From 43a123c1ae6613b3efeed291fa552ecd909d3acf Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Tue, 16 Apr 2024 21:23:18 +0200 Subject: Adding upstream version 1.20.14. Signed-off-by: Daniel Baumann --- src/strings/compare_test.go | 119 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 src/strings/compare_test.go (limited to 'src/strings/compare_test.go') diff --git a/src/strings/compare_test.go b/src/strings/compare_test.go new file mode 100644 index 0000000..a435784 --- /dev/null +++ b/src/strings/compare_test.go @@ -0,0 +1,119 @@ +// 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" + "unsafe" +) + +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) { + // unsafeString converts a []byte to a string with no allocation. + // The caller must not modify b while the result string is in use. + unsafeString := func(b []byte) string { + return unsafe.String(unsafe.SliceData(b), len(b)) + } + + 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 := unsafeString(a), unsafeString(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(unsafeString(a[:len]), unsafeString(b[:len])) + if cmp != 1 { + t.Errorf(`CompareAbigger(%d,%d) = %d`, len, k, cmp) + } + b[k] = a[k] + 1 + cmp = Compare(unsafeString(a[:len]), unsafeString(b[:len])) + if cmp != -1 { + t.Errorf(`CompareBbigger(%d,%d) = %d`, len, k, cmp) + } + b[k] = a[k] + } + lastLen = len + } +} -- cgit v1.2.3