C# coercion operator?

Question

I got this test:

[Fact]
public void EverythingIsMappedJustFine(){
  new AutoMapperTask().Execute();
  Mapper.AssertConfigurationIsValid();
}

It throws a bit strange exception:

Test 'Unit.Web.Bootstrap.AutoMapperFacts.EverythingIsMappedJustFine' failed:
System.InvalidOperationException : No coercion operator is defined
between types 'System.Void' and 'System.Object'.
at System.Linq.Expressions.Expression.GetUserDefinedCoercionOrThrow(ExpressionType coercionType, Expression expression, Type convertToType)
...
at AutoMapper.DelegateFactory.CreateGet(MethodInfo method)

Unfortunately - I couldn't reproduce this on smaller scale and can't figure out what exactly is going on.

What is coercion operator?

---

This might be useful. But I'm failing to extract and dumb down necessary information bits.

Answer 1

I still don't know what exactly is coercion operator, but at least - I solved my problem found reason.

After some automapper debugging was able to reproduce problem:

namespace mappertest{
  using AutoMapper;
  using NUnit.Framework;
  [TestFixture]
  public class FooFacts{
    [Test]
    public void MapToFizz(){
      Mapper.Initialize(c=>c.AddProfile(new FooProfile()));
      var foo=new Foo {Bar="BarValue"};
      var fooModel=Mapper.Map<Foo,FooModel>(foo);
      Assert.AreEqual("BarValue",fooModel.Bar);
    }
  }
  public class FooProfile:Profile{
    protected override void Configure(){
      CreateMap<Foo,FooModel>();
    }
  }
  public class Foo{
    public string Bar{get;set;}
    public void Fizz() {}
  }
  public class FooModel{
    public string Bar{get;set;}
    public FizzModel Fizz { get;set;}
  }
  public class FizzModel{}
}

Quite simple as it turns out - source has method which is named just like destination property.