libgo/go/strings/strings_test.go

   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 strings_test
   6
   7 import (
   8         "bytes"
   9         "io"
  10         "math/rand"
  11         "reflect"
  12         . "strings"
  13         "testing"
  14         "unicode"
  15         "unicode/utf8"
  16         "unsafe"
  17 )
  18
  19 func eq(a, b []string) bool {
  20         if len(a) != len(b) {
  21                 return false
  22         }
  23         for i := 0; i < len(a); i++ {
  24                 if a[i] != b[i] {
  25                         return false
  26                 }
  27         }
  28         return true
  29 }
  30
  31 var abcd = "abcd"
  32 var faces = "☺☻☹"
  33 var commas = "1,2,3,4"
  34 var dots = "1....2....3....4"
  35
  36 type IndexTest struct {
  37         s   string
  38         sep string
  39         out int
  40 }
  41
  42 var indexTests = []IndexTest{
  43         {"", "", 0},
  44         {"", "a", -1},
  45         {"", "foo", -1},
  46         {"fo", "foo", -1},
  47         {"foo", "foo", 0},
  48         {"oofofoofooo", "f", 2},
  49         {"oofofoofooo", "foo", 4},
  50         {"barfoobarfoo", "foo", 3},
  51         {"foo", "", 0},
  52         {"foo", "o", 1},
  53         {"abcABCabc", "A", 3},
  54         // cases with one byte strings - test special case in Index()
  55         {"", "a", -1},
  56         {"x", "a", -1},
  57         {"x", "x", 0},
  58         {"abc", "a", 0},
  59         {"abc", "b", 1},
  60         {"abc", "c", 2},
  61         {"abc", "x", -1},
  62 }
  63
  64 var lastIndexTests = []IndexTest{
  65         {"", "", 0},
  66         {"", "a", -1},
  67         {"", "foo", -1},
  68         {"fo", "foo", -1},
  69         {"foo", "foo", 0},
  70         {"foo", "f", 0},
  71         {"oofofoofooo", "f", 7},
  72         {"oofofoofooo", "foo", 7},
  73         {"barfoobarfoo", "foo", 9},
  74         {"foo", "", 3},
  75         {"foo", "o", 2},
  76         {"abcABCabc", "A", 3},
  77         {"abcABCabc", "a", 6},
  78 }
  79
  80 var indexAnyTests = []IndexTest{
  81         {"", "", -1},
  82         {"", "a", -1},
  83         {"", "abc", -1},
  84         {"a", "", -1},
  85         {"a", "a", 0},
  86         {"aaa", "a", 0},
  87         {"abc", "xyz", -1},
  88         {"abc", "xcz", 2},
  89         {"a☺b☻c☹d", "uvw☻xyz", 2 + len("☺")},
  90         {"aRegExp*", ".(|)*+?^$[]", 7},
  91         {dots + dots + dots, " ", -1},
  92 }
  93 var lastIndexAnyTests = []IndexTest{
  94         {"", "", -1},
  95         {"", "a", -1},
  96         {"", "abc", -1},
  97         {"a", "", -1},
  98         {"a", "a", 0},
  99         {"aaa", "a", 2},
 100         {"abc", "xyz", -1},
 101         {"abc", "ab", 1},
 102         {"a☺b☻c☹d", "uvw☻xyz", 2 + len("☺")},
 103         {"a.RegExp*", ".(|)*+?^$[]", 8},
 104         {dots + dots + dots, " ", -1},
 105 }
 106
 107 // Execute f on each test case.  funcName should be the name of f; it's used
 108 // in failure reports.
 109 func runIndexTests(t *testing.T, f func(s, sep string) int, funcName string, testCases []IndexTest) {
 110         for _, test := range testCases {
 111                 actual := f(test.s, test.sep)
 112                 if actual != test.out {
 113                         t.Errorf("%s(%q,%q) = %v; want %v", funcName, test.s, test.sep, actual, test.out)
 114                 }
 115         }
 116 }
 117
 118 func TestIndex(t *testing.T)        { runIndexTests(t, Index, "Index", indexTests) }
 119 func TestLastIndex(t *testing.T)    { runIndexTests(t, LastIndex, "LastIndex", lastIndexTests) }
 120 func TestIndexAny(t *testing.T)     { runIndexTests(t, IndexAny, "IndexAny", indexAnyTests) }
 121 func TestLastIndexAny(t *testing.T) { runIndexTests(t, LastIndexAny, "LastIndexAny", lastIndexAnyTests) }
 122
 123 var indexRuneTests = []struct {
 124         s    string
 125         rune rune
 126         out  int
 127 }{
 128         {"a A x", 'A', 2},
 129         {"some_text=some_value", '=', 9},
 130         {"☺a", 'a', 3},
 131         {"a☻☺b", '☺', 4},
 132 }
 133
 134 func TestIndexRune(t *testing.T) {
 135         for _, test := range indexRuneTests {
 136                 if actual := IndexRune(test.s, test.rune); actual != test.out {
 137                         t.Errorf("IndexRune(%q,%d)= %v; want %v", test.s, test.rune, actual, test.out)
 138                 }
 139         }
 140 }
 141
 142 const benchmarkString = "some_text=some☺value"
 143
 144 func BenchmarkIndexRune(b *testing.B) {
 145         if got := IndexRune(benchmarkString, '☺'); got != 14 {
 146                 b.Fatalf("wrong index: expected 14, got=%d", got)
 147         }
 148         for i := 0; i < b.N; i++ {
 149                 IndexRune(benchmarkString, '☺')
 150         }
 151 }
 152
 153 func BenchmarkIndexRuneFastPath(b *testing.B) {
 154         if got := IndexRune(benchmarkString, 'v'); got != 17 {
