HACKING.pod(3) contributing to TAP::Harness


This is the guide for TAP::Harness internals contributors (developers, testers, documenters.)

If you are looking for more information on how to use TAP::Harness, you probably want <http://testanything.org/testing-with-tap/perl/tap::parser-cookbook.html> instead.

Getting Started

See the resources section in META.yml or Build.PL for links to the project mailing list, bug tracker, svn repository, etc.

For ease of reference, at the time of writing the SVN repository was at:


To get the latest version of trunk:

  git clone git://github.com/Perl-Toolchain-Gang/Test-Harness.git

For best results, read the rest of this file, check RT for bugs which scratch your itch, join the mailing list, etc.



The project comes with a ".perltidyrc", which perltidy will automatically use if the project root is your working directory. This is setup by default to read and write the perl code on a pipe. To configure your editor:
  • vim

    In ".vimrc", you can add the following lines:

     nnoremap <Leader>pt :%!perltidy -q<cr> " only work in 'normal' mode
     vnoremap <Leader>pt :!perltidy -q<cr>  " only work in 'visual' mode

    In other words, if your "Leader" is a backslash, you can type "\pt" to reformat the file using the ".perltidyrc". If you are in visual mode (selecting lines with shift-v), then only the code you have currently have selected will be reformatted.

  • emacs

    For emacs, you can use this snippet from Sam Tregar (<http://use.perl.org/~samtregar/journal/30185>):

     (defun perltidy-region ()
        "Run perltidy on the current region."
          (shell-command-on-region (point) (mark) "perltidy -q" nil t)
     (defun perltidy-all ()
        "Run perltidy on the current region."
        (let ((p (point)))
            (shell-command-on-region (point-min) (point-max) "perltidy -q" nil t)
          (goto-char p)
     (global-set-key "\M-t" `perltidy-region)
     (global-set-key "\M-T" `perltidy-all)

Tests and Coverage


Writing for Compatibility


Use TAP::Object

TAP::Object is the common base class to all TAP::* modules, and should be for any that you write.

Exception Handling

Exceptions should be raised with Carp:

  require Carp;
  Carp::croak("Unsupported syntax version: $version");
  require Carp;
  Carp::confess("Unsupported syntax version: $version");

Deprecation cycle

Any documented sub that needs to be changed or removed (and would therefore cause a backwards-compat issue) must go through a deprecation cycle to give developers a chance to adjust:

  1. Document the deprecation
  2. Carp a suitable message
  3. Release
  4. Change the code
  5. Release


The end-user and API documentation is all in the 'lib/' directory. In .pm files, the pod is ``inline'' to the code. See perlpod for more about pod.

Pod Commands

For compatibility's sake, we do not use the =head3 and =head4 commands.
"=head1 SECTION"
Sections begin with an "=head1" command and are all-caps.

"=head2 method"
The "=head2" command documents a method. The name of the method should have no adornment (e.g. don't C<method> or C<method($list, $of, $params)>.)

These sections should begin with a short description of what the method does, followed by one or more examples of usage. If needed, elaborate on the subtleties of the parameters and context after (and/or between) the example(s).

  =head2 this_method
  This method does some blah blah blah.
    my @answer = $thing->this_method(@arguments);
  =head2 that_thing
  Returns true if the thing is true.
    if($thing->that_thing) {
"=item parameter"
Use "=item" commands for method arguments and parameters (and etc.) In most html pod formatters, these do not get added to the table-of-contents at the top of the page.

Pod Formatting Codes

Be careful of the wording of "L<Some::Module>". Older pod formatters would render this as ``the Some::Module manpage'', so it is best to either word your links as ""(see <Some::Module> for details.)"`` or use the ''explicit rendering`` form of ''"<Some::Module|Some::Module>"".


The version numbers are updated by Perl::Version.


The following ``formats'' are used with "=begin"/"=end" and "=for" commands for pod which is not part of the public end-user/API documentation.
Use this if you are uncertain about a change to some pod or think it needs work.

  =head2 some_method
  =for note
    This is either falsely documented or a bug -- see ...
  =begin developer
  Long-winded explanation of why some code is the way it is or various
  other subtleties which might incite head-scratching and WTF'ing.
  =end developer
  =for deprecated
    removed in 0.09, kill by ~0.25

Committing to Subversion

If you have commit access, please bear this in mind.

Development is done either on trunk or a branch, as appropriate:

If it's something that might be controversial, break the build or take a long time (more than a couple of weeks) to complete then it'd probably be appropriate to branch. Otherwise it can go in trunk.

If in doubt discuss it on the mailing list before you commit.