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 "#to_s" do
  33       it "returns the string form of an edge" do
  34         v1 = Vertex.new :name => :v1
  35         v2 = Vertex.new :name => :v2
  36         e.type = :test
  37         e << v1 << v2
  38         e.to_s.should == '<E: test [<V: v1>, <V: v2>] >'
  39       end
  40     end
  41
  42     describe "#<<" do
  43       it "adds a new vertex to an edge (with a connection)" do
  44         e.connections.should be_empty
  45         e << v1
  46         e.should have(1).connections
  47         e.should have(1).vertices
  48         e.vertices.should include(v1)
  49         v1.edges.should include(e)
  50         e << v2
  51         e.should have(2).connections
  52         e.should have(2).vertices
  53         e.vertices.should include(v1)
  54         e.vertices.should include(v2)
  55         v2.edges.should include(e)
  56       end
  57
  58       it 'adds several vertices to an edge' do
  59         e.connections.should be_empty
  60         e << v1 << v2
  61         e.vertices.should include(v1)
  62         e.vertices.should include(v2)
  63         e.should have(2).vertices
  64       end
  65
  66       it 'adds a self-loop' do
  67         e.connections.should be_empty
  68         e << v1 << v1
  69         e.vertices.should include(v1)
  70         e.should have(2).vertices
  71         e.vertices.uniq.length.should == 1
  72       end
  73     end # #<<
  74
  75     describe 'connection_at' do
  76       it 'returns the connection that links to a vertex' do
  77         e.connections.should be_empty
  78         e << v1 << v2
  79
  80         e.connection_at(v1).end.should be v1
  81         e.connection_at(v2).end.should be v2
  82       end
  83
  84       it 'returns nil if there is no connection to that vertex' do
  85         e.connections.should be_empty
  86         e << v1 << v2
  87
  88         e.connection_at(v3).should be nil
  89       end
  90
  91       it 'returns the vertex for a self-loop' do
  92         e.connections.should be_empty
  93         e << v1 << v1
  94
  95         e.connection_at(v1).end.should be v1
  96       end
  97     end # #connection_at
  98
  99     describe 'other_end' do
 100       it 'returns the vertex at the other end of the given one' do
 101         e.connections.should be_empty
 102         e << v1 << v2
 103
 104         e.other_end(v1).should be v2
 105         e.other_end(v2).should be v1
 106       end
 107
 108       it 'returns the same vertex in a self-loop' do
 109         e.connections.should be_empty
 110         e << v1 << v1
 111
 112         e.other_end(v1).should be v1
 113       end
 114
 115       it 'returns one of the connected edges if given a vertex not connected to it' do
 116         e.connections.should be_empty
 117         e << v1 << v2
 118
 119         [v1, v2].should include e.other_end(v3)
 120       end
 121
 122       it 'returns nil if it cannot return something sensible' do
 123         e.other_end(v1).should be_nil
 124         e << v1
 125         e.other_end(v1).should be_nil
 126       end
 127     end # other_end
 128
 129     describe '#to_dot' do
 130       it 'describes an edge in dot notation' do
 131         e << v1 << v2
 132         e.to_dot.should == "#{v1.object_id.to_s} -- #{v2.object_id.to_s};"
 133       end
 134
 135       it 'describes an edge in dot notation, using given attributes' do
 136         e << v1 << v2
 137         e.name = 'Edge name'
 138         edot = e.to_dot :label => :name
 139         edot.should == "#{v1.object_id.to_s} -- #{v2.object_id.to_s} {label = \"#{e.name}\"};"
 140       end
 141
 142       it 'describes an edge in dot notation, given a block' do
 143         e << v1 << v2
 144         e.to_dot {|e| e.object_id.to_s}.should == e.object_id.to_s
 145       end
 146     end # dot
 147   end # Edge
 148
 149   describe Connection do
 150     let (:c) {Connection.new }
 151
 152     describe 'adds attribues' do
 153       it 'adds then reports arbitrary attributes' do
 154         c.score = 15
 155         c.score.should == 15
 156       end
 157     end # adds attributes
 158   end # Connection
 159
 160 end