Subversion Repositories openrisc

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package strings_test

import (
        "bytes"
        "io"
        "reflect"
        . "strings"
        "testing"
        "unicode"
        "unicode/utf8"
        "unsafe"
)

func eq(a, b []string) bool {
        if len(a) != len(b) {
                return false
        }
        for i := 0; i < len(a); i++ {
                if a[i] != b[i] {
                        return false
                }
        }
        return true
}

var abcd = "abcd"
var faces = "☺☻☹"
var commas = "1,2,3,4"
var dots = "1....2....3....4"

type IndexTest struct {
        s   string
        sep string
        out int
}

var indexTests = []IndexTest{
        {"", "", 0},
        {"", "a", -1},
        {"", "foo", -1},
        {"fo", "foo", -1},
        {"foo", "foo", 0},
        {"oofofoofooo", "f", 2},
        {"oofofoofooo", "foo", 4},
        {"barfoobarfoo", "foo", 3},
        {"foo", "", 0},
        {"foo", "o", 1},
        {"abcABCabc", "A", 3},
        // cases with one byte strings - test special case in Index()
        {"", "a", -1},
        {"x", "a", -1},
        {"x", "x", 0},
        {"abc", "a", 0},
        {"abc", "b", 1},
        {"abc", "c", 2},
        {"abc", "x", -1},
}

var lastIndexTests = []IndexTest{
        {"", "", 0},
        {"", "a", -1},
        {"", "foo", -1},
        {"fo", "foo", -1},
        {"foo", "foo", 0},
        {"foo", "f", 0},
        {"oofofoofooo", "f", 7},
        {"oofofoofooo", "foo", 7},
        {"barfoobarfoo", "foo", 9},
        {"foo", "", 3},
        {"foo", "o", 2},
        {"abcABCabc", "A", 3},
        {"abcABCabc", "a", 6},
}

var indexAnyTests = []IndexTest{
        {"", "", -1},
        {"", "a", -1},
        {"", "abc", -1},
        {"a", "", -1},
        {"a", "a", 0},
        {"aaa", "a", 0},
        {"abc", "xyz", -1},
        {"abc", "xcz", 2},
        {"a☺b☻c☹d", "uvw☻xyz", 2 + len("☺")},
        {"aRegExp*", ".(|)*+?^$[]", 7},
        {dots + dots + dots, " ", -1},
}
var lastIndexAnyTests = []IndexTest{
        {"", "", -1},
        {"", "a", -1},
        {"", "abc", -1},
        {"a", "", -1},
        {"a", "a", 0},
        {"aaa", "a", 2},
        {"abc", "xyz", -1},
        {"abc", "ab", 1},
        {"a☺b☻c☹d", "uvw☻xyz", 2 + len("☺")},
        {"a.RegExp*", ".(|)*+?^$[]", 8},
        {dots + dots + dots, " ", -1},
}

// Execute f on each test case.  funcName should be the name of f; it's used
// in failure reports.
func runIndexTests(t *testing.T, f func(s, sep string) int, funcName string, testCases []IndexTest) {
        for _, test := range testCases {
                actual := f(test.s, test.sep)
                if actual != test.out {
                        t.Errorf("%s(%q,%q) = %v; want %v", funcName, test.s, test.sep, actual, test.out)
                }
        }
}

func TestIndex(t *testing.T)        { runIndexTests(t, Index, "Index", indexTests) }
func TestLastIndex(t *testing.T)    { runIndexTests(t, LastIndex, "LastIndex", lastIndexTests) }
func TestIndexAny(t *testing.T)     { runIndexTests(t, IndexAny, "IndexAny", indexAnyTests) }
func TestLastIndexAny(t *testing.T) { runIndexTests(t, LastIndexAny, "LastIndexAny", lastIndexAnyTests) }

var indexRuneTests = []struct {
        s    string
        rune rune
        out  int
}{
        {"a A x", 'A', 2},
        {"some_text=some_value", '=', 9},
        {"☺a", 'a', 3},
        {"a☻☺b", '☺', 4},
}

func TestIndexRune(t *testing.T) {
        for _, test := range indexRuneTests {
                if actual := IndexRune(test.s, test.rune); actual != test.out {
                        t.Errorf("IndexRune(%q,%d)= %v; want %v", test.s, test.rune, actual, test.out)
                }
        }
}

const benchmarkString = "some_text=some☺value"