 155                 b.Fatalf("wrong index: expected 17, got=%d", got)
 156         }
 157         for i := 0; i < b.N; i++ {
 158                 IndexRune(benchmarkString, 'v')
 159         }
 160 }
 161
 162 func BenchmarkIndex(b *testing.B) {
 163         if got := Index(benchmarkString, "v"); got != 17 {
 164                 b.Fatalf("wrong index: expected 17, got=%d", got)
 165         }
 166         for i := 0; i < b.N; i++ {
 167                 Index(benchmarkString, "v")
 168         }
 169 }
 170
 171 func BenchmarkIndexByte(b *testing.B) {
 172         if got := IndexByte(benchmarkString, 'v'); got != 17 {
 173                 b.Fatalf("wrong index: expected 17, got=%d", got)
 174         }
 175         for i := 0; i < b.N; i++ {
 176                 IndexByte(benchmarkString, 'v')
 177         }
 178 }
 179
 180 var explodetests = []struct {
 181         s string
 182         n int
 183         a []string
 184 }{
 185         {"", -1, []string{}},
 186         {abcd, 4, []string{"a", "b", "c", "d"}},
 187         {faces, 3, []string{"☺", "☻", "☹"}},
 188         {abcd, 2, []string{"a", "bcd"}},
 189 }
 190
 191 func TestExplode(t *testing.T) {
 192         for _, tt := range explodetests {
 193                 a := SplitN(tt.s, "", tt.n)
 194                 if !eq(a, tt.a) {
 195                         t.Errorf("explode(%q, %d) = %v; want %v", tt.s, tt.n, a, tt.a)
 196                         continue
 197                 }
 198                 s := Join(a, "")
 199                 if s != tt.s {
 200                         t.Errorf(`Join(explode(%q, %d), "") = %q`, tt.s, tt.n, s)
 201                 }
 202         }
 203 }
 204
 205 type SplitTest struct {
 206         s   string
 207         sep string
 208         n   int
 209         a   []string
 210 }
 211
 212 var splittests = []SplitTest{
 213         {abcd, "a", 0, nil},
 214         {abcd, "a", -1, []string{"", "bcd"}},
 215         {abcd, "z", -1, []string{"abcd"}},
 216         {abcd, "", -1, []string{"a", "b", "c", "d"}},
 217         {commas, ",", -1, []string{"1", "2", "3", "4"}},
 218         {dots, "...", -1, []string{"1", ".2", ".3", ".4"}},
 219         {faces, "☹", -1, []string{"☺☻", ""}},
 220         {faces, "~", -1, []string{faces}},
 221         {faces, "", -1, []string{"☺", "☻", "☹"}},
 222         {"1 2 3 4", " ", 3, []string{"1", "2", "3 4"}},
 223         {"1 2", " ", 3, []string{"1", "2"}},
 224         {"123", "", 2, []string{"1", "23"}},
 225         {"123", "", 17, []string{"1", "2", "3"}},
 226 }
 227
 228 func TestSplit(t *testing.T) {
 229         for _, tt := range splittests {
 230                 a := SplitN(tt.s, tt.sep, tt.n)
 231                 if !eq(a, tt.a) {
 232                         t.Errorf("Split(%q, %q, %d) = %v; want %v", tt.s, tt.sep, tt.n, a, tt.a)
 233                         continue
 234                 }
 235                 if tt.n == 0 {
 236                         continue
 237                 }
 238                 s := Join(a, tt.sep)
 239                 if s != tt.s {
 240                         t.Errorf("Join(Split(%q, %q, %d), %q) = %q", tt.s, tt.sep, tt.n, tt.sep, s)
 241                 }
 242                 if tt.n < 0 {
 243                         b := Split(tt.s, tt.sep)
 244                         if !reflect.DeepEqual(a, b) {
 245                                 t.Errorf("Split disagrees with SplitN(%q, %q, %d) = %v; want %v", tt.s, tt.sep, tt.n, b, a)
 246                         }
 247                 }
 248         }
 249 }
 250
 251 var splitaftertests = []SplitTest{
 252         {abcd, "a", -1, []string{"a", "bcd"}},
 253         {abcd, "z", -1, []string{"abcd"}},
 254         {abcd, "", -1, []string{"a", "b", "c", "d"}},
 255         {commas, ",", -1, []string{"1,", "2,", "3,", "4"}},
 256         {dots, "...", -1, []string{"1...", ".2...", ".3...", ".4"}},
 257         {faces, "☹", -1, []string{"☺☻☹", ""}},
 258         {faces, "~", -1, []string{faces}},
 259         {faces, "", -1, []string{"☺", "☻", "☹"}},
 260         {"1 2 3 4", " ", 3, []string{"1 ", "2 ", "3 4"}},
 261         {"1 2 3", " ", 3, []string{"1 ", "2 ", "3"}},
 262         {"1 2", " ", 3, []string{"1 ", "2"}},
 263         {"123", "", 2, []string{"1", "23"}},
 264         {"123", "", 17, []string{"1", "2", "3"}},
 265 }
 266
 267 func TestSplitAfter(t *testing.T) {
 268         for _, tt := range splitaftertests {
 269                 a := SplitAfterN(tt.s, tt.sep, tt.n)
 270                 if !eq(a, tt.a) {
 271                         t.Errorf(`Split(%q, %q, %d) = %v; want %v`, tt.s, tt.sep, tt.n, a, tt.a)
 272                         continue
 273                 }
 274                 s := Join(a, "")
 275                 if s != tt.s {
 276                         t.Errorf(`Join(Split(%q, %q, %d), %q) = %q`, tt.s, tt.sep, tt.n, tt.sep, s)
 277                 }
 278                 if tt.n < 0 {
