NAME

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

SYNOPSIS

  use Some::Class;
  use Test::MockObject::Extends;
  my $object      = Some::Class->new();
  my $mock_object = Test::MockObject::Extends->new( $object );
  $mock_object->set_true( 'parent_method' );

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.

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.

mock( $methodname, $sub_ref )
See the documentation for Test::MockObject for all of the ways to mock methods and to retrieve method logging information.
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.
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:

* 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_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.

BUGS

No known bugs.

COPYRIGHT

Copyright (c) 2004 - 2005, chromatic. All rights reserved. You may use, modify, and distribute this module under the same terms as Perl 5.8.x.