func BenchmarkIndexRune(b *testing.B) {
        if got := IndexRune(benchmarkString, '☺'); got != 14 {
                b.Fatalf("wrong index: expected 14, got=%d", got)
        }
        for i := 0; i < b.N; i++ {
                IndexRune(benchmarkString, '☺')
        }
}

func BenchmarkIndexRuneFastPath(b *testing.B) {
        if got := IndexRune(benchmarkString, 'v'); got != 17 {
                b.Fatalf("wrong index: expected 17, got=%d", got)
        }
        for i := 0; i < b.N; i++ {
                IndexRune(benchmarkString, 'v')
        }
}

func BenchmarkIndex(b *testing.B) {
        if got := Index(benchmarkString, "v"); got != 17 {
                b.Fatalf("wrong index: expected 17, got=%d", got)
        }
        for i := 0; i < b.N; i++ {
                Index(benchmarkString, "v")
        }
}

var explodetests = []struct {
        s string
        n int
        a []string
}{
        {"", -1, []string{}},
        {abcd, 4, []string{"a", "b", "c", "d"}},
        {faces, 3, []string{"☺", "☻", "☹"}},
        {abcd, 2, []string{"a", "bcd"}},
}

func TestExplode(t *testing.T) {
        for _, tt := range explodetests {
                a := SplitN(tt.s, "", tt.n)
                if !eq(a, tt.a) {
                        t.Errorf("explode(%q, %d) = %v; want %v", tt.s, tt.n, a, tt.a)
                        continue
                }
                s := Join(a, "")
                if s != tt.s {
                        t.Errorf(`Join(explode(%q, %d), "") = %q`, tt.s, tt.n, s)
                }
        }
}

type SplitTest struct {
        s   string
        sep string
        n   int
        a   []string
}

var splittests = []SplitTest{
        {abcd, "a", 0, nil},
        {abcd, "a", -1, []string{"", "bcd"}},
        {abcd, "z", -1, []string{"abcd"}},
        {abcd, "", -1, []string{"a", "b", "c", "d"}},
        {commas, ",", -1, []string{"1", "2", "3", "4"}},
        {dots, "...", -1, []string{"1", ".2", ".3", ".4"}},
        {faces, "☹", -1, []string{"☺☻", ""}},
        {faces, "~", -1, []string{faces}},
        {faces, "", -1, []string{"☺", "☻", "☹"}},
        {"1 2 3 4", " ", 3, []string{"1", "2", "3 4"}},
        {"1 2", " ", 3, []string{"1", "2"}},
        {"123", "", 2, []string{"1", "23"}},
        {"123", "", 17, []string{"1", "2", "3"}},
}

func TestSplit(t *testing.T) {
        for _, tt := range splittests {
                a := SplitN(tt.s, tt.sep, tt.n)
                if !eq(a, tt.a) {
                        t.Errorf("Split(%q, %q, %d) = %v; want %v", tt.s, tt.sep, tt.n, a, tt.a)
                        continue
                }
                if tt.n == 0 {
                        continue
                }
                s := Join(a, tt.sep)
                if s != tt.s {
                        t.Errorf("Join(Split(%q, %q, %d), %q) = %q", tt.s, tt.sep, tt.n, tt.sep, s)
                }
                if tt.n < 0 {
                        b := Split(tt.s, tt.sep)
                        if !reflect.DeepEqual(a, b) {
                                t.Errorf("Split disagrees with SplitN(%q, %q, %d) = %v; want %v", tt.s, tt.sep, tt.n, b, a)
                        }
                }
        }
}

var splitaftertests = []SplitTest{
        {abcd, "a", -1, []string{"a", "bcd"}},
        {abcd, "z", -1, []string{"abcd"}},
        {abcd, "", -1, []string{"a", "b", "c", "d"}},
        {commas, ",", -1, []string{"1,", "2,", "3,", "4"}},
        {dots, "...", -1, []string{"1...", ".2...", ".3...", ".4"}},
        {faces, "☹", -1, []string{"☺☻☹", ""}},
        {faces, "~", -1, []string{faces}},
        {faces, "", -1, []string{"☺", "☻", "☹"}},
        {"1 2 3 4", " ", 3, []string{"1 ", "2 ", "3 4"}},
        {"1 2 3", " ", 3, []string{"1 ", "2 ", "3"}},
        {"1 2", " ", 3, []string{"1 ", "2"}},
        {"123", "", 2, []string{"1", "23"}},
        {"123", "", 17, []string{"1", "2", "3"}},
}

