Ruby class to encapsulate an angle

angle.rb

module CpuSim::Cpu

  class Angle

    def self.zero
      new(0)
    end

    def self.radians(v)
      new(v)
    end

    def self.degrees(v)
      radians(v / 180 * Math::PI)
    end

    def self.revolutions(v)
      radians(v * 2 * Math::PI)
    end

    private_class_method :new

    attr_reader :radians

    def initialize(radians)
      @radians = radians
    end

    def revolutions
      @radians / (2 * Math::PI)
    end

    def degrees
      revolutions * 360
    end

    def normalize
      self.class.radians(@radians % (2 * Math::PI))
    end

    def +(other)
      self.class.radians(@radians + other.radians)
    end

  end

end

angle_spec.rb

module CpuSim::Cpu

  RSpec.describe Angle do

    it "should make a zero angle" do
      angle = Angle.zero
      expect(angle.radians).to eq 0
    end

    it "should be created from revolutions" do
      angle = Angle.revolutions(0.5)
      expect(angle.radians).to be_within(0.001).of(Math::PI)
    end

    it "should be created from degrees" do
      angle = Angle.degrees(180)
      expect(angle.radians).to be_within(0.001).of(Math::PI)
    end

    it "should be zero radians" do
      angle = Angle.radians(0)
      expect(angle.radians).to eq 0
    end

    it "should be PI radians" do
      angle = Angle.radians(Math::PI)
      expect(angle.radians).to eq Math::PI
    end

    it "should be 2 PI radians" do
      angle = Angle.radians(2 * Math::PI)
      expect(angle.radians).to eq 2 * Math::PI
    end

    it "should normalize 0" do
      angle = Angle.zero
      angle = angle.normalize
      expect(angle.radians).to eq 0
    end

    it "should normalize -2 * PI radians" do
      angle = Angle.radians(-2 * Math::PI)
      angle = angle.normalize
      expect(angle.radians).to eq 0
    end

    it "should normalize -PI radians" do
      angle = Angle.radians(-Math::PI)
      angle = angle.normalize
      expect(angle.radians).to eq Math::PI
    end

    it "should normalize PI radians" do
      angle = Angle.radians(Math::PI)
      angle = angle.normalize
      expect(angle.radians).to eq Math::PI
    end

    it "should normalize 2 PI radians" do
      angle = Angle.radians(2 * Math::PI)
      angle = angle.normalize
      expect(angle.radians).to eq 0
    end

    it "should normalize 3 PI radians" do
      angle = Angle.radians(3 * Math::PI)
      angle = angle.normalize
      expect(angle.radians).to eq Math::PI
    end
    it "should add two angles" do
      angle1 = Angle.radians(Math::PI)
      angle2 = Angle.radians(2 * Math::PI)
      angle3 = angle1 + angle2
      expect(angle3.radians).to eq(3 * Math::PI)
    end

    it "should know its number of revolutions" do
      angle = Angle.radians(3 * Math::PI)
      expect(angle.revolutions).to be_within(0.001).of(1.5)
    end

    it "should know its number of degrees" do
      angle = Angle.radians(3 * Math::PI)
      expect(angle.degrees).to be_within(0.001).of(540)
    end

  end

end