An Expression Parser for CodeDom

using System;
using System.CodeDom;
using System.CodeDom.Compiler;
using System.IO;
using System.Text;
using NUnit.Framework;
using Microsoft.CSharp;
using CodeDomExpParser;
 
namespace CodeDomExpParser.TestHarness
{
	/// <summary>
	/// Eating my own dog food.
	/// </summary>
	[TestFixture]
	public class DogFood
	{
		private void WriteExpression(CodeExpression ce) 
		{
			CSharpCodeProvider prov = new CSharpCodeProvider();
			StringBuilder sb = new StringBuilder();
			ICodeGenerator gen = prov.CreateGenerator();
			gen.GenerateCodeFromExpression(ce, new StringWriter(sb), new CodeGeneratorOptions());
			Console.WriteLine(sb.ToString());
		}

		[Test]
		public void Test01() 
		{
			CodeExpression ce1 = new CodeMethodInvokeExpression(
				new CodeMethodReferenceExpression(new CodeVariableReferenceExpression("parseObj"), "Parse"), 
				new CodeExpression[] {   new CodeVariableReferenceExpression("xr"), 
										 new CodeFieldReferenceExpression(new CodeThisReferenceExpression(), "_XmiObjects") });
			Console.WriteLine("Expected:");
			WriteExpression(ce1);

			Parser p = new Parser();
			CodeExpression ce2 = p.ParseExpression("parseObj.Parse(xr, this._XmiObjects)");
			Console.WriteLine("Parsed:");
			WriteExpression(ce2);
		}

		[Test]
		public void Test02() 
		{
			CodeExpression ce1 = new CodeMethodInvokeExpression(
				new CodeMethodReferenceExpression(new CodeCastExpression(typeof(string), 
				new CodeVariableReferenceExpression("parseObj")), "Parse"), 
				new CodeExpression[] {   new CodeVariableReferenceExpression("xr"), 
										 new CodeFieldReferenceExpression(new CodeThisReferenceExpression(), "_XmiObjects") });
			Console.WriteLine("Expected:");
			WriteExpression(ce1);

			Parser p = new Parser();
			p.Fields.Add("_XmiObjects");
			CodeExpression ce2 = p.ParseExpression("((string)parseObj).Parse(xr, this._XmiObjects)");
			Console.WriteLine("Parsed:");
			WriteExpression(ce2);
		}

		[Test]
		public void Test03() 
		{
			CodeExpression ce1 = new CodeBinaryOperatorExpression(
				new CodePropertyReferenceExpression(new CodeVariableReferenceExpression("xr"), "HasAttributes"),
				CodeBinaryOperatorType.BooleanAnd, new CodeMethodInvokeExpression(
				new CodeMethodReferenceExpression(new CodeVariableReferenceExpression("xr"), "MoveToAttribute"), 
				new CodeExpression[] { new CodePrimitiveExpression("xmi.value") }));
			Console.WriteLine("Expected:");
			WriteExpression(ce1);

			Parser p = new Parser();
			CodeExpression ce2 = p.ParseExpression("xr.HasAttributes && xr.MoveToAttribute(\"xmi.value\")");
			Console.WriteLine("Parsed:");
			WriteExpression(ce2);
		}

		[Test]
		public void Test04() 
		{
			CodeExpression ce1 = new CodeCastExpression(
				new CodeTypeReference(typeof(string)), 
				new CodeMethodInvokeExpression(new CodeMethodReferenceExpression(
				new CodeTypeReferenceExpression(typeof(Convert)), "ChangeType"), 
				new CodeExpression[] {   new CodePropertyReferenceExpression(
										 new CodeVariableReferenceExpression("xr"), "Value"), 
										 new CodeTypeOfExpression(new CodeTypeReference(typeof(string))) }));
			Console.WriteLine("Expected:");
			WriteExpression(ce1);

			Parser p = new Parser();
			CodeExpression ce2 = p.ParseExpression("(string)Convert.ChangeType(xr.Value, typeof(string))");
			Console.WriteLine("Parsed:");
			WriteExpression(ce2);
		}
	}
}