NAME¶

Test::Magpie - Mocking framework with method stubs and behaviour verification

SYNOPSIS¶

    use Test::Magpie;
    # create the mock object and stub
    my $baker = mock;
    when($mock)->bake_loaf('white')->then_return($bread);
    # execute the code under test
    my $bakery = Bakery->new( bakers => [ $baker ] );
    my @loaves = $bakery->buy_loaf( amount => 2, type => 'white' );
    # verify the interactions with the mock object
    verify($baker, times => 2)->bake_loaf('white');

DESCRIPTION¶

Test::Magpie is a test double framework heavily inspired by the Mockito framework for Java, and also the Python-Mockito project. In Mockito, you "spy" on objects for their behaviour, rather than being upfront about what should happen. I find this approach to be significantly more flexible and easier to work with than mocking systems like EasyMock, so I created a Perl implementation.

Mock objects

Mock objects, represented by Test::Magpie::Mock objects, are objects that pretend to be everything you could ever want them to be. A mock object can have any method called on it, does every roles, and isa subclass of any superclass. This allows you to easily throw a mock object around it will be treated as though it was a real object.

Method stubbing

Any method can be called on a mock object, and it will be logged as an invocation. By default, method calls return "undef" in scalar context or an empty list in list context. Often, though, clients will be interested in the result of calling a method with some arguments. So you may specify how a method stub should respond when it is called.

Verify interactions

After calling your concrete code (the code under test) you may want to check that the code did operate correctly on the mock. To do this, you can use verifications to make sure code was called, with correct parameters and the correct amount of times.

Argument matching

Magpie gives you some helpful methods to validate arguments passed in to calls. You can check equality between arguments, or consume a general type of argument, or consume multiple arguments. See Test::Magpie::ArgumentMatcher for the juicy details.

FUNCTIONS¶

    $mock = mock;
    $mock->method(@args);

    $mock = mock($class);
    is( ref($mock), $class );

    when($mock)->method(@args)->then_return(1, 2, 3);
    when($mock)->invalid(@args)->then_die('exception');

    verify($mock)->method(@args)
    # prints: ok 1 - method("foo") was called 1 time(s)

    verify($mock, $test_name)->method(@args)
    # prints: ok 1 - record inserted into database'

    verify( $mock, times    => 3,     )->method(@args)
    verify( $mock, at_least => 3      )->method(@args)
    verify( $mock, at_most  => 5      )->method(@args)
    verify( $mock, between  => [3, 5] )->method(@args)

    verify($mock, times => 3, $test_name)->method(@args)

    $invocation = inspect($mock)->method(@args);
    is( $invocation->method_name, 'foo' );
    is_deeply( [$invocation->arguments], [qw( bar baz )] );

    verify($mock, times => at_least($n))->method(@args);

    verify($mock, times => at_most($n))->method(@args);

EXPORTS¶

This module exports the following functions by default:

• mock
• when
• verify

All other functions need to be imported explicitly.

AUTHORS¶

• Oliver Charles <oliver.g.charles@googlemail.com>
• Steven Lee <stevenwh.lee@gmail.com>

COPYRIGHT AND LICENSE¶

This software is copyright (c) 2013 by Oliver Charles.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.