Skip to content

G
go
Commit b19c32ac authored by Nigel Tao's avatar Nigel Tao
Browse files
Options

strings: more thorough Replacer tests. 

This verifies existing behavior. Some replacements are arguably wrong
(these are marked with TODO) but changing behavior is left for a
follow-up CL.

Also fix that BenchmarkGenericMatch wasn't actually matching anything.

R=rsc, eric.d.eisner
CC=bradfitz, golang-dev
https://golang.org/cl/6488110
parent b4840366
Hide whitespace changes
Inline Side-by-side
Showing with 259 additions and 60 deletions
src/pkg/strings/replace_test.go
View file @ b19c32ac
......@@ -7,105 +7,289 @@ package strings_test
import (
"bytes"
"fmt"
"log"
. "strings"
"testing"
)
var _ = log.Printf
type ReplacerTest struct {
r *Replacer
in string
out string
}
var htmlEscaper = NewReplacer(
"&", "&",
"<", "&lt;",
">", "&gt;",
`"`, "&quot;",
"'", "&apos;",
)
var htmlEscaper = NewReplacer("&", "&amp;", "<", "&lt;", ">", "&gt;", "\"", "&quot;")
var htmlUnescaper = NewReplacer(
"&amp;", "&",
"&lt;", "<",
"&gt;", ">",
"&quot;", `"`,
"&apos;", "'",
)
// The http package's old HTML escaping function.
func oldhtmlEscape(s string) string {
func oldHTMLEscape(s string) string {
s = Replace(s, "&", "&amp;", -1)
s = Replace(s, "<", "&lt;", -1)
s = Replace(s, ">", "&gt;", -1)
s = Replace(s, "\"", "&quot;", -1)
s = Replace(s, `"`, "&quot;", -1)
s = Replace(s, "'", "&apos;", -1)
return s
}
var replacer = NewReplacer("aaa", "3[aaa]", "aa", "2[aa]", "a", "1[a]", "i", "i",
"longerst", "most long", "longer", "medium", "long", "short",
"X", "Y", "Y", "Z")
var capitalLetters = NewReplacer("a", "A", "b", "B")
var blankToXReplacer = NewReplacer("", "X", "o", "O")
// 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
var ReplacerTests = []ReplacerTest{
// byte->string
{htmlEscaper, "No changes", "No changes"},
{htmlEscaper, "I <3 escaping & stuff", "I &lt;3 escaping &amp; stuff"},
{htmlEscaper, "&&&", "&amp;&amp;&amp;"},
// 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...)
// generic
{replacer, "fooaaabar", "foo3[aaa]b1[a]r"},
{replacer, "long, longerst, longer", "short, most long, medium"},
{replacer, "XiX", "YiY"},
// 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, "", ""},
// byte->byte
{capitalLetters, "brad", "BrAd"},
{capitalLetters, Repeat("a", (32<<10)+123), Repeat("A", (32<<10)+123)},
testCase{inc, "brad", "csbe"},
testCase{inc, "\x00\xff", "\x01\x00"},
testCase{inc, "", ""},
// hitting "" special case
{blankToXReplacer, "oo", "XOXOX"},
}
testCase{NewReplacer("a", "1", "a", "2"), "brad", "br2d"}, // TODO: should this be "br1d"?
)
func TestReplacer(t *testing.T) {
for i, tt := range ReplacerTests {
if s := tt.r.Replace(tt.in); s != tt.out {
t.Errorf("%d. Replace(%q) = %q, want %q", i, tt.in, s, tt.out)
// 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 &lt;3 escaping &amp; stuff"},
testCase{htmlEscaper, "&&&", "&amp;&amp;&amp;"},
testCase{htmlEscaper, "", ""},
testCase{repeat, "brad", "bbrrrrrrrrrrrrrrrrrradddd"},
testCase{repeat, "abba", "abbbba"},
testCase{repeat, "", ""},
testCase{NewReplacer("a", "11", "a", "22"), "brad", "br22d"}, // TODO: should this be "br11d"?
)
// The remaining test cases have variable length old strings.
testCases = append(testCases,
testCase{htmlUnescaper, "&amp;amp;", "&amp;"},
testCase{htmlUnescaper, "&lt;b&gt;HTML&apos;s neat&lt;/b&gt;", "<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", "", "")
