Source file src/bytes/bytes_test.go

Documentation: bytes

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package bytes_test
     6  
     7  import (
     8  	. "bytes"
     9  	"fmt"
    10  	"internal/testenv"
    11  	"math"
    12  	"math/rand"
    13  	"reflect"
    14  	"strings"
    15  	"testing"
    16  	"unicode"
    17  	"unicode/utf8"
    18  	"unsafe"
    19  )
    20  
    21  func eq(a, b []string) bool {
    22  	if len(a) != len(b) {
    23  		return false
    24  	}
    25  	for i := 0; i < len(a); i++ {
    26  		if a[i] != b[i] {
    27  			return false
    28  		}
    29  	}
    30  	return true
    31  }
    32  
    33  func sliceOfString(s [][]byte) []string {
    34  	result := make([]string, len(s))
    35  	for i, v := range s {
    36  		result[i] = string(v)
    37  	}
    38  	return result
    39  }
    40  
    41  // For ease of reading, the test cases use strings that are converted to byte
    42  // slices before invoking the functions.
    43  
    44  var abcd = "abcd"
    45  var faces = "☺☻☹"
    46  var commas = "1,2,3,4"
    47  var dots = "1....2....3....4"
    48  
    49  type BinOpTest struct {
    50  	a string
    51  	b string
    52  	i int
    53  }
    54  
    55  func TestEqual(t *testing.T) {
    56  	// Run the tests and check for allocation at the same time.
    57  	allocs := testing.AllocsPerRun(10, func() {
    58  		for _, tt := range compareTests {
    59  			eql := Equal(tt.a, tt.b)
    60  			if eql != (tt.i == 0) {
    61  				t.Errorf(`Equal(%q, %q) = %v`, tt.a, tt.b, eql)
    62  			}
    63  		}
    64  	})
    65  	if allocs > 0 {
    66  		t.Errorf("Equal allocated %v times", allocs)
    67  	}
    68  }
    69  
    70  func TestEqualExhaustive(t *testing.T) {
    71  	var size = 128
    72  	if testing.Short() {
    73  		size = 32
    74  	}
    75  	a := make([]byte, size)
    76  	b := make([]byte, size)
    77  	b_init := make([]byte, size)
    78  	// randomish but deterministic data
    79  	for i := 0; i < size; i++ {
    80  		a[i] = byte(17 * i)
    81  		b_init[i] = byte(23*i + 100)
    82  	}
    83  
    84  	for len := 0; len <= size; len++ {
    85  		for x := 0; x <= size-len; x++ {
    86  			for y := 0; y <= size-len; y++ {
    87  				copy(b, b_init)
    88  				copy(b[y:y+len], a[x:x+len])
    89  				if !Equal(a[x:x+len], b[y:y+len]) || !Equal(b[y:y+len], a[x:x+len]) {
    90  					t.Errorf("Equal(%d, %d, %d) = false", len, x, y)
    91  				}
    92  			}
    93  		}
    94  	}
    95  }
    96  
    97  // make sure Equal returns false for minimally different strings. The data
    98  // is all zeros except for a single one in one location.
    99  func TestNotEqual(t *testing.T) {
   100  	var size = 128
   101  	if testing.Short() {
   102  		size = 32
   103  	}
   104  	a := make([]byte, size)
   105  	b := make([]byte, size)
   106  
   107  	for len := 0; len <= size; len++ {
   108  		for x := 0; x <= size-len; x++ {
   109  			for y := 0; y <= size-len; y++ {
   110  				for diffpos := x; diffpos < x+len; diffpos++ {
   111  					a[diffpos] = 1
   112  					if Equal(a[x:x+len], b[y:y+len]) || Equal(b[y:y+len], a[x:x+len]) {
   113  						t.Errorf("NotEqual(%d, %d, %d, %d) = true", len, x, y, diffpos)
   114  					}
   115  					a[diffpos] = 0
   116  				}
   117  			}
   118  		}
   119  	}
   120  }
   121  
   122  var indexTests = []BinOpTest{
   123  	{"", "", 0},
   124  	{"", "a", -1},
   125  	{"", "foo", -1},
   126  	{"fo", "foo", -1},
   127  	{"foo", "baz", -1},
   128  	{"foo", "foo", 0},
   129  	{"oofofoofooo", "f", 2},
   130  	{"oofofoofooo", "foo", 4},
   131  	{"barfoobarfoo", "foo", 3},
   132  	{"foo", "", 0},
   133  	{"foo", "o", 1},
   134  	{"abcABCabc", "A", 3},
   135  	// cases with one byte strings - test IndexByte and special case in Index()
   136  	{"", "a", -1},
   137  	{"x", "a", -1},
   138  	{"x", "x", 0},
   139  	{"abc", "a", 0},
   140  	{"abc", "b", 1},
   141  	{"abc", "c", 2},
   142  	{"abc", "x", -1},
   143  	{"barfoobarfooyyyzzzyyyzzzyyyzzzyyyxxxzzzyyy", "x", 33},
   144  	{"fofofofooofoboo", "oo", 7},
   145  	{"fofofofofofoboo", "ob", 11},
   146  	{"fofofofofofoboo", "boo", 12},
   147  	{"fofofofofofoboo", "oboo", 11},
   148  	{"fofofofofoooboo", "fooo", 8},
   149  	{"fofofofofofoboo", "foboo", 10},
   150  	{"fofofofofofoboo", "fofob", 8},
   151  	{"fofofofofofofoffofoobarfoo", "foffof", 12},
   152  	{"fofofofofoofofoffofoobarfoo", "foffof", 13},
   153  	{"fofofofofofofoffofoobarfoo", "foffofo", 12},
   154  	{"fofofofofoofofoffofoobarfoo", "foffofo", 13},
   155  	{"fofofofofoofofoffofoobarfoo", "foffofoo", 13},
   156  	{"fofofofofofofoffofoobarfoo", "foffofoo", 12},
   157  	{"fofofofofoofofoffofoobarfoo", "foffofoob", 13},
   158  	{"fofofofofofofoffofoobarfoo", "foffofoob", 12},
   159  	{"fofofofofoofofoffofoobarfoo", "foffofooba", 13},
   160  	{"fofofofofofofoffofoobarfoo", "foffofooba", 12},
   161  	{"fofofofofoofofoffofoobarfoo", "foffofoobar", 13},
   162  	{"fofofofofofofoffofoobarfoo", "foffofoobar", 12},
   163  	{"fofofofofoofofoffofoobarfoo", "foffofoobarf", 13},
   164  	{"fofofofofofofoffofoobarfoo", "foffofoobarf", 12},
   165  	{"fofofofofoofofoffofoobarfoo", "foffofoobarfo", 13},
   166  	{"fofofofofofofoffofoobarfoo", "foffofoobarfo", 12},
   167  	{"fofofofofoofofoffofoobarfoo", "foffofoobarfoo", 13},
   168  	{"fofofofofofofoffofoobarfoo", "foffofoobarfoo", 12},
   169  	{"fofofofofoofofoffofoobarfoo", "ofoffofoobarfoo", 12},
   170  	{"fofofofofofofoffofoobarfoo", "ofoffofoobarfoo", 11},
   171  	{"fofofofofoofofoffofoobarfoo", "fofoffofoobarfoo", 11},
   172  	{"fofofofofofofoffofoobarfoo", "fofoffofoobarfoo", 10},
   173  	{"fofofofofoofofoffofoobarfoo", "foobars", -1},
   174  	{"foofyfoobarfoobar", "y", 4},
   175  	{"oooooooooooooooooooooo", "r", -1},
   176  	{"oxoxoxoxoxoxoxoxoxoxoxoy", "oy", 22},
   177  	{"oxoxoxoxoxoxoxoxoxoxoxox", "oy", -1},
   178  	// test fallback to Rabin-Karp.
   179  	{"000000000000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000000001", 5},
   180  }
   181  
   182  var lastIndexTests = []BinOpTest{
   183  	{"", "", 0},
   184  	{"", "a", -1},
   185  	{"", "foo", -1},
   186  	{"fo", "foo", -1},
   187  	{"foo", "foo", 0},
   188  	{"foo", "f", 0},
   189  	{"oofofoofooo", "f", 7},
   190  	{"oofofoofooo", "foo", 7},
   191  	{"barfoobarfoo", "foo", 9},
   192  	{"foo", "", 3},
   193  	{"foo", "o", 2},
   194  	{"abcABCabc", "A", 3},
   195  	{"abcABCabc", "a", 6},
   196  }
   197  
   198  var indexAnyTests = []BinOpTest{
   199  	{"", "", -1},
   200  	{"", "a", -1},
   201  	{"", "abc", -1},
   202  	{"a", "", -1},
   203  	{"a", "a", 0},
   204  	{"\x80", "\xffb", 0},
   205  	{"aaa", "a", 0},
   206  	{"abc", "xyz", -1},
   207  	{"abc", "xcz", 2},
   208  	{"ab☺c", "x☺yz", 2},
   209  	{"a☺b☻c☹d", "cx", len("a☺b☻")},
   210  	{"a☺b☻c☹d", "uvw☻xyz", len("a☺b")},
   211  	{"aRegExp*", ".(|)*+?^$[]", 7},
   212  	{dots + dots + dots, " ", -1},
   213  	{"012abcba210", "\xffb", 4},
   214  	{"012\x80bcb\x80210", "\xffb", 3},
   215  	{"0123456\xcf\x80abc", "\xcfb\x80", 10},
   216  }
   217  
   218  var lastIndexAnyTests = []BinOpTest{
   219  	{"", "", -1},
   220  	{"", "a", -1},
   221  	{"", "abc", -1},
   222  	{"a", "", -1},
   223  	{"a", "a", 0},
   224  	{"\x80", "\xffb", 0},
   225  	{"aaa", "a", 2},
   226  	{"abc", "xyz", -1},
   227  	{"abc", "ab", 1},
   228  	{"ab☺c", "x☺yz", 2},
   229  	{"a☺b☻c☹d", "cx", len("a☺b☻")},
   230  	{"a☺b☻c☹d", "uvw☻xyz", len("a☺b")},
   231  	{"a.RegExp*", ".(|)*+?^$[]", 8},
   232  	{dots + dots + dots, " ", -1},
   233  	{"012abcba210", "\xffb", 6},
   234  	{"012\x80bcb\x80210", "\xffb", 7},
   235  	{"0123456\xcf\x80abc", "\xcfb\x80", 10},
   236  }
   237  
   238  // Execute f on each test case.  funcName should be the name of f; it's used
   239  // in failure reports.
   240  func runIndexTests(t *testing.T, f func(s, sep []byte) int, funcName string, testCases []BinOpTest) {
   241  	for _, test := range testCases {
   242  		a := []byte(test.a)
   243  		b := []byte(test.b)
   244  		actual := f(a, b)
   245  		if actual != test.i {
   246  			t.Errorf("%s(%q,%q) = %v; want %v", funcName, a, b, actual, test.i)
   247  		}
   248  	}
   249  	var allocTests = []struct {
   250  		a []byte
   251  		b []byte
   252  		i int
   253  	}{
   254  		// case for function Index.
   255  		{[]byte("000000000000000000000000000000000000000000000000000000000000000000000001"), []byte("0000000000000000000000000000000000000000000000000000000000000000001"), 5},
   256  		// case for function LastIndex.
