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     describe "#initialize" do
   7       it "creates an empty edge" do
   8         e = Edge.new
   9         e.connections.should be_empty
  10       end
  11
  12       it "creates an edge with some parameters" do
  13         e = Edge.new :value1 => 1, :value2 => "value2", :value3 => :v3
  14         e.value1.should == 1
  15         e.value2.should == "value2"
  16         e.value3.should == :v3
  17         e.value4.should be_nil
  18       end
  19     end # #initialize
  20
  21     describe "adds attribues" do
  22       it "adds then reports arbitrary attributes" do
  23         e.score = 15
  24         e.score.should == 15
  25       end
  26     end # adds attributes
  27
  28     describe "#to_s" do
  29       it "returns the string form of an edge" do
  30         v1 = Vertex.new :name => :v1
  31         v2 = Vertex.new :name => :v2
  32         e.type = :test
  33         e << v1 << v2
  34         e.to_s.should == '<E: test [<V: v1>, <V: v2>] >'
  35       end
  36     end
  37
  38     describe "#<<" do
  39       it "adds a new vertex to an edge (with a connection)" do
  40         e.connections.should be_empty
  41         v1 = Vertex.new :name => :v1
  42         v2 = Vertex.new :name => :v2
  43         e << v1
  44         e.should have(1).connections
  45         e.should have(1).vertices
  46         e.vertices.should include(v1)
  47         v1.edges.should include(e)
  48         e << v2
  49         e.should have(2).connections
  50         e.should have(2).vertices
  51         e.vertices.should include(v1)
  52         e.vertices.should include(v2)
  53         v2.edges.should include(e)
  54       end
  55
  56       it "adds several vertices to an edge" do
  57         e.connections.should be_empty
  58         v1 = Vertex.new :name => :v1
  59         v2 = Vertex.new :name => :v2
  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         v1 = Vertex.new
  69         e << v1 << v1
  70         e.vertices.should include(v1)
  71         e.should have(2).vertices
  72         e.vertices.uniq.length.should == 1
  73       end
  74     end # #<<
  75
  76     describe "connection_at" do
  77       it "returns the connection that links to a vertex" do
  78         e.connections.should be_empty
  79         v1 = Vertex.new :name => :v1
  80         v2 = Vertex.new :name => :v2
  81         e << v1 << v2
  82
  83         e.connection_at(v1).end.should be v1
  84         e.connection_at(v2).end.should be v2
  85       end
  86
  87       it "returns nil if there is no connection to that vertex" do
  88         e.connections.should be_empty
  89         v1 = Vertex.new :name => :v1
  90         v2 = Vertex.new :name => :v2
  91         v3 = Vertex.new :name => :v3
  92         e << v1 << v2
  93
  94         e.connection_at(v3).should be nil
  95       end
  96
  97       it "returns the vertex for a self-loop" do
  98         e.connections.should be_empty
  99         v1 = Vertex.new :name => :v1
 100         e << v1 << v1
 101
 102         e.connection_at(v1).end.should be v1
 103       end
 104     end # #connection_at
 105
 106     describe "other_end" do
 107       it "returns the vertex at the other end of the given one" do
 108         e.connections.should be_empty
 109         v1 = Vertex.new :name => :v1
 110         v2 = Vertex.new :name => :v2
 111         e << v1 << v2
 112
 113         e.other_end(v1).should be v2
 114         e.other_end(v2).should be v1
 115       end
 116
 117       it "returns the same vertex in a self-loop" do
 118         e.connections.should be_empty
 119         v1 = Vertex.new :name => :v1
 120         e << v1 << v1
 121
 122         e.other_end(v1).should be v1
 123       end
 124
 125       it "returns one of the connected edges if given a vertex not connected to it" do
 126         e.connections.should be_empty
 127         v1 = Vertex.new :name => :v1
 128         v2 = Vertex.new :name => :v2
 129         v3 = Vertex.new :name => :v3
 130         e << v1 << v2
 131
 132         [v1, v2].should include e.other_end(v3)
 133       end
 134
 135       it "returns nil if it can't return something sensible" do
 136         v1 = Vertex.new :name => :v1
 137         e.other_end(v1).should be_nil
 138         e << v1
 139         e.other_end(v1).should be_nil
 140       end
 141     end # other_end
 142   end # Edge
 143
 144   describe Connection do
 145     let (:c) {Connection.new }
 146
 147     describe "adds attribues" do
 148       it "adds then reports arbitrary attributes" do
 149         c.score = 15
 150         c.score.should == 15
 151       end
 152     end # adds attributes
 153   end # Connection
 154
 155 end