add filter for Subject: tags

Some mailing lists add annoying tags into the Subject line which
discourages readers from doing proper mail organization on the
client side.  They also waste precious screen space and
attention span.

Remove them from our archives to reduce clutter.

1 files changed, 27 insertions, 0 deletions

diff --git a/t/filter_subjecttag.t b/t/filter_subjecttag.t
new file mode 100644
index 00000000..54a219e7
--- /dev/null
+++ b/t/filter_subjecttag.t
@@ -0,0 +1,27 @@
+# Copyright (C) 2017 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+use strict;
+use warnings;
+use Test::More;
+use Email::MIME;
+use_ok 'PublicInbox::Filter::SubjectTag';
+
+my $f = eval { PublicInbox::Filter::SubjectTag->new };
+like($@, qr/tag not defined/, 'error without args');
+$f = PublicInbox::Filter::SubjectTag->new('-tag', '[foo]');
+is(ref $f, 'PublicInbox::Filter::SubjectTag', 'new object created');
+
+my $mime = Email::MIME->new(<<EOF);
+To: you <you\@example.com>
+Subject: =?UTF-8?B?UmU6IFtmb29dIEVsw4PCqWFub3I=?=
+
+EOF
+
+$mime = $f->delivery($mime);
+is($mime->header('Subject'), "Re: El\xc3\xa9anor", 'filtered with Re:');
+
+$mime->header_str_set('Subject', '[FOO] bar');
+$mime = $f->delivery($mime);
+is($mime->header('Subject'), 'bar', 'filtered non-reply');
+
+done_testing();