t/mro/basic_02_dfs.t

   1 #!./perl
   2
   3 use strict;
   4 use warnings;
   5 BEGIN {
   6     unless (-d 'blib') {
   7         chdir 't' if -d 't';
   8         @INC = '../lib';
   9     }
  10 }
  11
  12 use Test::More tests => 10;
  13
  14 =pod
  15
  16 This example is take from: http://www.python.org/2.3/mro.html
  17
  18 "My first example"
  19 class O: pass
  20 class F(O): pass
  21 class E(O): pass
  22 class D(O): pass
  23 class C(D,F): pass
  24 class B(D,E): pass
  25 class A(B,C): pass
  26
  27
  28                           6
  29                          ---
  30 Level 3                 | O |                  (more general)
  31                       /  ---  \
  32                      /    |    \                      |
  33                     /     |     \                     |
  34                    /      |      \                    |
  35                   ---    ---    ---                   |
  36 Level 2        3 | D | 4| E |  | F | 5                |
  37                   ---    ---    ---                   |
  38                    \  \ _ /       |                   |
  39                     \    / \ _    |                   |
  40                      \  /      \  |                   |
  41                       ---      ---                    |
  42 Level 1            1 | B |    | C | 2                 |
  43                       ---      ---                    |
  44                         \      /                      |
  45                          \    /                      \ /
  46                            ---
  47 Level 0                 0 | A |                (more specialized)
  48                            ---
  49
  50 =cut
  51
  52 {
  53     package Test::O;
  54     use mro 'dfs';
  55
  56     package Test::F;
  57     use mro 'dfs';
  58     use base 'Test::O';
  59
  60     package Test::E;
  61     use base 'Test::O';
  62     use mro 'dfs';
  63
  64     sub C_or_E { 'Test::E' }
  65
  66     package Test::D;
  67     use mro 'dfs';
  68     use base 'Test::O';
  69
  70     sub C_or_D { 'Test::D' }
  71
  72     package Test::C;
  73     use base ('Test::D', 'Test::F');
  74     use mro 'dfs';
  75
  76     sub C_or_D { 'Test::C' }
  77     sub C_or_E { 'Test::C' }
  78
  79     package Test::B;
  80     use mro 'dfs';
  81     use base ('Test::D', 'Test::E');
  82
  83     package Test::A;
  84     use base ('Test::B', 'Test::C');
  85     use mro 'dfs';
  86 }
  87
  88 is_deeply(
  89     mro::get_linear_isa('Test::F'),
  90     [ qw(Test::F Test::O) ],
  91     '... got the right MRO for Test::F');
  92
  93 is_deeply(
  94     mro::get_linear_isa('Test::E'),
  95     [ qw(Test::E Test::O) ],
  96     '... got the right MRO for Test::E');
  97
  98 is_deeply(
  99     mro::get_linear_isa('Test::D'),
 100     [ qw(Test::D Test::O) ],
 101     '... got the right MRO for Test::D');
 102
 103 is_deeply(
 104     mro::get_linear_isa('Test::C'),
 105     [ qw(Test::C Test::D Test::O Test::F) ],
 106     '... got the right MRO for Test::C');
 107
 108 is_deeply(
 109     mro::get_linear_isa('Test::B'),
 110     [ qw(Test::B Test::D Test::O Test::E) ],
 111     '... got the right MRO for Test::B');
 112
 113 is_deeply(
 114     mro::get_linear_isa('Test::A'),
 115     [ qw(Test::A Test::B Test::D Test::O Test::E Test::C Test::F) ],
 116     '... got the right MRO for Test::A');
 117
 118 is(Test::A->C_or_D, 'Test::D', '... got the expected method output');
 119 is(Test::A->can('C_or_D')->(), 'Test::D', '... can got the expected method output');
 120 is(Test::A->C_or_E, 'Test::E', '... got the expected method output');
 121 is(Test::A->can('C_or_E')->(), 'Test::E', '... can got the expected method output');