//go:build js && wasm

package bytes_test

import (
	"bytes"
	"testing"
)

func TestIssue65571(t *testing.T) {
	b := make([]byte, 1<<31+1)
	b[1<<31] = 1
	i := bytes.IndexByte(b, 1)
	if i != 1<<31 {
		t.Errorf("IndexByte(b, 1) = %d; want %d", i, 1<<31)
	}

		Equal(b[len(b)-i:], b[:i])
	}
}

func TestIndexByteNearPageBoundary(t *testing.T) {
	t.Parallel()
	b := dangerousSlice(t)
	for i := range b {
		idx := IndexByte(b[i:], 1)
		if idx != -1 {
			t.Fatalf("IndexByte(b[%d:])=%d, want -1\n", i, idx)
		}
	}
}

func TestIndexNearPageBoundary(t *testing.T) {
	t.Parallel()
	q := dangerousSlice(t)
	if len(q) > 64 {

			b1[j] = 'x'
			pos := IndexByte(b1, 'x')
			if pos != j {
				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
			}
			b1[j] = 0
			pos = IndexByte(b1, 'x')
			if pos != -1 {
				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
			}
		}
		// different end alignments
		b1 = b[:i]
		for j := 0; j < len(b1); j++ {
			b1[j] = 'x'
			pos := IndexByte(b1, 'x')
			if pos != j {

func ContainsFunc(b []byte, f func(rune) bool) bool {
	return IndexFunc(b, f) >= 0
}

// IndexByte returns the index of the first instance of c in b, or -1 if c is not present in b.
func IndexByte(b []byte, c byte) int {
	return bytealg.IndexByte(b, c)
}

func indexBytePortable(s []byte, c byte) int {
	for i, b := range s {
		if b == c {
			return i
		}
	}
	return -1

	limit := dirent.Reclen - fixedHdr
	if limit > nameBufLen {
		limit = nameBufLen
	}
	// Avoid bugs in long file names
	// https://github.com/golang/tools/commit/5f9a5413737ba4b4f692214aebee582b47c8be74
	nameLen := bytes.IndexByte(nameBuf[:limit], 0)
	if nameLen < 0 {
		return 0, fmt.Errorf("failed to find terminating 0 byte in dirent")
	}
	return uint64(nameLen), nil

			k := strings.TrimSpace(strings.ToUpper(v[0]))
			if k == "INDEX" || k == "UNIQUEINDEX" {
				var (
					name       string
					tag        = strings.Join(v[1:], ":")
					idx        = strings.IndexByte(tag, ',')
					tagSetting = strings.Join(strings.Split(tag, ",")[1:], ",")
					settings   = ParseTagSetting(tagSetting, ",")
					length, _  = strconv.Atoi(settings["LENGTH"])
				)

				if idx == -1 {

// It returns a single-use iterator.
func Lines(s []byte) iter.Seq[[]byte] {
	return func(yield func([]byte) bool) {
		for len(s) > 0 {
			var line []byte
			if i := IndexByte(s, '\n'); i >= 0 {
				line, s = s[:i+1], s[i+1:]
			} else {
				line, s = s, nil
			}
			if !yield(line[:len(line):len(line)]) {
				return
			}
		}
	}
}

	input := bufio.NewScanner(bytes.NewReader(valueBuffer.Bytes()))
	for input.Scan() {
		line := strings.TrimSpace(input.Text())
		if line == "" {
			continue
		}
		// Find first separator.
		idx := strings.IndexByte(line, trailerKVSeparator[0])
		if idx <= 0 || idx >= len(line) {
			if cr.debug {
				fmt.Printf("Could not find separator, got %q\n", line)
			}
			return errMalformedEncoding
		}

// list with an empty final value but stops at the token "STOP".
func ExampleScanner_earlyStop() {
	onComma := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
		i := bytes.IndexByte(data, ',')
		if i == -1 {
			if !atEOF {
				return 0, nil, nil
			}
			// If we have reached the end, return the last token.
			return 0, data, bufio.ErrFinalToken
		}

	fmt.Println(bytes.Index([]byte("chicken"), []byte("dmr")))
	// Output:
	// 4
	// -1
}

func ExampleIndexByte() {
	fmt.Println(bytes.IndexByte([]byte("chicken"), byte('k')))
	fmt.Println(bytes.IndexByte([]byte("chicken"), byte('g')))
	// Output:
	// 4
	// -1
}

func ExampleIndexFunc() {
	f := func(c rune) bool {
		return unicode.Is(unicode.Han, c)
	}