blankToXOToO := NewReplacer("", "X", "o", "O")
blankNoOp1 := NewReplacer("", "")
blankNoOp2 := NewReplacer("", "", "", "A")
blankFoo := NewReplacer("", "X", "foobar", "R", "foobaz", "Z")
testCases = append(testCases,
testCase{blankToX1, "foo", "XfooX"}, // TODO: should this be "XfXoXoX"?
testCase{blankToX1, "", "X"},
testCase{blankToX2, "foo", "XfooX"}, // TODO: should this be "XfXoXoX"?
testCase{blankToX2, "", "X"},
testCase{blankToXOToO, "oo", "XOXOX"},
testCase{blankToXOToO, "ii", "XiiX"}, // TODO: should this be "XiXiX"?
testCase{blankToXOToO, "iooi", "XiOXOXiX"}, // TODO: should this be "XiXOXOXiX"?
testCase{blankToXOToO, "", "X"},
testCase{blankNoOp1, "foo", "foo"},
testCase{blankNoOp1, "", ""},
testCase{blankNoOp2, "foo", "foo"},
testCase{blankNoOp2, "", ""},
testCase{blankFoo, "foobarfoobaz", "XRXZX"},
testCase{blankFoo, "foobar-foobaz", "XRX-ZX"}, // TODO: should this be "XRX-XZX"?
testCase{blankFoo, "", "X"},
)
// 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 := tt.r.WriteString(&buf, tt.in)
n, err := tc.r.WriteString(&buf, tc.in)
if err != nil {
t.Errorf("%d. WriteString: %v", i, err)
continue
}
got := buf.String()
if got != tt.out {
t.Errorf("%d. WriteString(%q) wrote %q, want %q", i, tt.in, got, tt.out)
if got != tc.out {
t.Errorf("%d. WriteString(%q) wrote %q, want %q", i, tc.in, got, tc.out)
continue
}
if n != len(tt.out) {
if n != len(tc.out) {
t.Errorf("%d. WriteString(%q) wrote correct string but reported %d bytes; want %d (%q)",
i, tt.in, n, len(tt.out), tt.out)
i, tc.in, n, len(tc.out), tc.out)
}
}
}
// pickAlgorithmTest is a test that verifies that given input for a
// Replacer that we pick the correct algorithm.
type pickAlgorithmTest struct {
r *Replacer
want string // name of algorithm
}
var pickAlgorithmTests = []pickAlgorithmTest{
{capitalLetters, "*strings.byteReplacer"},
{NewReplacer("12", "123"), "*strings.genericReplacer"},
{NewReplacer("1", "12"), "*strings.byteStringReplacer"},
{htmlEscaper, "*strings.byteStringReplacer"},
}
// TestPickAlgorithm tests that NewReplacer picks the correct algorithm.
func TestPickAlgorithm(t *testing.T) {
for i, tt := range pickAlgorithmTests {
got := fmt.Sprintf("%T", tt.r.Replacer())
if got != tt.want {
t.Errorf("%d. algorithm = %s, want %s", i, got, tt.want)
testCases := []struct {
r *Replacer
want string
}{
{capitalLetters, "*strings.byteReplacer"},
{NewReplacer("12", "123"), "*strings.genericReplacer"},
{NewReplacer("1", "12"), "*strings.byteStringReplacer"},
{htmlEscaper, "*strings.byteStringReplacer"},
}
for i, tc := range testCases {
got := fmt.Sprintf("%T", tc.r.Replacer())
if got != tc.want {
t.Errorf("%d. algorithm = %s, want %s", i, got, tc.want)
}
}
}
func BenchmarkGenericMatch(b *testing.B) {
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++ {
......@@ -113,6 +297,21 @@ func BenchmarkGenericMatch(b *testing.B) {
}
}
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&apos;s &lt;b&gt;HTML&lt;/b&gt;!", 100)
for i := 0; i < b.N; i++ {
htmlUnescaper.Replace(str)
}
}
func BenchmarkByteByteNoMatch(b *testing.B) {
str := Repeat("A", 100) + Repeat("B", 100)
for i := 0; i < b.N; i++ {
......@@ -144,7 +343,7 @@ func BenchmarkHTMLEscapeNew(b *testing.B) {
func BenchmarkHTMLEscapeOld(b *testing.B) {
str := "I <3 to escape HTML & other text too."
for i := 0; i < b.N; i++ {
oldhtmlEscape(str)
oldHTMLEscape(str)
}
}
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7