JonPSmith/EfCore.GenericServices/SingleFieldMethodMappingTests (https://github.com/JonPSmith/EfCore.GenericServices/issues/31)

EfCore.GenericServices.Testing.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netcoreapp2.2</TargetFramework>
    <RootNamespace>EfCore.GenericServices.Testing</RootNamespace>

    <IsPackable>false</IsPackable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="EfCore.TestSupport" Version="2.0.0" />
    <PackageReference Include="EFCore.GenericServices" Version="2.0.2" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SQLite" Version="2.2.6" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
    <PackageReference Include="xunit" Version="2.4.1" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.1" />
  </ItemGroup>

</Project>

SingleFieldMethodMappingTests.cs

using System;
using System.ComponentModel;
using System.Threading.Tasks;
using GenericServices;
using GenericServices.PublicButHidden;
using GenericServices.Setup;
using Microsoft.EntityFrameworkCore;
using TestSupport.EfHelpers;
using Xunit;

namespace EfCore.GenericServices.Testing
{
    public class SingleFieldMethodMappingTests
    {

        [Fact]
        public async Task Root_method_call_fails()
        {
            // arrange
            var options = SqliteInMemory.CreateOptions<RootContext>();
            using (var context = new RootContext(options))
            {
                context.Database.EnsureCreated();
                var utData = context.SetupSingleDtoAndEntities<SetItemDto>();
                var service = new CrudServicesAsync(context, utData.ConfigAndMapper);

                // act
                var dto = new SetItemDto
                {
                    Id = 1,
                    Item = "A item!"
                };
                await service.UpdateAndSaveAsync(dto);//, nameof(Root.SetItem)); // DEBUG: Exceptions is thrown. It has the same result when excplicitly setting the method name or not
            }
        }

        public class SetItemDto : ILinkToEntity<Root>
        {
            [ReadOnly(true)]
            public int Id { get; set; }
            public string Item { get; set; }
        }

        public class Root
        {
            public int Id { get; set; }
            public void SetItem(string item, RootContext context = null)
            {
                if (item is null)
                    throw new ArgumentNullException(nameof(item));
                // This method is never called
            }
        }

        public class RootContext : DbContext
        {
            public RootContext(DbContextOptions<RootContext> options) : base(options) { }
            protected override void OnModelCreating(ModelBuilder builder)
            {
                builder.Entity<Root>().Property(e => e.Id).ValueGeneratedNever();
                builder.Entity<Root>().HasData(new Root { Id = 1 });
            }
        }
    }
}