   257  		{[]byte("000000000000000000000000000000000000000000000000000000000000000010000"), []byte("00000000000000000000000000000000000000000000000000000000000001"), 3},
   258  	}
   259  	allocs := testing.AllocsPerRun(100, func() {
   260  		if i := Index(allocTests[1].a, allocTests[1].b); i != allocTests[1].i {
   261  			t.Errorf("Index([]byte(%q), []byte(%q)) = %v; want %v", allocTests[1].a, allocTests[1].b, i, allocTests[1].i)
   262  		}
   263  		if i := LastIndex(allocTests[0].a, allocTests[0].b); i != allocTests[0].i {
   264  			t.Errorf("LastIndex([]byte(%q), []byte(%q)) = %v; want %v", allocTests[0].a, allocTests[0].b, i, allocTests[0].i)
   265  		}
   266  	})
   267  	if allocs != 0 {
   268  		t.Errorf("expected no allocations, got %f", allocs)
   269  	}
   270  }
   271  
   272  func runIndexAnyTests(t *testing.T, f func(s []byte, chars string) int, funcName string, testCases []BinOpTest) {
   273  	for _, test := range testCases {
   274  		a := []byte(test.a)
   275  		actual := f(a, test.b)
   276  		if actual != test.i {
   277  			t.Errorf("%s(%q,%q) = %v; want %v", funcName, a, test.b, actual, test.i)
   278  		}
   279  	}
   280  }
   281  
   282  func TestIndex(t *testing.T)     { runIndexTests(t, Index, "Index", indexTests) }
   283  func TestLastIndex(t *testing.T) { runIndexTests(t, LastIndex, "LastIndex", lastIndexTests) }
   284  func TestIndexAny(t *testing.T)  { runIndexAnyTests(t, IndexAny, "IndexAny", indexAnyTests) }
   285  func TestLastIndexAny(t *testing.T) {
   286  	runIndexAnyTests(t, LastIndexAny, "LastIndexAny", lastIndexAnyTests)
   287  }
   288  
   289  func TestIndexByte(t *testing.T) {
   290  	for _, tt := range indexTests {
   291  		if len(tt.b) != 1 {
   292  			continue
   293  		}
   294  		a := []byte(tt.a)
   295  		b := tt.b[0]
   296  		pos := IndexByte(a, b)
   297  		if pos != tt.i {
   298  			t.Errorf(`IndexByte(%q, '%c') = %v`, tt.a, b, pos)
   299  		}
   300  		posp := IndexBytePortable(a, b)
   301  		if posp != tt.i {
   302  			t.Errorf(`indexBytePortable(%q, '%c') = %v`, tt.a, b, posp)
   303  		}
   304  	}
   305  }
   306  
   307  func TestLastIndexByte(t *testing.T) {
   308  	testCases := []BinOpTest{
   309  		{"", "q", -1},
   310  		{"abcdef", "q", -1},
   311  		{"abcdefabcdef", "a", len("abcdef")},      // something in the middle
   312  		{"abcdefabcdef", "f", len("abcdefabcde")}, // last byte
   313  		{"zabcdefabcdef", "z", 0},                 // first byte
   314  		{"a☺b☻c☹d", "b", len("a☺")},               // non-ascii
   315  	}
   316  	for _, test := range testCases {
   317  		actual := LastIndexByte([]byte(test.a), test.b[0])
   318  		if actual != test.i {
   319  			t.Errorf("LastIndexByte(%q,%c) = %v; want %v", test.a, test.b[0], actual, test.i)
   320  		}
   321  	}
   322  }
   323  
   324  // test a larger buffer with different sizes and alignments
   325  func TestIndexByteBig(t *testing.T) {
   326  	var n = 1024
   327  	if testing.Short() {
   328  		n = 128
   329  	}
   330  	b := make([]byte, n)
   331  	for i := 0; i < n; i++ {
   332  		// different start alignments
   333  		b1 := b[i:]
   334  		for j := 0; j < len(b1); j++ {
   335  			b1[j] = 'x'
   336  			pos := IndexByte(b1, 'x')
   337  			if pos != j {
   338  				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
   339  			}
   340  			b1[j] = 0
   341  			pos = IndexByte(b1, 'x')
   342  			if pos != -1 {
   343  				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
   344  			}
   345  		}
   346  		// different end alignments
   347  		b1 = b[:i]
   348  		for j := 0; j < len(b1); j++ {
   349  			b1[j] = 'x'
   350  			pos := IndexByte(b1, 'x')
   351  			if pos != j {
   352  				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
   353  			}
   354  			b1[j] = 0
   355  			pos = IndexByte(b1, 'x')
   356  			if pos != -1 {
   357  				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
   358  			}
   359  		}
   360  		// different start and end alignments
   361  		b1 = b[i/2 : n-(i+1)/2]
   362  		for j := 0; j < len(b1); j++ {
   363  			b1[j] = 'x'
   364  			pos := IndexByte(b1, 'x')
   365  			if pos != j {
   366  				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
   367  			}
   368  			b1[j] = 0
   369  			pos = IndexByte(b1, 'x')
   370  			if pos != -1 {
   371  				t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
   372  			}
   373  		}
   374  	}
   375  }
   376  
   377  // test a small index across all page offsets
   378  func TestIndexByteSmall(t *testing.T) {
   379  	b := make([]byte, 5015) // bigger than a page
   380  	// Make sure we find the correct byte even when straddling a page.
   381  	for i := 0; i <= len(b)-15; i++ {
   382  		for j := 0; j < 15; j++ {
   383  			b[i+j] = byte(100 + j)
   384  		}
   385  		for j := 0; j < 15; j++ {
   386  			p := IndexByte(b[i:i+15], byte(100+j))
   387  			if p != j {
   388  				t.Errorf("IndexByte(%q, %d) = %d", b[i:i+15], 100+j, p)
   389  			}
   390  		}
   391  		for j := 0; j < 15; j++ {
   392  			b[i+j] = 0
   393  		}
   394  	}
   395  	// Make sure matches outside the slice never trigger.
   396  	for i := 0; i <= len(b)-15; i++ {
   397  		for j := 0; j < 15; j++ {
   398  			b[i+j] = 1
   399  		}
   400  		for j := 0; j < 15; j++ {
   401  			p := IndexByte(b[i:i+15], byte(0))
   402  			if p != -1 {
   403  				t.Errorf("IndexByte(%q, %d) = %d", b[i:i+15], 0, p)
   404  			}
   405  		}
   406  		for j := 0; j < 15; j++ {
   407  			b[i+j] = 0
   408  		}
   409  	}
   410  }
   411  
   412  func TestIndexRune(t *testing.T) {
   413  	tests := []struct {
   414  		in   string
   415  		rune rune
   416  		want int
   417  	}{
   418  		{"", 'a', -1},
   419  		{"", '☺', -1},
   420  		{"foo", '☹', -1},
   421  		{"foo", 'o', 1},
   422  		{"foo☺bar", '☺', 3},
   423  		{"foo☺☻☹bar", '☹', 9},
   424  		{"a A x", 'A', 2},
   425  		{"some_text=some_value", '=', 9},
   426  		{"☺a", 'a', 3},
   427  		{"a☻☺b", '☺', 4},
   428  
   429  		// RuneError should match any invalid UTF-8 byte sequence.
   430  		{"�", '�', 0},
   431  		{"\xff", '�', 0},
   432  		{"☻x�", '�', len("☻x")},
   433  		{"☻x\xe2\x98", '�', len("☻x")},
   434  		{"☻x\xe2\x98�", '�', len("☻x")},
   435  		{"☻x\xe2\x98x", '�', len("☻x")},
   436  
   437  		// Invalid rune values should never match.
   438  		{"a☺b☻c☹d\xe2\x98�\xff�\xed\xa0\x80", -1, -1},
   439  		{"a☺b☻c☹d\xe2\x98�\xff�\xed\xa0\x80", 0xD800, -1}, // Surrogate pair
   440  		{"a☺b☻c☹d\xe2\x98�\xff�\xed\xa0\x80", utf8.MaxRune + 1, -1},
   441  	}
   442  	for _, tt := range tests {
   443  		if got := IndexRune([]byte(tt.in), tt.rune); got != tt.want {
   444  			t.Errorf("IndexRune(%q, %d) = %v; want %v", tt.in, tt.rune, got, tt.want)
   445  		}
   446  	}
   447  
   448  	haystack := []byte("test世界")
   449  	allocs := testing.AllocsPerRun(1000, func() {
   450  		if i := IndexRune(haystack, 's'); i != 2 {
   451  			t.Fatalf("'s' at %d; want 2", i)
   452  		}
   453  		if i := IndexRune(haystack, '世'); i != 4 {
   454  			t.Fatalf("'世' at %d; want 4", i)
   455  		}
   456  	})
   457  	if allocs != 0 {
   458  		t.Errorf("expected no allocations, got %f", allocs)
   459  	}
   460  }
   461  
   462  // test count of a single byte across page offsets
   463  func TestCountByte(t *testing.T) {
   464  	b := make([]byte, 5015) // bigger than a page
   465  	windows := []int{1, 2, 3, 4, 15, 16, 17, 31, 32, 33, 63, 64, 65, 128}
   466  	testCountWindow := func(i, window int) {
   467  		for j := 0; j < window; j++ {
   468  			b[i+j] = byte(100)
   469  			p := Count(b[i:i+window], []byte{100})
   470  			if p != j+1 {
   471  				t.Errorf("TestCountByte.Count(%q, 100) = %d", b[i:i+window], p)
   472  			}
   473  		}
   474  	}
   475  
   476  	maxWnd := windows[len(windows)-1]
   477  
   478  	for i := 0; i <= 2*maxWnd; i++ {
   479  		for _, window := range windows {
   480  			if window > len(b[i:]) {
   481  				window = len(b[i:])
   482  			}
   483  			testCountWindow(i, window)
   484  			for j := 0; j < window; j++ {
   485  				b[i+j] = byte(0)
   486  			}
   487  		}
   488  	}
   489  	for i := 4096 - (maxWnd + 1); i < len(b); i++ {
   490  		for _, window := range windows {
   491  			if window > len(b[i:]) {
   492  				window = len(b[i:])
   493  			}
   494  			testCountWindow(i, window)
   495  			for j := 0; j < window; j++ {
   496  				b[i+j] = byte(0)
   497  			}
   498  		}
   499  	}
   500  }
   501  
   502  // Make sure we don't count bytes outside our window
   503  func TestCountByteNoMatch(t *testing.T) {
   504  	b := make([]byte, 5015)
   505  	windows := []int{1, 2, 3, 4, 15, 16, 17, 31, 32, 33, 63, 64, 65, 128}
   506  	for i := 0; i <= len(b); i++ {
   507  		for _, window := range windows {
   508  			if window > len(b[i:]) {
   509  				window = len(b[i:])
   510  			}
   511  			// Fill the window with non-match
   512  			for j := 0; j < window; j++ {
   513  				b[i+j] = byte(100)
   514  			}
   515  			// Try to find something that doesn't exist
   516  			p := Count(b[i:i+window], []byte{0})
   517  			if p != 0 {
   518  				t.Errorf("TestCountByteNoMatch(%q, 0) = %d", b[i:i+window], p)
   519  			}
   520  			for j := 0; j < window; j++ {
   521  				b[i+j] = byte(0)
   522  			}
   523  		}
   524  	}
   525  }
   526  
   527  var bmbuf []byte
   528  
   529  func valName(x int) string {
   530  	if s := x >> 20; s<<20 == x {
   531  		return fmt.Sprintf("%dM", s)
   532  	}
   533  	if s := x >> 10; s<<10 == x {
   534  		return fmt.Sprintf("%dK", s)
   535  	}
   536  	return fmt.Sprint(x)
   537  }
   538  
   539  func benchBytes(b *testing.B, sizes []int, f func(b *testing.B, n int)) {
   540  	for _, n := range sizes {
   541  		if isRaceBuilder && n > 4<<10 {
   542  			continue
   543  		}
   544  		b.Run(valName(n), func(b *testing.B) {
   545  			if len(bmbuf) < n {
   546  				bmbuf = make([]byte, n)
   547  			}
   548  			b.SetBytes(int64(n))
   549  			f(b, n)
   550  		})
   551  	}
   552  }
   553  
   554  var indexSizes = []int{10, 32, 4 << 10, 4 << 20, 64 << 20}
   555  
   556  var isRaceBuilder = strings.HasSuffix(testenv.Builder(), "-race")
   557  
   558  func BenchmarkIndexByte(b *testing.B) {
   559  	benchBytes(b, indexSizes, bmIndexByte(IndexByte))
   560  }
   561  
   562  func BenchmarkIndexBytePortable(b *testing.B) {
   563  	benchBytes(b, indexSizes, bmIndexByte(IndexBytePortable))
   564  }
   565  
   566  func bmIndexByte(index func([]byte, byte) int) func(b *testing.B, n int) {
   567  	return func(b *testing.B, n int) {
   568  		buf := bmbuf[0:n]
   569  		buf[n-1] = 'x'
   570  		for i := 0; i < b.N; i++ {
   571  			j := index(buf, 'x')
   572  			if j != n-1 {
   573  				b.Fatal("bad index", j)
   574  			}
   575  		}
   576  		buf[n-1] = '\x00'
   577  	}
   578  }
   579  
   580  func BenchmarkIndexRune(b *testing.B) {
   581  	benchBytes(b, indexSizes, bmIndexRune(IndexRune))
   582  }
   583  
   584  func BenchmarkIndexRuneASCII(b *testing.B) {
   585  	benchBytes(b, indexSizes, bmIndexRuneASCII(IndexRune))
   586  }
   587  
   588  func bmIndexRuneASCII(index func([]byte, rune) int) func(b *testing.B, n int) {
   589  	return func(b *testing.B, n int) {
   590  		buf := bmbuf[0:n]
   591  		buf[n-1] = 'x'
   592  		for i := 0; i < b.N; i++ {
   593  			j := index(buf, 'x')
   594  			if j != n-1 {
   595  				b.Fatal("bad index", j)
   596  			}
   597  		}
   598  		buf[n-1] = '\x00'
   599  	}
   600  }
   601  
   602  func bmIndexRune(index func([]byte, rune) int) func(b *testing.B, n int) {
   603  	return func(b *testing.B, n int) {
   604  		buf := bmbuf[0:n]
   605  		utf8.EncodeRune(buf[n-3:], '世')
   606  		for i := 0; i < b.N; i++ {
   607  			j := index(buf, '世')
   608  			if j != n-3 {
   609  				b.Fatal("bad index", j)
   610  			}
   611  		}
   612  		buf[n-3] = '\x00'
   613  		buf[n-2] = '\x00'
   614  		buf[n-1] = '\x00'
   615  	}
   616  }
   617  
   618  func BenchmarkEqual(b *testing.B) {
   619  	b.Run("0", func(b *testing.B) {
   620  		var buf [4]byte
   621  		buf1 := buf[0:0]
   622  		buf2 := buf[1:1]
   623  		for i := 0; i < b.N; i++ {
   624  			eq := Equal(buf1, buf2)
   625  			if !eq {
   626  				b.Fatal("bad equal")
   627  			}
   628  		}
   629  	})
   630  
   631  	sizes := []int{1, 6, 9, 15, 16, 20, 32, 4 << 10, 4 << 20, 64 << 20}
   632  	benchBytes(b, sizes, bmEqual(Equal))
   633  }
   634  
   635  func bmEqual(equal func([]byte, []byte) bool) func(b *testing.B, n int) {
   636  	return func(b *testing.B, n int) {
   637  		if len(bmbuf) < 2*n {
   638  			bmbuf = make([]byte, 2*n)
   639  		}
   640  		buf1 := bmbuf[0:n]
   641  		buf2 := bmbuf[n : 2*n]
   642  		buf1[n-1] = 'x'
   643  		buf2[n-1] = 'x'
   644  		for i := 0; i < b.N; i++ {
   645  			eq := equal(buf1, buf2)
   646  			if !eq {
   647  				b.Fatal("bad equal")
   648  			}
   649  		}
   650  		buf1[n-1] = '\x00'
   651  		buf2[n-1] = '\x00'
   652  	}
   653  }
   654  
   655  func BenchmarkEqualBothUnaligned(b *testing.B) {
   656  	sizes := []int{64, 4 << 10}
   657  	if !isRaceBuilder {
   658  		sizes = append(sizes, []int{4 << 20, 64 << 20}...)