 279                         b := SplitAfter(tt.s, tt.sep)
 280                         if !reflect.DeepEqual(a, b) {
 281                                 t.Errorf("SplitAfter disagrees with SplitAfterN(%q, %q, %d) = %v; want %v", tt.s, tt.sep, tt.n, b, a)
 282                         }
 283                 }
 284         }
 285 }
 286
 287 type FieldsTest struct {
 288         s string
 289         a []string
 290 }
 291
 292 var fieldstests = []FieldsTest{
 293         {"", []string{}},
 294         {" ", []string{}},
 295         {" \t ", []string{}},
 296         {"  abc  ", []string{"abc"}},
 297         {"1 2 3 4", []string{"1", "2", "3", "4"}},
 298         {"1  2  3  4", []string{"1", "2", "3", "4"}},
 299         {"1\t\t2\t\t3\t4", []string{"1", "2", "3", "4"}},
 300         {"1\u20002\u20013\u20024", []string{"1", "2", "3", "4"}},
 301         {"\u2000\u2001\u2002", []string{}},
 302         {"\n™\t™\n", []string{"™", "™"}},
 303         {faces, []string{faces}},
 304 }
 305
 306 func TestFields(t *testing.T) {
 307         for _, tt := range fieldstests {
 308                 a := Fields(tt.s)
 309                 if !eq(a, tt.a) {
 310                         t.Errorf("Fields(%q) = %v; want %v", tt.s, a, tt.a)
 311                         continue
 312                 }
 313         }
 314 }
 315
 316 var FieldsFuncTests = []FieldsTest{
 317         {"", []string{}},
 318         {"XX", []string{}},
 319         {"XXhiXXX", []string{"hi"}},
 320         {"aXXbXXXcX", []string{"a", "b", "c"}},
 321 }
 322
 323 func TestFieldsFunc(t *testing.T) {
 324         for _, tt := range fieldstests {
 325                 a := FieldsFunc(tt.s, unicode.IsSpace)
 326                 if !eq(a, tt.a) {
 327                         t.Errorf("FieldsFunc(%q, unicode.IsSpace) = %v; want %v", tt.s, a, tt.a)
 328                         continue
 329                 }
 330         }
 331         pred := func(c rune) bool { return c == 'X' }
 332         for _, tt := range FieldsFuncTests {
 333                 a := FieldsFunc(tt.s, pred)
 334                 if !eq(a, tt.a) {
 335                         t.Errorf("FieldsFunc(%q) = %v, want %v", tt.s, a, tt.a)
 336                 }
 337         }
 338 }
 339
 340 // Test case for any function which accepts and returns a single string.
 341 type StringTest struct {
 342         in, out string
 343 }
 344
 345 // Execute f on each test case.  funcName should be the name of f; it's used
 346 // in failure reports.
 347 func runStringTests(t *testing.T, f func(string) string, funcName string, testCases []StringTest) {
 348         for _, tc := range testCases {
 349                 actual := f(tc.in)
 350                 if actual != tc.out {
 351                         t.Errorf("%s(%q) = %q; want %q", funcName, tc.in, actual, tc.out)
 352                 }
 353         }
 354 }
 355
 356 var upperTests = []StringTest{
 357         {"", ""},
 358         {"abc", "ABC"},
 359         {"AbC123", "ABC123"},
 360         {"azAZ09_", "AZAZ09_"},
 361         {"\u0250\u0250\u0250\u0250\u0250", "\u2C6F\u2C6F\u2C6F\u2C6F\u2C6F"}, // grows one byte per char
 362 }
 363
 364 var lowerTests = []StringTest{
 365         {"", ""},
 366         {"abc", "abc"},
 367         {"AbC123", "abc123"},
 368         {"azAZ09_", "azaz09_"},
 369         {"\u2C6D\u2C6D\u2C6D\u2C6D\u2C6D", "\u0251\u0251\u0251\u0251\u0251"}, // shrinks one byte per char
 370 }
 371
 372 const space = "\t\v\r\f\n\u0085\u00a0\u2000\u3000"
 373
 374 var trimSpaceTests = []StringTest{
 375         {"", ""},
 376         {"abc", "abc"},
 377         {space + "abc" + space, "abc"},
 378         {" ", ""},
 379         {" \t\r\n \t\t\r\r\n\n ", ""},
 380         {" \t\r\n x\t\t\r\r\n\n ", "x"},
 381         {" \u2000\t\r\n x\t\t\r\r\ny\n \u3000", "x\t\t\r\r\ny"},
 382         {"1 \t\r\n2", "1 \t\r\n2"},
 383         {" x\x80", "x\x80"},
 384         {" x\xc0", "x\xc0"},
 385         {"x \xc0\xc0 ", "x \xc0\xc0"},
 386         {"x \xc0", "x \xc0"},
 387         {"x \xc0 ", "x \xc0"},
 388         {"x \xc0\xc0 ", "x \xc0\xc0"},
 389         {"x ☺\xc0\xc0 ", "x ☺\xc0\xc0"},
 390         {"x ☺ ", "x ☺"},
 391 }
 392
 393 func tenRunes(ch rune) string {
 394         r := make([]rune, 10)
 395         for i := range r {
 396                 r[i] = ch
 397         }
 398         return string(r)
 399 }
 400
 401 // User-defined self-inverse mapping function
 402 func rot13(r rune) rune {
 403         step := rune(13)
 404         if r >= 'a' && r <= 'z' {
 405                 return ((r - 'a' + step) % 26) + 'a'
 406         }
 407         if r >= 'A' && r <= 'Z' {
 408                 return ((r - 'A' + step) % 26) + 'A'
 409         }
 410         return r
 411 }
 412
 413 func TestMap(t *testing.T) {
 414         // Run a couple of awful growth/shrinkage tests
 415         a := tenRunes('a')
 416         // 1.  Grow.  This triggers two reallocations in Map.
