Define direction. Turn_right method to return the next value in the a…

…rray. Add direction_spec

lib/direction.rb

@@ -0,0 +1,37 @@
+# Direction
+class Direction
+  attr_reader :start_direction
+
+  def initialize(start_direction)
+    @start_direction = start_direction
+
+    @directions_array = %w[WEST NORTH EAST SOUTH]
+  end
+
+  def turn_right(current_direction)
+    puts 'turn right'
+
+    # does the current direction exist?
+    return unless @directions_array.include?(current_direction)
+
+    i = @directions_array.index { |e| e == current_direction }
+
+    unless current_direction == @directions_array.last
+      i += 1
+
+      new_direction = @directions_array.fetch(i)
+      puts "New Direction: #{new_direction}"
+
+      return new_direction
+    end
+
+    puts "New Direction: #{@directions_array.first}"
+  end
+end
+
+direction = Direction.new('NORTH')
+
+puts "Starting at #{direction.start_direction}"
+current_direction = direction.start_direction
+
+direction.turn_right(current_direction)

spec/direction_spec.rb

@@ -0,0 +1,30 @@
+require 'rspec'
+require 'spec_helper'
+require './lib/direction'
+
+describe Direction do
+  describe '#initialize' do
+    it 'should have a start_direction attribute which is a String' do
+      instance = Direction.new('NORTH')
+
+      expect(instance.start_direction).to be_a String
+    end
+  end
+
+  describe '#turn_right' do
+    it 'should return the next value in the directions array' do
+      instance = Direction.new('NORTH')
+      current_direction = 'NORTH'
+
+      expect(instance.turn_right(current_direction)).to be_a String
+      expect(instance.turn_right(current_direction)).to eq 'EAST'
+    end
+
+    it 'should return nil if the current_direction is empty' do
+      instance = Direction.new('NORTH')
+      current_direction = ''
+
+      expect(instance.turn_right(current_direction)).to be_nil
+    end
+  end
+end