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// Copyright 2010 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 suffixarray
import (
"bytes"
"container/vector"
"regexp"
"sort"
"strings"
"testing"
)
type testCase struct {
name string // name of test case
source string // source to index
patterns []string // patterns to lookup
}
var testCases = []testCase{
{
"empty string",
"",
[]string{
"",
"foo",
"(foo)",
".*",
"a*",
},
},
{
"all a's",
"aaaaaaaaaa", // 10 a's
[]string{
"",
"a",
"aa",
"aaa",
"aaaa",
"aaaaa",
"aaaaaa",
"aaaaaaa",
"aaaaaaaa",
"aaaaaaaaa",
"aaaaaaaaaa",
"aaaaaaaaaaa", // 11 a's
".",
".*",
"a+",
"aa+",
"aaaa[b]?",
"aaa*",
},
},
{
"abc",
"abc",
[]string{
"a",
"b",
"c",
"ab",
"bc",
"abc",
"a.c",
"a(b|c)",
"abc?",
},
},
{
"barbara*3",
"barbarabarbarabarbara",
[]string{
"a",
"bar",
"rab",
"arab",
"barbar",
"bara?bar",
},
},
{
"typing drill",
"Now is the time for all good men to come to the aid of their country.",
[]string{
"Now",
"the time",
"to come the aid",
"is the time for all good men to come to the aid of their",
"to (come|the)?",
},
},
}
// find all occurrences of s in source; report at most n occurences
func find(src, s string, n int) []int {
var res vector.IntVector
if s != "" && n != 0 {
// find at most n occurrences of s in src
for i := -1; n < 0 || len(res) < n; {
j := strings.Index(src[i+1:], s)
if j < 0 {
break
}
i += j + 1
res.Push(i)
}
}
return res
}
func testLookup(t *testing.T, tc *testCase, x *Index, s string, n int) {
res := x.Lookup([]byte(s), n)
exp := find(tc.source, s, n)
// check that the lengths match
if len(res) != len(exp) {
t.Errorf("test %q, lookup %q (n = %d): expected %d results; got %d", tc.name, s, n, len(exp), len(res))
}
// if n >= 0 the number of results is limited --- unless n >= all results,
// we may obtain different positions from the Index and from find (because
// Index may not find the results in the same order as find) => in general
// we cannot simply check that the res and exp lists are equal
// check that each result is in fact a correct match and there are no duplicates
sort.SortInts(res)
for i, r := range res {
if r < 0 || len(tc.source) <= r {
t.Errorf("test %q, lookup %q, result %d (n = %d): index %d out of range [0, %d[", tc.name, s, i, n, r, len(tc.source))
} else if !strings.HasPrefix(tc.source[r:], s) {
t.Errorf("test %q, lookup %q, result %d (n = %d): index %d not a match", tc.name, s, i, n, r)
}
if i > 0 && res[i-1] == r {
t.Errorf("test %q, lookup %q, result %d (n = %d): found duplicate index %d", tc.name, s, i, n, r)
}
}
if n < 0 {
// all results computed - sorted res and exp must be equal
for i, r := range res {
e := exp[i]
if r != e {
t.Errorf("test %q, lookup %q, result %d: expected index %d; got %d", tc.name, s, i, e, r)
}
}
}
}
func testFindAllIndex(t *testing.T, tc *testCase, x *Index, rx *regexp.Regexp, n int) {
res := x.FindAllIndex(rx, n)
exp := rx.FindAllStringIndex(tc.source, n)
// check that the lengths match
if len(res) != len(exp) {
t.Errorf("test %q, FindAllIndex %q (n = %d): expected %d results; got %d", tc.name, rx, n, len(exp), len(res))
}
// if n >= 0 the number of results is limited --- unless n >= all results,
// we may obtain different positions from the Index and from regexp (because
// Index may not find the results in the same order as regexp) => in general
// we cannot simply check that the res and exp lists are equal
// check that each result is in fact a correct match and the result is sorted
for i, r := range res {
if r[0] < 0 || r[0] > r[1] || len(tc.source) < r[1] {
t.Errorf("test %q, FindAllIndex %q, result %d (n == %d): illegal match [%d, %d]", tc.name, rx, i, n, r[0], r[1])
} else if !rx.MatchString(tc.source[r[0]:r[1]]) {
t.Errorf("test %q, FindAllIndex %q, result %d (n = %d): [%d, %d] not a match", tc.name, rx, i, n, r[0], r[1])
}
}
if n < 0 {
// all results computed - sorted res and exp must be equal
for i, r := range res {
e := exp[i]
if r[0] != e[0] || r[1] != e[1] {
t.Errorf("test %q, FindAllIndex %q, result %d: expected match [%d, %d]; got [%d, %d]",
tc.name, rx, i, e[0], e[1], r[0], r[1])
}
}
}
}
func testLookups(t *testing.T, tc *testCase, x *Index, n int) {
for _, pat := range tc.patterns {
testLookup(t, tc, x, pat, n)
if rx, err := regexp.Compile(pat); err == nil {
testFindAllIndex(t, tc, x, rx, n)
}
}
}
// index is used to hide the sort.Interface
type index Index
func (x *index) Len() int { return len(x.sa) }
func (x *index) Less(i, j int) bool { return bytes.Compare(x.at(i), x.at(j)) < 0 }
func (x *index) Swap(i, j int) { x.sa[i], x.sa[j] = x.sa[j], x.sa[i] }
func (a *index) at(i int) []byte { return a.data[a.sa[i]:] }
func testConstruction(t *testing.T, tc *testCase, x *Index) {
if !sort.IsSorted((*index)(x)) {
t.Errorf("testConstruction failed %s", tc.name)
}
}
func TestIndex(t *testing.T) {
for _, tc := range testCases {
x := New([]byte(tc.source))
testConstruction(t, &tc, x)
testLookups(t, &tc, x, 0)
testLookups(t, &tc, x, 1)
testLookups(t, &tc, x, 10)
testLookups(t, &tc, x, 2e9)
testLookups(t, &tc, x, -1)
}
}
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