 417         maxRune := func(rune) rune { return unicode.MaxRune }
 418         m := Map(maxRune, a)
 419         expect := tenRunes(unicode.MaxRune)
 420         if m != expect {
 421                 t.Errorf("growing: expected %q got %q", expect, m)
 422         }
 423
 424         // 2. Shrink
 425         minRune := func(rune) rune { return 'a' }
 426         m = Map(minRune, tenRunes(unicode.MaxRune))
 427         expect = a
 428         if m != expect {
 429                 t.Errorf("shrinking: expected %q got %q", expect, m)
 430         }
 431
 432         // 3. Rot13
 433         m = Map(rot13, "a to zed")
 434         expect = "n gb mrq"
 435         if m != expect {
 436                 t.Errorf("rot13: expected %q got %q", expect, m)
 437         }
 438
 439         // 4. Rot13^2
 440         m = Map(rot13, Map(rot13, "a to zed"))
 441         expect = "a to zed"
 442         if m != expect {
 443                 t.Errorf("rot13: expected %q got %q", expect, m)
 444         }
 445
 446         // 5. Drop
 447         dropNotLatin := func(r rune) rune {
 448                 if unicode.Is(unicode.Latin, r) {
 449                         return r
 450                 }
 451                 return -1
 452         }
 453         m = Map(dropNotLatin, "Hello, 세계")
 454         expect = "Hello"
 455         if m != expect {
 456                 t.Errorf("drop: expected %q got %q", expect, m)
 457         }
 458
 459         // 6. Identity
 460         identity := func(r rune) rune {
 461                 return r
 462         }
 463         orig := "Input string that we expect not to be copied."
 464         m = Map(identity, orig)
 465         if (*reflect.StringHeader)(unsafe.Pointer(&orig)).Data !=
 466                 (*reflect.StringHeader)(unsafe.Pointer(&m)).Data {
 467                 t.Error("unexpected copy during identity map")
 468         }
 469 }
 470
 471 func TestToUpper(t *testing.T) { runStringTests(t, ToUpper, "ToUpper", upperTests) }
 472
 473 func TestToLower(t *testing.T) { runStringTests(t, ToLower, "ToLower", lowerTests) }
 474
 475 func BenchmarkMapNoChanges(b *testing.B) {
 476         identity := func(r rune) rune {
 477                 return r
 478         }
 479         for i := 0; i < b.N; i++ {
 480                 Map(identity, "Some string that won't be modified.")
 481         }
 482 }
 483
 484 func TestSpecialCase(t *testing.T) {
 485         lower := "abcçdefgğhıijklmnoöprsştuüvyz"
 486         upper := "ABCÇDEFGĞHIİJKLMNOÖPRSŞTUÜVYZ"
 487         u := ToUpperSpecial(unicode.TurkishCase, upper)
 488         if u != upper {
 489                 t.Errorf("Upper(upper) is %s not %s", u, upper)
 490         }
 491         u = ToUpperSpecial(unicode.TurkishCase, lower)
 492         if u != upper {
 493                 t.Errorf("Upper(lower) is %s not %s", u, upper)
 494         }
 495         l := ToLowerSpecial(unicode.TurkishCase, lower)
 496         if l != lower {
 497                 t.Errorf("Lower(lower) is %s not %s", l, lower)
 498         }
 499         l = ToLowerSpecial(unicode.TurkishCase, upper)
 500         if l != lower {
 501                 t.Errorf("Lower(upper) is %s not %s", l, lower)
 502         }
 503 }
 504
 505 func TestTrimSpace(t *testing.T) { runStringTests(t, TrimSpace, "TrimSpace", trimSpaceTests) }
 506
 507 var trimTests = []struct {
 508         f            string
 509         in, arg, out string
 510 }{
 511         {"Trim", "abba", "a", "bb"},
 512         {"Trim", "abba", "ab", ""},
 513         {"TrimLeft", "abba", "ab", ""},
 514         {"TrimRight", "abba", "ab", ""},
 515         {"TrimLeft", "abba", "a", "bba"},
 516         {"TrimRight", "abba", "a", "abb"},
 517         {"Trim", "<tag>", "<>", "tag"},
 518         {"Trim", "* listitem", " *", "listitem"},
 519         {"Trim", `"quote"`, `"`, "quote"},
 520         {"Trim", "\u2C6F\u2C6F\u0250\u0250\u2C6F\u2C6F", "\u2C6F", "\u0250\u0250"},
 521         //empty string tests
 522         {"Trim", "abba", "", "abba"},
 523         {"Trim", "", "123", ""},
 524         {"Trim", "", "", ""},
 525         {"TrimLeft", "abba", "", "abba"},
 526         {"TrimLeft", "", "123", ""},
 527         {"TrimLeft", "", "", ""},
 528         {"TrimRight", "abba", "", "abba"},
 529         {"TrimRight", "", "123", ""},
 530         {"TrimRight", "", "", ""},
 531         {"TrimRight", "☺\xc0", "☺", "☺\xc0"},
 532         {"TrimPrefix", "aabb", "a", "abb"},
 533         {"TrimPrefix", "aabb", "b", "aabb"},
 534         {"TrimSuffix", "aabb", "a", "aabb"},
 535         {"TrimSuffix", "aabb", "b", "aab"},
 536 }
 537
 538 func TestTrim(t *testing.T) {
 539         for _, tc := range trimTests {
 540                 name := tc.f
 541                 var f func(string, string) string
 542                 switch name {
 543                 case "Trim":
 544                         f = Trim
 545                 case "TrimLeft":
 546                         f = TrimLeft
 547                 case "TrimRight":
 548                         f = TrimRight
 549                 case "TrimPrefix":
 550                         f = TrimPrefix
 551                 case "TrimSuffix":
 552                         f = TrimSuffix
 553                 default:
 554                         t.Errorf("Undefined trim function %s", name)
 555                 }
 556                 actual := f(tc.in, tc.arg)
 557                 if actual != tc.out {
