implement basic autocomplete package

autocomplete/autocomplete_test.go

@@ -0,0 +1,64 @@
+package autocomplete_test
+
+import (
+	"slices"
+	"testing"
+
+	"git.sunturtle.xyz/zephyr/horsebot/autocomplete"
+)
+
+func these(s ...string) []string { return s }
+
+func TestAutocomplete(t *testing.T) {
+	cases := []struct {
+		name   string
+		add    []string
+		search string
+		want   []string
+	}{
+		{
+			name:   "empty",
+			add:    nil,
+			search: "",
+			want:   nil,
+		},
+		{
+			name:   "exact",
+			add:    these("bocchi"),
+			search: "bocchi",
+			want:   these("bocchi"),
+		},
+		{
+			name:   "extra",
+			add:    these("bocchi", "ryo", "nijika", "kita"),
+			search: "bocchi",
+			want:   these("bocchi"),
+		},
+		{
+			name:   "short",
+			add:    these("bocchi", "ryo", "nijika", "kita"),
+			search: "o",
+			want:   these("bocchi", "ryo"),
+		},
+		{
+			name:   "map",
+			add:    these("Corazón ☆ Ardiente"),
+			search: "corazo",
+			want:   these("Corazón ☆ Ardiente"),
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			var set autocomplete.Set
+			for _, s := range c.add {
+				set.Add(s, s)
+			}
+			got := set.Find(nil, c.search)
+			slices.Sort(c.want)
+			slices.Sort(got)
+			if !slices.Equal(c.want, got) {
+				t.Errorf("wrong results: want %q, got %q", c.want, got)
+			}
+		})
+	}
+}