public async Task TReturn_only()
        {
            var resolver = new ScopedAsyncFieldResolver <string>(context =>
            {
                context.RequestServices.ShouldBe(_scopedServiceProvider);
                return(Task.FromResult("success"));
            });

            (await resolver.Resolve(_scopedContext)).ShouldBe("success");
            VerifyScoped();
        }
        public async Task TSource_and_TReturn()
        {
            var resolver = new ScopedAsyncFieldResolver <string, int>(context =>
            {
                context.Source.ShouldBe("test");
                context.RequestServices.ShouldBe(_scopedServiceProvider);
                return(Task.FromResult(2));
            });

            _scopedContext.Source = "test";
            (await resolver.Resolve(_scopedContext)).ShouldBe(2);
            VerifyScoped();
        }
        public void RequiresRequestServices_TSource_and_TReturn()
        {
            var resolver = new ScopedAsyncFieldResolver <string, int>(context => Task.FromResult(5));

            Should.Throw <MissingRequestServicesException>(() => resolver.Resolve(new ResolveFieldContext()));
        }