roman.rb

require 'rspec'


def from_roman(roman)
  if roman.include? "X"
    roman[0] == "X" ? 10 * roman.count("X") + ones(roman) : 9
  else
    ones(roman)
  end
end

def ones(roman)
  if roman.include? "V"
    roman[0] == "V" ?  5 + roman.count("I") : 4
  else
    roman.count('I')
  end
end

describe "Roman Numeral Converter" do
  it "converts I" do
    expect(from_roman("I")).to eq(1)
  end

  it "converts III" do
    expect(from_roman("III")).to eq(3)
  end

  it "converts V" do
    expect(from_roman("V")).to eq(5)
  end

  it "converts VI" do
    expect(from_roman("VI")).to eq(6)
  end

  it "converts IV" do
    expect(from_roman("IV")).to eq(4)
  end

  it "converts X" do
    expect(from_roman("X")).to eq(10)
  end

  it "converts XI" do
    expect(from_roman("XI")).to eq(11)
  end

  it "converts IX" do
    expect(from_roman("IX")).to eq(9)
  end

  it "converts XIV" do
    expect(from_roman("XIV")).to eq(14)
  end

  it "converts XX" do
    expect(from_roman("XX")).to eq(20)
  end
end