--- /dev/null
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use Test::More tests => 6;
+
+BEGIN {
+ use lib 'opt', '../opt', '..';
+ use_ok('c3');
+ # uncomment this line, and re-run the
+ # test to see the normal p5 dispatch order
+ #$Class::C3::TURN_OFF_C3 = 1;
+}
+
+=pod
+
+This tests the classic diamond inheritence pattern.
+
+ <A>
+ / \
+<B> <C>
+ \ /
+ <D>
+
+=cut
+
+{
+ package Diamond_A;
+ use c3;
+ sub hello { 'Diamond_A::hello' }
+ sub foo { 'Diamond_A::foo' }
+}
+{
+ package Diamond_B;
+ use base 'Diamond_A';
+ use c3;
+ sub foo { 'Diamond_B::foo => ' . (shift)->next::method() }
+}
+{
+ package Diamond_C;
+ use c3;
+ use base 'Diamond_A';
+
+ sub hello { 'Diamond_C::hello => ' . (shift)->next::method() }
+ sub foo { 'Diamond_C::foo => ' . (shift)->next::method() }
+}
+{
+ package Diamond_D;
+ use base ('Diamond_B', 'Diamond_C');
+ use c3;
+
+ sub foo { 'Diamond_D::foo => ' . (shift)->next::method() }
+}
+
+Class::C3::initialize();
+
+is_deeply(
+ [ Class::C3::calculateMRO('Diamond_D') ],
+ [ qw(Diamond_D Diamond_B Diamond_C Diamond_A) ],
+ '... got the right MRO for Diamond_D');
+
+is(Diamond_D->hello, 'Diamond_C::hello => Diamond_A::hello', '... method resolved itself as expected');
+
+is(Diamond_D->can('hello')->('Diamond_D'),
+ 'Diamond_C::hello => Diamond_A::hello',
+ '... can(method) resolved itself as expected');
+
+is(UNIVERSAL::can("Diamond_D", 'hello')->('Diamond_D'),
+ 'Diamond_C::hello => Diamond_A::hello',
+ '... can(method) resolved itself as expected');
+
+is(Diamond_D->foo,
+ 'Diamond_D::foo => Diamond_B::foo => Diamond_C::foo => Diamond_A::foo',
+ '... method foo resolved itself as expected');