NAME

Perl::Critic::Policy::Community::Wantarray - Don't write context-sensitive functions using wantarray

DESCRIPTION

Context-sensitive functions, while one way to write functions that DWIM (Do What I Mean), tend to instead lead to unexpected behavior when the function is accidentally used in a different context, especially if the function's behavior changes significantly based on context. This also can lead to vulnerabilities when a function is intended to be used as a scalar, but is used in a list, such as a hash constructor or function parameter list. Instead, functions should be explicitly documented to return either a scalar value or a list, so there is no potential for confusion or vulnerability.

  return wantarray ? ('a','b','c') : 3; # not ok
  return CORE::wantarray ? ('a', 'b', 'c') : 3; # not ok
  return ('a','b','c');                 # ok
  return 3;                             # ok

  sub get_stuff {
    return wantarray ? @things : \@things;
  }
  my $stuff = Stuff->new(stuff => get_stuff()); # oops! function will return a list!

AFFILIATION

This policy is part of Perl::Critic::Community.

CONFIGURATION

This policy is not configurable except for the standard options.

AUTHOR

Dan Book, dbook@cpan.org

COPYRIGHT AND LICENSE

Copyright 2015, Dan Book.

This library is free software; you may redistribute it and/or modify it under the terms of the Artistic License version 2.0.

SEE ALSO

Perl::Critic