+my $tmpdir = File::Temp->newdir('pi-inbox-XXXX', TMPDIR => 1);
+$x->{inboxdir} = $tmpdir->dirname;
+is_deeply($x->cloneurl, [], 'no cloneurls');
+is($x->description, '($INBOX_DIR/description missing)', 'default description');
+{
+ open my $fh, '>', "$x->{inboxdir}/cloneurl" or die;
+ print $fh "https://example.com/inbox\n" or die;
+ close $fh or die;
+ open $fh, '>', "$x->{inboxdir}/description" or die;
+ print $fh "\xc4\x80blah\n" or die;
+ close $fh or die;
+}
+is_deeply($x->cloneurl, ['https://example.com/inbox'], 'cloneurls update');
+ok(utf8::valid($x->description), 'description is utf8::valid');
+is($x->description, "\x{100}blah", 'description updated');
+is(unlink(glob("$x->{inboxdir}/*")), 2, 'unlinked cloneurl & description');
+is_deeply($x->cloneurl, ['https://example.com/inbox'], 'cloneurls memoized');
+is($x->description, "\x{100}blah", 'description memoized');
+
+$x->{name} = "2\x{100}wide";
+$x->{newsgroup} = '2.wide';
+like($x->mailboxid, qr/\AM32c48077696465-[0-9a-f]+\z/,
+ '->mailboxid w/o slice (JMAP)');
+like($x->mailboxid(78), qr/\AM322e77696465-4e-[0-9a-f]+\z/,
+ '->mailboxid w/ slice (IMAP)');