for my $hashref (@testarray) {
    for my $hit ( @{ $hashref->{hits}{hits} } ) {
        print "hit: '$hit->{_id}'\n";
        for my $key ( keys %{ $hit->{_source} } ) {
            my $val = $hit->{_source}{$key};
            print "key: '$key', val: '$val'\n";
        }
    }
}