mono/mcs/class/System.Core/Test/System.Linq.Expressions/ExpressionTest.cs

//
// ExpressionTest.cs
//
// Author:
//   Jb Evain ([email protected])
//
// (C) 2008 Novell, Inc. (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.Collections.Generic;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Linq;
using System.Linq.Expressions;

using NUnit.Framework;

namespace MonoTests.System.Linq.Expressions {

	[TestFixture]
	[Category("SRE")]
	public class ExpressionTest {

		[Test]
		[ExpectedException (typeof (ArgumentNullException))]
		public void GetFuncTypeArgNull ()
		{
			Expression.GetFuncType (null);
		}

		static Type [] GetTestTypeArray (int length)
		{
			return Enumerable.Range (0, length - 1)
				.Select (i => typeof (int))
				.ToArray ();
		}

		[Test]
		[ExpectedException (typeof (ArgumentException))]
		public void GetFuncTypeArgEmpty ()
		{
			Expression.GetFuncType (Type.EmptyTypes);
		}

		[Test]
		[ExpectedException (typeof (ArgumentException))]
		public void GetFuncTypeArgTooBig ()
		{
			Expression.GetFuncType (GetTestTypeArray (64));
		}

		[Test]
		public void GetFuncTypeTest ()
		{
			var func = Expression.GetFuncType (new [] {typeof (int)});
			Assert.AreEqual (typeof (Func<int>), func);

			func = Expression.GetFuncType (new [] {typeof (int), typeof (int)});
			Assert.AreEqual (typeof (Func<int, int>), func);

			func = Expression.GetFuncType (new [] {typeof (int), typeof (int), typeof (int)});
			Assert.AreEqual (typeof (Func<int, int, int>), func);

			func = Expression.GetFuncType (new [] {typeof (int), typeof (int), typeof (int), typeof (int)});
			Assert.AreEqual (typeof (Func<int, int, int, int>), func);

			func = Expression.GetFuncType (new [] {typeof (int), typeof (int), typeof (int), typeof (int), typeof (int)});
			Assert.AreEqual (typeof (Func<int, int, int, int, int>), func);
		}

		[Test]
		[ExpectedException (typeof (ArgumentNullException))]
		public void GetActionTypeArgNull ()
		{
			Expression.GetActionType (null);
		}

		[Test]
		[ExpectedException (typeof (ArgumentException))]
		public void GetActionTypeArgTooBig ()
		{
			Expression.GetActionType (GetTestTypeArray (45));
		}

		[Test]
		public void GetActionTypeTest ()
		{
			var action = Expression.GetActionType (new Type [0]);
			Assert.AreEqual (typeof (Action), action);

			action = Expression.GetActionType (new [] {typeof (int)});
			Assert.AreEqual (typeof (Action<int>), action);

			action = Expression.GetActionType (new [] {typeof (int), typeof (int)});
			Assert.AreEqual (typeof (Action<int, int>), action);

			action = Expression.GetActionType (new [] {typeof (int), typeof (int), typeof (int)});
			Assert.AreEqual (typeof (Action<int, int, int>), action);

			action = Expression.GetActionType (new [] {typeof (int), typeof (int), typeof (int), typeof (int)});
			Assert.AreEqual (typeof (Action<int, int, int, int>), action);
		}

		[Test]
		[ExpectedException (typeof (ArgumentNullException))]
		public void ParameterNullType ()
		{
			Expression.Parameter (null, "foo");
		}

		[Test]
		public void ParameterNullName ()
		{
			var p = Expression.Parameter (typeof (string), null);
			Assert.AreEqual (null, p.Name);
			Assert.AreEqual (typeof (string), p.Type);
		}

		[Test]
		public void ParameterEmptyName ()
		{
			var p = Expression.Parameter (typeof (string), "");
			Assert.AreEqual ("", p.Name);
			Assert.AreEqual (typeof (string), p.Type);
		}

		[Test]
		public void Parameter ()
		{
			var p = Expression.Parameter (typeof (string), "foo");
			Assert.AreEqual ("foo", p.Name);
			Assert.AreEqual (typeof (string), p.Type);
			Assert.AreEqual ("foo", p.ToString ());
		}

		[Test]
		[Category ("NotDotNet")]
		[ExpectedException (typeof (ArgumentException))]
		public void VoidParameter ()
		{
			Expression.Parameter (typeof (void), "hello");
		}

		static int buffer;

		public static int Identity (int i)
		{
			buffer = i;
			return i;
		}

		[Test]
		public void CompileActionDiscardingRetValue ()
		{
			var p = Expression.Parameter (typeof (int), "i");
			var identity = GetType ().GetMethod ("Identity", BindingFlags.Static | BindingFlags.Public );
			Assert.IsNotNull (identity);

			var lambda = Expression.Lambda<Action<int>> (Expression.Call (identity, p), p);

			var method = lambda.Compile ();

			buffer = 0;

			method (42);
			Assert.AreEqual (42, buffer);
		}

		[Test]
		public void ExpressionDelegateTarget ()
		{
			var p = Expression.Parameter (typeof (string), "str");
			var identity = Expression.Lambda<Func<string, string>> (p, p).Compile ();

			Assert.AreEqual (typeof (Func<string, string>), identity.GetType ());
			Assert.IsNotNull (identity.Target);
		}

		[Test]
		public void SimpleHoistedParameter ()
		{
			var p = Expression.Parameter (typeof (string), "s");

			var f = Expression.Lambda<Func<string, Func<string>>> (
				Expression.Lambda<Func<string>> (
					p,
					new ParameterExpression [0]),
				p).Compile ();

			var f2 = f ("x");

			Assert.AreEqual ("x", f2 ());
		}

		[Test]
		public void TwoHoistingLevels ()
		{
			var p1 = Expression.Parameter (typeof (string), "x");
			var p2 = Expression.Parameter (typeof (string), "y");

			Expression<Func<string, Func<string, Func<string>>>> e =
				Expression.Lambda<Func<string, Func<string, Func<string>>>> (
					Expression.Lambda<Func<string, Func<string>>> (
						Expression.Lambda<Func<string>> (
							Expression.Call (
								typeof (string).GetMethod ("Concat", new [] { typeof (string), typeof (string) }),
								new [] { p1, p2 }),
							new ParameterExpression [0]),
						new [] { p2 }),
					new [] { p1 });

			var f = e.Compile ();
			var f2 = f ("Hello ");
			var f3 = f2 ("World !");

			Assert.AreEqual ("Hello World !", f3 ());
		}

		[Test]
		public void HoistedParameter ()
		{
			var i = Expression.Parameter (typeof (int), "i");

			var l = Expression.Lambda<Func<int, string>> (
				Expression.Invoke (
					Expression.Lambda<Func<string>> (
						Expression.Call (i, typeof (int).GetMethod ("ToString", Type.EmptyTypes)))), i).Compile ();

			Assert.AreEqual ("42", l (42));
		}
	}
}