 558                         t.Errorf("%s(%q, %q) = %q; want %q", name, tc.in, tc.arg, actual, tc.out)
 559                 }
 560         }
 561 }
 562
 563 type predicate struct {
 564         f    func(rune) bool
 565         name string
 566 }
 567
 568 var isSpace = predicate{unicode.IsSpace, "IsSpace"}
 569 var isDigit = predicate{unicode.IsDigit, "IsDigit"}
 570 var isUpper = predicate{unicode.IsUpper, "IsUpper"}
 571 var isValidRune = predicate{
 572         func(r rune) bool {
 573                 return r != utf8.RuneError
 574         },
 575         "IsValidRune",
 576 }
 577
 578 func not(p predicate) predicate {
 579         return predicate{
 580                 func(r rune) bool {
 581                         return !p.f(r)
 582                 },
 583                 "not " + p.name,
 584         }
 585 }
 586
 587 var trimFuncTests = []struct {
 588         f       predicate
 589         in, out string
 590 }{
 591         {isSpace, space + " hello " + space, "hello"},
 592         {isDigit, "\u0e50\u0e5212hello34\u0e50\u0e51", "hello"},
 593         {isUpper, "\u2C6F\u2C6F\u2C6F\u2C6FABCDhelloEF\u2C6F\u2C6FGH\u2C6F\u2C6F", "hello"},
 594         {not(isSpace), "hello" + space + "hello", space},
 595         {not(isDigit), "hello\u0e50\u0e521234\u0e50\u0e51helo", "\u0e50\u0e521234\u0e50\u0e51"},
 596         {isValidRune, "ab\xc0a\xc0cd", "\xc0a\xc0"},
 597         {not(isValidRune), "\xc0a\xc0", "a"},
 598 }
 599
 600 func TestTrimFunc(t *testing.T) {
 601         for _, tc := range trimFuncTests {
 602                 actual := TrimFunc(tc.in, tc.f.f)
 603                 if actual != tc.out {
 604                         t.Errorf("TrimFunc(%q, %q) = %q; want %q", tc.in, tc.f.name, actual, tc.out)
 605                 }
 606         }
 607 }
 608
 609 var indexFuncTests = []struct {
 610         in          string
 611         f           predicate
 612         first, last int
 613 }{
 614         {"", isValidRune, -1, -1},
 615         {"abc", isDigit, -1, -1},
 616         {"0123", isDigit, 0, 3},
 617         {"a1b", isDigit, 1, 1},
 618         {space, isSpace, 0, len(space) - 3}, // last rune in space is 3 bytes
 619         {"\u0e50\u0e5212hello34\u0e50\u0e51", isDigit, 0, 18},
 620         {"\u2C6F\u2C6F\u2C6F\u2C6FABCDhelloEF\u2C6F\u2C6FGH\u2C6F\u2C6F", isUpper, 0, 34},
 621         {"12\u0e50\u0e52hello34\u0e50\u0e51", not(isDigit), 8, 12},
 622
 623         // tests of invalid UTF-8
 624         {"\x801", isDigit, 1, 1},
 625         {"\x80abc", isDigit, -1, -1},
 626         {"\xc0a\xc0", isValidRune, 1, 1},
 627         {"\xc0a\xc0", not(isValidRune), 0, 2},
 628         {"\xc0☺\xc0", not(isValidRune), 0, 4},
 629         {"\xc0☺\xc0\xc0", not(isValidRune), 0, 5},
 630         {"ab\xc0a\xc0cd", not(isValidRune), 2, 4},
 631         {"a\xe0\x80cd", not(isValidRune), 1, 2},
 632         {"\x80\x80\x80\x80", not(isValidRune), 0, 3},
 633 }
 634
 635 func TestIndexFunc(t *testing.T) {
 636         for _, tc := range indexFuncTests {
 637                 first := IndexFunc(tc.in, tc.f.f)
 638                 if first != tc.first {
 639                         t.Errorf("IndexFunc(%q, %s) = %d; want %d", tc.in, tc.f.name, first, tc.first)
 640                 }
 641                 last := LastIndexFunc(tc.in, tc.f.f)
 642                 if last != tc.last {
 643                         t.Errorf("LastIndexFunc(%q, %s) = %d; want %d", tc.in, tc.f.name, last, tc.last)
 644                 }
 645         }
 646 }
 647
 648 func equal(m string, s1, s2 string, t *testing.T) bool {
 649         if s1 == s2 {
 650                 return true
 651         }
 652         e1 := Split(s1, "")
 653         e2 := Split(s2, "")
 654         for i, c1 := range e1 {
 655                 if i >= len(e2) {
 656                         break
 657                 }
 658                 r1, _ := utf8.DecodeRuneInString(c1)
 659                 r2, _ := utf8.DecodeRuneInString(e2[i])
 660                 if r1 != r2 {
 661                         t.Errorf("%s diff at %d: U+%04X U+%04X", m, i, r1, r2)
 662                 }
 663         }
 664         return false
 665 }
 666
 667 func TestCaseConsistency(t *testing.T) {
 668         // Make a string of all the runes.
 669         numRunes := int(unicode.MaxRune + 1)
 670         if testing.Short() {
 671                 numRunes = 1000
 672         }
 673         a := make([]rune, numRunes)
 674         for i := range a {
 675                 a[i] = rune(i)
 676         }
 677         s := string(a)
 678         // convert the cases.
 679         upper := ToUpper(s)
 680         lower := ToLower(s)
 681
 682         // Consistency checks
 683         if n := utf8.RuneCountInString(upper); n != numRunes {
 684                 t.Error("rune count wrong in upper:", n)
 685         }
 686         if n := utf8.RuneCountInString(lower); n != numRunes {
 687                 t.Error("rune count wrong in lower:", n)
 688         }
 689         if !equal("ToUpper(upper)", ToUpper(upper), upper, t) {
 690                 t.Error("ToUpper(upper) consistency fail")
 691         }
 692         if !equal("ToLower(lower)", ToLower(lower), lower, t) {
 693                 t.Error("ToLower(lower) consistency fail")
 694         }
 695         /*
 696                   These fail because of non-one-to-oneness of the data, such as multiple
 697                   upper case 'I' mapping to 'i'.  We comment them out but keep them for
 698                   interest.
