spec/graph/edge_spec.rb

   1 require File.expand_path(File.dirname(__FILE__) + '/../spec_helper')
   2
   3 module GraphNjae
   4   describe Edge do
   5     let (:e) { Edge.new }
   6     let(:v1) {Vertex.new :name => :v1}
   7     let(:v2) {Vertex.new :name => :v2}
   8     let(:v3) {Vertex.new :name => :v3}
   9
  10     describe '#initialize' do
  11       it 'creates an empty edge' do
  12         e = Edge.new
  13         e.connections.should be_empty
  14       end
  15
  16       it 'creates an edge with some parameters' do
  17         e = Edge.new :value1 => 1, :value2 => 'value2', :value3 => :v3
  18         e.value1.should == 1
  19         e.value2.should == 'value2'
  20         e.value3.should == :v3
  21         e.value4.should be_nil
  22       end
  23     end # #initialize
  24
  25     describe 'adds attribues' do
  26       it 'adds then reports arbitrary attributes' do
  27         e.score = 15
  28         e.score.should == 15
  29       end
  30     end # adds attributes
  31
  32     describe '#<<' do
  33       it 'adds a new vertex to an edge (with a connection)' do
  34         e.connections.should be_empty
  35         e << v1
  36         e.should have(1).connections
  37         e.should have(1).vertices
  38         e.vertices.should include(v1)
  39         v1.edges.should include(e)
  40         e << v2
  41         e.should have(2).connections
  42         e.should have(2).vertices
  43         e.vertices.should include(v1)
  44         e.vertices.should include(v2)
  45         v2.edges.should include(e)
  46       end
  47
  48       it 'adds several vertices to an edge' do
  49         e.connections.should be_empty
  50         e << v1 << v2
  51         e.vertices.should include(v1)
  52         e.vertices.should include(v2)
  53         e.should have(2).vertices
  54       end
  55
  56       it 'adds a self-loop' do
  57         e.connections.should be_empty
  58         e << v1 << v1
  59         e.vertices.should include(v1)
  60         e.should have(2).vertices
  61         e.vertices.uniq.length.should == 1
  62       end
  63     end # #<<
  64
  65     describe 'connection_at' do
  66       it 'returns the connection that links to a vertex' do
  67         e.connections.should be_empty
  68         e << v1 << v2
  69
  70         e.connection_at(v1).end.should be v1
  71         e.connection_at(v2).end.should be v2
  72       end
  73
  74       it 'returns nil if there is no connection to that vertex' do
  75         e.connections.should be_empty
  76         e << v1 << v2
  77
  78         e.connection_at(v3).should be nil
  79       end
  80
  81       it 'returns the vertex for a self-loop' do
  82         e.connections.should be_empty
  83         e << v1 << v1
  84
  85         e.connection_at(v1).end.should be v1
  86       end
  87     end # #connection_at
  88
  89     describe 'other_end' do
  90       it 'returns the vertex at the other end of the given one' do
  91         e.connections.should be_empty
  92         e << v1 << v2
  93
  94         e.other_end(v1).should be v2
  95         e.other_end(v2).should be v1
  96       end
  97
  98       it 'returns the same vertex in a self-loop' do
  99         e.connections.should be_empty
 100         e << v1 << v1
 101
 102         e.other_end(v1).should be v1
 103       end
 104
 105       it 'returns one of the connected edges if given a vertex not connected to it' do
 106         e.connections.should be_empty
 107         e << v1 << v2
 108
 109         [v1, v2].should include e.other_end(v3)
 110       end
 111
 112       it 'returns nil if it cannot return something sensible' do
 113         e.other_end(v1).should be_nil
 114         e << v1
 115         e.other_end(v1).should be_nil
 116       end
 117     end # other_end
 118
 119     describe '#to_dot' do
 120       it 'describes an edge in dot notation' do
 121         e << v1 << v2
 122         e.to_dot.should == "#{v1.object_id.to_s} -- #{v2.object_id.to_s};"
 123       end
 124
 125       it 'describes an edge in dot notation, using given attributes' do
 126         e << v1 << v2
 127         e.name = 'Edge name'
 128         edot = e.to_dot :label => :name
 129         edot.should == "#{v1.object_id.to_s} -- #{v2.object_id.to_s} {label = \"#{e.name}\"};"
 130       end
 131
 132       it 'describes an edge in dot notation, given a block' do
 133         e << v1 << v2
 134         e.to_dot {|e| e.object_id.to_s}.should == e.object_id.to_s
 135       end
 136     end # dot
 137   end # Edge
 138
 139   describe Connection do
 140     let (:c) {Connection.new }
 141
 142     describe 'adds attribues' do
 143       it 'adds then reports arbitrary attributes' do
 144         c.score = 15
 145         c.score.should == 15
 146       end
 147     end # adds attributes
 148   end # Connection
 149
 150 end