func TestSplitAfter(t *testing.T) {
        for _, tt := range splitaftertests {
                a := SplitAfterN(tt.s, tt.sep, tt.n)
                if !eq(a, tt.a) {
                        t.Errorf(`Split(%q, %q, %d) = %v; want %v`, tt.s, tt.sep, tt.n, a, tt.a)
                        continue
                }
                s := Join(a, "")
                if s != tt.s {
                        t.Errorf(`Join(Split(%q, %q, %d), %q) = %q`, tt.s, tt.sep, tt.n, tt.sep, s)
                }
                if tt.n < 0 {
                        b := SplitAfter(tt.s, tt.sep)
                        if !reflect.DeepEqual(a, b) {
                                t.Errorf("SplitAfter disagrees with SplitAfterN(%q, %q, %d) = %v; want %v", tt.s, tt.sep, tt.n, b, a)
                        }
                }
        }
}

type FieldsTest struct {
        s string
        a []string
}

var fieldstests = []FieldsTest{
        {"", []string{}},
        {" ", []string{}},
        {" \t ", []string{}},
        {"  abc  ", []string{"abc"}},
        {"1 2 3 4", []string{"1", "2", "3", "4"}},
        {"1  2  3  4", []string{"1", "2", "3", "4"}},
        {"1\t\t2\t\t3\t4", []string{"1", "2", "3", "4"}},
        {"1\u20002\u20013\u20024", []string{"1", "2", "3", "4"}},
        {"\u2000\u2001\u2002", []string{}},
        {"\n™\t™\n", []string{"™", "™"}},
        {faces, []string{faces}},
}

func TestFields(t *testing.T) {
        for _, tt := range fieldstests {
                a := Fields(tt.s)
                if !eq(a, tt.a) {
                        t.Errorf("Fields(%q) = %v; want %v", tt.s, a, tt.a)
                        continue
                }
        }
}

var FieldsFuncTests = []FieldsTest{
        {"", []string{}},
        {"XX", []string{}},
        {"XXhiXXX", []string{"hi"}},
        {"aXXbXXXcX", []string{"a", "b", "c"}},
}

func TestFieldsFunc(t *testing.T) {
        pred := func(c rune) bool { return c == 'X' }
        for _, tt := range FieldsFuncTests {
                a := FieldsFunc(tt.s, pred)
                if !eq(a, tt.a) {
                        t.Errorf("FieldsFunc(%q) = %v, want %v", tt.s, a, tt.a)
                }
        }
}

// Test case for any function which accepts and returns a single string.
type StringTest struct {
        in, out string
}

// Execute f on each test case.  funcName should be the name of f; it's used
// in failure reports.
func runStringTests(t *testing.T, f func(string) string, funcName string, testCases []StringTest) {
        for _, tc := range testCases {
                actual := f(tc.in)
                if actual != tc.out {
                        t.Errorf("%s(%q) = %q; want %q", funcName, tc.in, actual, tc.out)
                }
        }
}

var upperTests = []StringTest{
        {"", ""},
        {"abc", "ABC"},
        {"AbC123", "ABC123"},
        {"azAZ09_", "AZAZ09_"},
        {"\u0250\u0250\u0250\u0250\u0250", "\u2C6F\u2C6F\u2C6F\u2C6F\u2C6F"}, // grows one byte per char
}

var lowerTests = []StringTest{
        {"", ""},
        {"abc", "abc"},
        {"AbC123", "abc123"},
        {"azAZ09_", "azaz09_"},
        {"\u2C6D\u2C6D\u2C6D\u2C6D\u2C6D", "\u0251\u0251\u0251\u0251\u0251"}, // shrinks one byte per char
}

const space = "\t\v\r\f\n\u0085\u00a0\u2000\u3000"

