Cannot correctly configure an EF Core Interceptor

Marfig

Hi,

Due to my inexperience, I'm having trouble properly configuring my script to execute after I added EF interceptors to my project. The interceptor itself is a SaveChangesInterceptor and works correctly. It has been added to my project service collection as a scoped service and is being injected in my DbContext constructor.

On my LINQPad script, I thought I could do the same. But this results in an error:

CS7036 There is no argument given that corresponds to the required parameter 'publishDomainEventsInterceptor' of 'SmesDbContext.SmesDbContext(DbContextOptions, PublishDomainEventsInterceptor)'

I understand I have to pass an instance of the interceptor to my DbContext constructor. But I can't see how I can do that on the LINQPad script. The only way I have to get the script to run is to remove the interceptor from the DbContext constructor n my project code.

async Task Main()
{
    Console.SetOut(TextWriter.Null);
    Debugger.Launch();

    Assembly applicationAssembly = AppDomain.CurrentDomain.GetAssemblies()
        .Single(assembly => assembly.GetName().Name == "Smes.Application");

    using IHost host = Host
    .CreateDefaultBuilder()
    .ConfigureServices((_, services) =>
        services
            .AddDbContext<SmesDbContext>((serviceProvider, options) =>
            {
                var interceptor = serviceProvider.GetRequiredService<PublishDomainEventsInterceptor>();

                options.UseLazyLoadingProxies()
                       .UseSqlServer("Server=(local);Database=SMESDATA;Trusted_Connection=True;Encrypt=false;")
                       .AddInterceptors(interceptor)
                       .LogTo(_ => { });
            })
            .AddScoped<IUnitOfWorkData, UnitOfWorkData>()
            .AddHttpContextAccessor()
            .AddScoped<PublishDomainEventsInterceptor>()
            .AddMediatR(cfg => cfg.RegisterServicesFromAssemblies(applicationAssembly))
            .AddScoped<IUserContextService, UserContextService>()
            .AddScoped<IDateTimeProvider, DateTimeProvider>())
    .Build();

    using (var scope = host.Services.CreateScope())
    {
        var services = scope.ServiceProvider;
        var data = services.GetRequiredService<IUnitOfWorkData>();
        var mediatr = services.GetRequiredService<IMediator>();

        await Execute(data, mediatr);
    }
}

Marfig

I found the problem. I removed the default DbContext constructor when injecting the interceptor. Once I added it back to my project code, the error went away.

It was not clear to me before that my connection on LINQPad was in error. There was nothing wrong with the script code. Just that the DbContext connection was not working anymore because of the lack of a compatible constructor.

JoeAlbahari

Thanks for sharing the info.