// 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"
"fmt"
. "strings"
"testing"
)
var htmlEscaper = NewReplacer(
"&", "&",
"<", "<",
">", ">",
`"`, """,
"'", "'",
)
var htmlUnescaper = NewReplacer(
"&", "&",
"<", "<",
">", ">",
""", `"`,
"'", "'",
)
// The http package's old HTML escaping function.
func oldHTMLEscape(s string) string {
s = Replace(s, "&", "&", -1)
s = Replace(s, "<", "<", -1)
s = Replace(s, ">", ">", -1)
s = Replace(s, `"`, """, -1)
s = Replace(s, "'", "'", -1)
return s
}
var capitalLetters = NewReplacer("a", "A", "b", "B")
// TestReplacer tests the replacer implementations.
func TestReplacer(t *testing.T) {
type testCase struct {
r *Replacer
in, out string
}
var testCases []testCase
// str converts 0xff to "\xff". This isn't just string(b) since that converts to UTF-8.
str := func(b byte) string {
return string([]byte{b})
}
var s []string
// inc maps "\x00"->"\x01", ..., "a"->"b", "b"->"c", ..., "\xff"->"\x00".
s = nil
for i := 0; i < 256; i++ {
s = append(s, str(byte(i)), str(byte(i+1)))
}
inc := NewReplacer(s...)
// Test cases with 1-byte old strings, 1-byte new strings.
testCases = append(testCases,
testCase{capitalLetters, "brad", "BrAd"},
testCase{capitalLetters, Repeat("a", (32<<10)+123), Repeat("A", (32<<10)+123)},
testCase{capitalLetters, "", ""},
testCase{inc, "brad", "csbe"},
testCase{inc, "\x00\xff", "\x01\x00"},
testCase{inc, "", ""},
testCase{NewReplacer("a", "1", "a", "2"), "brad", "br1d"},
)
// repeat maps "a"->"a", "b"->"bb", "c"->"ccc", ...
s = nil
for i := 0; i < 256; i++ {
n := i + 1 - 'a'
if n < 1 {
n = 1
}
s = append(s, str(byte(i)), Repeat(str(byte(i)), n))
}
repeat := NewReplacer(s...)
// Test cases with 1-byte old strings, variable length new strings.
testCases = append(testCases,
testCase{htmlEscaper, "No changes", "No changes"},
testCase{htmlEscaper, "I <3 escaping & stuff", "I <3 escaping & stuff"},
testCase{htmlEscaper, "&&&", "&&&"},
testCase{htmlEscaper, "", ""},
testCase{repeat, "brad", "bbrrrrrrrrrrrrrrrrrradddd"},
testCase{repeat, "abba", "abbbba"},
testCase{repeat, "", ""},
testCase{NewReplacer("a", "11", "a", "22"), "brad", "br11d"},
)
// The remaining test cases have variable length old strings.
testCases = append(testCases,
testCase{htmlUnescaper, "&amp;", "&"},
testCase{htmlUnescaper, "<b>HTML's neat</b>", "<b>HTML's neat</b>"},
testCase{htmlUnescaper, "", ""},
testCase{NewReplacer("a", "1", "a", "2", "xxx", "xxx"), "brad", "br1d"},
testCase{NewReplacer("a", "1", "aa", "2", "aaa", "3"), "aaaa", "1111"},
testCase{NewReplacer("aaa", "3", "aa", "2", "a", "1"), "aaaa", "31"},
)
// gen1 has multiple old strings of variable length. There is no
// overall non-empty common prefix, but some pairwise common prefixes.
gen1 := NewReplacer(
"aaa", "3[aaa]",
"aa", "2[aa]",
"a", "1[a]",
"i", "i",
"longerst", "most long",
"longer", "medium",
"long", "short",
"xx", "xx",
"x", "X",
"X", "Y",
"Y", "Z",
)
testCases = append(testCases,
testCase{gen1, "fooaaabar", "foo3[aaa]b1[a]r"},
testCase{gen1, "long, longerst, longer", "short, most long, medium"},
testCase{gen1, "xxxxx", "xxxxX"},
testCase{gen1, "XiX", "YiY"},
testCase{gen1, "", ""},
)
// gen2 has multiple old strings with no pairwise common prefix.
gen2 := NewReplacer(
"roses", "red",
"violets", "blue",
"sugar", "sweet",
)
testCases = append(testCases,
testCase{gen2, "roses are red, violets are blue...", "red are red, blue are blue..."},
testCase{gen2, "", ""},
)
// gen3 has multiple old strings with an overall common prefix.
