Perl build, unit testing, code coverage: A complete working example

Question

Most Stackoverflow answers that I have found in regards to the Perl build process and unit testing and code coverage simply point me to CPAN for the documentation there. There's absolutely nothing wrong with pointing to CPAN modules because that's where the full documentation is supposed to reside. I've had trouble finding complete working code examples in many cases, though.

I've been searching all over the Internet for actual working code samples that I can download or paste into my IDE, like your typical tutorial "Hello World" example source code, but of an example that demonstrates the build process with unit testing and code coverage analysis. Does anyone have a small example of a complete working project that demonstrates these technologies and processes?

(I do have a small working example and I will answer my own question with it, but there are probably other SO users who have better examples than the ones I came up with.)

Answer 1

In response to Kurt, I would propose this alternative to his BuiltTest.PL script.

use strict;
use warnings;
use Module::Build;

my $build = Module::Build->resume (
  properties => {
    config_dir => '_build',
  },
);

$build->dispatch('build');
$build->dispatch('test');

It reuses the database build by Build.PL (and thus assumes that already ran).

Answer 2

I cover this in Intermediate Perl as well as Mastering Perl. Kurt, however, has given a nice summary.

I combine all of this into a release script using Module::Release though. I type one command and it all happens.

Answer 3

The fantastically helpful module-starter generates an easy-to-use skeleton project which handles module installation, creation of documentation and a good layout for module files to live in, and -- I think -- code coverage support. It's IMO a great start for any Perl module-related endeavour.

Also: using CPAN-related tools like Module::Build -- even for modules which are likely never going to be released publically -- is a very good idea.

Answer 4

(disclosure: I'm the author)

Once you have everything sorted as described above, you could take the next step and use Devel::CoverX::Covered to e.g.

• Given a source file, list the test files that provide coverage to that source file. This can be done on a file, sub routine and row level.
• Given a test file, list the source files and subs covered by that test file.
• Given a source file, report efficiently on the coverage details per row, or sub.

See the synopsis for concrete command line examples.

In Devel::PerlySense there's Emacs support to display the coverage information in the source code buffer (screen shot), and to navigate to/from covering test files.