1 // Copyright 2013 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
7 // Derived from bytes/compare_test.go.
8 // Benchmarks omitted since the underlying implementation is identical.
17 var compareTests
= []struct {
31 // test runtime·memeq's chunked implementation
32 {"abcdefgh", "abcdefgh", 0},
33 {"abcdefghi", "abcdefghi", 0},
34 {"abcdefghi", "abcdefghj", -1},
37 func TestCompare(t
*testing
.T
) {
38 for _
, tt
:= range compareTests
{
39 cmp
:= Compare(tt
.a
, tt
.b
)
41 t
.Errorf(`Compare(%q, %q) = %v`, tt
.a
, tt
.b
, cmp
)
46 func TestCompareIdenticalString(t
*testing
.T
) {
47 var s
= "Hello Gophers!"
48 if Compare(s
, s
) != 0 {
51 if Compare(s
, s
[:1]) != 1 {
52 t
.Error("s > s[:1] failed")
56 func TestCompareStrings(t
*testing
.T
) {
57 // unsafeString converts a []byte to a string with no allocation.
58 // The caller must not modify b while the result string is in use.
59 unsafeString
:= func(b
[]byte) string {
60 return *(*string)(unsafe
.Pointer(&b
))
63 lengths
:= make([]int, 0) // lengths to test in ascending order
64 for i
:= 0; i
<= 128; i
++ {
65 lengths
= append(lengths
, i
)
67 lengths
= append(lengths
, 256, 512, 1024, 1333, 4095, 4096, 4097)
69 if !testing
.Short() || testenv
.Builder() != "" {
70 lengths
= append(lengths
, 65535, 65536, 65537, 99999)
73 n
:= lengths
[len(lengths
)-1]
74 a
:= make([]byte, n
+1)
75 b
:= make([]byte, n
+1)
77 for _
, len := range lengths
{
78 // randomish but deterministic data. No 0 or 255.
79 for i
:= 0; i
< len; i
++ {
80 a
[i
] = byte(1 + 31*i%254
)
81 b
[i
] = byte(1 + 31*i%254
)
83 // data past the end is different
84 for i
:= len; i
<= n
; i
++ {
89 sa
, sb
:= unsafeString(a
), unsafeString(b
)
90 cmp
:= Compare(sa
[:len], sb
[:len])
92 t
.Errorf(`CompareIdentical(%d) = %d`, len, cmp
)
95 cmp
= Compare(sa
[:len-1], sb
[:len])
97 t
.Errorf(`CompareAshorter(%d) = %d`, len, cmp
)
99 cmp
= Compare(sa
[:len], sb
[:len-1])
101 t
.Errorf(`CompareBshorter(%d) = %d`, len, cmp
)
104 for k
:= lastLen
; k
< len; k
++ {
106 cmp
= Compare(unsafeString(a
[:len]), unsafeString(b
[:len]))
108 t
.Errorf(`CompareAbigger(%d,%d) = %d`, len, k
, cmp
)
111 cmp
= Compare(unsafeString(a
[:len]), unsafeString(b
[:len]))
113 t
.Errorf(`CompareBbigger(%d,%d) = %d`, len, k
, cmp
)