var trimSpaceTests = []StringTest{
        {"", ""},
        {"abc", "abc"},
        {space + "abc" + space, "abc"},
        {" ", ""},
        {" \t\r\n \t\t\r\r\n\n ", ""},
        {" \t\r\n x\t\t\r\r\n\n ", "x"},
        {" \u2000\t\r\n x\t\t\r\r\ny\n \u3000", "x\t\t\r\r\ny"},
        {"1 \t\r\n2", "1 \t\r\n2"},
        {" x\x80", "x\x80"},
        {" x\xc0", "x\xc0"},
        {"x \xc0\xc0 ", "x \xc0\xc0"},
        {"x \xc0", "x \xc0"},
        {"x \xc0 ", "x \xc0"},
        {"x \xc0\xc0 ", "x \xc0\xc0"},
        {"x ☺\xc0\xc0 ", "x ☺\xc0\xc0"},
        {"x ☺ ", "x ☺"},
}

func tenRunes(ch rune) string {
        r := make([]rune, 10)
        for i := range r {
                r[i] = ch
        }
        return string(r)
}

// User-defined self-inverse mapping function
func rot13(r rune) rune {
        step := rune(13)
        if r >= 'a' && r <= 'z' {
                return ((r - 'a' + step) % 26) + 'a'
        }
        if r >= 'A' && r <= 'Z' {
                return ((r - 'A' + step) % 26) + 'A'
        }
        return r
}

func TestMap(t *testing.T) {
        // Run a couple of awful growth/shrinkage tests
        a := tenRunes('a')
        // 1.  Grow.  This triggers two reallocations in Map.
        maxRune := func(rune) rune { return unicode.MaxRune }
        m := Map(maxRune, a)
        expect := tenRunes(unicode.MaxRune)
        if m != expect {
                t.Errorf("growing: expected %q got %q", expect, m)
        }

        // 2. Shrink
        minRune := func(rune) rune { return 'a' }
        m = Map(minRune, tenRunes(unicode.MaxRune))
        expect = a
        if m != expect {
                t.Errorf("shrinking: expected %q got %q", expect, m)
        }

        // 3. Rot13
        m = Map(rot13, "a to zed")
        expect = "n gb mrq"
        if m != expect {
                t.Errorf("rot13: expected %q got %q", expect, m)
        }

        // 4. Rot13^2
        m = Map(rot13, Map(rot13, "a to zed"))
        expect = "a to zed"
        if m != expect {
                t.Errorf("rot13: expected %q got %q", expect, m)
        }

        // 5. Drop
        dropNotLatin := func(r rune) rune {
                if unicode.Is(unicode.Latin, r) {
                        return r
                }
                return -1
        }
        m = Map(dropNotLatin, "Hello, 세계")
        expect = "Hello"
        if m != expect {
                t.Errorf("drop: expected %q got %q", expect, m)
        }

        // 6. Identity
        identity := func(r rune) rune {
                return r
        }
        orig := "Input string that we expect not to be copied."
        m = Map(identity, orig)
        if (*reflect.StringHeader)(unsafe.Pointer(&orig)).Data !=
                (*reflect.StringHeader)(unsafe.Pointer(&m)).Data {
                t.Error("unexpected copy during identity map")
        }
}

func TestToUpper(t *testing.T) { runStringTests(t, ToUpper, "ToUpper", upperTests) }

func TestToLower(t *testing.T) { runStringTests(t, ToLower, "ToLower", lowerTests) }

func BenchmarkMapNoChanges(b *testing.B) {
        identity := func(r rune) rune {
                return r
        }
        for i := 0; i < b.N; i++ {
                Map(identity, "Some string that won't be modified.")
        }
}

func TestSpecialCase(t *testing.T) {
        lower := "abcçdefgğhıijklmnoöprsştuüvyz"
        upper := "ABCÇDEFGĞHIİJKLMNOÖPRSŞTUÜVYZ"
        u := ToUpperSpecial(unicode.TurkishCase, upper)
        if u != upper {
                t.Errorf("Upper(upper) is %s not %s", u, upper)
        }
        u = ToUpperSpecial(unicode.TurkishCase, lower)
        if u != upper {
                t.Errorf("Upper(lower) is %s not %s", u, upper)
        }
        l := ToLowerSpecial(unicode.TurkishCase, lower)
        if l != lower {
                t.Errorf("Lower(lower) is %s not %s", l, lower)
        }
        l = ToLowerSpecial(unicode.TurkishCase, upper)
        if l != lower {
                t.Errorf("Lower(upper) is %s not %s", l, lower)
        }
}

func TestTrimSpace(t *testing.T) { runStringTests(t, TrimSpace, "TrimSpace", trimSpaceTests) }