   659  	}
   660  	maxSize := 2 * (sizes[len(sizes)-1] + 8)
   661  	if len(bmbuf) < maxSize {
   662  		bmbuf = make([]byte, maxSize)
   663  	}
   664  
   665  	for _, n := range sizes {
   666  		for _, off := range []int{0, 1, 4, 7} {
   667  			buf1 := bmbuf[off : off+n]
   668  			buf2Start := (len(bmbuf) / 2) + off
   669  			buf2 := bmbuf[buf2Start : buf2Start+n]
   670  			buf1[n-1] = 'x'
   671  			buf2[n-1] = 'x'
   672  			b.Run(fmt.Sprint(n, off), func(b *testing.B) {
   673  				b.SetBytes(int64(n))
   674  				for i := 0; i < b.N; i++ {
   675  					eq := Equal(buf1, buf2)
   676  					if !eq {
   677  						b.Fatal("bad equal")
   678  					}
   679  				}
   680  			})
   681  			buf1[n-1] = '\x00'
   682  			buf2[n-1] = '\x00'
   683  		}
   684  	}
   685  }
   686  
   687  func BenchmarkIndex(b *testing.B) {
   688  	benchBytes(b, indexSizes, func(b *testing.B, n int) {
   689  		buf := bmbuf[0:n]
   690  		buf[n-1] = 'x'
   691  		for i := 0; i < b.N; i++ {
   692  			j := Index(buf, buf[n-7:])
   693  			if j != n-7 {
   694  				b.Fatal("bad index", j)
   695  			}
   696  		}
   697  		buf[n-1] = '\x00'
   698  	})
   699  }
   700  
   701  func BenchmarkIndexEasy(b *testing.B) {
   702  	benchBytes(b, indexSizes, func(b *testing.B, n int) {
   703  		buf := bmbuf[0:n]
   704  		buf[n-1] = 'x'
   705  		buf[n-7] = 'x'
   706  		for i := 0; i < b.N; i++ {
   707  			j := Index(buf, buf[n-7:])
   708  			if j != n-7 {
   709  				b.Fatal("bad index", j)
   710  			}
   711  		}
   712  		buf[n-1] = '\x00'
   713  		buf[n-7] = '\x00'
   714  	})
   715  }
   716  
   717  func BenchmarkCount(b *testing.B) {
   718  	benchBytes(b, indexSizes, func(b *testing.B, n int) {
   719  		buf := bmbuf[0:n]
   720  		buf[n-1] = 'x'
   721  		for i := 0; i < b.N; i++ {
   722  			j := Count(buf, buf[n-7:])
   723  			if j != 1 {
   724  				b.Fatal("bad count", j)
   725  			}
   726  		}
   727  		buf[n-1] = '\x00'
   728  	})
   729  }
   730  
   731  func BenchmarkCountEasy(b *testing.B) {
   732  	benchBytes(b, indexSizes, func(b *testing.B, n int) {
   733  		buf := bmbuf[0:n]
   734  		buf[n-1] = 'x'
   735  		buf[n-7] = 'x'
   736  		for i := 0; i < b.N; i++ {
   737  			j := Count(buf, buf[n-7:])
   738  			if j != 1 {
   739  				b.Fatal("bad count", j)
   740  			}
   741  		}
   742  		buf[n-1] = '\x00'
   743  		buf[n-7] = '\x00'
   744  	})
   745  }
   746  
   747  func BenchmarkCountSingle(b *testing.B) {
   748  	benchBytes(b, indexSizes, func(b *testing.B, n int) {
   749  		buf := bmbuf[0:n]
   750  		step := 8
   751  		for i := 0; i < len(buf); i += step {
   752  			buf[i] = 1
   753  		}
   754  		expect := (len(buf) + (step - 1)) / step
   755  		for i := 0; i < b.N; i++ {
   756  			j := Count(buf, []byte{1})
   757  			if j != expect {
   758  				b.Fatal("bad count", j, expect)
   759  			}
   760  		}
   761  		for i := 0; i < len(buf); i++ {
   762  			buf[i] = 0
   763  		}
   764  	})
   765  }
   766  
   767  type SplitTest struct {
   768  	s   string
   769  	sep string
   770  	n   int
   771  	a   []string
   772  }
   773  
   774  var splittests = []SplitTest{
   775  	{"", "", -1, []string{}},
   776  	{abcd, "a", 0, nil},
   777  	{abcd, "", 2, []string{"a", "bcd"}},
   778  	{abcd, "a", -1, []string{"", "bcd"}},
   779  	{abcd, "z", -1, []string{"abcd"}},
   780  	{abcd, "", -1, []string{"a", "b", "c", "d"}},
   781  	{commas, ",", -1, []string{"1", "2", "3", "4"}},
   782  	{dots, "...", -1, []string{"1", ".2", ".3", ".4"}},
   783  	{faces, "☹", -1, []string{"☺☻", ""}},
   784  	{faces, "~", -1, []string{faces}},
   785  	{faces, "", -1, []string{"☺", "☻", "☹"}},
   786  	{"1 2 3 4", " ", 3, []string{"1", "2", "3 4"}},
   787  	{"1 2", " ", 3, []string{"1", "2"}},
   788  	{"123", "", 2, []string{"1", "23"}},
   789  	{"123", "", 17, []string{"1", "2", "3"}},
   790  	{"bT", "T", math.MaxInt / 4, []string{"b", ""}},
   791  	{"\xff-\xff", "", -1, []string{"\xff", "-", "\xff"}},
   792  	{"\xff-\xff", "-", -1, []string{"\xff", "\xff"}},
   793  }
   794  
   795  func TestSplit(t *testing.T) {
   796  	for _, tt := range splittests {
   797  		a := SplitN([]byte(tt.s), []byte(tt.sep), tt.n)
   798  
   799  		// Appending to the results should not change future results.
   800  		var x []byte
   801  		for _, v := range a {
   802  			x = append(v, 'z')
   803  		}
   804  
   805  		result := sliceOfString(a)
   806  		if !eq(result, tt.a) {
   807  			t.Errorf(`Split(%q, %q, %d) = %v; want %v`, tt.s, tt.sep, tt.n, result, tt.a)
   808  			continue
   809  		}
   810  		if tt.n == 0 || len(a) == 0 {
   811  			continue
   812  		}
   813  
   814  		if want := tt.a[len(tt.a)-1] + "z"; string(x) != want {
   815  			t.Errorf("last appended result was %s; want %s", x, want)
   816  		}
   817  
   818  		s := Join(a, []byte(tt.sep))
   819  		if string(s) != tt.s {
   820  			t.Errorf(`Join(Split(%q, %q, %d), %q) = %q`, tt.s, tt.sep, tt.n, tt.sep, s)
   821  		}
   822  		if tt.n < 0 {
   823  			b := Split([]byte(tt.s), []byte(tt.sep))
   824  			if !reflect.DeepEqual(a, b) {
   825  				t.Errorf("Split disagrees withSplitN(%q, %q, %d) = %v; want %v", tt.s, tt.sep, tt.n, b, a)
   826  			}
   827  		}
   828  		if len(a) > 0 {
   829  			in, out := a[0], s
   830  			if cap(in) == cap(out) && &in[:1][0] == &out[:1][0] {
   831  				t.Errorf("Join(%#v, %q) didn't copy", a, tt.sep)
   832  			}
   833  		}
   834  	}
   835  }
   836  
   837  var splitaftertests = []SplitTest{
   838  	{abcd, "a", -1, []string{"a", "bcd"}},
   839  	{abcd, "z", -1, []string{"abcd"}},
   840  	{abcd, "", -1, []string{"a", "b", "c", "d"}},
   841  	{commas, ",", -1, []string{"1,", "2,", "3,", "4"}},
   842  	{dots, "...", -1, []string{"1...", ".2...", ".3...", ".4"}},
   843  	{faces, "☹", -1, []string{"☺☻☹", ""}},
   844  	{faces, "~", -1, []string{faces}},
   845  	{faces, "", -1, []string{"☺", "☻", "☹"}},
   846  	{"1 2 3 4", " ", 3, []string{"1 ", "2 ", "3 4"}},
   847  	{"1 2 3", " ", 3, []string{"1 ", "2 ", "3"}},
   848  	{"1 2", " ", 3, []string{"1 ", "2"}},
   849  	{"123", "", 2, []string{"1", "23"}},
   850  	{"123", "", 17, []string{"1", "2", "3"}},
   851  }
   852  
   853  func TestSplitAfter(t *testing.T) {
   854  	for _, tt := range splitaftertests {
   855  		a := SplitAfterN([]byte(tt.s), []byte(tt.sep), tt.n)
   856  
   857  		// Appending to the results should not change future results.
