Mojo::UserAgent post-request processing to add meta charset

mojo-ua-post-process.pl

#!/Users/brian/bin/perls/perl5.22.0
use v5.20;

use feature qw(signatures);
no warnings qw(experimental::signatures);

use Data::Dumper;
use Mojo::UserAgent;

my $ua = Mojo::UserAgent->new;

my $tx = $ua->build_tx( GET => 'http://blogs.perl.org' );

$tx->res->on(
	finish => \&process_meta_options
	);

$tx = $ua->start( $tx );
say "At end, charset is ", $tx->res->content->charset;

sub process_meta_options ( $res ) {
	$res
		->dom
		->find( 'head meta[charset]' )  # HTML 5
		->map( sub {
			my $content_type = $res->headers->header( 'Content-type' );
			return unless my $meta_charset = $_->{charset};
			$content_type =! s/;.*//;
			$res->headers->header( 'Content-type', "$content_type; charset=$_->{charset}" );
			} );
	}