Casting error in Get and GetAsync methods

[hfrances]

Hello, when I try to call to Get / GetAsync methods, I get an error.

Code examples:

Entities.MyItem rdo;

rdo = conn.Get<Entities.MyItem>(new { Id = pk });
rdo = await conn.GetAsync<Entities.MyItem>(new { Id = pk });

Error message: Microsoft.CSharp.RuntimeBinder.RuntimeBinderException: Cannot implicitly convert type 'object' to 'System.Collections.Generic.IEnumerable'. An explicit conversion exists (are you missing a cast?) Stack Trace: at CallSite.Target(Closure , CallSite , Object ) at System.Dynamic.UpdateDelegates.UpdateAndExecute1[T0,TRet](CallSite site, T0 arg0) at DapperExtensions.DapperImplementor.InternalGet[T](IDbConnection connection, Object id, IDbTransaction transaction, Nullable1 commandTimeout, IList1 colsToSelect, IList1 includedProperties) at System.Dynamic.UpdateDelegates.UpdateAndExecute7[T0,T1,T2,T3,T4,T5,T6,TRet](CallSite site, T0 arg0, T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6) at DapperExtensions.DapperImplementor.Get[T](IDbConnection connection, Object id, IDbTransaction transaction, Nullable1 commandTimeout, IList1 includedProperties) at System.Dynamic.UpdateDelegates.UpdateAndExecute5[T0,T1,T2,T3,T4,TRet](CallSite site, T0 arg0, T1 arg1, T2 arg2, T3 arg3, T4 arg4) at DapperExtensions.DapperExtensions.Get[T](IDbConnection connection, Object id, IDbTransaction transaction, Nullable1 commandTimeout)

Possible solution:

I appreciate your support.

[valfrid-ly]

In your suggestion you are returning SYNC from an async method. Did you run the unit tests??

[valfrid-ly]

With the suggested change we have a problem in Async Method.

And looking carefully you're changing the result type

Here is the original one returning Task:

public async Task<T> GetAsync<T>(IDbConnection connection, dynamic id, IDbTransaction transaction = null, int? commandTimeout = null, bool buffered = false, IList<IProjection> colsToSelect = null, IList<IReferenceMap> includedProperties = null) where T : class
{
  return await Task.FromResult(InternalGet<T>(connection, id, transaction, commandTimeout, colsToSelect, includedProperties));
}

Here is your suggestion, returning T:

public async Task<T> GetAsync<T>(IDbConnection connection, dynamic id, IDbTransaction transaction = null, int? commandTimeout = null, bool buffered = false, IList<IProjection> colsToSelect = null, IList<IReferenceMap> includedProperties = null) where T : class
{
    return (T)InternalGet<T>(connection, id, transaction, commandTimeout, colsToSelect, includedProperties);
}

It'll cause issues for those who are expecting a Task to get their results like this:

function MyItem Foo()
{
  var myResult := await conn.GetAsync<Entities.MyItem>(new { Id = pk });
 return myResult.Result;
}

What can be done is this:

public async Task<T> GetAsync<T>(IDbConnection connection, dynamic id, IDbTransaction transaction = null, int? commandTimeout = null, bool buffered = false,
            IList<IProjection> colsToSelect = null, IList<IReferenceMap> includedProperties = null) where T : class
{
    return await Task.FromResult((T)InternalGet<T>(connection, id, transaction, commandTimeout, colsToSelect, includedProperties));
}

For the sync method the fix is ok

[hfrances]

Hello, thanks for your quick response. I have fixed my mistake in async methods according to your comment. This is the final code:

[valfrid-ly]

The change in DapperAsyncExtensions is unnecessary as "Instance.GetAsync" already returns Task<T>