   858  		var x []byte
   859  		for _, v := range a {
   860  			x = append(v, 'z')
   861  		}
   862  
   863  		result := sliceOfString(a)
   864  		if !eq(result, tt.a) {
   865  			t.Errorf(`Split(%q, %q, %d) = %v; want %v`, tt.s, tt.sep, tt.n, result, tt.a)
   866  			continue
   867  		}
   868  
   869  		if want := tt.a[len(tt.a)-1] + "z"; string(x) != want {
   870  			t.Errorf("last appended result was %s; want %s", x, want)
   871  		}
   872  
   873  		s := Join(a, nil)
   874  		if string(s) != tt.s {
   875  			t.Errorf(`Join(Split(%q, %q, %d), %q) = %q`, tt.s, tt.sep, tt.n, tt.sep, s)
   876  		}
   877  		if tt.n < 0 {
   878  			b := SplitAfter([]byte(tt.s), []byte(tt.sep))
   879  			if !reflect.DeepEqual(a, b) {
   880  				t.Errorf("SplitAfter disagrees withSplitAfterN(%q, %q, %d) = %v; want %v", tt.s, tt.sep, tt.n, b, a)
   881  			}
   882  		}
   883  	}
   884  }
   885  
   886  type FieldsTest struct {
   887  	s string
   888  	a []string
   889  }
   890  
   891  var fieldstests = []FieldsTest{
   892  	{"", []string{}},
   893  	{" ", []string{}},
   894  	{" \t ", []string{}},
   895  	{"  abc  ", []string{"abc"}},
   896  	{"1 2 3 4", []string{"1", "2", "3", "4"}},
   897  	{"1  2  3  4", []string{"1", "2", "3", "4"}},
   898  	{"1\t\t2\t\t3\t4", []string{"1", "2", "3", "4"}},
   899  	{"1\u20002\u20013\u20024", []string{"1", "2", "3", "4"}},
   900  	{"\u2000\u2001\u2002", []string{}},
   901  	{"\n™\t™\n", []string{"™", "™"}},
   902  	{faces, []string{faces}},
   903  }
   904  
   905  func TestFields(t *testing.T) {
   906  	for _, tt := range fieldstests {
   907  		b := []byte(tt.s)
   908  		a := Fields(b)
   909  
   910  		// Appending to the results should not change future results.
   911  		var x []byte
   912  		for _, v := range a {
   913  			x = append(v, 'z')
   914  		}
   915  
   916  		result := sliceOfString(a)
   917  		if !eq(result, tt.a) {
   918  			t.Errorf("Fields(%q) = %v; want %v", tt.s, a, tt.a)
   919  			continue
   920  		}
   921  
   922  		if string(b) != tt.s {
   923  			t.Errorf("slice changed to %s; want %s", string(b), tt.s)
   924  		}
   925  		if len(tt.a) > 0 {
   926  			if want := tt.a[len(tt.a)-1] + "z"; string(x) != want {
   927  				t.Errorf("last appended result was %s; want %s", x, want)
   928  			}
   929  		}
   930  	}
   931  }
   932  
   933  func TestFieldsFunc(t *testing.T) {
   934  	for _, tt := range fieldstests {
   935  		a := FieldsFunc([]byte(tt.s), unicode.IsSpace)
   936  		result := sliceOfString(a)
   937  		if !eq(result, tt.a) {
   938  			t.Errorf("FieldsFunc(%q, unicode.IsSpace) = %v; want %v", tt.s, a, tt.a)
   939  			continue
   940  		}
   941  	}
   942  	pred := func(c rune) bool { return c == 'X' }
   943  	var fieldsFuncTests = []FieldsTest{
   944  		{"", []string{}},
   945  		{"XX", []string{}},
   946  		{"XXhiXXX", []string{"hi"}},
   947  		{"aXXbXXXcX", []string{"a", "b", "c"}},
   948  	}
   949  	for _, tt := range fieldsFuncTests {
   950  		b := []byte(tt.s)
   951  		a := FieldsFunc(b, pred)
   952  
   953  		// Appending to the results should not change future results.
   954  		var x []byte
   955  		for _, v := range a {
   956  			x = append(v, 'z')
   957  		}
   958  
   959  		result := sliceOfString(a)
   960  		if !eq(result, tt.a) {
   961  			t.Errorf("FieldsFunc(%q) = %v, want %v", tt.s, a, tt.a)
   962  		}
   963  
   964  		if string(b) != tt.s {
   965  			t.Errorf("slice changed to %s; want %s", b, tt.s)
   966  		}
   967  		if len(tt.a) > 0 {
   968  			if want := tt.a[len(tt.a)-1] + "z"; string(x) != want {
   969  				t.Errorf("last appended result was %s; want %s", x, want)
   970  			}
   971  		}
   972  	}
   973  }
   974  
   975  // Test case for any function which accepts and returns a byte slice.
   976  // For ease of creation, we write the input byte slice as a string.
   977  type StringTest struct {
   978  	in  string
   979  	out []byte
   980  }
   981  
   982  var upperTests = []StringTest{
   983  	{"", []byte("")},
   984  	{"ONLYUPPER", []byte("ONLYUPPER")},
   985  	{"abc", []byte("ABC")},
   986  	{"AbC123", []byte("ABC123")},
   987  	{"azAZ09_", []byte("AZAZ09_")},
   988  	{"longStrinGwitHmixofsmaLLandcAps", []byte("LONGSTRINGWITHMIXOFSMALLANDCAPS")},
   989  	{"long\u0250string\u0250with\u0250nonascii\u2C6Fchars", []byte("LONG\u2C6FSTRING\u2C6FWITH\u2C6FNONASCII\u2C6FCHARS")},
   990  	{"\u0250\u0250\u0250\u0250\u0250", []byte("\u2C6F\u2C6F\u2C6F\u2C6F\u2C6F")}, // grows one byte per char
   991  	{"a\u0080\U0010FFFF", []byte("A\u0080\U0010FFFF")},                           // test utf8.RuneSelf and utf8.MaxRune
   992  }
   993  
   994  var lowerTests = []StringTest{
   995  	{"", []byte("")},
   996  	{"abc", []byte("abc")},
   997  	{"AbC123", []byte("abc123")},
   998  	{"azAZ09_", []byte("azaz09_")},
   999  	{"longStrinGwitHmixofsmaLLandcAps", []byte("longstringwithmixofsmallandcaps")},
  1000  	{"LONG\u2C6FSTRING\u2C6FWITH\u2C6FNONASCII\u2C6FCHARS", []byte("long\u0250string\u0250with\u0250nonascii\u0250chars")},
  1001  	{"\u2C6D\u2C6D\u2C6D\u2C6D\u2C6D", []byte("\u0251\u0251\u0251\u0251\u0251")}, // shrinks one byte per char
  1002  	{"A\u0080\U0010FFFF", []byte("a\u0080\U0010FFFF")},                           // test utf8.RuneSelf and utf8.MaxRune
  1003  }
  1004  
  1005  const space = "\t\v\r\f\n\u0085\u00a0\u2000\u3000"
  1006  
  1007  var trimSpaceTests = []StringTest{
  1008  	{"", nil},
  1009  	{"  a", []byte("a")},
  1010  	{"b  ", []byte("b")},
  1011  	{"abc", []byte("abc")},
  1012  	{space + "abc" + space, []byte("abc")},
  1013  	{" ", nil},
  1014  	{"\u3000 ", nil},
  1015  	{" \u3000", nil},
  1016  	{" \t\r\n \t\t\r\r\n\n ", nil},
  1017  	{" \t\r\n x\t\t\r\r\n\n ", []byte("x")},
  1018  	{" \u2000\t\r\n x\t\t\r\r\ny\n \u3000", []byte("x\t\t\r\r\ny")},
  1019  	{"1 \t\r\n2", []byte("1 \t\r\n2")},
  1020  	{" x\x80", []byte("x\x80")},
  1021  	{" x\xc0", []byte("x\xc0")},
  1022  	{"x \xc0\xc0 ", []byte("x \xc0\xc0")},
  1023  	{"x \xc0", []byte("x \xc0")},
  1024  	{"x \xc0 ", []byte("x \xc0")},
  1025  	{"x \xc0\xc0 ", []byte("x \xc0\xc0")},
  1026  	{"x ☺\xc0\xc0 ", []byte("x ☺\xc0\xc0")},
  1027  	{"x ☺ ", []byte("x ☺")},
  1028  }
  1029  
  1030  // Execute f on each test case.  funcName should be the name of f; it's used
  1031  // in failure reports.
  1032  func runStringTests(t *testing.T, f func([]byte) []byte, funcName string, testCases []StringTest) {
  1033  	for _, tc := range testCases {
  1034  		actual := f([]byte(tc.in))
  1035  		if actual == nil && tc.out != nil {
  1036  			t.Errorf("%s(%q) = nil; want %q", funcName, tc.in, tc.out)
  1037  		}
  1038  		if actual != nil && tc.out == nil {
  1039  			t.Errorf("%s(%q) = %q; want nil", funcName, tc.in, actual)
  1040  		}
  1041  		if !Equal(actual, tc.out) {
  1042  			t.Errorf("%s(%q) = %q; want %q", funcName, tc.in, actual, tc.out)
  1043  		}
  1044  	}
  1045  }
  1046  
  1047  func tenRunes(r rune) string {
  1048  	runes := make([]rune, 10)
  1049  	for i := range runes {
  1050  		runes[i] = r
  1051  	}
  1052  	return string(runes)
  1053  }
  1054  
  1055  // User-defined self-inverse mapping function
  1056  func rot13(r rune) rune {
  1057  	const step = 13
  1058  	if r >= 'a' && r <= 'z' {
  1059  		return ((r - 'a' + step) % 26) + 'a'
  1060  	}
  1061  	if r >= 'A' && r <= 'Z' {
  1062  		return ((r - 'A' + step) % 26) + 'A'
  1063  	}
  1064  	return r
  1065  }
  1066  
  1067  func TestMap(t *testing.T) {
  1068  	// Run a couple of awful growth/shrinkage tests
  1069  	a := tenRunes('a')
  1070  
  1071  	// 1.  Grow. This triggers two reallocations in Map.