var trimTests = []struct {
        f               string
        in, cutset, out string
}{
        {"Trim", "abba", "a", "bb"},
        {"Trim", "abba", "ab", ""},
        {"TrimLeft", "abba", "ab", ""},
        {"TrimRight", "abba", "ab", ""},
        {"TrimLeft", "abba", "a", "bba"},
        {"TrimRight", "abba", "a", "abb"},
        {"Trim", "<tag>", "<>", "tag"},
        {"Trim", "* listitem", " *", "listitem"},
        {"Trim", `"quote"`, `"`, "quote"},
        {"Trim", "\u2C6F\u2C6F\u0250\u0250\u2C6F\u2C6F", "\u2C6F", "\u0250\u0250"},
        //empty string tests
        {"Trim", "abba", "", "abba"},
        {"Trim", "", "123", ""},
        {"Trim", "", "", ""},
        {"TrimLeft", "abba", "", "abba"},
        {"TrimLeft", "", "123", ""},
        {"TrimLeft", "", "", ""},
        {"TrimRight", "abba", "", "abba"},
        {"TrimRight", "", "123", ""},
        {"TrimRight", "", "", ""},
        {"TrimRight", "☺\xc0", "☺", "☺\xc0"},
}

func TestTrim(t *testing.T) {
        for _, tc := range trimTests {
                name := tc.f
                var f func(string, string) string
                switch name {
                case "Trim":
                        f = Trim
                case "TrimLeft":
                        f = TrimLeft
                case "TrimRight":
                        f = TrimRight
                default:
                        t.Errorf("Undefined trim function %s", name)
                }
                actual := f(tc.in, tc.cutset)
                if actual != tc.out {
                        t.Errorf("%s(%q, %q) = %q; want %q", name, tc.in, tc.cutset, actual, tc.out)
                }
        }
}

type predicate struct {
        f    func(rune) bool
        name string
}

var isSpace = predicate{unicode.IsSpace, "IsSpace"}
var isDigit = predicate{unicode.IsDigit, "IsDigit"}
var isUpper = predicate{unicode.IsUpper, "IsUpper"}
var isValidRune = predicate{
        func(r rune) bool {
                return r != utf8.RuneError
        },
        "IsValidRune",
}

func not(p predicate) predicate {
        return predicate{
                func(r rune) bool {
                        return !p.f(r)
                },
                "not " + p.name,
        }
}

var trimFuncTests = []struct {
        f       predicate
        in, out string
}{
        {isSpace, space + " hello " + space, "hello"},
        {isDigit, "\u0e50\u0e5212hello34\u0e50\u0e51", "hello"},
        {isUpper, "\u2C6F\u2C6F\u2C6F\u2C6FABCDhelloEF\u2C6F\u2C6FGH\u2C6F\u2C6F", "hello"},
        {not(isSpace), "hello" + space + "hello", space},
        {not(isDigit), "hello\u0e50\u0e521234\u0e50\u0e51helo", "\u0e50\u0e521234\u0e50\u0e51"},
        {isValidRune, "ab\xc0a\xc0cd", "\xc0a\xc0"},
        {not(isValidRune), "\xc0a\xc0", "a"},
}

func TestTrimFunc(t *testing.T) {
        for _, tc := range trimFuncTests {
                actual := TrimFunc(tc.in, tc.f.f)
                if actual != tc.out {
                        t.Errorf("TrimFunc(%q, %q) = %q; want %q", tc.in, tc.f.name, actual, tc.out)
                }
        }
}

var indexFuncTests = []struct {
        in          string
        f           predicate
        first, last int
}{
        {"", isValidRune, -1, -1},
        {"abc", isDigit, -1, -1},
        {"0123", isDigit, 0, 3},
        {"a1b", isDigit, 1, 1},
        {space, isSpace, 0, len(space) - 3}, // last rune in space is 3 bytes
        {"\u0e50\u0e5212hello34\u0e50\u0e51", isDigit, 0, 18},
        {"\u2C6F\u2C6F\u2C6F\u2C6FABCDhelloEF\u2C6F\u2C6FGH\u2C6F\u2C6F", isUpper, 0, 34},
        {"12\u0e50\u0e52hello34\u0e50\u0e51", not(isDigit), 8, 12},

