triangle_program.rb

require './lib/triangles'
 
  
def main
  @sides = []
  puts "Please enter a side length"
  @sides << gets.chomp
  puts "Please enter another side length"
  @sides << gets.chomp
  puts "Please enter a third side length"
  @sides << gets.chomp

  @sides.map! do |side|
    side.to_i
  end
  @triangle = Triangle.new(@sides[0], @sides[1], @sides[2])
  puts "Your triangle is #{@triangle.type}."
  puts "\n\n"
  main 
end

main


  

triangles.rb

class Triangle
  def initialize(side1, side2, side3)
    @side1 = side1
    @side2 = side2
    @side3 = side3
  end
  
  def type
    if @side1 == @side2 && @side1 == @side3 
      "equilateral"
    elsif (@side1 == @side2  || @side1 == @side3) && valid_triangle? 
      "isosceles"
    elsif (@side1 != @side2 || @side1 != @side3) && valid_triangle?
      "scalene"
    else 
      "not a triangle"  
    end  
  end  

  def valid_triangle? 
    sides = [@side1, @side2, @side3]
    small_sides = @side1 + @side2 + @side3 - sides.max
    if sides.max >= small_sides
      false
    else
      true
    end
  end
end

triangles_spec.rb

require 'rspec'
require 'triangles'

describe Triangle do 
  it 'is initialized with three side lengths' do 
    test_triangle = Triangle.new(3, 3, 3)
    test_triangle.should be_an_instance_of Triangle 
  end

  describe "type" do 
    it 'returns equilateral when all three sides are equal' do
      test_triangle = Triangle.new(3,3,3)
      test_triangle.type.should eq "equilateral"
    end  

    it 'returns isosceles when two sides are equal' do 
      test_triangle = Triangle.new(4, 4, 3)
      test_triangle.type.should eq "isosceles"
    end

    it 'returns scalene if no sides are equal' do
      test_triangle = Triangle.new(3,4,5)
      test_triangle.type.should eq "scalene"
    end  

    it 'returns "not a triangle" if one side is greater than or equal to the sum of the other two sides' do 
      test_triangle = Triangle.new(6, 2, 1)
      test_triangle.type.should eq "not a triangle"
    end
  end

  describe 'valid_triangle?' do
    it 'checks if the triangle is a valid triangle' do 
      test_triangle = Triangle.new(6,2,1)
      test_triangle.valid_triangle?.should eq false
    end  
  end
end