Tim and Rob's solution to the number to LCD kata in Ruby.

numberToLCD.rb

class InvalidIntegerError < RuntimeError
end
  
class NumberToLCD
  
  @numbers = {
    "1" => ["   ",
            "  |",
            "  |"],
    "2" => [" _ ",
            " _|",
            "|_ "],
    "3" => [" _ ",
            " _|",
            " _|"],
    "4" => ["   ",
            "|_|",
            "  |"],
    "5" => [" _ ",
            "|_ ",
            " _|"],
    "6" => [" _ ",
            "|_ ",
            "|_|"],
    "7" => [" _ ",
            "  |",
            "  |"],
    "8" => [" _ ",
            "|_|",
            "|_|"],
    "9" => [" _ ",
            "|_|",
            " _|"],
    "0" => [" _ ",
            "| |",
            "|_|"]
  }
  
  def self.convert number  
    
    unless number.is_a? Integer
      raise InvalidIntegerError
    end
    
    result = ["","",""]

    number.to_s.each_char do |i|
      result[0] << @numbers[i][0]
      result[1] << @numbers[i][1]
      result[2] << @numbers[i][2]      
    end
    
    result[0] << "\n"    
    result[1] << "\n"    

    result.join
  end
end

numberToLCDSpec.rb

require 'rspec'
require './numberToLCD'

describe 'NumberToLCD' do
  
  it "should test" do
    expect( 1 ).should == 1
  end
  
  it "should convert 1 to \n   \n  |\n  |" do
    expect NumberToLCD.convert(1).should ==
      "   \n" +
      "  |\n" +
      "  |"
  end
  
  it "should convert 2" do
    expect NumberToLCD.convert(2).should == 
      " _ \n" +
      " _|\n" +
      "|_ "
  end
  
  it "should convert 12" do
    expect NumberToLCD.convert(12).should == 
      "    _ \n" +
      "  | _|\n" +
      "  ||_ "
  end
  
  it "should convert 1234567890" do
    expect NumberToLCD.convert(1234567890).should ==
      "    _  _     _  _  _  _  _  _ \n" +
      "  | _| _||_||_ |_   ||_||_|| |\n" +
      "  ||_  _|  | _||_|  ||_| _||_|"
  end
  
  it "should convert 333" do
    expect NumberToLCD.convert(333).should ==
      " _  _  _ \n" +
      " _| _| _|\n" +
      " _| _| _|"
  end
  
  it "should throw an error when converting abc" do
    lambda {NumberToLCD.convert("abc")}.should raise_error InvalidIntegerError
  end
end