+$exp = 'https://example.net/foo@example.net';
+PublicInbox::Hval::obfuscate_addrs($ibx, my $res = $exp);
+is($res, $exp, 'does not obfuscate URL with Message-ID');
+
+is(PublicInbox::Hval::to_filename('foo bar '), 'foo-bar',
+ 'to_filename has no trailing -');
+
+is(PublicInbox::Hval::to_filename("foo bar\nanother line\n"), 'foo-bar',
+ 'to_filename has no repeated -, and nothing past LF');
+
+is(PublicInbox::Hval::to_filename("foo....bar"), 'foo.bar',
+ 'to_filename squeezes -');
+
+is(PublicInbox::Hval::to_filename(''), undef, 'empty string returns undef');
+
+my $s = "\0\x07\n";
+PublicInbox::Hval::src_escape($s);
+is($s, "\\0\\a\n", 'src_escape works as intended');
+
+foreach my $s ('Hello/World.pm', 'Zcat', 'hello world.c', 'Eléanor', '$at') {
+ my $attr = to_attr($s);
+ is(from_attr($attr), $s, "$s => $attr => $s round trips");
+}
+
+{
+ my $bad = to_attr('foo//bar');
+ ok(!$bad, 'double-slash rejected');
+}
+