 699                   For instance: CAPITAL LETTER I WITH DOT ABOVE:
 700                         unicode.ToUpper(unicode.ToLower('\u0130')) != '\u0130'
 701
 702                 if !equal("ToUpper(lower)", ToUpper(lower), upper, t) {
 703                         t.Error("ToUpper(lower) consistency fail");
 704                 }
 705                 if !equal("ToLower(upper)", ToLower(upper), lower, t) {
 706                         t.Error("ToLower(upper) consistency fail");
 707                 }
 708         */
 709 }
 710
 711 var RepeatTests = []struct {
 712         in, out string
 713         count   int
 714 }{
 715         {"", "", 0},
 716         {"", "", 1},
 717         {"", "", 2},
 718         {"-", "", 0},
 719         {"-", "-", 1},
 720         {"-", "----------", 10},
 721         {"abc ", "abc abc abc ", 3},
 722 }
 723
 724 func TestRepeat(t *testing.T) {
 725         for _, tt := range RepeatTests {
 726                 a := Repeat(tt.in, tt.count)
 727                 if !equal("Repeat(s)", a, tt.out, t) {
 728                         t.Errorf("Repeat(%v, %d) = %v; want %v", tt.in, tt.count, a, tt.out)
 729                         continue
 730                 }
 731         }
 732 }
 733
 734 func runesEqual(a, b []rune) bool {
 735         if len(a) != len(b) {
 736                 return false
 737         }
 738         for i, r := range a {
 739                 if r != b[i] {
 740                         return false
 741                 }
 742         }
 743         return true
 744 }
 745
 746 var RunesTests = []struct {
 747         in    string
 748         out   []rune
 749         lossy bool
 750 }{
 751         {"", []rune{}, false},
 752         {" ", []rune{32}, false},
 753         {"ABC", []rune{65, 66, 67}, false},
 754         {"abc", []rune{97, 98, 99}, false},
 755         {"\u65e5\u672c\u8a9e", []rune{26085, 26412, 35486}, false},
 756         {"ab\x80c", []rune{97, 98, 0xFFFD, 99}, true},
 757         {"ab\xc0c", []rune{97, 98, 0xFFFD, 99}, true},
 758 }
 759
 760 func TestRunes(t *testing.T) {
 761         for _, tt := range RunesTests {
 762                 a := []rune(tt.in)
 763                 if !runesEqual(a, tt.out) {
 764                         t.Errorf("[]rune(%q) = %v; want %v", tt.in, a, tt.out)
 765                         continue
 766                 }
 767                 if !tt.lossy {
 768                         // can only test reassembly if we didn't lose information
 769                         s := string(a)
 770                         if s != tt.in {
 771                                 t.Errorf("string([]rune(%q)) = %x; want %x", tt.in, s, tt.in)
 772                         }
 773                 }
 774         }
 775 }
 776
 777 func TestReadByte(t *testing.T) {
 778         testStrings := []string{"", abcd, faces, commas}
 779         for _, s := range testStrings {
 780                 reader := NewReader(s)
 781                 if e := reader.UnreadByte(); e == nil {
 782                         t.Errorf("Unreading %q at beginning: expected error", s)
 783                 }
 784                 var res bytes.Buffer
 785                 for {
 786                         b, e := reader.ReadByte()
 787                         if e == io.EOF {
 788                                 break
 789                         }
 790                         if e != nil {
 791                                 t.Errorf("Reading %q: %s", s, e)
 792                                 break
 793                         }
 794                         res.WriteByte(b)
 795                         // unread and read again
 796                         e = reader.UnreadByte()
 797                         if e != nil {
 798                                 t.Errorf("Unreading %q: %s", s, e)
 799                                 break
 800                         }
 801                         b1, e := reader.ReadByte()
 802                         if e != nil {
 803                                 t.Errorf("Reading %q after unreading: %s", s, e)
 804                                 break
 805                         }
 806                         if b1 != b {
 807                                 t.Errorf("Reading %q after unreading: want byte %q, got %q", s, b, b1)
 808                                 break
 809                         }
 810                 }
 811                 if res.String() != s {
 812                         t.Errorf("Reader(%q).ReadByte() produced %q", s, res.String())
 813                 }
 814         }
 815 }
 816
 817 func TestReadRune(t *testing.T) {
 818         testStrings := []string{"", abcd, faces, commas}
 819         for _, s := range testStrings {
 820                 reader := NewReader(s)
 821                 if e := reader.UnreadRune(); e == nil {
 822                         t.Errorf("Unreading %q at beginning: expected error", s)
 823                 }
 824                 res := ""
 825                 for {
 826                         r, z, e := reader.ReadRune()
 827                         if e == io.EOF {
 828                                 break
 829                         }
 830                         if e != nil {
 831                                 t.Errorf("Reading %q: %s", s, e)
 832                                 break
 833                         }
 834                         res += string(r)
 835                         // unread and read again
 836                         e = reader.UnreadRune()
 837                         if e != nil {
 838                                 t.Errorf("Unreading %q: %s", s, e)
 839                                 break
 840                         }
 841                         r1, z1, e := reader.ReadRune()
 842                         if e != nil {
 843                                 t.Errorf("Reading %q after unreading: %s", s, e)
 844                                 break
