Ruby Weekly Challenge - RGB

rgb.spec

def rgb(r, g, b)
  "#{to_padded_hex(r)}#{to_padded_hex(g)}#{to_padded_hex(b)}".upcase
end

def to_padded_hex(n)
  n = 0 if n < 0
  n = 255 if n > 255
  n.to_s(16).rjust(2, "0")
end

rgb_spec.rb

require_relative '../rgb.rb'

describe "#rgb" do
  context "when a negative value is supplied" do
    it "sets the negative value at 0" do
      expect(rgb(-40, 255, 255)).to eql "00FFFF"
    end
  end

  context "when a value > 255 is supplied" do
    it "sets the large value at 255" do
      expect(rgb(300, 0, 255)).to eql "FF00FF"
    end
  end

  context "when a valid rgb value is supplied" do
    it "returns hex version of the rgb decimal value" do
      expect(rgb(0, 0, 0)).to eql "000000"
    end

    it "returns hex version of the rgb decimal value" do
      expect(rgb(255, 255, 255)).to eql "FFFFFF"
    end
  end
end