TDD Shapes

circle.rb

class Circle

  def initialize(radius)
    @radius = radius
  end

  def area
    (Math::PI * (@radius*@radius)).round(2)
  end

  def perimeter
    (2 * Math::PI * @radius).round(2)
  end

end

rectangle.rb

class Trapazoid

  def initialize(bottom_base, top_base, height)
    @bottom_base = bottom_base
    @top_base = top_base
    @height = height
  end

  def area
    @height * @bottom_base * @top_base
  end

  def perimeter
    @height * (@bottom_base + @top_base) / 2
  end

end

shapes_spec.rb

require_relative 'square'
require_relative 'triangle'
require_relative 'rectangle'
require_relative 'circle'
require_relative 'trapazoid'
require 'rspec'

describe Square do 

  let(:square) { Square.new(5) }

  it "should calculate the area of the square" do
    expect(square.calculate_area).to eql(25)
  end

  it "should calulate the perimeter of the square" do
    expect(square.perimeter).to eql(20)
  end

end

describe Triangle do

  let(:triangle) { Triangle.new(10, 5, 5, 5) }
  
  it "should calculate the perimeter of a triange" do
    expect(triangle.perimeter).to eql(20)
  end

  it "should calculate the area of the triange" do
    expect(Triangle.new(2, 5, 1,3).perimeter).to eql(6)
  end

  it "should calculate the area of the triangle" do
    expect(triangle.area).to eql(25)
  end

  it "calculate the area of a triangel" do
    expect(Triangle.new(5).area).to eql(10)
  end

  it "should calculate area of the triangle" do
    expect(Triangle.new(5, 3, 8, 15).perimeter).to eql(28)
  end

end

describe Rectangle do

  let(:rectangle) { Rectangle.new(5,10)}

  it "should calculate the perimeter of the rectangle" do
    expect(rectangle.perimeter).to eql(30)
  end

  it "should calculate the area of the triangle" do
    expect(rectangle.area).to eql(50)
  end

end

describe Circle do

  let(:circle) { Circle.new(5) }

  it "should calculate the area of a circle" do
    expect(circle.area).to eql(78.54)
  end

  it "should calculate the perimeter of a circle" do
    expect(circle.perimeter).to eql(31.42)
  end
end

describe Trapazoid do

  let(:trapazoid) { Trapazoid.new(10,20,40) }

  it "should calculate the area of the trapazoid" do
    expect(trapazoid.area).to eql(8000)
  end

  it "should calculate the perimeter of the trapazoid" do
    expect(trapazoid.perimeter).to eql(600)
  end
  
end

square.rb

class Square

  def initialize(width)
    @width = width
  end

  def calculate_area
    @width * @width
  end

  def perimeter
    @width * 4
  end

end

triangle.rb

class Triangle

  def initialize(base, height = base-1, side1 = base, side2 = base)
    @base = base
    @side1 = side1
    @side2 = side2
    @height = height

  end

  def perimeter
    @base + @side1 + @side2
  end

  def area
    @base * @height / 2
  end

end