// Copyright 2011 The Go Authors. All rights reserved.// Use of this source code is governed by a BSD-style// license that can be found in the LICENSE file. package binary import (	"bytes"	"io"	"testing") func testConstant(t *testing.T, w uint, max int) {	buf := make([]byte, MaxVarintLen64)	n := PutUvarint(buf, 1<<w-1)	if n != max {		t.Errorf("MaxVarintLen%d = %d; want %d", w, max, n)	}} func TestConstants(t *testing.T) {	testConstant(t, 16, MaxVarintLen16)	testConstant(t, 32, MaxVarintLen32)	testConstant(t, 64, MaxVarintLen64)} func testVarint(t *testing.T, x int64) {	buf := make([]byte, MaxVarintLen64)	n := PutVarint(buf, x)	y, m := Varint(buf[0:n])	if x != y {		t.Errorf("Varint(%d): got %d", x, y)	}	if n != m {		t.Errorf("Varint(%d): got n = %d; want %d", x, m, n)	} 	y, err := ReadVarint(bytes.NewReader(buf))	if err != nil {		t.Errorf("ReadVarint(%d): %s", x, err)	}	if x != y {		t.Errorf("ReadVarint(%d): got %d", x, y)	}} func testUvarint(t *testing.T, x uint64) {	buf := make([]byte, MaxVarintLen64)	n := PutUvarint(buf, x)	y, m := Uvarint(buf[0:n])	if x != y {		t.Errorf("Uvarint(%d): got %d", x, y)	}	if n != m {		t.Errorf("Uvarint(%d): got n = %d; want %d", x, m, n)	} 	y, err := ReadUvarint(bytes.NewReader(buf))	if err != nil {		t.Errorf("ReadUvarint(%d): %s", x, err)	}	if x != y {		t.Errorf("ReadUvarint(%d): got %d", x, y)	}} var tests = []int64{	-1 << 63,	-1<<63 + 1,	-1,	0,	1,	2,	10,	20,	63,	64,	65,	127,	128,	129,	255,	256,	257,	1<<63 - 1,} func TestVarint(t *testing.T) {	for _, x := range tests {		testVarint(t, x)		testVarint(t, -x)	}	for x := int64(0x7); x != 0; x <<= 1 {		testVarint(t, x)		testVarint(t, -x)	}} func TestUvarint(t *testing.T) {	for _, x := range tests {		testUvarint(t, uint64(x))	}	for x := uint64(0x7); x != 0; x <<= 1 {		testUvarint(t, x)	}} func TestBufferTooSmall(t *testing.T) {	buf := []byte{0x80, 0x80, 0x80, 0x80}	for i := 0; i <= len(buf); i++ {		buf := buf[0:i]		x, n := Uvarint(buf)		if x != 0 || n != 0 {			t.Errorf("Uvarint(%v): got x = %d, n = %d", buf, x, n)		} 		x, err := ReadUvarint(bytes.NewReader(buf))		if x != 0 || err != io.EOF {			t.Errorf("ReadUvarint(%v): got x = %d, err = %s", buf, x, err)		}	}} func testOverflow(t *testing.T, buf []byte, n0 int, err0 error) {	x, n := Uvarint(buf)	if x != 0 || n != n0 {		t.Errorf("Uvarint(%v): got x = %d, n = %d; want 0, %d", buf, x, n, n0)	} 	x, err := ReadUvarint(bytes.NewReader(buf))	if x != 0 || err != err0 {		t.Errorf("ReadUvarint(%v): got x = %d, err = %s; want 0, %s", buf, x, err, err0)	}} func TestOverflow(t *testing.T) {	testOverflow(t, []byte{0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x2}, -10, overflow)	testOverflow(t, []byte{0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x1, 0, 0}, -13, overflow)} func TestNonCanonicalZero(t *testing.T) {	buf := []byte{0x80, 0x80, 0x80, 0}	x, n := Uvarint(buf)	if x != 0 || n != 4 {		t.Errorf("Uvarint(%v): got x = %d, n = %d; want 0, 4", buf, x, n) 	}} func BenchmarkPutUvarint32(b *testing.B) {	buf := make([]byte, MaxVarintLen32)	b.SetBytes(4)	for i := 0; i < b.N; i++ {		for j := uint(0); j < MaxVarintLen32; j++ {			PutUvarint(buf, 1<<(j*7))		}	}} func BenchmarkPutUvarint64(b *testing.B) {	buf := make([]byte, MaxVarintLen64)	b.SetBytes(8)	for i := 0; i < b.N; i++ {		for j := uint(0); j < MaxVarintLen64; j++ {			PutUvarint(buf, 1<<(j*7))		}	}}