[Module-build-general] idea: ./Build cover, for test coverage testing

[Mark S. <ma...@su...>]

You may be aware of Devel::Cover, a new module that with quality
assurance by reporting on how thoroughly a test suite is covering the
code in a Perl module.

However, I noticed that when I used the suggested syntax with a module
that used Module::Build, it generated an empty report. I tried this with
Data::FormValidator using the recommended syntax:

 HARNESS_PERL_SWITCHES=-MDevel::Cover make test
 cover -report html

I found this code from Richard Clamp on the web which allowed me to 
use Devel::Cover with module build. It adds a new 'cover' target the Build
script:

        sub ACTION_cover {
            my $self = shift;
            $self->depends_on('build');

            system qw( cover -delete );

            # sometimes we get failing tests, which makes Test::Harness
            # die.  catch that
            eval {
                local $ENV{PERL5OPT} = "-MDevel::Cover=-summary,0";
                $self->ACTION_test(@_);
            };
            system qw( cover -report html );
        }

####

This seems me like something that could eventually be suitable for the
core Module::Build. In the meantime, enjoy using the above code
to test your own module's test coverage.

Here are some real reports I generated with it:

Data::FormValidator
http://mark.stosberg.com/dfv/cover_db/cover_db.html

DBD::Pg
http://mark.stosberg.com/Tech/perl/dbd_pg/cover_db/cover_db.html

	Mark

--
http://mark.stosberg.com/