| // Copyright 2013 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 |
| |
| // Derived from bytes/compare_test.go. |
| // Benchmarks omitted since the underlying implementation is identical. |
| |
| import ( |
| "internal/testenv" |
| . "strings" |
| "testing" |
| ) |
| |
| var compareTests = []struct { |
| a, b string |
| i int |
| }{ |
| {"", "", 0}, |
| {"a", "", 1}, |
| {"", "a", -1}, |
| {"abc", "abc", 0}, |
| {"ab", "abc", -1}, |
| {"abc", "ab", 1}, |
| {"x", "ab", 1}, |
| {"ab", "x", -1}, |
| {"x", "a", 1}, |
| {"b", "x", -1}, |
| // test runtime·memeq's chunked implementation |
| {"abcdefgh", "abcdefgh", 0}, |
| {"abcdefghi", "abcdefghi", 0}, |
| {"abcdefghi", "abcdefghj", -1}, |
| } |
| |
| func TestCompare(t *testing.T) { |
| for _, tt := range compareTests { |
| cmp := Compare(tt.a, tt.b) |
| if cmp != tt.i { |
| t.Errorf(`Compare(%q, %q) = %v`, tt.a, tt.b, cmp) |
| } |
| } |
| } |
| |
| func TestCompareIdenticalString(t *testing.T) { |
| var s = "Hello Gophers!" |
| if Compare(s, s) != 0 { |
| t.Error("s != s") |
| } |
| if Compare(s, s[:1]) != 1 { |
| t.Error("s > s[:1] failed") |
| } |
| } |
| |
| func TestCompareStrings(t *testing.T) { |
| lengths := make([]int, 0) // lengths to test in ascending order |
| for i := 0; i <= 128; i++ { |
| lengths = append(lengths, i) |
| } |
| lengths = append(lengths, 256, 512, 1024, 1333, 4095, 4096, 4097) |
| |
| if !testing.Short() || testenv.Builder() != "" { |
| lengths = append(lengths, 65535, 65536, 65537, 99999) |
| } |
| |
| n := lengths[len(lengths)-1] |
| a := make([]byte, n+1) |
| b := make([]byte, n+1) |
| lastLen := 0 |
| for _, len := range lengths { |
| // randomish but deterministic data. No 0 or 255. |
| for i := 0; i < len; i++ { |
| a[i] = byte(1 + 31*i%254) |
| b[i] = byte(1 + 31*i%254) |
| } |
| // data past the end is different |
| for i := len; i <= n; i++ { |
| a[i] = 8 |
| b[i] = 9 |
| } |
| |
| sa, sb := string(a), string(b) |
| cmp := Compare(sa[:len], sb[:len]) |
| if cmp != 0 { |
| t.Errorf(`CompareIdentical(%d) = %d`, len, cmp) |
| } |
| if len > 0 { |
| cmp = Compare(sa[:len-1], sb[:len]) |
| if cmp != -1 { |
| t.Errorf(`CompareAshorter(%d) = %d`, len, cmp) |
| } |
| cmp = Compare(sa[:len], sb[:len-1]) |
| if cmp != 1 { |
| t.Errorf(`CompareBshorter(%d) = %d`, len, cmp) |
| } |
| } |
| for k := lastLen; k < len; k++ { |
| b[k] = a[k] - 1 |
| cmp = Compare(string(a[:len]), string(b[:len])) |
| if cmp != 1 { |
| t.Errorf(`CompareAbigger(%d,%d) = %d`, len, k, cmp) |
| } |
| b[k] = a[k] + 1 |
| cmp = Compare(string(a[:len]), string(b[:len])) |
| if cmp != -1 { |
| t.Errorf(`CompareBbigger(%d,%d) = %d`, len, k, cmp) |
| } |
| b[k] = a[k] |
| } |
| lastLen = len |
| } |
| } |