Test suite for LCDConverter

LCDConverter.cs

using System;

namespace CodingKata 
{
    class LCDConverter 
    {

        public string ConvertToLCD (int number)
        {
            if ( number < 0 ) throw new ArgumentOutOfRangeException("Only positive numbers please");

            var result = "";
            int i      = 0;
            foreach ( var c in number.ToString() )
            {
                string lcdDigit = "";
                int n = (int) char.GetNumericValue(c);
                switch ( n ) 
                {
                    #region switch assign to lcdDigit
                    case 0: lcdDigit =
                         " _ \n"+
                         "| |\n"+
                         "|_|\n";
                        break; 
                    case 1: lcdDigit =  
                        "   \n"+
                        "  |\n"+
                        "  |\n";
                        break; 
                    case 2: lcdDigit =  
                        " _ \n"+
                        " _|\n"+
                        "|_ \n";
                        break; 
                    case 3: lcdDigit =  
                        " _ \n"+
                        " _|\n"+
                        " _|\n";
                        break; 
                    case 4: lcdDigit =  
                        "   \n"+
                        "|_|\n"+
                        "  |\n";
                        break; 
                    case 5: lcdDigit =  
                        " _ \n"+
                        "|_ \n"+
                        " _|\n";
                        break; 
                    case 6: lcdDigit = 
                        " _ \n"+
                        "|_ \n"+
                        "|_|\n";
                        break; 
                    case 7: lcdDigit = 
                        " _ \n"+
                        "  |\n"+
                        "  |\n";
                        break; 
                   
                    case 8: lcdDigit =  
                        " _ \n"+
                        "|_|\n"+
                        "|_|\n";
                        break; 
                    case 9: lcdDigit =
                        " _ \n"+
                        "|_|\n"+
                        " _|\n";
                        break;
                    #endregion
                }
                result = i == 0 ? lcdDigit : result
                        .Insert( 9 * i+2 , lcdDigit.Substring (8,3))
                        .Insert( 6 * i+1 , lcdDigit.Substring (4,3))
                        .Insert( 3 * i   , lcdDigit.Substring (0,3)) ;                                
                i++;
            }
            return result;
        }

        public static void Main()
        {
            Console.WriteLine ( new LCDConverter().ConvertToLCD(1234567890) );
            Console.WriteLine ( new LCDConverter().ConvertToLCD(-1) );
        }
    }
}

LCDConverterTest.cs

using NUnit.Framework;

namespace CodingKata
{
    [TestFixture()]
    public class LCDConverterTest
    {
        
        private LCDConverter main;
        
        [TestFixtureSetUpAttribute]
        public void SetUp()
        {
             main = new LCDConverter();
        }
        
        [Test()]
        public void TestOne()
        {
            // Original test:
            // Assert.AreEqual( numeros[1], main.ConvertToLCD( 1 ) );
            // later refactored to:
            testNumberInArray ( 1 );
            // after the second test "TestSeven"
        }
        [Test()]
        public void TestSeven()
        {
            // Second test.
            // Refactor to extract method "testNumberInArray"
            testNumberInArray ( 7 );
        }
        private void testNumberInArray( int n ) 
        {
            Assert.AreEqual( numeros[n], main.ConvertToLCD( n ) );
        }
        [Test()]
        public void Test0To9 ()
        {
            // Third test, everything was easy up to this point
            // because a simple switch did the trick
            for ( var i = 0 ; i < numeros.Length; i++ ) 
            {    
                testNumberInArray ( i );
            }    
        }
    
        [Test()]
        public void TestGreaterThan9()
        {
            Assert.AreEqual(
                "    _ \n"+
                "  || |\n" +
                "  ||_|\n", 
                main.ConvertToLCD(10)
            );
            Assert.AreEqual(
                "    _ \n"+
                "|_| _|\n"+
                "  ||_ \n",
                main.ConvertToLCD( 42 )
            );
        }
        [Test()]
        public void TestGreaterThan99()
        {
            Assert.AreEqual(
                "    _  _ \n"+
                "  || || |\n"+
                "  ||_||_|\n", 
                main.ConvertToLCD(100)
            );
        }
        [Test()]
        public void TestDadaaaaa()
        {
            Assert.AreEqual(
                "    _  _     _  _  _  _  _  _ \n"+
                "  | _| _||_||_ |_   ||_||_|| |\n"+
                "  ||_  _|  | _||_|  ||_| _||_|\n",                
                main.ConvertToLCD(1234567890)
            );
        }
        [Test()]
        public void TestNegative()
        {
            try
            {
                main.ConvertToLCD( -1 );
                Assert.Fail("Should've failed with negative");
            }
            catch( System.ArgumentOutOfRangeException ){}
            catch
            {
                Assert.Fail("Shouldn't have thrown anything else");
            }
        }
        // using verbatim string didn't look as I expected
        string [] numeros = new string [] {
@" _ 
| |
|_|
",
@"   
  |
  |
",
@" _ 
 _|
|_ 
",
@" _ 
 _|
 _|
",
@"   
|_|
  |
",
@" _ 
|_ 
 _|
",
@" _ 
|_ 
|_|
",
@" _ 
  |
  |
",
@" _ 
|_|
|_|
",
@" _ 
|_|
 _|
"
};                
        
    }
}

Solo un comentario: el mensaje de la excepción en la validación inicial dice "solo > 0", cuando 0 es un argumento válido =)

Me llama la atención lo compacta y "tersa" que resulta la versión en Go. Necesito ponerme a estudiar, ya que hay algunos detalles sintácticos que todavía no me entran en la cabeza.

Muy buena solución... Y con pruebas además!!

je! :) si... corregido.

Si.. esta padré Go , verdad? Más aún, esa versión fue una transliteración de la de C# pero hice una pregunta en SO y me hicieron una revisión que es mucho más eficiente
Ahí la dejo:

http://stackoverflow.com/a/9780750/20654