 845                         }
 846                         if r1 != r {
 847                                 t.Errorf("Reading %q after unreading: want rune %q, got %q", s, r, r1)
 848                                 break
 849                         }
 850                         if z1 != z {
 851                                 t.Errorf("Reading %q after unreading: want size %d, got %d", s, z, z1)
 852                                 break
 853                         }
 854                 }
 855                 if res != s {
 856                         t.Errorf("Reader(%q).ReadRune() produced %q", s, res)
 857                 }
 858         }
 859 }
 860
 861 var UnreadRuneErrorTests = []struct {
 862         name string
 863         f    func(*Reader)
 864 }{
 865         {"Read", func(r *Reader) { r.Read([]byte{0}) }},
 866         {"ReadByte", func(r *Reader) { r.ReadByte() }},
 867         {"UnreadRune", func(r *Reader) { r.UnreadRune() }},
 868         {"Seek", func(r *Reader) { r.Seek(0, 1) }},
 869         {"WriteTo", func(r *Reader) { r.WriteTo(&bytes.Buffer{}) }},
 870 }
 871
 872 func TestUnreadRuneError(t *testing.T) {
 873         for _, tt := range UnreadRuneErrorTests {
 874                 reader := NewReader("0123456789")
 875                 if _, _, err := reader.ReadRune(); err != nil {
 876                         // should not happen
 877                         t.Fatal(err)
 878                 }
 879                 tt.f(reader)
 880                 err := reader.UnreadRune()
 881                 if err == nil {
 882                         t.Errorf("Unreading after %s: expected error", tt.name)
 883                 }
 884         }
 885 }
 886
 887 var ReplaceTests = []struct {
 888         in       string
 889         old, new string
 890         n        int
 891         out      string
 892 }{
 893         {"hello", "l", "L", 0, "hello"},
 894         {"hello", "l", "L", -1, "heLLo"},
 895         {"hello", "x", "X", -1, "hello"},
 896         {"", "x", "X", -1, ""},
 897         {"radar", "r", "<r>", -1, "<r>ada<r>"},
 898         {"", "", "<>", -1, "<>"},
 899         {"banana", "a", "<>", -1, "b<>n<>n<>"},
 900         {"banana", "a", "<>", 1, "b<>nana"},
 901         {"banana", "a", "<>", 1000, "b<>n<>n<>"},
 902         {"banana", "an", "<>", -1, "b<><>a"},
 903         {"banana", "ana", "<>", -1, "b<>na"},
 904         {"banana", "", "<>", -1, "<>b<>a<>n<>a<>n<>a<>"},
 905         {"banana", "", "<>", 10, "<>b<>a<>n<>a<>n<>a<>"},
 906         {"banana", "", "<>", 6, "<>b<>a<>n<>a<>n<>a"},
 907         {"banana", "", "<>", 5, "<>b<>a<>n<>a<>na"},
 908         {"banana", "", "<>", 1, "<>banana"},
 909         {"banana", "a", "a", -1, "banana"},
 910         {"banana", "a", "a", 1, "banana"},
 911         {"☺☻☹", "", "<>", -1, "<>☺<>☻<>☹<>"},
 912 }
 913
 914 func TestReplace(t *testing.T) {
 915         for _, tt := range ReplaceTests {
 916                 if s := Replace(tt.in, tt.old, tt.new, tt.n); s != tt.out {
 917                         t.Errorf("Replace(%q, %q, %q, %d) = %q, want %q", tt.in, tt.old, tt.new, tt.n, s, tt.out)
 918                 }
 919         }
 920 }
 921
 922 var TitleTests = []struct {
 923         in, out string
 924 }{
 925         {"", ""},
 926         {"a", "A"},
 927         {" aaa aaa aaa ", " Aaa Aaa Aaa "},
 928         {" Aaa Aaa Aaa ", " Aaa Aaa Aaa "},
 929         {"123a456", "123a456"},
 930         {"double-blind", "Double-Blind"},
 931         {"ÿøû", "Ÿøû"},
 932         {"with_underscore", "With_underscore"},
 933         {"unicode \xe2\x80\xa8 line separator", "Unicode \xe2\x80\xa8 Line Separator"},
 934 }
 935
 936 func TestTitle(t *testing.T) {
 937         for _, tt := range TitleTests {
 938                 if s := Title(tt.in); s != tt.out {
 939                         t.Errorf("Title(%q) = %q, want %q", tt.in, s, tt.out)
 940                 }
 941         }
 942 }
 943
 944 var ContainsTests = []struct {
 945         str, substr string
 946         expected    bool
 947 }{
 948         {"abc", "bc", true},
 949         {"abc", "bcd", false},
 950         {"abc", "", true},
 951         {"", "a", false},
 952 }
 953
 954 func TestContains(t *testing.T) {
 955         for _, ct := range ContainsTests {
 956                 if Contains(ct.str, ct.substr) != ct.expected {
 957                         t.Errorf("Contains(%s, %s) = %v, want %v",
 958                                 ct.str, ct.substr, !ct.expected, ct.expected)
 959                 }
 960         }
 961 }
 962
 963 var ContainsAnyTests = []struct {
 964         str, substr string
 965         expected    bool
 966 }{
 967         {"", "", false},
 968         {"", "a", false},
 969         {"", "abc", false},
 970         {"a", "", false},
 971         {"a", "a", true},
 972         {"aaa", "a", true},
 973         {"abc", "xyz", false},
 974         {"abc", "xcz", true},
 975         {"a☺b☻c☹d", "uvw☻xyz", true},
 976         {"aRegExp*", ".(|)*+?^$[]", true},
 977         {dots + dots + dots, " ", false},
 978 }
 979
 980 func TestContainsAny(t *testing.T) {
 981         for _, ct := range ContainsAnyTests {
 982                 if ContainsAny(ct.str, ct.substr) != ct.expected {
 983                         t.Errorf("ContainsAny(%s, %s) = %v, want %v",
 984                                 ct.str, ct.substr, !ct.expected, ct.expected)
 985                 }
 986         }
 987 }
 988
 989 var ContainsRuneTests = []struct {
 990         str      string
 991         r        rune
 992         expected bool
 993 }{
 994         {"", 'a', false},
 995         {"a", 'a', true},
 996         {"aaa", 'a', true},
 997         {"abc", 'y', false},
 998         {"abc", 'c', true},
 999         {"a☺b☻c☹d", 'x', false},
1000         {"a☺b☻c☹d", '☻', true},
1001         {"aRegExp*", '*', true},
1002 }
1003
1004 func TestContainsRune(t *testing.T) {
1005         for _, ct := range ContainsRuneTests {