gen3 := NewReplacer(
"abracadabra", "poof",
"abracadabrakazam", "splat",
"abraham", "lincoln",
"abrasion", "scrape",
"abraham", "isaac",
)
testCases = append(testCases,
testCase{gen3, "abracadabrakazam abraham", "poofkazam lincoln"},
testCase{gen3, "abrasion abracad", "scrape abracad"},
testCase{gen3, "abba abram abrasive", "abba abram abrasive"},
testCase{gen3, "", ""},
)
// foo{1,2,3,4} have multiple old strings with an overall common prefix
// and 1- or 2- byte extensions from the common prefix.
foo1 := NewReplacer(
"foo1", "A",
"foo2", "B",
"foo3", "C",
)
foo2 := NewReplacer(
"foo1", "A",
"foo2", "B",
"foo31", "C",
"foo32", "D",
)
foo3 := NewReplacer(
"foo11", "A",
"foo12", "B",
"foo31", "C",
"foo32", "D",
)
foo4 := NewReplacer(
"foo12", "B",
"foo32", "D",
)
testCases = append(testCases,
testCase{foo1, "fofoofoo12foo32oo", "fofooA2C2oo"},
testCase{foo1, "", ""},
testCase{foo2, "fofoofoo12foo32oo", "fofooA2Doo"},
testCase{foo2, "", ""},
testCase{foo3, "fofoofoo12foo32oo", "fofooBDoo"},
testCase{foo3, "", ""},
testCase{foo4, "fofoofoo12foo32oo", "fofooBDoo"},
testCase{foo4, "", ""},
)
// genAll maps "\x00\x01\x02...\xfe\xff" to "[all]", amongst other things.
allBytes := make([]byte, 256)
for i := range allBytes {
allBytes[i] = byte(i)
}
allString := string(allBytes)
genAll := NewReplacer(
allString, "[all]",
"\xff", "[ff]",
"\x00", "[00]",
)
testCases = append(testCases,
testCase{genAll, allString, "[all]"},
testCase{genAll, "a\xff" + allString + "\x00", "a[ff][all][00]"},
testCase{genAll, "", ""},
)
// Test cases with empty old strings.
blankToX1 := NewReplacer("", "X")
blankToX2 := NewReplacer("", "X", "", "")
blankHighPriority := NewReplacer("", "X", "o", "O")
blankLowPriority := NewReplacer("o", "O", "", "X")
blankNoOp1 := NewReplacer("", "")
blankNoOp2 := NewReplacer("", "", "", "A")
blankFoo := NewReplacer("", "X", "foobar", "R", "foobaz", "Z")
testCases = append(testCases,
testCase{blankToX1, "foo", "XfXoXoX"},
testCase{blankToX1, "", "X"},
testCase{blankToX2, "foo", "XfXoXoX"},
testCase{blankToX2, "", "X"},
testCase{blankHighPriority, "oo", "XOXOX"},
testCase{blankHighPriority, "ii", "XiXiX"},
testCase{blankHighPriority, "oiio", "XOXiXiXOX"},
testCase{blankHighPriority, "iooi", "XiXOXOXiX"},
testCase{blankHighPriority, "", "X"},
testCase{blankLowPriority, "oo", "OOX"},
testCase{blankLowPriority, "ii", "XiXiX"},
testCase{blankLowPriority, "oiio", "OXiXiOX"},
testCase{blankLowPriority, "iooi", "XiOOXiX"},
testCase{blankLowPriority, "", "X"},
testCase{blankNoOp1, "foo", "foo"},
testCase{blankNoOp1, "", ""},
testCase{blankNoOp2, "foo", "foo"},
testCase{blankNoOp2, "", ""},
testCase{blankFoo, "foobarfoobaz", "XRXZX"},
testCase{blankFoo, "foobar-foobaz", "XRX-XZX"},
testCase{blankFoo, "", "X"},
)
// single string replacer
abcMatcher := NewReplacer("abc", "[match]")
testCases = append(testCases,
testCase{abcMatcher, "", ""},
testCase{abcMatcher, "ab", "ab"},
testCase{abcMatcher, "abc", "[match]"},
testCase{abcMatcher, "abcd", "[match]d"},
testCase{abcMatcher, "cabcabcdabca", "c[match][match]d[match]a"},
)
// Issue 6659 cases (more single string replacer)
noHello := NewReplacer("Hello", "")
testCases = append(testCases,
testCase{noHello, "Hello", ""},
testCase{noHello, "Hellox", "x"},
testCase{noHello, "xHello", "x"},
testCase{noHello, "xHellox", "xx"},
)
// No-arg test cases.
