Test2::Manual::Tooling::Formatter(3perl)      Perl Programmers Reference Guide


NAME
       Test2::Manual::Tooling::Formatter - How to write a custom formatter, in
       our case a JSONL formatter.

DESCRIPTION
       This tutorial explains a minimal formatter that outputs each event as a
       json string on its own line. A true formatter will probably be
       significantly more complicated, but this will give you the basics
       needed to get started.

COMPLETE CODE UP FRONT
           package Test2::Formatter::MyFormatter;
           use strict;
           use warnings;

           use JSON::MaybeXS qw/encode_json/;

           use base qw/Test2::Formatter/;

           sub new { bless {}, shift }

           sub encoding {};

           sub write {
               my ($self, $e, $num, $f) = @_;
               $f ||= $e->facet_data;

               print encode_json($f), "\n";
           }

           1;

LINE BY LINE
       use base qw/Test2::Formatter/;
           All formatters should inherit from Test2::Formatter.

       sub new { bless {}, shift }
           Formatters need to be instantiable objects, this is a minimal new()
           method.

       sub encoding {};
           For this example we leave this sub empty. In general you should
           implement this sub to make sure you honor situations where the
           encoding is set. Test2::V0 itself will try to set the encoding to
           UTF8.

       sub write { ... }
           The write() method is the most important, each event is sent here.

       my ($self, $e, $num, $f) = @_;
           The write() method receives 3 or 4 arguments, the fourth is
           optional.

           $self
               The formatter itself.

           $e  The event being written

           $num
               The most recent assertion number. If the event being processed
               is an assertion then this will have been bumped by 1 since the
               last call to write. For non assertions this number is set to
               the most recent assertion.

           $f  This MAY be a hashref containing all the facet data from the
               event. More often then not this will be undefined. This is only
               set if the facet data was needed by the hub, and it usually is
               not.

       $f ||= $e->facet_data;
           We want to dump the event facet data. This will set $f to the facet
           data unless we already have the facet data.

       print encode_json($f), "\n";
           This line prints the JSON encoded facet data, and a newline.

SEE ALSO
       Test2::Manual - Primary index of the manual.

SOURCE
       The source code repository for Test2-Manual can be found at
       https://github.com/Test-More/Test2-Suite/.

MAINTAINERS
       Chad Granum <exodist@cpan.org>

AUTHORS
       Chad Granum <exodist@cpan.org>

COPYRIGHT
       Copyright 2018 Chad Granum <exodist@cpan.org>.

       This program is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.

       See http://dev.perl.org/licenses/

perl v5.40.0                      2024-09-01
                                      Test2::Manual::Tooling::Formatter(3perl)