Stopping Jint from silently ignoring prohibited assignments?

[biwa]

It's not possible to assign values to C# object properties that only have a getter, re-assigning methods is not possible, either. That's good. But if a script tries to do that it's just silently ignored. For example this program:

using System;
using Jint;
using Jint.Runtime;
using Jint.Runtime.Interop;

namespace jinttestx
{
	public class MyClass
	{
		public int MyProp => 1;

		public void MyMethod(string s) => Console.WriteLine($"From C#: {s}");
	}

	class Program
	{

		static void Main(string[] args)
		{
			Engine engine = new Engine();
			engine.SetValue("log", new Action<object>(Console.WriteLine));
			engine.SetValue("MyClass", TypeReference.CreateTypeReference(engine, typeof(MyClass)));

			try
			{
				engine.Execute(@"
const mc = new MyClass();
log(mc.MyProp); // Prints 1
mc.MyProp = 2; // Doesn't actually change MyProp to 2 (good!)
log(mc.MyProp); // Prints 1

mc.MyMethod('test'); // Prints From C#: test
mc.MyMethod = s => log(`From JS: ${s}`); // doesn't reassign (good!)
mc.MyMethod('test'); // Prints From C#: test
			");
			}
			catch(Exception e)
			{
				Console.WriteLine(e.Message);
				if (e is JavaScriptException jse)
					Console.WriteLine(jse.JavaScriptStackTrace);
			}

			Console.ReadKey();
		}
	}
}

First it tries to assign the value 2 to a property that only has a getter. Jint doesn't complain about it, but the value stays at 1. Same with trying to assign a new method. Jint doesn't complain about it, but doesn't actually assign the new method.

Is there a way to get Jint to throw an exception if a script tries to do something like that?

[lahma]

Everything is always possible and PRs with test cases are appreciated 😉 The thing here is that this follows the JS behavior, JS acts no-op when such assignment doesn't do anything.