test based on RT bug # 20879

diff --git a/t/006_complex_merge.t b/t/006_complex_merge.t
new file mode 100644 (file)
index 0000000..2fa233f
--- /dev/null
+++ b/t/006_complex_merge.t
@@ -0,0 +1,151 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use Test::More tests => 12;
+
+BEGIN {
+    use_ok('Algorithm::C3');
+}
+
+=pod
+
+This example is taken from: http://rt.cpan.org/Public/Bug/Display.html?id=20879
+
+               ---     ---     ---
+Level 5     8 | A | 9 | B | A | C |    (More General)
+               ---     ---     ---       V
+                  \     |     /          |
+                   \    |    /           |
+                    \   |   /            |
+                     \  |  /             |
+                       ---               |
+Level 4             7 | D |              |
+                       ---               |
+                      /   \              |
+                     /     \             |
+                  ---       ---          |
+Level 3        4 | G |   6 | E |         |
+                  ---       ---          |
+                   |         |           |
+                   |         |           |
+                  ---       ---          |
+Level 2        3 | H |   5 | F |         |
+                  ---       ---          |
+                      \   /  |           |
+                       \ /   |           |
+                        \    |           |
+                       / \   |           |
+                      /   \  |           |
+                  ---       ---          |
+Level 1        1 | J |   2 | I |         |
+                  ---       ---          |
+                    \       /            |
+                     \     /             |
+                       ---               v
+Level 0             0 | K |            (More Specialized)
+                       ---
+
+
+0123456789A
+KJIHGFEDABC
+
+=cut
+
+{
+    package Test::A;
+    sub x { 1 }
+
+    package Test::B;
+    sub x { 1 }
+
+    package Test::C;
+    sub x { 1 }
+
+    package Test::D;
+    use base qw/Test::A Test::B Test::C/;
+
+    package Test::E;
+    use base qw/Test::D/;
+
+    package Test::F;
+    use base qw/Test::E/;
+
+    package Test::G;
+    use base qw/Test::D/;
+
+    package Test::H;
+    use base qw/Test::G/;
+
+    package Test::I;
+    use base qw/Test::H Test::F/;
+
+    package Test::J;
+    use base qw/Test::F/;
+
+    package Test::K;
+    use base qw/Test::J Test::I/;
+}
+
+use Class::C3;
+
+sub supers {
+    no strict 'refs';
+    @{$_[0] . '::ISA'};
+}
+
+is_deeply(
+    [ Algorithm::C3::merge('Test::A', \&supers) ],
+    [ qw(Test::A) ],
+    '... got the right C3 merge order for Test::A');
+
+is_deeply(
+    [ Algorithm::C3::merge('Test::B', \&supers) ],
+    [ qw(Test::B) ],
+    '... got the right C3 merge order for Test::B');
+
+is_deeply(
+    [ Algorithm::C3::merge('Test::C', \&supers) ],
+    [ qw(Test::C) ],
+    '... got the right C3 merge order for Test::C');
+
+is_deeply(
+    [ Algorithm::C3::merge('Test::D', \&supers) ],
+    [ qw(Test::D Test::A Test::B Test::C) ],
+    '... got the right C3 merge order for Test::D');
+
+is_deeply(
+    [ Algorithm::C3::merge('Test::E', \&supers) ],
+    [ qw(Test::E Test::D Test::A Test::B Test::C) ],
+    '... got the right C3 merge order for Test::E');
+
+is_deeply(
+    [ Algorithm::C3::merge('Test::F', \&supers) ],
+    [ qw(Test::F Test::E Test::D Test::A Test::B Test::C) ],
+    '... got the right C3 merge order for Test::F');
+
+is_deeply(
+    [ Algorithm::C3::merge('Test::G', \&supers) ],
+    [ qw(Test::G Test::D Test::A Test::B Test::C) ],
+    '... got the right C3 merge order for Test::G');
+
+is_deeply(
+    [ Algorithm::C3::merge('Test::H', \&supers) ],
+    [ qw(Test::H Test::G Test::D Test::A Test::B Test::C) ],
+    '... got the right C3 merge order for Test::H');
+
+is_deeply(
+    [ Algorithm::C3::merge('Test::I', \&supers) ],
+    [ qw(Test::I Test::H Test::G Test::F Test::E Test::D Test::A Test::B Test::C) ],
+    '... got the right C3 merge order for Test::I');
+
+is_deeply(
+    [ Algorithm::C3::merge('Test::J', \&supers) ],
+    [ qw(Test::J Test::F Test::E Test::D Test::A Test::B Test::C) ],
+    '... got the right C3 merge order for Test::J');
+
+is_deeply(
+    [ Algorithm::C3::merge('Test::K', \&supers) ],
+    [ qw(Test::K Test::J Test::I Test::H Test::G Test::F Test::E Test::D Test::A Test::B Test::C) ],
+    '... got the right C3 merge order for Test::K');