Beefy Boxes and Bandwidth Generously Provided by pair Networks
P is for Practical
 
PerlMonks  

[solved] Test question: how to exercise conditional module load?

by radiantmatrix (Parson)
on Jun 17, 2008 at 19:54 UTC ( #692580=perlquestion: print w/ replies, xml ) Need Help??
radiantmatrix has asked for the wisdom of the Perl Monks concerning the following question:

I like to use Devel::Cover to make sure that my test suite adequately covers my code. I've run into a bit of a conundrum on how to test something.

BEGIN { eval { require YAML::Syck; YAML::Syck->import }; #1 if ($@) { require YAML; YAML->import; #2 } }

Yes, I know I could use Best (use Best qw/YAML::Syck YAML/;), but for this project, it's not an option due to bureaucratic considerations.

My problem is that my tests only exercise the statements in #1, and not in #2 -- or vice-versa. I'm looking for a way that my test script can, e.g. temporarily make require YAML::Syck or YAML::Syck->import die so that I can automatically prove the fallback works.

I have tried to search for answers, but can't seem to find a set of search terms that provides any enlightenment. So, I turn to the Monestary: any ideas?

Updates:

<radiant.matrix>
Ramblings and references
“A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort.” Herm Albright
I haven't found a problem yet that can't be solved by a well-placed trebuchet

Comment on [solved] Test question: how to exercise conditional module load?
Select or Download Code
Re: Test question: how to exercise conditional module load?
by Corion (Pope) on Jun 17, 2008 at 19:58 UTC

    You can always fake things in Perl:

    $INC{YAML::Syck} = 1; # fake that YAML::Syck is loaded sub YAML::Syck::import { die }; # but make the ->import call fail require Your::Module; # Now it will try to use YAML

    You can also use my module, Test::Without::Module, but there are other modules as well for testing in the absence of modules.

      Thanks! It didn't work quite perfectly as provided, but it was enough info to get me a working solution:

      { local %INC; delete $INC{YAML.pm}; # make sure YAML isn't loaded $INC{'YAML/Syck.pm'} = 1; # fake loading of YAML::Syck sub YAML::Syck::import { die } require My::Module; ok( $INC{'YAML.pm'}, 'YAML loaded when YAML::Syck not present' ); }

      Thanks again!

      <radiant.matrix>
      Ramblings and references
      “A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort.” Herm Albright
      I haven't found a problem yet that can't be solved by a well-placed trebuchet

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: perlquestion [id://692580]
Approved by Corion
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others drinking their drinks and smoking their pipes about the Monastery: (6)
As of 2014-07-30 05:40 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    My favorite superfluous repetitious redundant duplicative phrase is:









    Results (229 votes), past polls