        // tests of invalid UTF-8
        {"\x801", isDigit, 1, 1},
        {"\x80abc", isDigit, -1, -1},
        {"\xc0a\xc0", isValidRune, 1, 1},
        {"\xc0a\xc0", not(isValidRune), 0, 2},
        {"\xc0☺\xc0", not(isValidRune), 0, 4},
        {"\xc0☺\xc0\xc0", not(isValidRune), 0, 5},
        {"ab\xc0a\xc0cd", not(isValidRune), 2, 4},
        {"a\xe0\x80cd", not(isValidRune), 1, 2},
        {"\x80\x80\x80\x80", not(isValidRune), 0, 3},
}

func TestIndexFunc(t *testing.T) {
        for _, tc := range indexFuncTests {
                first := IndexFunc(tc.in, tc.f.f)
                if first != tc.first {
                        t.Errorf("IndexFunc(%q, %s) = %d; want %d", tc.in, tc.f.name, first, tc.first)
                }
                last := LastIndexFunc(tc.in, tc.f.f)
                if last != tc.last {
                        t.Errorf("LastIndexFunc(%q, %s) = %d; want %d", tc.in, tc.f.name, last, tc.last)
                }
        }
}

func equal(m string, s1, s2 string, t *testing.T) bool {
        if s1 == s2 {
                return true
        }
        e1 := Split(s1, "")
        e2 := Split(s2, "")
        for i, c1 := range e1 {
                if i > len(e2) {
                        break
                }
                r1, _ := utf8.DecodeRuneInString(c1)
                r2, _ := utf8.DecodeRuneInString(e2[i])
                if r1 != r2 {
                        t.Errorf("%s diff at %d: U+%04X U+%04X", m, i, r1, r2)
                }
        }
        return false
}

func TestCaseConsistency(t *testing.T) {
        // Make a string of all the runes.
        numRunes := int(unicode.MaxRune + 1)
        if testing.Short() {
                numRunes = 1000
        }
        a := make([]rune, numRunes)
        for i := range a {
                a[i] = rune(i)
        }
        s := string(a)
        // convert the cases.
        upper := ToUpper(s)
        lower := ToLower(s)

        // Consistency checks
        if n := utf8.RuneCountInString(upper); n != numRunes {
                t.Error("rune count wrong in upper:", n)
        }
        if n := utf8.RuneCountInString(lower); n != numRunes {
                t.Error("rune count wrong in lower:", n)
        }
        if !equal("ToUpper(upper)", ToUpper(upper), upper, t) {
                t.Error("ToUpper(upper) consistency fail")
        }
        if !equal("ToLower(lower)", ToLower(lower), lower, t) {
                t.Error("ToLower(lower) consistency fail")
        }
        /*
                  These fail because of non-one-to-oneness of the data, such as multiple
                  upper case 'I' mapping to 'i'.  We comment them out but keep them for
                  interest.
                  For instance: CAPITAL LETTER I WITH DOT ABOVE:
                        unicode.ToUpper(unicode.ToLower('\u0130')) != '\u0130'

                if !equal("ToUpper(lower)", ToUpper(lower), upper, t) {
                        t.Error("ToUpper(lower) consistency fail");
                }
                if !equal("ToLower(upper)", ToLower(upper), lower, t) {
                        t.Error("ToLower(upper) consistency fail");
                }
        */
}

var RepeatTests = []struct {
        in, out string
        count   int
}{
        {"", "", 0},
        {"", "", 1},
        {"", "", 2},
        {"-", "", 0},
        {"-", "-", 1},
        {"-", "----------", 10},
        {"abc ", "abc abc abc ", 3},
}

func TestRepeat(t *testing.T) {
        for _, tt := range RepeatTests {
                a := Repeat(tt.in, tt.count)
                if !equal("Repeat(s)", a, tt.out, t) {
                        t.Errorf("Repeat(%v, %d) = %v; want %v", tt.in, tt.count, a, tt.out)
                        continue
                }
        }
}

func runesEqual(a, b []rune) bool {
        if len(a) != len(b) {
                return false
        }
        for i, r := range a {
                if r != b[i] {
                        return false
                }
        }
        return true
}

var RunesTests = []struct {
        in    string
        out   []rune
        lossy bool
}{
        {"", []rune{}, false},
        {" ", []rune{32}, false},
        {"ABC", []rune{65, 66, 67}, false},
        {"abc", []rune{97, 98, 99}, false},
        {"\u65e5\u672c\u8a9e", []rune{26085, 26412, 35486}, false},
        {"ab\x80c", []rune{97, 98, 0xFFFD, 99}, true},
        {"ab\xc0c", []rune{97, 98, 0xFFFD, 99}, true},
}

