	case formatS2:
		r = s2.NewReader(bf)
	case formatZstd:
		// Limit to 16 MiB per stream.
		dec, err := zstd.NewReader(bf, zstd.WithDecoderMaxWindow(16<<20))
		if err != nil {

		zr, err := zstd.NewReader(scannedReader, zstd.WithDecoderConcurrency(2), zstd.WithDecoderMaxWindow(64<<20))
		if err != nil {
			return nil, errInvalidCompression(err, compType)
		}
		r = zr
		pr.closer = zr.IOReadCloser()
	case lz4Type:
		r = lz4.NewReader(scannedReader)
	case s2Type:
		r = s2.NewReader(scannedReader)
	case snappyType:
		r = s2.NewReader(scannedReader, s2.ReaderMaxBlockSize(64<<10))

func (r *Reader) startReaders(newReader func(io.Reader) *csv.Reader) error {
	if r.args.FileHeaderInfo != none {
		// Read column names
		// Get one line.
		b, err := r.nextSplit(0, nil)
		if err != nil {
			r.err = err
			return err
		}
		if !utf8.Valid(b) {
			return errInvalidTextEncodingError()
		}
		reader := newReader(bytes.NewReader(b))
		record, err := reader.Read()
		if err != nil {

		t.Fatal(err)
	}
	for _, file := range files {
		t.Run(file.Name(), func(t *testing.T) {
			f, err := os.Open(filepath.Join("testdata", file.Name()))
			if err != nil {
				t.Fatal(err)
			}
			r := NewReader(f, &ReaderArgs{})
			var record sql.Record
			for {
				record, err = r.Read(record)
				if err != nil {
					break
				}
			}
			r.Close()
			if err != io.EOF {

	for range r.valueCh {
		// Drain values so we don't leak a goroutine.
		// Since we have closed the input, it should fail rather quickly.
	}
	return err
}

// NewReader - creates new JSON reader using readCloser.
func NewReader(readCloser io.ReadCloser, args *ReaderArgs) *Reader {
	readCloser = &syncReadCloser{rc: readCloser}
	d := jstream.NewDecoder(io.LimitReader(readCloser, maxDocumentSize), 0).ObjectAsKVS().MaxDepth(100)

		b, err := os.ReadFile(filepath.Join("testdata", de.Name()))
		if err != nil {
			f.Fatalf("failed to read testdata: %s", err)
		}
		f.Add(b)
	}

	f.Fuzz(func(t *testing.T, b []byte) {
		r, err := NewReader(bytes.NewReader(b), int64(len(b)))
		if err != nil {
			return
		}

		type file struct {
			header  *FileHeader
			content []byte
		}
		files := []file{}

		for _, f := range r.File {

	m.wg.Wait()
	close(m.opCh)
	atomic.StoreInt32(&m.closed, 1)

	if len(m.opCh) > 0 {
		healingLogEvent(context.Background(), "Saving MRF healing data (%d entries)", len(m.opCh))
	}

	newReader := func() io.ReadCloser {
		r, w := io.Pipe()
		go func() {
			// Initialize MRF meta header.
			var data [4]byte
			binary.LittleEndian.PutUint16(data[0:2], healMRFMetaFormat)

	}
	if err := w.Close(); err != nil {
		f.Fatalf("failed to write archive: %s", err)
	}
	f.Add(b.Bytes())

	f.Fuzz(func(t *testing.T, b []byte) {
		r := NewReader(bytes.NewReader(b))
		type file struct {
			header  *Header
			content []byte
		}
		files := []file{}
		for {
			hdr, err := r.Next()
			if err == io.EOF {
				break
			}
			if err != nil {
				return

		err = io.ErrShortWrite
	}
	return
}

// Reset resets the [Reader] to be reading from b.
func (r *Reader) Reset(b []byte) { *r = Reader{b, 0, -1} }

// NewReader returns a new [Reader] reading from b.