Package Info

perl-Devel-Hide


Forces the unavailability of specified Perl modules (for testing)


Unspecified

Given a list of Perl modules/filenames, this module makes 'require' and 'use' statements fail (no matter the specified files/modules are installed or not).

They die with a message like:

Can't locate Module/ToHide.pm in @INC (hidden)

The original intent of this module is to allow Perl developers to test for alternative behavior when some modules are not available. In a Perl installation, where many modules are already installed, there is a chance to screw things up because you take for granted things that may not be there in other machines.

For example, to test if your distribution does the right thing when a module is missing, you can do

perl -MDevel::Hide=Test::Pod Makefile.PL

forcing 'Test::Pod' to not be found (whether it is installed or not).

Another use case is to force a module which can choose between two requisites to use the one which is not the default. For example, 'XML::Simple' needs a parser module and may use 'XML::Parser' or 'XML::SAX' (preferring the latter). If you have both of them installed, it will always try 'XML::SAX'. But you can say:

perl -MDevel::Hide=XML::SAX script_which_uses_xml_simple.pl

NOTE. This module does not use Carp. As said before, denial dies.

This module is pretty trivial. It uses a code reference in @INC to get rid of specific modules during require - denying they can be successfully loaded and stopping the search before they have a chance to be found.

There are three alternative ways to include modules in the hidden list:

  • import()

this is probably the most commonly used method, called automagically when you do this:

use Devel::Hide qw(Foo Bar::Baz);

or

perl -MDevel::Hide=...

  • setting @Devel::Hide::HIDDEN

  • environment variable DEVEL_HIDE_PM

both of these two only support 'global' hiding, whereas 'import()' supports lexical hiding as well.

Optionally, you can provide some arguments before the list of modules:

  • -from:children

propagate the list of hidden modules to your process' child processes. This works by populating 'PERL5OPT', and is incompatible with Taint mode, as explained in perlrun. Of course, this is unnecessary if your child processes are just forks of the current one.

  • -lexically

This is only available on perl 5.10.0 and later. It is a fatal error to try to use it on an older perl.

Everything following this will only have effect until the end of the current scope. Yes, that includes '-quiet'.

  • -quiet

suppresses diagnostic output. You will still get told about errors. This is passed to child processes if -from:children is in effect.


License: Artistic-1.0 OR GPL-1.0-or-later
URL: https://metacpan.org/release/Devel-Hide

Categories

Releases

Package Version Update ID Released Package Hub Version Platforms Subpackages
0.0015-bp155.2.10 info GA Release 2023-05-17 15 SP5
  • AArch64
  • ppc64le
  • s390x
  • x86-64
  • perl-Devel-Hide
0.0015-bp154.1.18 info GA Release 2022-05-09 15 SP4
  • AArch64
  • ppc64le
  • s390x
  • x86-64
  • perl-Devel-Hide
0.0009-bp153.1.14 info GA Release 2021-03-06 15 SP3
  • AArch64
  • ppc64le
  • s390x
  • x86-64
  • perl-Devel-Hide
0.0009-bp152.3.13 info GA Release 2020-04-16 15 SP2
  • AArch64
  • ppc64le
  • s390x
  • x86-64
  • perl-Devel-Hide
0.0009-bp151.3.1 info GA Release 2019-07-17 15 SP1
  • AArch64
  • ppc64le
  • s390x
  • x86-64
  • perl-Devel-Hide
0.0009-bp151.2.12 info GA Release 2019-05-18 15 SP1
  • AArch64
  • ppc64le
  • s390x
  • x86-64
  • perl-Devel-Hide
0.0009-bp150.2.4 info GA Release 2018-07-30 15
  • AArch64
  • ppc64le
  • s390x
  • x86-64
  • perl-Devel-Hide