  1072  	maxRune := func(r rune) rune { return unicode.MaxRune }
  1073  	m := Map(maxRune, []byte(a))
  1074  	expect := tenRunes(unicode.MaxRune)
  1075  	if string(m) != expect {
  1076  		t.Errorf("growing: expected %q got %q", expect, m)
  1077  	}
  1078  
  1079  	// 2. Shrink
  1080  	minRune := func(r rune) rune { return 'a' }
  1081  	m = Map(minRune, []byte(tenRunes(unicode.MaxRune)))
  1082  	expect = a
  1083  	if string(m) != expect {
  1084  		t.Errorf("shrinking: expected %q got %q", expect, m)
  1085  	}
  1086  
  1087  	// 3. Rot13
  1088  	m = Map(rot13, []byte("a to zed"))
  1089  	expect = "n gb mrq"
  1090  	if string(m) != expect {
  1091  		t.Errorf("rot13: expected %q got %q", expect, m)
  1092  	}
  1093  
  1094  	// 4. Rot13^2
  1095  	m = Map(rot13, Map(rot13, []byte("a to zed")))
  1096  	expect = "a to zed"
  1097  	if string(m) != expect {
  1098  		t.Errorf("rot13: expected %q got %q", expect, m)
  1099  	}
  1100  
  1101  	// 5. Drop
  1102  	dropNotLatin := func(r rune) rune {
  1103  		if unicode.Is(unicode.Latin, r) {
  1104  			return r
  1105  		}
  1106  		return -1
  1107  	}
  1108  	m = Map(dropNotLatin, []byte("Hello, 세계"))
  1109  	expect = "Hello"
  1110  	if string(m) != expect {
  1111  		t.Errorf("drop: expected %q got %q", expect, m)
  1112  	}
  1113  
  1114  	// 6. Invalid rune
  1115  	invalidRune := func(r rune) rune {
  1116  		return utf8.MaxRune + 1
  1117  	}
  1118  	m = Map(invalidRune, []byte("x"))
  1119  	expect = "\uFFFD"
  1120  	if string(m) != expect {
  1121  		t.Errorf("invalidRune: expected %q got %q", expect, m)
  1122  	}
  1123  }
  1124  
  1125  func TestToUpper(t *testing.T) { runStringTests(t, ToUpper, "ToUpper", upperTests) }
  1126  
  1127  func TestToLower(t *testing.T) { runStringTests(t, ToLower, "ToLower", lowerTests) }
  1128  
  1129  func BenchmarkToUpper(b *testing.B) {
  1130  	for _, tc := range upperTests {
  1131  		tin := []byte(tc.in)
  1132  		b.Run(tc.in, func(b *testing.B) {
  1133  			for i := 0; i < b.N; i++ {
  1134  				actual := ToUpper(tin)
  1135  				if !Equal(actual, tc.out) {
  1136  					b.Errorf("ToUpper(%q) = %q; want %q", tc.in, actual, tc.out)
  1137  				}
  1138  			}
  1139  		})
  1140  	}
  1141  }
  1142  
  1143  func BenchmarkToLower(b *testing.B) {
  1144  	for _, tc := range lowerTests {
  1145  		tin := []byte(tc.in)
  1146  		b.Run(tc.in, func(b *testing.B) {
  1147  			for i := 0; i < b.N; i++ {
  1148  				actual := ToLower(tin)
  1149  				if !Equal(actual, tc.out) {
  1150  					b.Errorf("ToLower(%q) = %q; want %q", tc.in, actual, tc.out)
  1151  				}
  1152  			}
  1153  		})
  1154  	}
  1155  }
  1156  
  1157  var toValidUTF8Tests = []struct {
  1158  	in   string
  1159  	repl string
  1160  	out  string
  1161  }{
  1162  	{"", "\uFFFD", ""},
  1163  	{"abc", "\uFFFD", "abc"},
  1164  	{"\uFDDD", "\uFFFD", "\uFDDD"},
  1165  	{"a\xffb", "\uFFFD", "a\uFFFDb"},
  1166  	{"a\xffb\uFFFD", "X", "aXb\uFFFD"},
  1167  	{"a☺\xffb☺\xC0\xAFc☺\xff", "", "a☺b☺c☺"},
  1168  	{"a☺\xffb☺\xC0\xAFc☺\xff", "日本語", "a☺日本語b☺日本語c☺日本語"},
  1169  	{"\xC0\xAF", "\uFFFD", "\uFFFD"},
  1170  	{"\xE0\x80\xAF", "\uFFFD", "\uFFFD"},
  1171  	{"\xed\xa0\x80", "abc", "abc"},
  1172  	{"\xed\xbf\xbf", "\uFFFD", "\uFFFD"},
  1173  	{"\xF0\x80\x80\xaf", "☺", "☺"},
  1174  	{"\xF8\x80\x80\x80\xAF", "\uFFFD", "\uFFFD"},
  1175  	{"\xFC\x80\x80\x80\x80\xAF", "\uFFFD", "\uFFFD"},
  1176  }
  1177  
  1178  func TestToValidUTF8(t *testing.T) {
  1179  	for _, tc := range toValidUTF8Tests {
  1180  		got := ToValidUTF8([]byte(tc.in), []byte(tc.repl))
  1181  		if !Equal(got, []byte(tc.out)) {
  1182  			t.Errorf("ToValidUTF8(%q, %q) = %q; want %q", tc.in, tc.repl, got, tc.out)
  1183  		}
  1184  	}
  1185  }
  1186  
  1187  func TestTrimSpace(t *testing.T) { runStringTests(t, TrimSpace, "TrimSpace", trimSpaceTests) }
  1188  
  1189  type RepeatTest struct {
  1190  	in, out string
  1191  	count   int
  1192  }
  1193  
  1194  var longString = "a" + string(make([]byte, 1<<16)) + "z"
  1195  
  1196  var RepeatTests = []RepeatTest{
  1197  	{"", "", 0},
  1198  	{"", "", 1},
  1199  	{"", "", 2},
  1200  	{"-", "", 0},
  1201  	{"-", "-", 1},
  1202  	{"-", "----------", 10},
  1203  	{"abc ", "abc abc abc ", 3},
  1204  	// Tests for results over the chunkLimit
  1205  	{string(rune(0)), string(make([]byte, 1<<16)), 1 << 16},
  1206  	{longString, longString + longString, 2},
  1207  }
  1208  
  1209  func TestRepeat(t *testing.T) {
  1210  	for _, tt := range RepeatTests {
  1211  		tin := []byte(tt.in)
  1212  		tout := []byte(tt.out)
  1213  		a := Repeat(tin, tt.count)
  1214  		if !Equal(a, tout) {
  1215  			t.Errorf("Repeat(%q, %d) = %q; want %q", tin, tt.count, a, tout)
  1216  			continue
  1217  		}
  1218  	}
  1219  }
  1220  
  1221  func repeat(b []byte, count int) (err error) {
  1222  	defer func() {
  1223  		if r := recover(); r != nil {
  1224  			switch v := r.(type) {
  1225  			case error:
  1226  				err = v
  1227  			default:
  1228  				err = fmt.Errorf("%s", v)
  1229  			}
  1230  		}
  1231  	}()
  1232  
  1233  	Repeat(b, count)
  1234  
  1235  	return
  1236  }
  1237  
  1238  // See Issue golang.org/issue/16237
  1239  func TestRepeatCatchesOverflow(t *testing.T) {
  1240  	tests := [...]struct {
  1241  		s      string
  1242  		count  int
  1243  		errStr string
  1244  	}{
  1245  		0: {"--", -2147483647, "negative"},
  1246  		1: {"", int(^uint(0) >> 1), ""},
  1247  		2: {"-", 10, ""},
  1248  		3: {"gopher", 0, ""},
  1249  		4: {"-", -1, "negative"},
  1250  		5: {"--", -102, "negative"},
  1251  		6: {string(make([]byte, 255)), int((^uint(0))/255 + 1), "overflow"},
  1252  	}
  1253  
  1254  	for i, tt := range tests {
  1255  		err := repeat([]byte(tt.s), tt.count)
  1256  		if tt.errStr == "" {
  1257  			if err != nil {
  1258  				t.Errorf("#%d panicked %v", i, err)
  1259  			}
  1260  			continue
  1261  		}
  1262  
  1263  		if err == nil || !strings.Contains(err.Error(), tt.errStr) {
  1264  			t.Errorf("#%d expected %q got %q", i, tt.errStr, err)
  1265  		}
  1266  	}
  1267  }
  1268  
  1269  func runesEqual(a, b []rune) bool {
  1270  	if len(a) != len(b) {
  1271  		return false
  1272  	}
  1273  	for i, r := range a {
  1274  		if r != b[i] {
  1275  			return false
  1276  		}
  1277  	}
  1278  	return true
  1279  }
  1280  
  1281  type RunesTest struct {
  1282  	in    string
  1283  	out   []rune
  1284  	lossy bool
  1285  }
  1286  
  1287  var RunesTests = []RunesTest{
  1288  	{"", []rune{}, false},
  1289  	{" ", []rune{32}, false},
  1290  	{"ABC", []rune{65, 66, 67}, false},
  1291  	{"abc", []rune{97, 98, 99}, false},
  1292  	{"\u65e5\u672c\u8a9e", []rune{26085, 26412, 35486}, false},
  1293  	{"ab\x80c", []rune{97, 98, 0xFFFD, 99}, true},
  1294  	{"ab\xc0c", []rune{97, 98, 0xFFFD, 99}, true},
  1295  }
  1296  
  1297  func TestRunes(t *testing.T) {
  1298  	for _, tt := range RunesTests {
  1299  		tin := []byte(tt.in)
  1300  		a := Runes(tin)
  1301  		if !runesEqual(a, tt.out) {
  1302  			t.Errorf("Runes(%q) = %v; want %v", tin, a, tt.out)
  1303  			continue
  1304  		}
  1305  		if !tt.lossy {
  1306  			// can only test reassembly if we didn't lose information
  1307  			s := string(a)
  1308  			if s != tt.in {
  1309  				t.Errorf("string(Runes(%q)) = %x; want %x", tin, s, tin)
  1310  			}
  1311  		}
  1312  	}
  1313  }
  1314  
  1315  type TrimTest struct {
  1316  	f            string
  1317  	in, arg, out string
  1318  }
  1319  
  1320  var trimTests = []TrimTest{
  1321  	{"Trim", "abba", "a", "bb"},
  1322  	{"Trim", "abba", "ab", ""},
  1323  	{"TrimLeft", "abba", "ab", ""},
  1324  	{"TrimRight", "abba", "ab", ""},
  1325  	{"TrimLeft", "abba", "a", "bba"},
  1326  	{"TrimLeft", "abba", "b", "abba"},
  1327  	{"TrimRight", "abba", "a", "abb"},
  1328  	{"TrimRight", "abba", "b", "abba"},
  1329  	{"Trim", "<tag>", "<>", "tag"},
  1330  	{"Trim", "* listitem", " *", "listitem"},
  1331  	{"Trim", `"quote"`, `"`, "quote"},
  1332  	{"Trim", "\u2C6F\u2C6F\u0250\u0250\u2C6F\u2C6F", "\u2C6F", "\u0250\u0250"},
  1333  	{"Trim", "\x80test\xff", "\xff", "test"},
  1334  	{"Trim", " Ġ ", " ", "Ġ"},
  1335  	{"Trim", " Ġİ0", "0 ", "Ġİ"},
  1336  	//empty string tests
  1337  	{"Trim", "abba", "", "abba"},
  1338  	{"Trim", "", "123", ""},
  1339  	{"Trim", "", "", ""},
  1340  	{"TrimLeft", "abba", "", "abba"},
  1341  	{"TrimLeft", "", "123", ""},
  1342  	{"TrimLeft", "", "", ""},
  1343  	{"TrimRight", "abba", "", "abba"},
  1344  	{"TrimRight", "", "123", ""},
  1345  	{"TrimRight", "", "", ""},
  1346  	{"TrimRight", "☺\xc0", "☺", "☺\xc0"},
  1347  	{"TrimPrefix", "aabb", "a", "abb"},
  1348  	{"TrimPrefix", "aabb", "b", "aabb"},
  1349  	{"TrimSuffix", "aabb", "a", "aabb"},
  1350  	{"TrimSuffix", "aabb", "b", "aab"},
  1351  }
  1352  
  1353  type TrimNilTest struct {
  1354  	f   string
  1355  	in  []byte
  1356  	arg string
  1357  	out []byte
  1358  }
  1359  
  1360  var trimNilTests = []TrimNilTest{
  1361  	{"Trim", nil, "", nil},
  1362  	{"Trim", []byte{}, "", nil},
  1363  	{"Trim", []byte{'a'}, "a", nil},
  1364  	{"Trim", []byte{'a', 'a'}, "a", nil},
  1365  	{"Trim", []byte{'a'}, "ab", nil},
  1366  	{"Trim", []byte{'a', 'b'}, "ab", nil},
