NAME

Devel::StrictMode - determine whether strict (but slow) tests should be enabled

SYNOPSIS

   package MyClass;
   
   use Moose;
   use Devel::StrictMode;
   
   has input_data => (
      is       => 'ro',
      isa      => STRICT ? "HashRef[ArrayRef[Str]]" : "HashRef",
      required => 1,
   );

DESCRIPTION

This module provides you with a constant "STRICT" which you can use to determine whether additional strict (but slow) runtime tests are executed by your code.

"STRICT" is true if any of the following environment variables have been set to true:

   PERL_STRICT
   EXTENDED_TESTING
   AUTHOR_TESTING
   RELEASE_TESTING

"STRICT" is false otherwise.

It is anticipated that you might set one or more of the above variables to true while running your test suite, but leave them all false in your production scenario.

Although not exported by default, a constant "LAX" is also provided, which returns the opposite of "STRICT".

Using STRICT with Moose/Moo/Mouse attributes

Type constraint checks ("isa") are conducted at run time. Slow checks can slow down your constructor and accessors. As shown above, "STRICT" can be used to alternate between a slower by stricter type constraint check, and a faster but looser one.

Don't try this if your attribute coerces. It will subtly break things.

Using STRICT to perform assertions in function and method calls

You may protect blocks of assertions with an "if (STRICT) { ... }" conditional to ensure that they only run in your testing environment.

   sub fibonacci
   {
      my $n = $_[0];
      
      if (STRICT)
      {
         die "expected exactly one argument"
            unless @_ == 1;
         die "expected argument to be a natural number"
            unless $n =~ /\A[0-9]+\z/;
      }
      
      $n < 2 ? $n : fibonacci($n-1)+fibonacci($n-2);
   }

Because "STRICT" is a constant, the Perl compiler will completely optimize away the "if" block when running in your production environment.

Using STRICT with pragmata

Thanks to if it's easy to use "STRICT" to conditionally load pragmata.

   use Devel::StrictMode;

   use strict;
   use warnings STRICT ? qw(FATAL all) : qw(all);
   
   no if STRICT, "bareword::filehandles";
   no if STRICT, "autovivification";

See also autovivification, bareword::filehandles, indirect, multidimensional, etc.

BUGS

Please report any bugs to <http://rt.cpan.org/Dist/Display.html?Queue=Devel-StrictMode>.

AUTHOR

Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

DISCLAIMER OF WARRANTIES

THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.