NAME

       Test::MockObject::Extends - mock part of an object or class

SYNOPSIS

         use Some::Class;
         use Test::MockObject::Extends;

         # create an object to mock
         my $object      = Some::Class->new();

         # wrap that same object with a mocking wrapper
         $object         = Test::MockObject::Extends->new( $object );

         # now chain mock and control calls
         $object->set_true( 'parent_method' )
                ->set_always( -grandparent_method => 1 )
                ->clear();

DESCRIPTION

       Test::MockObject::Extends lets you mock one or more methods of an existing object or
       class.  This can be very handy when you're testing a well-factored module that does almost
       exactly what you want.  Wouldn't it be handy to take control of a method or two to make
       sure you receive testable results?  Now you can.

METHODS

       "new( $object | $class )"
           "new()" takes one optional argument, the object or class to mock.  If you're mocking a
           method for an object that holds internal state, create an appropriate object, then
           pass it to this constructor.  NOTE: this will modify the object in place.

           If you're mocking an object that does not need state, as in the cases where there's no
           internal data or you'll only be calling class methods, or where you'll be mocking all
           of the access to internal data, you can pass in the name of the class to mock
           partially.

           If you've not yet loaded the class, this method will try to load it for you.  This may
           fail, so beware.

           If you pass no arguments, it will assume you really meant to create a normal
           "Test::MockObject" object and will oblige you.

           Note that if you pass a class, the object returned will appear to be an instance of
           that class; this does not mock the class itself.

       "mock( $methodname, $sub_ref )"
           See the documentation for Test::MockObject for all of the ways to mock methods and to
           retrieve method logging information.  These methods return the invocant, so you can
           chain them.

       "unmock( $methodname )"
           Removes any active mocking of the named method.  This means any calls to that method
           will hit the method of that name in the class being mocked, if it exists.  This method
           returns the invocant, you can chain it.

       "isa( $class )"
           As you'd expect from a mocked object, this will return true for the class it's
           mocking.

INTERNAL METHODS

       To do its magic, this module uses several internal methods:

       •   "check_class_loaded( $parent_class )"

           This verifies that you have the mockee defined.  If not, it attempts to load the
           corresponding module for you.

       •   "gen_autoload( $extended )"

           Returns an AUTOLOAD subroutine for the mock object that checks that the extended
           object (or class) can perform the requested method, that Test::MockObject can perform
           it, or that the parent has an appropriate AUTOLOAD of its own.  (It should have its
           own "can()" in that case too though.)

       •   "gen_can( $extended )"

           Returns a "can()" method for the mock object that respects the same execution order as
           "gen_autoload()".

       •   "gen_isa( $extended )"

           Returns an "isa()" method for the mock object that claims to be the $extended object
           appropriately.

       •   "gen_get_parents( $extended )"

           Returns a "__get_parents()" method for the mock object that claims to be the $extended
           object appropriately.

       •   "gen_package( $extended )"

           Creates a new unique package for the mock object with the appropriate methods already
           installed.

       •   "get_class( $invocant )"

           Returns the class name of the invocant, whether it's an object or a class name.

CAVEATS

       There may be some weird corner cases with dynamically generated methods in the mocked
       class.  You really should use subroutine declarations though, or at least set "can()"
       appropriately.

       There are also potential name collisions with methods in this module or
       "Test::MockObject", though this should be rare.

AUTHOR

       chromatic, <chromatic at wgz dot org>

       Documentation bug fixed by Stevan Little.  Additional AUTOLOAD approach suggested by Adam
       Kennedy.  Other bugs reported by Paul the Nomad and Praveen Ray.  Thank you all!

BUGS

       No known bugs.

COPYRIGHT

       Copyright (c) 2004 - 2011, chromatic.  All rights reserved.  You may use, modify, and
       distribute this module under the same terms as Perl 5.10