  1367  	{"Trim", []byte("☺"), "☺", nil},
  1368  	{"TrimLeft", nil, "", nil},
  1369  	{"TrimLeft", []byte{}, "", nil},
  1370  	{"TrimLeft", []byte{'a'}, "a", nil},
  1371  	{"TrimLeft", []byte{'a', 'a'}, "a", nil},
  1372  	{"TrimLeft", []byte{'a'}, "ab", nil},
  1373  	{"TrimLeft", []byte{'a', 'b'}, "ab", nil},
  1374  	{"TrimLeft", []byte("☺"), "☺", nil},
  1375  	{"TrimRight", nil, "", nil},
  1376  	{"TrimRight", []byte{}, "", []byte{}},
  1377  	{"TrimRight", []byte{'a'}, "a", []byte{}},
  1378  	{"TrimRight", []byte{'a', 'a'}, "a", []byte{}},
  1379  	{"TrimRight", []byte{'a'}, "ab", []byte{}},
  1380  	{"TrimRight", []byte{'a', 'b'}, "ab", []byte{}},
  1381  	{"TrimRight", []byte("☺"), "☺", []byte{}},
  1382  	{"TrimPrefix", nil, "", nil},
  1383  	{"TrimPrefix", []byte{}, "", []byte{}},
  1384  	{"TrimPrefix", []byte{'a'}, "a", []byte{}},
  1385  	{"TrimPrefix", []byte("☺"), "☺", []byte{}},
  1386  	{"TrimSuffix", nil, "", nil},
  1387  	{"TrimSuffix", []byte{}, "", []byte{}},
  1388  	{"TrimSuffix", []byte{'a'}, "a", []byte{}},
  1389  	{"TrimSuffix", []byte("☺"), "☺", []byte{}},
  1390  }
  1391  
  1392  func TestTrim(t *testing.T) {
  1393  	toFn := func(name string) (func([]byte, string) []byte, func([]byte, []byte) []byte) {
  1394  		switch name {
  1395  		case "Trim":
  1396  			return Trim, nil
  1397  		case "TrimLeft":
  1398  			return TrimLeft, nil
  1399  		case "TrimRight":
  1400  			return TrimRight, nil
  1401  		case "TrimPrefix":
  1402  			return nil, TrimPrefix
  1403  		case "TrimSuffix":
  1404  			return nil, TrimSuffix
  1405  		default:
  1406  			t.Errorf("Undefined trim function %s", name)
  1407  			return nil, nil
  1408  		}
  1409  	}
  1410  
  1411  	for _, tc := range trimTests {
  1412  		name := tc.f
  1413  		f, fb := toFn(name)
  1414  		if f == nil && fb == nil {
  1415  			continue
  1416  		}
  1417  		var actual string
  1418  		if f != nil {
  1419  			actual = string(f([]byte(tc.in), tc.arg))
  1420  		} else {
  1421  			actual = string(fb([]byte(tc.in), []byte(tc.arg)))
  1422  		}
  1423  		if actual != tc.out {
  1424  			t.Errorf("%s(%q, %q) = %q; want %q", name, tc.in, tc.arg, actual, tc.out)
  1425  		}
  1426  	}
  1427  
  1428  	for _, tc := range trimNilTests {
  1429  		name := tc.f
  1430  		f, fb := toFn(name)
  1431  		if f == nil && fb == nil {
  1432  			continue
  1433  		}
  1434  		var actual []byte
  1435  		if f != nil {
  1436  			actual = f(tc.in, tc.arg)
  1437  		} else {
  1438  			actual = fb(tc.in, []byte(tc.arg))
  1439  		}
  1440  		report := func(s []byte) string {
  1441  			if s == nil {
  1442  				return "nil"
  1443  			} else {
  1444  				return fmt.Sprintf("%q", s)
  1445  			}
  1446  		}
  1447  		if len(actual) != 0 {
  1448  			t.Errorf("%s(%s, %q) returned non-empty value", name, report(tc.in), tc.arg)
  1449  		} else {
  1450  			actualNil := actual == nil
  1451  			outNil := tc.out == nil
  1452  			if actualNil != outNil {
  1453  				t.Errorf("%s(%s, %q) got nil %t; want nil %t", name, report(tc.in), tc.arg, actualNil, outNil)
  1454  			}
  1455  		}
  1456  	}
  1457  }
  1458  
  1459  type predicate struct {
  1460  	f    func(r rune) bool
  1461  	name string
  1462  }
  1463  
  1464  var isSpace = predicate{unicode.IsSpace, "IsSpace"}
  1465  var isDigit = predicate{unicode.IsDigit, "IsDigit"}
  1466  var isUpper = predicate{unicode.IsUpper, "IsUpper"}
  1467  var isValidRune = predicate{
  1468  	func(r rune) bool {
  1469  		return r != utf8.RuneError
  1470  	},
  1471  	"IsValidRune",
  1472  }
  1473  
  1474  type TrimFuncTest struct {
  1475  	f        predicate
  1476  	in       string
  1477  	trimOut  []byte
  1478  	leftOut  []byte
  1479  	rightOut []byte
  1480  }
  1481  
  1482  func not(p predicate) predicate {
  1483  	return predicate{
  1484  		func(r rune) bool {
  1485  			return !p.f(r)
  1486  		},
  1487  		"not " + p.name,
  1488  	}
  1489  }
  1490  
  1491  var trimFuncTests = []TrimFuncTest{
  1492  	{isSpace, space + " hello " + space,
  1493  		[]byte("hello"),
  1494  		[]byte("hello " + space),
  1495  		[]byte(space + " hello")},
  1496  	{isDigit, "\u0e50\u0e5212hello34\u0e50\u0e51",
  1497  		[]byte("hello"),
  1498  		[]byte("hello34\u0e50\u0e51"),
  1499  		[]byte("\u0e50\u0e5212hello")},
  1500  	{isUpper, "\u2C6F\u2C6F\u2C6F\u2C6FABCDhelloEF\u2C6F\u2C6FGH\u2C6F\u2C6F",
  1501  		[]byte("hello"),
  1502  		[]byte("helloEF\u2C6F\u2C6FGH\u2C6F\u2C6F"),
  1503  		[]byte("\u2C6F\u2C6F\u2C6F\u2C6FABCDhello")},
  1504  	{not(isSpace), "hello" + space + "hello",
  1505  		[]byte(space),
  1506  		[]byte(space + "hello"),
  1507  		[]byte("hello" + space)},
  1508  	{not(isDigit), "hello\u0e50\u0e521234\u0e50\u0e51helo",
  1509  		[]byte("\u0e50\u0e521234\u0e50\u0e51"),
  1510  		[]byte("\u0e50\u0e521234\u0e50\u0e51helo"),
  1511  		[]byte("hello\u0e50\u0e521234\u0e50\u0e51")},
  1512  	{isValidRune, "ab\xc0a\xc0cd",
  1513  		[]byte("\xc0a\xc0"),
  1514  		[]byte("\xc0a\xc0cd"),
  1515  		[]byte("ab\xc0a\xc0")},
  1516  	{not(isValidRune), "\xc0a\xc0",
  1517  		[]byte("a"),
  1518  		[]byte("a\xc0"),
  1519  		[]byte("\xc0a")},
  1520  	// The nils returned by TrimLeftFunc are odd behavior, but we need
  1521  	// to preserve backwards compatibility.
  1522  	{isSpace, "",
  1523  		nil,
  1524  		nil,
  1525  		[]byte("")},
  1526  	{isSpace, " ",
  1527  		nil,
  1528  		nil,
  1529  		[]byte("")},
  1530  }
  1531  
  1532  func TestTrimFunc(t *testing.T) {
  1533  	for _, tc := range trimFuncTests {
  1534  		trimmers := []struct {
  1535  			name string
  1536  			trim func(s []byte, f func(r rune) bool) []byte
  1537  			out  []byte
  1538  		}{
  1539  			{"TrimFunc", TrimFunc, tc.trimOut},
  1540  			{"TrimLeftFunc", TrimLeftFunc, tc.leftOut},
  1541  			{"TrimRightFunc", TrimRightFunc, tc.rightOut},
  1542  		}
  1543  		for _, trimmer := range trimmers {
  1544  			actual := trimmer.trim([]byte(tc.in), tc.f.f)
  1545  			if actual == nil && trimmer.out != nil {
  1546  				t.Errorf("%s(%q, %q) = nil; want %q", trimmer.name, tc.in, tc.f.name, trimmer.out)
  1547  			}
  1548  			if actual != nil && trimmer.out == nil {
  1549  				t.Errorf("%s(%q, %q) = %q; want nil", trimmer.name, tc.in, tc.f.name, actual)
  1550  			}
  1551  			if !Equal(actual, trimmer.out) {
  1552  				t.Errorf("%s(%q, %q) = %q; want %q", trimmer.name, tc.in, tc.f.name, actual, trimmer.out)
  1553  			}
  1554  		}
  1555  	}
  1556  }
  1557  
  1558  type IndexFuncTest struct {
  1559  	in          string
  1560  	f           predicate
  1561  	first, last int
  1562  }
  1563  
  1564  var indexFuncTests = []IndexFuncTest{
  1565  	{"", isValidRune, -1, -1},
  1566  	{"abc", isDigit, -1, -1},
  1567  	{"0123", isDigit, 0, 3},
  1568  	{"a1b", isDigit, 1, 1},
  1569  	{space, isSpace, 0, len(space) - 3}, // last rune in space is 3 bytes
  1570  	{"\u0e50\u0e5212hello34\u0e50\u0e51", isDigit, 0, 18},
  1571  	{"\u2C6F\u2C6F\u2C6F\u2C6FABCDhelloEF\u2C6F\u2C6FGH\u2C6F\u2C6F", isUpper, 0, 34},
  1572  	{"12\u0e50\u0e52hello34\u0e50\u0e51", not(isDigit), 8, 12},
  1573  
  1574  	// tests of invalid UTF-8
  1575  	{"\x801", isDigit, 1, 1},
  1576  	{"\x80abc", isDigit, -1, -1},
  1577  	{"\xc0a\xc0", isValidRune, 1, 1},
  1578  	{"\xc0a\xc0", not(isValidRune), 0, 2},
  1579  	{"\xc0☺\xc0", not(isValidRune), 0, 4},
  1580  	{"\xc0☺\xc0\xc0", not(isValidRune), 0, 5},
  1581  	{"ab\xc0a\xc0cd", not(isValidRune), 2, 4},
  1582  	{"a\xe0\x80cd", not(isValidRune), 1, 2},
  1583  }
  1584  
  1585  func TestIndexFunc(t *testing.T) {
  1586  	for _, tc := range indexFuncTests {
  1587  		first := IndexFunc([]byte(tc.in), tc.f.f)
  1588  		if first != tc.first {
  1589  			t.Errorf("IndexFunc(%q, %s) = %d; want %d", tc.in, tc.f.name, first, tc.first)
  1590  		}
  1591  		last := LastIndexFunc([]byte(tc.in), tc.f.f)
  1592  		if last != tc.last {
  1593  			t.Errorf("LastIndexFunc(%q, %s) = %d; want %d", tc.in, tc.f.name, last, tc.last)
  1594  		}
  1595  	}
  1596  }
  1597  
  1598  type ReplaceTest struct {
  1599  	in       string
  1600  	old, new string
  1601  	n        int
  1602  	out      string
  1603  }
  1604  
  1605  var ReplaceTests = []ReplaceTest{
  1606  	{"hello", "l", "L", 0, "hello"},
  1607  	{"hello", "l", "L", -1, "heLLo"},
  1608  	{"hello", "x", "X", -1, "hello"},
  1609  	{"", "x", "X", -1, ""},
  1610  	{"radar", "r", "<r>", -1, "<r>ada<r>"},
  1611  	{"", "", "<>", -1, "<>"},
  1612  	{"banana", "a", "<>", -1, "b<>n<>n<>"},
  1613  	{"banana", "a", "<>", 1, "b<>nana"},
  1614  	{"banana", "a", "<>", 1000, "b<>n<>n<>"},
  1615  	{"banana", "an", "<>", -1, "b<><>a"},
  1616  	{"banana", "ana", "<>", -1, "b<>na"},
  1617  	{"banana", "", "<>", -1, "<>b<>a<>n<>a<>n<>a<>"},
  1618  	{"banana", "", "<>", 10, "<>b<>a<>n<>a<>n<>a<>"},
  1619  	{"banana", "", "<>", 6, "<>b<>a<>n<>a<>n<>a"},
  1620  	{"banana", "", "<>", 5, "<>b<>a<>n<>a<>na"},
  1621  	{"banana", "", "<>", 1, "<>banana"},
  1622  	{"banana", "a", "a", -1, "banana"},
  1623  	{"banana", "a", "a", 1, "banana"},
  1624  	{"☺☻☹", "", "<>", -1, "<>☺<>☻<>☹<>"},
  1625  }
  1626  
  1627  func TestReplace(t *testing.T) {
  1628  	for _, tt := range ReplaceTests {
  1629  		in := append([]byte(tt.in), "<spare>"...)
