SYNOPSIS # see EXAMPLES for a full use case and caveats use Mock::Sub; my $foo = Mock::Sub->mock('Package::foo'); my $bar = Mock::Sub->mock('Package::bar'); my $baz = Mock::Sub->mock('Package::baz'); # wait until the mocked sub is called Package::foo(); # then... $foo->name; # name of sub that's mocked $foo->called; # was the sub called? $foo->call_count; # how many times was it called? # create a mock object to reduce typing when multiple subs # are mocked my $mock = Mock::Sub->new; my $foo = $mock->('Package::foo'); my $bar = $mock->('Package::bar'); # have the mocked sub return something when it's called $foo = $mock->('Package::foo', return_value => 'True'); # have the mocked sub perform an action $foo = $mock->('Package::foo', side_effect => sub { die "eval catch"; }); # reset the mocked sub for re-use within the same scope $foo->reset; DESCRIPTION Easy to use and very lightweight module for mocking out sub calls. Very useful for testing areas of your own modules where getting coverage may be difficult due to nothing to test against, and/or to reduce test run time by eliminating the need to call subs that you really don't want or need to test. EXAMPLE Here's a full example to get further coverage where it's difficult if not impossible to test certain areas of your code (eg: you have if/else statements, but they don't do anything but call other subs. You don't want to test the subs that are called, nor do you want to add statements to your code). Note that if the end subroutine you're testing is NOT Object Oriented (and you're importing them into your module that you're testing), you have to mock them as part of your own namespace (ie. instead of Other::first, you'd mock MyModule::first). # module you're testing: package MyPackage; use Other; use Exporter qw(import); @EXPORT_OK = qw(test); my $other = Other->new; sub test { my $arg = shift; if ($arg == 1){ # how do you test this... there's no return etc. $other->first(); } if ($arg == 2){ $other->second(); } } # your test file use MyPackage qw(test); use Mock::Sub; use Test::More tests => 2; my $mock = Mock::Sub->new; my $first = $mock->mock('Other::first'); my $second = $mock->mock('Other::second'); # coverage for first if() in MyPackage::test test(1); is ($first->called, 1, "1st if() statement covered"); # coverage for second if() test(2); is ($second->called, 1, "2nd if() statement covered"); METHODS `new' Instantiates and returns a new Mock::Sub object. `mock('sub', %opts)' Instantiates a new object on each call. 'sub' is the name of the subroutine to mock (requires full package name if the sub isn't in `main::'). Options: return_value: Set this to have the mocked sub return anything you wish. side_effect: Send in a code reference containing an action you'd like the mocked sub to perform (`die()' is useful for testing with `eval()'). Note that only one of these parameters may be sent in at a time. `called' Returns true if the sub being mocked has been called. `call_count' Returns the number of times the mocked sub has been called. `name' Returns the full name of the sub being mocked, as entered into `mock()'. `reset' Resets the functional parameters (`return_value', `side_effect'), along with `called()' and `call_count' back to undef/untrue. NOTES I didn't make this a `Test::' module (although it started that way) because I can see more uses than placing it into that category. AUTHOR Steve Bertrand, `<steveb at cpan.org>' BUGS Please report any bugs or requests at https://github.com/stevieb9/mock-sub/issues REPOSITORY https://github.com/stevieb9/mock-sub BUILD RESULTS Travis-CI: https://travis-ci.org/stevieb9/mock-sub CPAN Testers: http://matrix.cpantesters.org/?dist=Mock-Sub SUPPORT You can find documentation for this module with the perldoc command. perldoc Mock::Sub ACKNOWLEDGEMENTS Python's MagicMock module. LICENSE AND COPYRIGHT Copyright 2015 Steve Bertrand. This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License. See http://dev.perl.org/licenses/ for more information.