func TestRunes(t *testing.T) {
        for _, tt := range RunesTests {
                a := []rune(tt.in)
                if !runesEqual(a, tt.out) {
                        t.Errorf("[]rune(%q) = %v; want %v", tt.in, a, tt.out)
                        continue
                }
                if !tt.lossy {
                        // can only test reassembly if we didn't lose information
                        s := string(a)
                        if s != tt.in {
                                t.Errorf("string([]rune(%q)) = %x; want %x", tt.in, s, tt.in)
                        }
                }
        }
}

func TestReadByte(t *testing.T) {
        testStrings := []string{"", abcd, faces, commas}
        for _, s := range testStrings {
                reader := NewReader(s)
                if e := reader.UnreadByte(); e == nil {
                        t.Errorf("Unreading %q at beginning: expected error", s)
                }
                var res bytes.Buffer
                for {
                        b, e := reader.ReadByte()
                        if e == io.EOF {
                                break
                        }
                        if e != nil {
                                t.Errorf("Reading %q: %s", s, e)
                                break
                        }
                        res.WriteByte(b)
                        // unread and read again
                        e = reader.UnreadByte()
                        if e != nil {
                                t.Errorf("Unreading %q: %s", s, e)
                                break
                        }
                        b1, e := reader.ReadByte()
                        if e != nil {
                                t.Errorf("Reading %q after unreading: %s", s, e)
                                break
                        }
                        if b1 != b {
                                t.Errorf("Reading %q after unreading: want byte %q, got %q", s, b, b1)
                                break
                        }
                }
                if res.String() != s {
                        t.Errorf("Reader(%q).ReadByte() produced %q", s, res.String())
                }
        }
}

func TestReadRune(t *testing.T) {
        testStrings := []string{"", abcd, faces, commas}
        for _, s := range testStrings {
                reader := NewReader(s)
                if e := reader.UnreadRune(); e == nil {
                        t.Errorf("Unreading %q at beginning: expected error", s)
                }
                res := ""
                for {
                        r, z, e := reader.ReadRune()
                        if e == io.EOF {
                                break
                        }
                        if e != nil {
                                t.Errorf("Reading %q: %s", s, e)
                                break
                        }
                        res += string(r)
                        // unread and read again
                        e = reader.UnreadRune()
                        if e != nil {
                                t.Errorf("Unreading %q: %s", s, e)
                                break
                        }
                        r1, z1, e := reader.ReadRune()
                        if e != nil {
                                t.Errorf("Reading %q after unreading: %s", s, e)
                                break
                        }
                        if r1 != r {
                                t.Errorf("Reading %q after unreading: want rune %q, got %q", s, r, r1)
                                break
                        }
                        if z1 != z {
                                t.Errorf("Reading %q after unreading: want size %d, got %d", s, z, z1)
                                break
                        }
                }
                if res != s {
                        t.Errorf("Reader(%q).ReadRune() produced %q", s, res)
                }
        }
}

var ReplaceTests = []struct {
        in       string
        old, new string
        n        int
        out      string
}{
        {"hello", "l", "L", 0, "hello"},
        {"hello", "l", "L", -1, "heLLo"},
        {"hello", "x", "X", -1, "hello"},
        {"", "x", "X", -1, ""},
        {"radar", "r", "<r>", -1, "<r>ada<r>"},
        {"", "", "<>", -1, "<>"},
        {"banana", "a", "<>", -1, "b<>n<>n<>"},
        {"banana", "a", "<>", 1, "b<>nana"},
        {"banana", "a", "<>", 1000, "b<>n<>n<>"},
        {"banana", "an", "<>", -1, "b<><>a"},
        {"banana", "ana", "<>", -1, "b<>na"},
        {"banana", "", "<>", -1, "<>b<>a<>n<>a<>n<>a<>"},
        {"banana", "", "<>", 10, "<>b<>a<>n<>a<>n<>a<>"},
        {"banana", "", "<>", 6, "<>b<>a<>n<>a<>n<>a"},
        {"banana", "", "<>", 5, "<>b<>a<>n<>a<>na"},
        {"banana", "", "<>", 1, "<>banana"},
        {"banana", "a", "a", -1, "banana"},
        {"banana", "a", "a", 1, "banana"},
        {"☺☻☹", "", "<>", -1, "<>☺<>☻<>☹<>"},
}

