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// Copyright 2022 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 lcs
import (
"log"
"math/rand"
"strings"
"testing"
)
type Btest struct {
a, b string
lcs []string
}
var Btests = []Btest{
{"aaabab", "abaab", []string{"abab", "aaab"}},
{"aabbba", "baaba", []string{"aaba"}},
{"cabbx", "cbabx", []string{"cabx", "cbbx"}},
{"c", "cb", []string{"c"}},
{"aaba", "bbb", []string{"b"}},
{"bbaabb", "b", []string{"b"}},
{"baaabb", "bbaba", []string{"bbb", "baa", "bab"}},
{"baaabb", "abbab", []string{"abb", "bab", "aab"}},
{"baaba", "aaabba", []string{"aaba"}},
{"ca", "cba", []string{"ca"}},
{"ccbcbc", "abba", []string{"bb"}},
{"ccbcbc", "aabba", []string{"bb"}},
{"ccb", "cba", []string{"cb"}},
{"caef", "axe", []string{"ae"}},
{"bbaabb", "baabb", []string{"baabb"}},
// Example from Myers:
{"abcabba", "cbabac", []string{"caba", "baba", "cbba"}},
{"3456aaa", "aaa", []string{"aaa"}},
{"aaa", "aaa123", []string{"aaa"}},
{"aabaa", "aacaa", []string{"aaaa"}},
{"1a", "a", []string{"a"}},
{"abab", "bb", []string{"bb"}},
{"123", "ab", []string{""}},
{"a", "b", []string{""}},
{"abc", "123", []string{""}},
{"aa", "aa", []string{"aa"}},
{"abcde", "12345", []string{""}},
{"aaa3456", "aaa", []string{"aaa"}},
{"abcde", "12345a", []string{"a"}},
{"ab", "123", []string{""}},
{"1a2", "a", []string{"a"}},
// for two-sided
{"babaab", "cccaba", []string{"aba"}},
{"aabbab", "cbcabc", []string{"bab"}},
{"abaabb", "bcacab", []string{"baab"}},
{"abaabb", "abaaaa", []string{"abaa"}},
{"bababb", "baaabb", []string{"baabb"}},
{"abbbaa", "cabacc", []string{"aba"}},
{"aabbaa", "aacaba", []string{"aaaa", "aaba"}},
}
func init() {
log.SetFlags(log.Lshortfile)
}
func check(t *testing.T, str string, lcs lcs, want []string) {
t.Helper()
if !lcs.valid() {
t.Errorf("bad lcs %v", lcs)
}
var got strings.Builder
for _, dd := range lcs {
got.WriteString(str[dd.X : dd.X+dd.Len])
}
ans := got.String()
for _, w := range want {
if ans == w {
return
}
}
t.Fatalf("str=%q lcs=%v want=%q got=%q", str, lcs, want, ans)
}
func checkDiffs(t *testing.T, before string, diffs []Diff, after string) {
t.Helper()
var ans strings.Builder
sofar := 0 // index of position in before
for _, d := range diffs {
if sofar < d.Start {
ans.WriteString(before[sofar:d.Start])
}
ans.WriteString(after[d.ReplStart:d.ReplEnd])
sofar = d.End
}
ans.WriteString(before[sofar:])
if ans.String() != after {
t.Fatalf("diff %v took %q to %q, not to %q", diffs, before, ans.String(), after)
}
}
func lcslen(l lcs) int {
ans := 0
for _, d := range l {
ans += int(d.Len)
}
return ans
}
// return a random string of length n made of characters from s
func randstr(s string, n int) string {
src := []rune(s)
x := make([]rune, n)
for i := 0; i < n; i++ {
x[i] = src[rand.Intn(len(src))]
}
return string(x)
}
func TestLcsFix(t *testing.T) {
tests := []struct{ before, after lcs }{
{lcs{diag{0, 0, 3}, diag{2, 2, 5}, diag{3, 4, 5}, diag{8, 9, 4}}, lcs{diag{0, 0, 2}, diag{2, 2, 1}, diag{3, 4, 5}, diag{8, 9, 4}}},
{lcs{diag{1, 1, 6}, diag{6, 12, 3}}, lcs{diag{1, 1, 5}, diag{6, 12, 3}}},
{lcs{diag{0, 0, 4}, diag{3, 5, 4}}, lcs{diag{0, 0, 3}, diag{3, 5, 4}}},
{lcs{diag{0, 20, 1}, diag{0, 0, 3}, diag{1, 20, 4}}, lcs{diag{0, 0, 3}, diag{3, 22, 2}}},
{lcs{diag{0, 0, 4}, diag{1, 1, 2}}, lcs{diag{0, 0, 4}}},
{lcs{diag{0, 0, 4}}, lcs{diag{0, 0, 4}}},
{lcs{}, lcs{}},
{lcs{diag{0, 0, 4}, diag{1, 1, 6}, diag{3, 3, 2}}, lcs{diag{0, 0, 1}, diag{1, 1, 6}}},
}
for n, x := range tests {
got := x.before.fix()
if len(got) != len(x.after) {
t.Errorf("got %v, expected %v, for %v", got, x.after, x.before)
}
olen := lcslen(x.after)
glen := lcslen(got)
if olen != glen {
t.Errorf("%d: lens(%d,%d) differ, %v, %v, %v", n, glen, olen, got, x.after, x.before)
}
}
}