levenshtein_test.gno

 1package levenshtein
 2
 3import (
 4	"testing"
 5
 6	"gno.land/p/nt/uassert/v0"
 7)
 8
 9func TestDistance(t *testing.T) {
10	cases := []struct {
11		a, b string
12		want int
13	}{
14		{"", "", 0},
15		{"abc", "", 3},
16		{"", "abc", 3},
17		{"abc", "abc", 0},
18		{"kitten", "sitting", 3},
19		{"flaw", "lawn", 2},
20		{"sunday", "saturday", 3},
21		{"gno", "gnoland", 4},
22		{"book", "back", 2},
23		// Rune-aware: each accented char is one edit, not several bytes.
24		{"café", "cafe", 1},
25		{"héllo", "hello", 1},
26	}
27	for _, tc := range cases {
28		got := Distance(tc.a, tc.b)
29		uassert.Equal(t, tc.want, got)
30		// Symmetry: distance is the same in both directions.
31		uassert.Equal(t, tc.want, Distance(tc.b, tc.a))
32	}
33}
34
35func TestSimilarity(t *testing.T) {
36	// Identical strings.
37	uassert.Equal(t, 100, Similarity("hello", "hello"))
38	// Both empty.
39	uassert.Equal(t, 100, Similarity("", ""))
40	// Completely different lengths / content.
41	uassert.Equal(t, 0, Similarity("abc", "xyz"))
42	// kitten/sitting: max len 7, distance 3 -> round((4/7)*100) = 57.
43	uassert.Equal(t, 57, Similarity("kitten", "sitting"))
44}
45
46func TestMatrix(t *testing.T) {
47	d := Matrix("kitten", "sitting")
48	// Dimensions: (6+1) x (7+1).
49	uassert.Equal(t, 7, len(d))
50	uassert.Equal(t, 8, len(d[0]))
51	// First row and column are the identity ramps.
52	for j := 0; j <= 7; j++ {
53		uassert.Equal(t, j, d[0][j])
54	}
55	for i := 0; i <= 6; i++ {
56		uassert.Equal(t, i, d[i][0])
57	}
58	// Bottom-right cell equals Distance.
59	uassert.Equal(t, Distance("kitten", "sitting"), d[6][7])
60}