facebook.rb

require 'rubygems'
require 'neography'

@neo = Neography::Rest.new

def create_person(name)
  @neo.create_node("name" => name)
end

def make_mutual_friends(node1, node2)
  @neo.create_relationship("friends", node1, node2)
  @neo.create_relationship("friends", node2, node1)
end

def suggestions_for(node)
  @neo.traverse(node,"nodes", {"order" => "breadth first", 
                                          "uniqueness" => "node global", 
                                          "relationships" => {"type"=> "friends", "direction" => "in"}, 
                                          "return filter" => {
                                            "language" => "javascript",
                                            "body" => "position.length() == 2;"},
                                          "depth" => 2})
end

johnathan = create_person('Johnathan')
mark      = create_person('Mark')
phill     = create_person('Phill')
mary      = create_person('Mary')
luke      = create_person('Luke')

make_mutual_friends(johnathan, mark)
make_mutual_friends(mark, mary)
make_mutual_friends(mark, phill)
make_mutual_friends(phill, mary)
make_mutual_friends(phill, luke)

puts "Johnathan should become friends with #{suggestions_for(johnathan).map{|n| n["data"]["name"]}.join(', ')}"

# RESULT
# Johnathan should become friends with Mary, Phill