1006                 if ContainsRune(ct.str, ct.r) != ct.expected {
1007                         t.Errorf("ContainsRune(%q, %q) = %v, want %v",
1008                                 ct.str, ct.r, !ct.expected, ct.expected)
1009                 }
1010         }
1011 }
1012
1013 var EqualFoldTests = []struct {
1014         s, t string
1015         out  bool
1016 }{
1017         {"abc", "abc", true},
1018         {"ABcd", "ABcd", true},
1019         {"123abc", "123ABC", true},
1020         {"αβδ", "ΑΒΔ", true},
1021         {"abc", "xyz", false},
1022         {"abc", "XYZ", false},
1023         {"abcdefghijk", "abcdefghijX", false},
1024         {"abcdefghijk", "abcdefghij\u212A", true},
1025         {"abcdefghijK", "abcdefghij\u212A", true},
1026         {"abcdefghijkz", "abcdefghij\u212Ay", false},
1027         {"abcdefghijKz", "abcdefghij\u212Ay", false},
1028 }
1029
1030 func TestEqualFold(t *testing.T) {
1031         for _, tt := range EqualFoldTests {
1032                 if out := EqualFold(tt.s, tt.t); out != tt.out {
1033                         t.Errorf("EqualFold(%#q, %#q) = %v, want %v", tt.s, tt.t, out, tt.out)
1034                 }
1035                 if out := EqualFold(tt.t, tt.s); out != tt.out {
1036                         t.Errorf("EqualFold(%#q, %#q) = %v, want %v", tt.t, tt.s, out, tt.out)
1037                 }
1038         }
1039 }
1040
1041 var CountTests = []struct {
1042         s, sep string
1043         num    int
1044 }{
1045         {"", "", 1},
1046         {"", "notempty", 0},
1047         {"notempty", "", 9},
1048         {"smaller", "not smaller", 0},
1049         {"12345678987654321", "6", 2},
1050         {"611161116", "6", 3},
1051         {"notequal", "NotEqual", 0},
1052         {"equal", "equal", 1},
1053         {"abc1231231123q", "123", 3},
1054         {"11111", "11", 2},
1055 }
1056
1057 func TestCount(t *testing.T) {
1058         for _, tt := range CountTests {
1059                 if num := Count(tt.s, tt.sep); num != tt.num {
1060                         t.Errorf("Count(\"%s\", \"%s\") = %d, want %d", tt.s, tt.sep, num, tt.num)
1061                 }
1062         }
1063 }
1064
1065 func makeBenchInputHard() string {
1066         tokens := [...]string{
1067                 "<a>", "<p>", "<b>", "<strong>",
1068                 "</a>", "</p>", "</b>", "</strong>",
1069                 "hello", "world",
1070         }
1071         x := make([]byte, 0, 1<<20)
1072         for len(x) < 1<<20 {
1073                 i := rand.Intn(len(tokens))
1074                 x = append(x, tokens[i]...)
1075         }
1076         return string(x)
1077 }
1078
1079 var benchInputHard = makeBenchInputHard()
1080
1081 func benchmarkIndexHard(b *testing.B, sep string) {
1082         for i := 0; i < b.N; i++ {
1083                 Index(benchInputHard, sep)
1084         }
1085 }
1086
1087 func benchmarkCountHard(b *testing.B, sep string) {
1088         for i := 0; i < b.N; i++ {
1089                 Count(benchInputHard, sep)
1090         }
1091 }
1092
1093 func BenchmarkIndexHard1(b *testing.B) { benchmarkIndexHard(b, "<>") }
1094 func BenchmarkIndexHard2(b *testing.B) { benchmarkIndexHard(b, "</pre>") }
1095 func BenchmarkIndexHard3(b *testing.B) { benchmarkIndexHard(b, "<b>hello world</b>") }
1096
1097 func BenchmarkCountHard1(b *testing.B) { benchmarkCountHard(b, "<>") }
1098 func BenchmarkCountHard2(b *testing.B) { benchmarkCountHard(b, "</pre>") }
1099 func BenchmarkCountHard3(b *testing.B) { benchmarkCountHard(b, "<b>hello world</b>") }
1100
1101 var benchInputTorture = Repeat("ABC", 1<<10) + "123" + Repeat("ABC", 1<<10)
1102 var benchNeedleTorture = Repeat("ABC", 1<<10+1)
1103
1104 func BenchmarkIndexTorture(b *testing.B) {
1105         for i := 0; i < b.N; i++ {
1106                 Index(benchInputTorture, benchNeedleTorture)
1107         }
1108 }
1109
1110 func BenchmarkCountTorture(b *testing.B) {
1111         for i := 0; i < b.N; i++ {
1112                 Count(benchInputTorture, benchNeedleTorture)
1113         }
1114 }
1115
1116 func BenchmarkCountTortureOverlapping(b *testing.B) {
1117         A := Repeat("ABC", 1<<20)
1118         B := Repeat("ABC", 1<<10)
1119         for i := 0; i < b.N; i++ {
1120                 Count(A, B)
1121         }
1122 }
1123
1124 var makeFieldsInput = func() string {
1125         x := make([]byte, 1<<20)
1126         // Input is ~10% space, ~10% 2-byte UTF-8, rest ASCII non-space.
1127         for i := range x {
1128                 switch rand.Intn(10) {
1129                 case 0:
1130                         x[i] = ' '
1131                 case 1:
1132                         if i > 0 && x[i-1] == 'x' {
1133                                 copy(x[i-1:], "χ")
1134                                 break
1135                         }
1136                         fallthrough
1137                 default:
1138                         x[i] = 'x'
1139                 }
1140         }
1141         return string(x)
1142 }
1143
1144 var fieldsInput = makeFieldsInput()
1145
1146 func BenchmarkFields(b *testing.B) {
1147         b.SetBytes(int64(len(fieldsInput)))
1148         for i := 0; i < b.N; i++ {
1149                 Fields(fieldsInput)
1150         }
1151 }
1152
1153 func BenchmarkFieldsFunc(b *testing.B) {
1154         b.SetBytes(int64(len(fieldsInput)))
1155         for i := 0; i < b.N; i++ {
1156                 FieldsFunc(fieldsInput, unicode.IsSpace)
1157         }
1158 }
1159
1160 func BenchmarkSplit1(b *testing.B) {
1161         for i := 0; i < b.N; i++ {
1162                 Split(benchInputHard, "")
1163         }
1164 }
1165
1166 func BenchmarkSplit2(b *testing.B) {
1167         for i := 0; i < b.N; i++ {
1168                 Split(benchInputHard, "/")
1169         }
1170 }
1171
1172 func BenchmarkSplit3(b *testing.B) {
1173         for i := 0; i < b.N; i++ {
1174                 Split(benchInputHard, "hello")
1175         }
1176 }