Testing if a Perl script compiles - compile_ok

A co-worker and I were pair programming a test suite the other day, and needed to test if a Perl script compiles - not a library or module but an executeable script, so the typical:

    require_ok()
    use_ok()

functions provided by Test::More don't do exactly what we wanted.

The short story is that we ended up doing something like this:

  eval {
     $output = `perl -c $script 2>&1`;
     chomp $output;
  };
  is($output, "$script syntax OK", "$script compiles");

We later looked for a more general, better solution, and a colleague posted on the perl-qa mailing list, but the bottom line is that a more elegant solution still involves executing a new perl interpreter, but in a platform-independent way (perhaps using IPC::Open3 or something.) It's also likely that a better test is to ignore the output altogether and just check the return code from the compile process (the call to perl -c.)

March 18, 2006 update: Jeff Thalhammer found that a colleague Pierre Denis provides a syntax_ok method in Test::Strict that does what we want.
More update - I was prodded by Randall Schwartz to post why you should be careful when "only" compiling Perl code - see BEGIN Blocks Considered Harmful.

Tags: perl, testing