  1630  		in = in[:len(tt.in)]
  1631  		out := Replace(in, []byte(tt.old), []byte(tt.new), tt.n)
  1632  		if s := string(out); s != tt.out {
  1633  			t.Errorf("Replace(%q, %q, %q, %d) = %q, want %q", tt.in, tt.old, tt.new, tt.n, s, tt.out)
  1634  		}
  1635  		if cap(in) == cap(out) && &in[:1][0] == &out[:1][0] {
  1636  			t.Errorf("Replace(%q, %q, %q, %d) didn't copy", tt.in, tt.old, tt.new, tt.n)
  1637  		}
  1638  		if tt.n == -1 {
  1639  			out := ReplaceAll(in, []byte(tt.old), []byte(tt.new))
  1640  			if s := string(out); s != tt.out {
  1641  				t.Errorf("ReplaceAll(%q, %q, %q) = %q, want %q", tt.in, tt.old, tt.new, s, tt.out)
  1642  			}
  1643  		}
  1644  	}
  1645  }
  1646  
  1647  type TitleTest struct {
  1648  	in, out string
  1649  }
  1650  
  1651  var TitleTests = []TitleTest{
  1652  	{"", ""},
  1653  	{"a", "A"},
  1654  	{" aaa aaa aaa ", " Aaa Aaa Aaa "},
  1655  	{" Aaa Aaa Aaa ", " Aaa Aaa Aaa "},
  1656  	{"123a456", "123a456"},
  1657  	{"double-blind", "Double-Blind"},
  1658  	{"ÿøû", "Ÿøû"},
  1659  	{"with_underscore", "With_underscore"},
  1660  	{"unicode \xe2\x80\xa8 line separator", "Unicode \xe2\x80\xa8 Line Separator"},
  1661  }
  1662  
  1663  func TestTitle(t *testing.T) {
  1664  	for _, tt := range TitleTests {
  1665  		if s := string(Title([]byte(tt.in))); s != tt.out {
  1666  			t.Errorf("Title(%q) = %q, want %q", tt.in, s, tt.out)
  1667  		}
  1668  	}
  1669  }
  1670  
  1671  var ToTitleTests = []TitleTest{
  1672  	{"", ""},
  1673  	{"a", "A"},
  1674  	{" aaa aaa aaa ", " AAA AAA AAA "},
  1675  	{" Aaa Aaa Aaa ", " AAA AAA AAA "},
  1676  	{"123a456", "123A456"},
  1677  	{"double-blind", "DOUBLE-BLIND"},
  1678  	{"ÿøû", "ŸØÛ"},
  1679  }
  1680  
  1681  func TestToTitle(t *testing.T) {
  1682  	for _, tt := range ToTitleTests {
  1683  		if s := string(ToTitle([]byte(tt.in))); s != tt.out {
  1684  			t.Errorf("ToTitle(%q) = %q, want %q", tt.in, s, tt.out)
  1685  		}
  1686  	}
  1687  }
  1688  
  1689  var EqualFoldTests = []struct {
  1690  	s, t string
  1691  	out  bool
  1692  }{
  1693  	{"abc", "abc", true},
  1694  	{"ABcd", "ABcd", true},
  1695  	{"123abc", "123ABC", true},
  1696  	{"αβδ", "ΑΒΔ", true},
  1697  	{"abc", "xyz", false},
  1698  	{"abc", "XYZ", false},
  1699  	{"abcdefghijk", "abcdefghijX", false},
  1700  	{"abcdefghijk", "abcdefghij\u212A", true},
  1701  	{"abcdefghijK", "abcdefghij\u212A", true},
  1702  	{"abcdefghijkz", "abcdefghij\u212Ay", false},
  1703  	{"abcdefghijKz", "abcdefghij\u212Ay", false},
  1704  }
  1705  
  1706  func TestEqualFold(t *testing.T) {
  1707  	for _, tt := range EqualFoldTests {
  1708  		if out := EqualFold([]byte(tt.s), []byte(tt.t)); out != tt.out {
  1709  			t.Errorf("EqualFold(%#q, %#q) = %v, want %v", tt.s, tt.t, out, tt.out)
  1710  		}
  1711  		if out := EqualFold([]byte(tt.t), []byte(tt.s)); out != tt.out {
  1712  			t.Errorf("EqualFold(%#q, %#q) = %v, want %v", tt.t, tt.s, out, tt.out)
  1713  		}
  1714  	}
  1715  }
  1716  
  1717  var cutTests = []struct {
  1718  	s, sep        string
  1719  	before, after string
  1720  	found         bool
  1721  }{
  1722  	{"abc", "b", "a", "c", true},
  1723  	{"abc", "a", "", "bc", true},
  1724  	{"abc", "c", "ab", "", true},
  1725  	{"abc", "abc", "", "", true},
  1726  	{"abc", "", "", "abc", true},
  1727  	{"abc", "d", "abc", "", false},
  1728  	{"", "d", "", "", false},
  1729  	{"", "", "", "", true},
  1730  }
  1731  
  1732  func TestCut(t *testing.T) {
  1733  	for _, tt := range cutTests {
  1734  		if before, after, found := Cut([]byte(tt.s), []byte(tt.sep)); string(before) != tt.before || string(after) != tt.after || found != tt.found {
  1735  			t.Errorf("Cut(%q, %q) = %q, %q, %v, want %q, %q, %v", tt.s, tt.sep, before, after, found, tt.before, tt.after, tt.found)
  1736  		}
  1737  	}
  1738  }
  1739  
  1740  var cutPrefixTests = []struct {
  1741  	s, sep string
  1742  	after  string
  1743  	found  bool
  1744  }{
  1745  	{"abc", "a", "bc", true},
  1746  	{"abc", "abc", "", true},
  1747  	{"abc", "", "abc", true},
  1748  	{"abc", "d", "abc", false},
  1749  	{"", "d", "", false},
  1750  	{"", "", "", true},
  1751  }
  1752  
  1753  func TestCutPrefix(t *testing.T) {
  1754  	for _, tt := range cutPrefixTests {
  1755  		if after, found := CutPrefix([]byte(tt.s), []byte(tt.sep)); string(after) != tt.after || found != tt.found {
  1756  			t.Errorf("CutPrefix(%q, %q) = %q, %v, want %q, %v", tt.s, tt.sep, after, found, tt.after, tt.found)
  1757  		}
  1758  	}
  1759  }
  1760  
  1761  var cutSuffixTests = []struct {
  1762  	s, sep string
  1763  	before string
  1764  	found  bool
  1765  }{
  1766  	{"abc", "bc", "a", true},
  1767  	{"abc", "abc", "", true},
  1768  	{"abc", "", "abc", true},
  1769  	{"abc", "d", "abc", false},
  1770  	{"", "d", "", false},
  1771  	{"", "", "", true},
  1772  }
  1773  
  1774  func TestCutSuffix(t *testing.T) {
  1775  	for _, tt := range cutSuffixTests {
  1776  		if before, found := CutSuffix([]byte(tt.s), []byte(tt.sep)); string(before) != tt.before || found != tt.found {
  1777  			t.Errorf("CutSuffix(%q, %q) = %q, %v, want %q, %v", tt.s, tt.sep, before, found, tt.before, tt.found)
  1778  		}
  1779  	}
  1780  }
  1781  
  1782  func TestBufferGrowNegative(t *testing.T) {
  1783  	defer func() {
  1784  		if err := recover(); err == nil {
  1785  			t.Fatal("Grow(-1) should have panicked")
  1786  		}
  1787  	}()
  1788  	var b Buffer
  1789  	b.Grow(-1)
  1790  }
  1791  
  1792  func TestBufferTruncateNegative(t *testing.T) {
  1793  	defer func() {
  1794  		if err := recover(); err == nil {
  1795  			t.Fatal("Truncate(-1) should have panicked")
  1796  		}
  1797  	}()
  1798  	var b Buffer
  1799  	b.Truncate(-1)
  1800  }
  1801  
  1802  func TestBufferTruncateOutOfRange(t *testing.T) {
  1803  	defer func() {
  1804  		if err := recover(); err == nil {
  1805  			t.Fatal("Truncate(20) should have panicked")
  1806  		}
  1807  	}()
  1808  	var b Buffer
  1809  	b.Write(make([]byte, 10))
  1810  	b.Truncate(20)
  1811  }
  1812  
  1813  var containsTests = []struct {
  1814  	b, subslice []byte
  1815  	want        bool
  1816  }{
  1817  	{[]byte("hello"), []byte("hel"), true},
  1818  	{[]byte("日本語"), []byte("日本"), true},
  1819  	{[]byte("hello"), []byte("Hello, world"), false},
  1820  	{[]byte("東京"), []byte("京東"), false},
  1821  }
  1822  
  1823  func TestContains(t *testing.T) {
  1824  	for _, tt := range containsTests {
  1825  		if got := Contains(tt.b, tt.subslice); got != tt.want {
  1826  			t.Errorf("Contains(%q, %q) = %v, want %v", tt.b, tt.subslice, got, tt.want)
  1827  		}
  1828  	}
  1829  }
  1830  
  1831  var ContainsAnyTests = []struct {
  1832  	b        []byte
  1833  	substr   string
  1834  	expected bool
  1835  }{
  1836  	{[]byte(""), "", false},
  1837  	{[]byte(""), "a", false},
  1838  	{[]byte(""), "abc", false},
  1839  	{[]byte("a"), "", false},
  1840  	{[]byte("a"), "a", true},
  1841  	{[]byte("aaa"), "a", true},
  1842  	{[]byte("abc"), "xyz", false},
  1843  	{[]byte("abc"), "xcz", true},
  1844  	{[]byte("a☺b☻c☹d"), "uvw☻xyz", true},
  1845  	{[]byte("aRegExp*"), ".(|)*+?^$[]", true},
  1846  	{[]byte(dots + dots + dots), " ", false},
  1847  }
  1848  
  1849  func TestContainsAny(t *testing.T) {
  1850  	for _, ct := range ContainsAnyTests {
  1851  		if ContainsAny(ct.b, ct.substr) != ct.expected {
  1852  			t.Errorf("ContainsAny(%s, %s) = %v, want %v",
  1853  				ct.b, ct.substr, !ct.expected, ct.expected)
  1854  		}
  1855  	}
  1856  }
  1857  
  1858  var ContainsRuneTests = []struct {
  1859  	b        []byte
  1860  	r        rune
  1861  	expected bool
  1862  }{
  1863  	{[]byte(""), 'a', false},
  1864  	{[]byte("a"), 'a', true},
  1865  	{[]byte("aaa"), 'a', true},
  1866  	{[]byte("abc"), 'y', false},
  1867  	{[]byte("abc"), 'c', true},
  1868  	{[]byte("a☺b☻c☹d"), 'x', false},
  1869  	{[]byte("a☺b☻c☹d"), '☻', true},
  1870  	{[]byte("aRegExp*"), '*', true},
  1871  }
  1872  
  1873  func TestContainsRune(t *testing.T) {
  1874  	for _, ct := range ContainsRuneTests {
  1875  		if ContainsRune(ct.b, ct.r) != ct.expected {
  1876  			t.Errorf("ContainsRune(%q, %q) = %v, want %v",
  1877  				ct.b, ct.r, !ct.expected, ct.expected)
  1878  		}
  1879  	}
  1880  }
  1881  
  1882  func TestContainsFunc(t *testing.T) {
  1883  	for _, ct := range ContainsRuneTests {
  1884  		if ContainsFunc(ct.b, func(r rune) bool {
  1885  			return ct.r == r
  1886  		}) != ct.expected {
  1887  			t.Errorf("ContainsFunc(%q, func(%q)) = %v, want %v",
  1888  				ct.b, ct.r, !ct.expected, ct.expected)
  1889  		}
  1890  	}
  1891  }
  1892  
  1893  var makeFieldsInput = func() []byte {
  1894  	x := make([]byte, 1<<20)
  1895  	// Input is ~10% space, ~10% 2-byte UTF-8, rest ASCII non-space.
  1896  	for i := range x {
  1897  		switch rand.Intn(10) {
  1898  		case 0:
  1899  			x[i] = ' '
  1900  		case 1:
  1901  			if i > 0 && x[i-1] == 'x' {
  1902  				copy(x[i-1:], "χ")
  1903  				break
  1904  			}
  1905  			fallthrough
  1906  		default:
  1907  			x[i] = 'x'
  1908  		}
  1909  	}
  1910  	return x
  1911  }
  1912  
  1913  var makeFieldsInputASCII = func() []byte {
  1914  	x := make([]byte, 1<<20)
  1915  	// Input is ~10% space, rest ASCII non-space.
  1916  	for i := range x {
  1917  		if rand.Intn(10) == 0 {
  1918  			x[i] = ' '
  1919  		} else {
  1920  			x[i] = 'x'
  1921  		}
  1922  	}
  1923  	return x
  1924  }
  1925  
  1926  var bytesdata = []struct {
  1927  	name string
  1928  	data []byte
  1929  }{
  1930  	{"ASCII", makeFieldsInputASCII()},
  1931  	{"Mixed", makeFieldsInput()},
  1932  }
  1933  
  1934  func BenchmarkFields(b *testing.B) {
  1935  	for _, sd := range bytesdata {
  1936  		b.Run(sd.name, func(b *testing.B) {
  1937  			for j := 1 << 4; j <= 1<<20; j <<= 4 {
  1938  				b.Run(fmt.Sprintf("%d", j), func(b *testing.B) {
  1939  					b.ReportAllocs()
  1940  					b.SetBytes(int64(j))
  1941  					data := sd.data[:j]
  1942  					for i := 0; i < b.N; i++ {
  1943  						Fields(data)
  1944  					}
  1945  				})
  1946  			}
  1947  		})
  1948  	}
  1949  }
  1950  
  1951  func BenchmarkFieldsFunc(b *testing.B) {
  1952  	for _, sd := range bytesdata {
  1953  		b.Run(sd.name, func(b *testing.B) {
  1954  			for j := 1 << 4; j <= 1<<20; j <<= 4 {
  1955  				b.Run(fmt.Sprintf("%d", j), func(b *testing.B) {
  1956  					b.ReportAllocs()
  1957  					b.SetBytes(int64(j))
  1958  					data := sd.data[:j]
  1959  					for i := 0; i < b.N; i++ {
  1960  						FieldsFunc(data, unicode.IsSpace)
  1961  					}
  1962  				})
  1963  			}
  1964  		})
  1965  	}
  1966  }
  1967  
  1968  func BenchmarkTrimSpace(b *testing.B) {
  1969  	tests := []struct {
  1970  		name  string
  1971  		input []byte
  1972  	}{
  1973  		{"NoTrim", []byte("typical")},
  1974  		{"ASCII", []byte("  foo bar  ")},
  1975  		{"SomeNonASCII", []byte("    \u2000\t\r\n x\t\t\r\r\ny\n \u3000    ")},
  1976  		{"JustNonASCII", []byte("\u2000\u2000\u2000☺☺☺☺\u3000\u3000\u3000")},
  1977  	}
  1978  	for _, test := range tests {
  1979  		b.Run(test.name, func(b *testing.B) {
  1980  			for i := 0; i < b.N; i++ {
  1981  				TrimSpace(test.input)
  1982  			}
  1983  		})
  1984  	}
  1985  }
  1986  
  1987  func BenchmarkToValidUTF8(b *testing.B) {
  1988  	tests := []struct {
  1989  		name  string
  1990  		input []byte
  1991  	}{
  1992  		{"Valid", []byte("typical")},
  1993  		{"InvalidASCII", []byte("foo\xffbar")},
  1994  		{"InvalidNonASCII", []byte("日本語\xff日本語")},
  1995  	}
  1996  	replacement := []byte("\uFFFD")
  1997  	b.ResetTimer()
  1998  	for _, test := range tests {
  1999  		b.Run(test.name, func(b *testing.B) {
  2000  			for i := 0; i < b.N; i++ {
  2001  				ToValidUTF8(test.input, replacement)
  2002  			}
  2003  		})
  2004  	}
  2005  }
  2006  
  2007  func makeBenchInputHard() []byte {
  2008  	tokens := [...]string{
  2009  		"<a>", "<p>", "<b>", "<strong>",
  2010  		"</a>", "</p>", "</b>", "</strong>",
  2011  		"hello", "world",
  2012  	}
  2013  	x := make([]byte, 0, 1<<20)
  2014  	for {
  2015  		i := rand.Intn(len(tokens))
  2016  		if len(x)+len(tokens[i]) >= 1<<20 {
  2017  			break
  2018  		}
  2019  		x = append(x, tokens[i]...)
