Re: Looking for help for unit tests and code coverage on an existing perl script (modulino References)

[eyepopslikeamosquito]

I would extract a module from your script and unit test the module directly via Test::More and the prove command. I like to keep my script mainlines as short as is practicable, with all the heavy lifting done in (unit-tested) module/s. There are many examples of this general approach on the CPAN; see, for example, the perltidy command, part of the Perl-Tidy distribution and the perlcritic command, part of the Perl-Critic distribution.

As an alternative, and perhaps a bit less work, you could re-structure your script as a "modulino", that is, a script that can masquerade as a module for ease of testing. This approach is described at:

• How a script becomes a module by brian_d_foy
• Effective Perl Programming, 2nd edition: Item 91, "Write programs as modulinos for easy testing"
• Dr Dobbs article by brian_d_foy
• Modulino: both script and module in Perl (perlmaven) by szabgab

... though modulinos are too sneaky/clever for my tastes ("scripts should use modules, not pretend to be modules").

References Added Later

• Modulino-Demo on CPAN by brian_d_foy
• Modulino-Demo code (brian's source code on github)

• Rescue legacy code with modulinos by brian_d_foy (perl.com article 2014)
• A quick pitch about perl modulinos by Fergus McMenemie, London PM 2019 (youtube: 4:38)

PM Nodes:

• Modulinos and CPAN-appropriateness (2007)
• Modulino trick for cgi scripts (2008)
• How do you test end-user scripts? (2010)
• Modulino, perl -d question. (2012)
• modulino and $VERSION (2014)
• modulino and perldoc (2014)
• Using guards for script execution? (2017)

• Re: Perl doesn't give error when module is not found 2 by soonix (2024)

• TDD of non-module code by davies (2012)
• Re: printing output of a perl script to the Email body by davies (2021)
• [Solved] Parameter injection for testing by davies (2022)
• Modulino to report ip address changes by davies (2022)
• Unable to release modulino to CPAN by davies (2022)

• Running modulino inside BEGIN by LanX (2024)

Updated: Many extra references were added long after the original reply was made.

[tizatron]

Good links there. Appreciate it.

In this theme, I went ahead and tried to setup an env similar to the layout described in this link:

StackOverFlow Complete build/unittest/codecoverage

couple of things that I did:

• Created the layout described. Made directories for 'lib' and 't'.
• Copied my script to lib. Flipped the extension to pm. Added a package statement to the script. Also added: __PACKAGE__->main( @ARGV ) unless caller();
• Wrapped the main block of code, what I called the implied main, in sub main{...}

Then I was able to add a stanza to my test file.

my $my_dev_1 = sample::main("my-dev-1");
is($my_dev_1, "---
classes:
  - all
  - dev
", "my dev 1 test");

Not sure how I feel about the sample::main("my-dev-1"). Would appreciate some feedback on that to see if I am calling this correctly.

That said, I was able to generate code cover from this setup.

$ ./Build test
$ ./Build testcover

---------------------------- ------ ------ ------ ------ ------ ------ ------
File                           stmt   bran   cond    sub    pod   time  total
---------------------------- ------ ------ ------ ------ ------ ------ ------
blib/lib/sample.pm             97.4   91.7    n/a  100.0    0.0  100.0   93.2
Total                          97.4   91.7    n/a  100.0    0.0  100.0   93.2
---------------------------- ------ ------ ------ ------ ------ ------ ------

That processes pumps out a cover.html file that kinda aligns more with what I was hoping to see. The changes to the original code are not significant, but they are changes, more than what I was hoping to make, perhaps digging in harder on Test::Output would help.