// after successful read
	if _, err := b.ReadBytes('m'); err != nil {
		t.Fatalf("ReadBytes: %v", err)
	}
	if err := b.UnreadByte(); err != nil {
		t.Fatalf("UnreadByte: %v", err)
	}
	c, err := b.ReadByte()
	if err != nil {
		t.Fatalf("ReadByte: %v", err)
	}
	if c != 'm' {
		t.Errorf("ReadByte = %q; want %q", c, 'm')
	}
}

// Tests that we occasionally compact. Issue 5154.

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

"use strict";

(() => {
	const enosys = () => {
		const err = new Error("not implemented");
		err.code = "ENOSYS";
		return err;
	};

	if (!globalThis.fs) {
		let outputBuf = "";
		globalThis.fs = {
			constants: { O_WRONLY: -1, O_RDWR: -1, O_CREAT: -1, O_TRUNC: -1, O_APPEND: -1, O_EXCL: -1 }, // unused

		{"𝟵𝟴𝟳𝟲𝟱.𝟰𝟯𝟮𝟭𝟬", time.Time{}, false}, // Unicode numbers (U+1D7EC to U+1D7F5)
		{"98765﹒43210", time.Time{}, false}, // Unicode period (U+FE52)
	}

	for _, v := range vectors {
		ts, err := parsePAXTime(v.in)
		ok := (err == nil)
		if v.ok != ok {
			if v.ok {
				t.Errorf("parsePAXTime(%q): got parsing failure, want success", v.in)
			} else {
				t.Errorf("parsePAXTime(%q): got parsing success, want failure", v.in)

	"go/format"
	"go/parser"
	"go/scanner"
	"go/token"
	"os"
	"strings"
)

func parse(name string, src []byte, flags parser.Mode) *ast.File {
	ast1, err := parser.ParseFile(fset, name, src, flags)
	if err != nil {
		if list, ok := err.(scanner.ErrorList); ok {
			// If err is a scanner.ErrorList, its String will print just
			// the first error and then (+n more errors).
			// Instead, turn it into a new Error that will return

func tryParse(t *testing.T, parse func()) (err error) {
	panicOnError = true
	defer func() {
		panicOnError = false

		e := recover()
		var ok bool
		if err, ok = e.(error); e != nil && !ok {
			t.Fatal(e)
		}
	}()

	parse()

	return nil
}

func testBadOperandParser(t *testing.T, parser *Parser, tests []badOperandTest) {
	for _, test := range tests {
		err := tryParse(t, func() {

func OpenReader(name string) (*ReadCloser, error) {
	f, err := os.Open(name)
	if err != nil {
		return nil, err
	}
	fi, err := f.Stat()
	if err != nil {
		f.Close()
		return nil, err
	}
	r := new(ReadCloser)
	if err = r.init(f, fi.Size()); err != nil && err != ErrInsecurePath {
		f.Close()
		return nil, err
	}
	r.f = f
	return r, err
}

		if f.method == Deflate {
			var buf bytes.Buffer
			w, err := flate.NewWriter(&buf, flate.BestSpeed)
			if err != nil {
				t.Fatalf("flate.NewWriter err = %v", err)
			}
			_, err = w.Write(f.content)
			if err != nil {
				t.Fatalf("flate Write err = %v", err)
			}
			err = w.Close()
			if err != nil {
				t.Fatalf("flate Writer.Close err = %v", err)
			}
			compressedContent = buf.Bytes()

		// If we've run out of data but have an error, give the split function
		// a chance to recover any remaining, possibly empty token.
		if s.end > s.start || s.err != nil {
			advance, token, err := s.split(s.buf[s.start:s.end], s.err != nil)
			if err != nil {
				if err == ErrFinalToken {
					s.token = token
					s.done = true
					// When token is not nil, it means the scanning stops

			}

			var cnt int
			var err error
			for {
				if _, err = tr.Next(); err != nil {
					break
				}
				cnt++
				if s2 == "manual" {
					if _, err = tr.writeTo(io.Discard); err != nil {
						break
					}
				}
			}
			if err != v.err {
				t.Errorf("test %d, NewReader(%s) with %s discard: got %v, want %v",
					i, s1, s2, err, v.err)
			}
			if cnt != v.cnt {

// ReadBytes returns err != nil if and only if the returned data does not end in
// delim.
func (b *Buffer) ReadBytes(delim byte) (line []byte, err error) {
	slice, err := b.readSlice(delim)
	// return a copy of slice. The buffer's backing array may
	// be overwritten by later calls.
	line = append(line, slice...)
	return line, err
}