Getting InvalidCastException when grouping over a projection

[rkonstantinov]

I'm not sure if this has been already addressed or not. I'm testing it with Beta 3 version.

The following code:

var db = new SampleContext();
var result = db.Blogs
    .Select(x => new { x.BlogId })
    .GroupBy(x => x.BlogId);
result.ToList();

is producing InvalidCastException:

System.InvalidCastException: Unable to cast object of type 'Microsoft.Data.Entity.Query.QuerySourceScope`1[<>f__AnonymousType0`1[System.Int32]]' to type 'Microsoft.Data.Entity.Query.QuerySourceScope`
   at Microsoft.Data.Entity.Query.QuerySourceScope.GetResult[TResult](IQuerySource querySource)

Here is the context and model declaration:

    public class SampleContext : DbContext
    {
        public DbSet<Blog> Blogs { get; set; }      

        protected override void OnConfiguring(DbContextOptions builder)
        {
            builder.UseSqlServer(@"Server=(localdb)\v11.0;Database=Samples;Trusted_Connection=True;");
        }
    }

    public class Blog
    {
        public int BlogId { get; set; }     
    }

[rowanmiller]

Confirmed this still repros on the latest bits (though with a different exception)

Unhandled Exception: System.ArgumentException: Expression of type 'System.Func`2[Microsoft.Data.Entity.Storage.ValueBuffer,System.Int32]' cannot be used for parameter of type 'System.Func`2[<>f__AnonymousType0`
1[System.Int32],System.Int32]' of method 'System.Collections.Generic.IEnumerable`1[System.Linq.IGrouping`2[System.Int32,<>f__AnonymousType0`1[System.Int32]]] _GroupBy[<>f__AnonymousType0`1,Int32,<>f__AnonymousT
ype0`1](System.Collections.Generic.IEnumerable`1[<>f__AnonymousType0`1[System.Int32]], System.Func`2[<>f__AnonymousType0`1[System.Int32],System.Int32], System.Func`2[<>f__AnonymousType0`1[System.Int32],<>f__Ano
nymousType0`1[System.Int32]])'
   at System.Linq.Expressions.Expression.ValidateOneArgument(MethodBase method, ExpressionType nodeKind, Expression arg, ParameterInfo pi)
   at System.Linq.Expressions.Expression.Call(MethodInfo method, Expression arg0, Expression arg1, Expression arg2)
   at Microsoft.Data.Entity.Query.ResultOperatorHandler.HandleGroup(EntityQueryModelVisitor entityQueryModelVisitor, GroupResultOperator groupResultOperator, QueryModel queryModel)
   at Microsoft.Data.Entity.Query.ResultOperatorHandler.<>c.<.cctor>b__25_9(EntityQueryModelVisitor v, ResultOperatorBase r, QueryModel q)
   at Microsoft.Data.Entity.Query.ResultOperatorHandler.HandleResultOperator(EntityQueryModelVisitor entityQueryModelVisitor, ResultOperatorBase resultOperator, QueryModel queryModel)
   at Microsoft.Data.Entity.Query.Internal.RelationalResultOperatorHandler.HandlerContext.EvalOnClient(Boolean requiresClientResultOperator)
   at Microsoft.Data.Entity.Query.Internal.RelationalResultOperatorHandler.HandleGroup(HandlerContext handlerContext)
   at Microsoft.Data.Entity.Query.Internal.RelationalResultOperatorHandler.HandleResultOperator(EntityQueryModelVisitor entityQueryModelVisitor, ResultOperatorBase resultOperator, QueryModel queryModel)
   at Microsoft.Data.Entity.Query.EntityQueryModelVisitor.VisitResultOperator(ResultOperatorBase resultOperator, QueryModel queryModel, Int32 index)
   at Microsoft.Data.Entity.Query.RelationalQueryModelVisitor.VisitResultOperator(ResultOperatorBase resultOperator, QueryModel queryModel, Int32 index)
   at Remotion.Linq.QueryModelVisitorBase.VisitResultOperators(ObservableCollection`1 resultOperators, QueryModel queryModel)
   at Remotion.Linq.QueryModelVisitorBase.VisitQueryModel(QueryModel queryModel)
   at Microsoft.Data.Entity.Query.EntityQueryModelVisitor.VisitQueryModel(QueryModel queryModel)
   at Microsoft.Data.Entity.Query.RelationalQueryModelVisitor.VisitQueryModel(QueryModel queryModel)
   at Microsoft.Data.Entity.Query.Internal.SqlServerQueryModelVisitor.VisitQueryModel(QueryModel queryModel)
   at Microsoft.Data.Entity.Query.EntityQueryModelVisitor.CreateQueryExecutor[TResult](QueryModel queryModel)
   at Microsoft.Data.Entity.Storage.Database.CompileQuery[TResult](QueryModel queryModel)
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.Data.Entity.Query.Internal.QueryCompiler.<>c__DisplayClass19_0`1.<CompileQuery>b__0()
   at Microsoft.Data.Entity.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
   at Microsoft.Data.Entity.Query.Internal.QueryCompiler.CompileQuery[TResult](Expression query)
   at Microsoft.Data.Entity.Query.Internal.QueryCompiler.Execute[TResult](Expression query)
   at Microsoft.Data.Entity.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)
   at Remotion.Linq.QueryableBase`1.GetEnumerator()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)