  2020  	}
  2021  	return x
  2022  }
  2023  
  2024  var benchInputHard = makeBenchInputHard()
  2025  
  2026  func benchmarkIndexHard(b *testing.B, sep []byte) {
  2027  	for i := 0; i < b.N; i++ {
  2028  		Index(benchInputHard, sep)
  2029  	}
  2030  }
  2031  
  2032  func benchmarkLastIndexHard(b *testing.B, sep []byte) {
  2033  	for i := 0; i < b.N; i++ {
  2034  		LastIndex(benchInputHard, sep)
  2035  	}
  2036  }
  2037  
  2038  func benchmarkCountHard(b *testing.B, sep []byte) {
  2039  	for i := 0; i < b.N; i++ {
  2040  		Count(benchInputHard, sep)
  2041  	}
  2042  }
  2043  
  2044  func BenchmarkIndexHard1(b *testing.B) { benchmarkIndexHard(b, []byte("<>")) }
  2045  func BenchmarkIndexHard2(b *testing.B) { benchmarkIndexHard(b, []byte("</pre>")) }
  2046  func BenchmarkIndexHard3(b *testing.B) { benchmarkIndexHard(b, []byte("<b>hello world</b>")) }
  2047  func BenchmarkIndexHard4(b *testing.B) {
  2048  	benchmarkIndexHard(b, []byte("<pre><b>hello</b><strong>world</strong></pre>"))
  2049  }
  2050  
  2051  func BenchmarkLastIndexHard1(b *testing.B) { benchmarkLastIndexHard(b, []byte("<>")) }
  2052  func BenchmarkLastIndexHard2(b *testing.B) { benchmarkLastIndexHard(b, []byte("</pre>")) }
  2053  func BenchmarkLastIndexHard3(b *testing.B) { benchmarkLastIndexHard(b, []byte("<b>hello world</b>")) }
  2054  
  2055  func BenchmarkCountHard1(b *testing.B) { benchmarkCountHard(b, []byte("<>")) }
  2056  func BenchmarkCountHard2(b *testing.B) { benchmarkCountHard(b, []byte("</pre>")) }
  2057  func BenchmarkCountHard3(b *testing.B) { benchmarkCountHard(b, []byte("<b>hello world</b>")) }
  2058  
  2059  func BenchmarkSplitEmptySeparator(b *testing.B) {
  2060  	for i := 0; i < b.N; i++ {
  2061  		Split(benchInputHard, nil)
  2062  	}
  2063  }
  2064  
  2065  func BenchmarkSplitSingleByteSeparator(b *testing.B) {
  2066  	sep := []byte("/")
  2067  	for i := 0; i < b.N; i++ {
  2068  		Split(benchInputHard, sep)
  2069  	}
  2070  }
  2071  
  2072  func BenchmarkSplitMultiByteSeparator(b *testing.B) {
  2073  	sep := []byte("hello")
  2074  	for i := 0; i < b.N; i++ {
  2075  		Split(benchInputHard, sep)
  2076  	}
  2077  }
  2078  
  2079  func BenchmarkSplitNSingleByteSeparator(b *testing.B) {
  2080  	sep := []byte("/")
  2081  	for i := 0; i < b.N; i++ {
  2082  		SplitN(benchInputHard, sep, 10)
  2083  	}
  2084  }
  2085  
  2086  func BenchmarkSplitNMultiByteSeparator(b *testing.B) {
  2087  	sep := []byte("hello")
  2088  	for i := 0; i < b.N; i++ {
  2089  		SplitN(benchInputHard, sep, 10)
  2090  	}
  2091  }
  2092  
  2093  func BenchmarkRepeat(b *testing.B) {
  2094  	for i := 0; i < b.N; i++ {
  2095  		Repeat([]byte("-"), 80)
  2096  	}
  2097  }
  2098  
  2099  func BenchmarkRepeatLarge(b *testing.B) {
  2100  	s := Repeat([]byte("@"), 8*1024)
  2101  	for j := 8; j <= 30; j++ {
  2102  		for _, k := range []int{1, 16, 4097} {
  2103  			s := s[:k]
  2104  			n := (1 << j) / k
  2105  			if n == 0 {
  2106  				continue
  2107  			}
  2108  			b.Run(fmt.Sprintf("%d/%d", 1<<j, k), func(b *testing.B) {
  2109  				for i := 0; i < b.N; i++ {
  2110  					Repeat(s, n)
  2111  				}
  2112  				b.SetBytes(int64(n * len(s)))
  2113  			})
  2114  		}
  2115  	}
  2116  }
  2117  
  2118  func BenchmarkBytesCompare(b *testing.B) {
  2119  	for n := 1; n <= 2048; n <<= 1 {
  2120  		b.Run(fmt.Sprint(n), func(b *testing.B) {
  2121  			var x = make([]byte, n)
  2122  			var y = make([]byte, n)
  2123  
  2124  			for i := 0; i < n; i++ {
  2125  				x[i] = 'a'
  2126  			}
  2127  
  2128  			for i := 0; i < n; i++ {
  2129  				y[i] = 'a'
  2130  			}
  2131  
  2132  			b.ResetTimer()
  2133  			for i := 0; i < b.N; i++ {
  2134  				Compare(x, y)
  2135  			}
  2136  		})
  2137  	}
  2138  }
  2139  
  2140  func BenchmarkIndexAnyASCII(b *testing.B) {
  2141  	x := Repeat([]byte{'#'}, 2048) // Never matches set
  2142  	cs := "0123456789abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz"
  2143  	for k := 1; k <= 2048; k <<= 4 {
  2144  		for j := 1; j <= 64; j <<= 1 {
  2145  			b.Run(fmt.Sprintf("%d:%d", k, j), func(b *testing.B) {
  2146  				for i := 0; i < b.N; i++ {
  2147  					IndexAny(x[:k], cs[:j])
  2148  				}
  2149  			})
  2150  		}
  2151  	}
  2152  }
  2153  
  2154  func BenchmarkIndexAnyUTF8(b *testing.B) {
  2155  	x := Repeat([]byte{'#'}, 2048) // Never matches set
  2156  	cs := "你好世界, hello world. 你好世界, hello world. 你好世界, hello world."
  2157  	for k := 1; k <= 2048; k <<= 4 {
  2158  		for j := 1; j <= 64; j <<= 1 {
  2159  			b.Run(fmt.Sprintf("%d:%d", k, j), func(b *testing.B) {
  2160  				for i := 0; i < b.N; i++ {
  2161  					IndexAny(x[:k], cs[:j])
  2162  				}
  2163  			})
  2164  		}
  2165  	}
  2166  }
  2167  
  2168  func BenchmarkLastIndexAnyASCII(b *testing.B) {
  2169  	x := Repeat([]byte{'#'}, 2048) // Never matches set
  2170  	cs := "0123456789abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz"
  2171  	for k := 1; k <= 2048; k <<= 4 {
  2172  		for j := 1; j <= 64; j <<= 1 {
  2173  			b.Run(fmt.Sprintf("%d:%d", k, j), func(b *testing.B) {
  2174  				for i := 0; i < b.N; i++ {
  2175  					LastIndexAny(x[:k], cs[:j])
  2176  				}
  2177  			})
  2178  		}
  2179  	}
  2180  }
  2181  
  2182  func BenchmarkLastIndexAnyUTF8(b *testing.B) {
  2183  	x := Repeat([]byte{'#'}, 2048) // Never matches set
  2184  	cs := "你好世界, hello world. 你好世界, hello world. 你好世界, hello world."
  2185  	for k := 1; k <= 2048; k <<= 4 {
  2186  		for j := 1; j <= 64; j <<= 1 {
  2187  			b.Run(fmt.Sprintf("%d:%d", k, j), func(b *testing.B) {
  2188  				for i := 0; i < b.N; i++ {
  2189  					LastIndexAny(x[:k], cs[:j])
  2190  				}
  2191  			})
  2192  		}
  2193  	}
  2194  }
  2195  
  2196  func BenchmarkTrimASCII(b *testing.B) {
  2197  	cs := "0123456789abcdef"
  2198  	for k := 1; k <= 4096; k <<= 4 {
  2199  		for j := 1; j <= 16; j <<= 1 {
  2200  			b.Run(fmt.Sprintf("%d:%d", k, j), func(b *testing.B) {
  2201  				x := Repeat([]byte(cs[:j]), k) // Always matches set
  2202  				for i := 0; i < b.N; i++ {
  2203  					Trim(x[:k], cs[:j])
  2204  				}
  2205  			})
  2206  		}
  2207  	}
  2208  }
  2209  
  2210  func BenchmarkTrimByte(b *testing.B) {
  2211  	x := []byte("  the quick brown fox   ")
  2212  	for i := 0; i < b.N; i++ {
  2213  		Trim(x, " ")
  2214  	}
  2215  }
  2216  
  2217  func BenchmarkIndexPeriodic(b *testing.B) {
  2218  	key := []byte{1, 1}
  2219  	for _, skip := range [...]int{2, 4, 8, 16, 32, 64} {
  2220  		b.Run(fmt.Sprintf("IndexPeriodic%d", skip), func(b *testing.B) {
  2221  			buf := make([]byte, 1<<16)
  2222  			for i := 0; i < len(buf); i += skip {
  2223  				buf[i] = 1
  2224  			}
  2225  			for i := 0; i < b.N; i++ {
  2226  				Index(buf, key)
  2227  			}
  2228  		})
  2229  	}
  2230  }
  2231  
  2232  func TestClone(t *testing.T) {
  2233  	var cloneTests = [][]byte{
  2234  		[]byte(nil),
  2235  		[]byte{},
  2236  		Clone([]byte{}),
  2237  		[]byte(strings.Repeat("a", 42))[:0],
  2238  		[]byte(strings.Repeat("a", 42))[:0:0],
  2239  		[]byte("short"),
  2240  		[]byte(strings.Repeat("a", 42)),
  2241  	}
  2242  	for _, input := range cloneTests {
  2243  		clone := Clone(input)
  2244  		if !Equal(clone, input) {
  2245  			t.Errorf("Clone(%q) = %q; want %q", input, clone, input)
  2246  		}
  2247  
  2248  		if input == nil && clone != nil {
  2249  			t.Errorf("Clone(%#v) return value should be equal to nil slice.", input)
  2250  		}
  2251  
  2252  		if input != nil && clone == nil {
  2253  			t.Errorf("Clone(%#v) return value should not be equal to nil slice.", input)
  2254  		}
  2255  
  2256  		if cap(input) != 0 && unsafe.SliceData(input) == unsafe.SliceData(clone) {
  2257  			t.Errorf("Clone(%q) return value should not reference inputs backing memory.", input)
  2258  		}
  2259  	}
  2260  }
  2261  

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