nop := NewReplacer()
testCases = append(testCases,
testCase{nop, "abc", "abc"},
testCase{nop, "", ""},
)
// Run the test cases.
for i, tc := range testCases {
if s := tc.r.Replace(tc.in); s != tc.out {
t.Errorf("%d. Replace(%q) = %q, want %q", i, tc.in, s, tc.out)
}
var buf bytes.Buffer
n, err := tc.r.WriteString(&buf, tc.in)
if err != nil {
t.Errorf("%d. WriteString: %v", i, err)
continue
}
got := buf.String()
if got != tc.out {
t.Errorf("%d. WriteString(%q) wrote %q, want %q", i, tc.in, got, tc.out)
continue
}
if n != len(tc.out) {
t.Errorf("%d. WriteString(%q) wrote correct string but reported %d bytes; want %d (%q)",
i, tc.in, n, len(tc.out), tc.out)
}
}
}
var algorithmTestCases = []struct {
r *Replacer
want string
}{
{capitalLetters, "*strings.byteReplacer"},
{htmlEscaper, "*strings.byteStringReplacer"},
{NewReplacer("12", "123"), "*strings.singleStringReplacer"},
{NewReplacer("1", "12"), "*strings.byteStringReplacer"},
{NewReplacer("", "X"), "*strings.genericReplacer"},
{NewReplacer("a", "1", "b", "12", "cde", "123"), "*strings.genericReplacer"},
}
// TestPickAlgorithm tests that NewReplacer picks the correct algorithm.
func TestPickAlgorithm(t *testing.T) {
for i, tc := range algorithmTestCases {
got := fmt.Sprintf("%T", tc.r.Replacer())
if got != tc.want {
t.Errorf("%d. algorithm = %s, want %s", i, got, tc.want)
}
}
}
type errWriter struct{}
func (errWriter) Write(p []byte) (n int, err error) {
return 0, fmt.Errorf("unwritable")
}
// TestWriteStringError tests that WriteString returns an error
// received from the underlying io.Writer.
func TestWriteStringError(t *testing.T) {
for i, tc := range algorithmTestCases {
n, err := tc.r.WriteString(errWriter{}, "abc")
if n != 0 || err == nil || err.Error() != "unwritable" {
t.Errorf("%d. WriteStringError = %d, %v, want 0, unwritable", i, n, err)
}
}
}
// TestGenericTrieBuilding verifies the structure of the generated trie. There
// is one node per line, and the key ending with the current line is in the
// trie if it ends with a "+".
func TestGenericTrieBuilding(t *testing.T) {
testCases := []struct{ in, out string }{
{"abc;abdef;abdefgh;xx;xy;z", `-
a-
.b-
..c+
..d-
...ef+
.....gh+
x-
.x+
.y+
z+
`},
{"abracadabra;abracadabrakazam;abraham;abrasion", `-
a-
.bra-
....c-
.....adabra+
...........kazam+
....h-
.....am+
....s-
.....ion+
`},
{"aaa;aa;a;i;longerst;longer;long;xx;x;X;Y", `-
X+
Y+
a+
.a+
..a+
i+
l-
.ong+
....er+
......st+
x+
.x+
`},
{"foo;;foo;foo1", `+
f-
.oo+
...1+
`},
}
for _, tc := range testCases {
keys := Split(tc.in, ";")
args := make([]string, len(keys)*2)
for i, key := range keys {
args[i*2] = key
}
got := NewReplacer(args...).PrintTrie()
// Remove tabs from tc.out
wantbuf := make([]byte, 0, len(tc.out))
for i := 0; i < len(tc.out); i++ {
if tc.out[i] != '\t' {
wantbuf = append(wantbuf, tc.out[i])
}
}
want := string(wantbuf)
if got != want {
t.Errorf("PrintTrie(%q)\ngot\n%swant\n%s", tc.in, got, want)
}
}
}
func BenchmarkGenericNoMatch(b *testing.B) {
str := Repeat("A", 100) + Repeat("B", 100)
generic := NewReplacer("a", "A", "b", "B", "12", "123") // varying lengths forces generic
for i := 0; i < b.N; i++ {
generic.Replace(str)
}
}
func BenchmarkGenericMatch1(b *testing.B) {
str := Repeat("a", 100) + Repeat("b", 100)
