// A terminal dot doesn't contribute to length:
	ch <- dnsNameTest{longDomain[len(longDomain)-253:] + ".", true}
	// 254 is bad:
	ch <- dnsNameTest{longDomain[len(longDomain)-254:], false}
}

func TestDNSName(t *testing.T) {
	ch := make(chan dnsNameTest)
	go emitDNSNameTest(ch)
	for tc := range ch {
		if isDomainName(tc.name) != tc.result {
			t.Errorf("isDomainName(%q) = %v; want %v", tc.name, !tc.result, tc.result)
		}