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 "#<<" do
  29       it "adds a new vertex to an edge (with a connection)" do
  30         e.connections.should be_empty
  31         v1 = Vertex.new :name => :v1
  32         v2 = Vertex.new :name => :v2
  33         e << v1
  34         e.should have(1).connections
  35         e.should have(1).vertices
  36         e.vertices.should include(v1)
  37         v1.edges.should include(e)
  38         e << v2
  39         e.should have(2).connections
  40         e.should have(2).vertices
  41         e.vertices.should include(v1)
  42         e.vertices.should include(v2)
  43         v2.edges.should include(e)
  44       end
  45
  46       it "adds several vertices to an edge" do
  47         e.connections.should be_empty
  48         v1 = Vertex.new :name => :v1
  49         v2 = Vertex.new :name => :v2
  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         v1 = Vertex.new
  59         e << v1 << v1
  60         e.vertices.should include(v1)
  61         e.should have(2).vertices
  62         e.vertices.uniq.length.should == 1
  63       end
  64     end # #<<
  65
  66     describe "connection_at" do
  67       it "returns the connection that links to a vertex" do
  68         e.connections.should be_empty
  69         v1 = Vertex.new :name => :v1
  70         v2 = Vertex.new :name => :v2
  71         e << v1 << v2
  72
  73         e.connection_at(v1).end.should be v1
  74         e.connection_at(v2).end.should be v2
  75       end
  76
  77       it "returns nil if there is no connection to that vertex" do
  78         e.connections.should be_empty
  79         v1 = Vertex.new :name => :v1
  80         v2 = Vertex.new :name => :v2
  81         v3 = Vertex.new :name => :v3
  82         e << v1 << v2
  83
  84         e.connection_at(v3).should be nil
  85       end
  86
  87       it "returns the vertex for a self-loop" do
  88         e.connections.should be_empty
  89         v1 = Vertex.new :name => :v1
  90         e << v1 << v1
  91
  92         e.connection_at(v1).end.should be v1
  93       end
  94     end # #connection_at
  95
  96     describe "other_end" do
  97       it "returns the vertex at the other end of the given one" do
  98         e.connections.should be_empty
  99         v1 = Vertex.new :name => :v1
 100         v2 = Vertex.new :name => :v2
 101         e << v1 << v2
 102
 103         e.other_end(v1).should be v2
 104         e.other_end(v2).should be v1
 105       end
 106
 107       it "returns the same vertex in a self-loop" do
 108         e.connections.should be_empty
 109         v1 = Vertex.new :name => :v1
 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         v1 = Vertex.new :name => :v1
 118         v2 = Vertex.new :name => :v2
 119         v3 = Vertex.new :name => :v3
 120         e << v1 << v2
 121
 122         [v1, v2].should include e.other_end(v3)
 123       end
 124
 125       it "returns nil if it can't return something sensible" do
 126         v1 = Vertex.new :name => :v1
 127         e.other_end(v1).should be_nil
 128         e << v1
 129         e.other_end(v1).should be_nil
 130       end
 131     end # other_end
 132   end # Edge
 133
 134   describe Connection do
 135     let (:c) {Connection.new }
 136
 137     describe "adds attribues" do
 138       it "adds then reports arbitrary attributes" do
 139         c.score = 15
 140         c.score.should == 15
 141       end
 142     end # adds attributes
 143   end # Connection
 144
 145 end