| // 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) |
| } |
| } |
| } |