func TestReplace(t *testing.T) {
        for _, tt := range ReplaceTests {
                if s := Replace(tt.in, tt.old, tt.new, tt.n); s != tt.out {
                        t.Errorf("Replace(%q, %q, %q, %d) = %q, want %q", tt.in, tt.old, tt.new, tt.n, s, tt.out)
                }
        }
}

var TitleTests = []struct {
        in, out string
}{
        {"", ""},
        {"a", "A"},
        {" aaa aaa aaa ", " Aaa Aaa Aaa "},
        {" Aaa Aaa Aaa ", " Aaa Aaa Aaa "},
        {"123a456", "123a456"},
        {"double-blind", "Double-Blind"},
        {"ÿøû", "Ÿøû"},
}

func TestTitle(t *testing.T) {
        for _, tt := range TitleTests {
                if s := Title(tt.in); s != tt.out {
                        t.Errorf("Title(%q) = %q, want %q", tt.in, s, tt.out)
                }
        }
}

var ContainsTests = []struct {
        str, substr string
        expected    bool
}{
        {"abc", "bc", true},
        {"abc", "bcd", false},
        {"abc", "", true},
        {"", "a", false},
}

func TestContains(t *testing.T) {
        for _, ct := range ContainsTests {
                if Contains(ct.str, ct.substr) != ct.expected {
                        t.Errorf("Contains(%s, %s) = %v, want %v",
                                ct.str, ct.substr, !ct.expected, ct.expected)
                }
        }
}

var ContainsAnyTests = []struct {
        str, substr string
        expected    bool
}{
        {"", "", false},
        {"", "a", false},
        {"", "abc", false},
        {"a", "", false},
        {"a", "a", true},
        {"aaa", "a", true},
        {"abc", "xyz", false},
        {"abc", "xcz", true},
        {"a☺b☻c☹d", "uvw☻xyz", true},
        {"aRegExp*", ".(|)*+?^$[]", true},
        {dots + dots + dots, " ", false},
}

func TestContainsAny(t *testing.T) {
        for _, ct := range ContainsAnyTests {
                if ContainsAny(ct.str, ct.substr) != ct.expected {
                        t.Errorf("ContainsAny(%s, %s) = %v, want %v",
                                ct.str, ct.substr, !ct.expected, ct.expected)
                }
        }
}

var ContainsRuneTests = []struct {
        str      string
        r        rune
        expected bool
}{
        {"", 'a', false},
        {"a", 'a', true},
        {"aaa", 'a', true},
        {"abc", 'y', false},
        {"abc", 'c', true},
        {"a☺b☻c☹d", 'x', false},
        {"a☺b☻c☹d", '☻', true},
        {"aRegExp*", '*', true},
}

func TestContainsRune(t *testing.T) {
        for _, ct := range ContainsRuneTests {
                if ContainsRune(ct.str, ct.r) != ct.expected {
                        t.Errorf("ContainsRune(%s, %s) = %v, want %v",
                                ct.str, ct.r, !ct.expected, ct.expected)
                }
        }
}

var EqualFoldTests = []struct {
        s, t string
        out  bool
}{
        {"abc", "abc", true},
        {"ABcd", "ABcd", true},
        {"123abc", "123ABC", true},
        {"αβδ", "ΑΒΔ", true},
        {"abc", "xyz", false},
        {"abc", "XYZ", false},
        {"abcdefghijk", "abcdefghijX", false},
        {"abcdefghijk", "abcdefghij\u212A", true},
        {"abcdefghijK", "abcdefghij\u212A", true},
        {"abcdefghijkz", "abcdefghij\u212Ay", false},
        {"abcdefghijKz", "abcdefghij\u212Ay", false},
}

func TestEqualFold(t *testing.T) {
        for _, tt := range EqualFoldTests {
                if out := EqualFold(tt.s, tt.t); out != tt.out {
                        t.Errorf("EqualFold(%#q, %#q) = %v, want %v", tt.s, tt.t, out, tt.out)
                }
                if out := EqualFold(tt.t, tt.s); out != tt.out {
                        t.Errorf("EqualFold(%#q, %#q) = %v, want %v", tt.t, tt.s, out, tt.out)
                }
        }
}