generic := NewReplacer("a", "A", "b", "B", "12", "123")
for i := 0; i < b.N; i++ {
generic.Replace(str)
}
}
func BenchmarkGenericMatch2(b *testing.B) {
str := Repeat("It's <b>HTML</b>!", 100)
for i := 0; i < b.N; i++ {
htmlUnescaper.Replace(str)
}
}
func benchmarkSingleString(b *testing.B, pattern, text string) {
r := NewReplacer(pattern, "[match]")
b.SetBytes(int64(len(text)))
b.ResetTimer()
for i := 0; i < b.N; i++ {
r.Replace(text)
}
}
func BenchmarkSingleMaxSkipping(b *testing.B) {
benchmarkSingleString(b, Repeat("b", 25), Repeat("a", 10000))
}
func BenchmarkSingleLongSuffixFail(b *testing.B) {
benchmarkSingleString(b, "b"+Repeat("a", 500), Repeat("a", 1002))
}
func BenchmarkSingleMatch(b *testing.B) {
benchmarkSingleString(b, "abcdef", Repeat("abcdefghijklmno", 1000))
}
func BenchmarkByteByteNoMatch(b *testing.B) {
str := Repeat("A", 100) + Repeat("B", 100)
for i := 0; i < b.N; i++ {
capitalLetters.Replace(str)
}
}
func BenchmarkByteByteMatch(b *testing.B) {
str := Repeat("a", 100) + Repeat("b", 100)
for i := 0; i < b.N; i++ {
capitalLetters.Replace(str)
}
}
func BenchmarkByteStringMatch(b *testing.B) {
str := "<" + Repeat("a", 99) + Repeat("b", 99) + ">"
for i := 0; i < b.N; i++ {
htmlEscaper.Replace(str)
}
}
func BenchmarkHTMLEscapeNew(b *testing.B) {
str := "I <3 to escape HTML & other text too."
for i := 0; i < b.N; i++ {
htmlEscaper.Replace(str)
}
}
func BenchmarkHTMLEscapeOld(b *testing.B) {
str := "I <3 to escape HTML & other text too."
for i := 0; i < b.N; i++ {
oldHTMLEscape(str)
}
}
func BenchmarkByteStringReplacerWriteString(b *testing.B) {
str := Repeat("I <3 to escape HTML & other text too.", 100)
buf := new(bytes.Buffer)
for i := 0; i < b.N; i++ {
htmlEscaper.WriteString(buf, str)
buf.Reset()
}
}
func BenchmarkByteReplacerWriteString(b *testing.B) {
str := Repeat("abcdefghijklmnopqrstuvwxyz", 100)
buf := new(bytes.Buffer)
for i := 0; i < b.N; i++ {
capitalLetters.WriteString(buf, str)
buf.Reset()
}
}
// BenchmarkByteByteReplaces compares byteByteImpl against multiple Replaces.
func BenchmarkByteByteReplaces(b *testing.B) {
str := Repeat("a", 100) + Repeat("b", 100)
for i := 0; i < b.N; i++ {
Replace(Replace(str, "a", "A", -1), "b", "B", -1)
}
}
// BenchmarkByteByteMap compares byteByteImpl against Map.
func BenchmarkByteByteMap(b *testing.B) {
str := Repeat("a", 100) + Repeat("b", 100)
fn := func(r rune) rune {
switch r {
case 'a':
return 'A'
case 'b':
return 'B'
}
return r
}
for i := 0; i < b.N; i++ {
Map(fn, str)
}
}
var mapdata = []struct{ name, data string }{
{"ASCII", "a b c d e f g h i j k l m n o p q r s t u v w x y z"},
{"Greek", "α β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ ς σ τ υ φ χ ψ ω"},
}
func BenchmarkMap(b *testing.B) {
mapidentity := func(r rune) rune {
return r
}
b.Run("identity", func(b *testing.B) {
for _, md := range mapdata {
b.Run(md.name, func(b *testing.B) {
for i := 0; i < b.N; i++ {
Map(mapidentity, md.data)
}
})
}
})
mapchange := func(r rune) rune {
if 'a' <= r && r <= 'z' {
return r + 'A' - 'a'
}
if 'α' <= r && r <= 'ω' {
return r + 'Α' - 'α'
}
return r
}
b.Run("change", func(b *testing.B) {
for _, md := range mapdata {
b.Run(md.name, func(b *testing.B) {
for i := 0; i < b.N; i++ {
Map(mapchange, md.data)
}
})
}
})
}
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