tailscale/util/truncate/truncate_test.go
M. J. Fromberger a75360ccd6
util: add truncate package (#7490)
This package handles cases where we need to truncate human-readable text to fit
a length constraint without leaving "ragged" multi-byte rune fragments at the
end of the truncated value.

Change-Id: Id972135d1880485f41b1fedfb65c2b8cc012d416
Signed-off-by: M. J. Fromberger <fromberger@tailscale.com>
2023-03-07 11:51:36 -08:00

37 lines
1000 B
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package truncate_test
import (
"testing"
"tailscale.com/util/truncate"
)
func TestString(t *testing.T) {
tests := []struct {
input string
size int
want string
}{
{"", 1000, ""}, // n > length
{"abc", 4, "abc"}, // n > length
{"abc", 3, "abc"}, // n == length
{"abcdefg", 4, "abcd"}, // n < length, safe
{"abcdefg", 0, ""}, // n < length, safe
{"abc\U0001fc2d", 3, "abc"}, // n < length, at boundary
{"abc\U0001fc2d", 4, "abc"}, // n < length, mid-rune
{"abc\U0001fc2d", 5, "abc"}, // n < length, mid-rune
{"abc\U0001fc2d", 6, "abc"}, // n < length, mid-rune
{"abc\U0001fc2defg", 7, "abc"}, // n < length, cut multibyte
}
for _, tc := range tests {
got := truncate.String(tc.input, tc.size)
if got != tc.want {
t.Errorf("truncate(%q, %d): got %q, want %q", tc.input, tc.size, got, tc.want)
}
}
}