viewbag not passed when using the cached template

[frmokoena]

Describe the bug ViewBag parameter is not passed the second time when template is retrieved from cache.

To Reproduce

A second call to below, gives a success 👍 in cacheResult but unfortunately only the model is reaching the view template when .RenderTemplateAsync<T>(cacheResult.Template.TemplatePageFactory(), model, viewBag); is called.

dynamic viewBag = new ExpandoObject();
viewBag.One = "something";
viewBag.Two = "other something";

var cacheResult = _engine.TemplateCache.RetrieveTemplate(viewName);

string result;
if (cacheResult.Success)
{
    result = await _engine
        .RenderTemplateAsync<T>(cacheResult.Template.TemplatePageFactory(), model, viewBag);
}
else
{
    result = await _engine
        .CompileRenderAsync<T>(viewName, model, viewBag);
}

Expected behavior

A viewbag to be passed in RenderTemplateAsync just like in .CompileRenderAsync<T>(viewRoute, model, viewBag);, but the folowing exception is thrown, (and indeed putting a breakpoint in my view shows that ViewBag is empty):

Microsoft.CSharp.RuntimeBinder.RuntimeBinderException
    HResult=0x80131500
    Message='System.Dynamic.ExpandoObject' does not contain a definition for 'One'
    Source=System.Linq.Expressions

Information

• OS: Windows 10
• Platform: .NET Core 2.1
• RazorLight version: 2.0.0-beta1

Additional context Add any other context about the problem here.

[MarcelChirtes]

Problem exist on RazorLight 2.0.0-beta1 But it looks that this is already fixed in gihub, https://github.com/toddams/RazorLight/blob/master/src/RazorLight/RazorLightEngine.cs

The workaround for me was to use the other method. Instead of:

await Engine.RenderTemplateAsync(found.Template.TemplatePageFactory(), model, ViewBag);

Used

await Engine.RenderTemplateAsync(found.Template.TemplatePageFactory(), (object)model, Type.GetTypeFromHandle(typeof(T).TypeHandle), ViewBag);

This is specific per nugget package, I see that on source code these two methods are obsolete. Checking decompiled Assembly, it looks like optional parameter ExpandoObject viewBag = null is not passed to next invocation if present, value sent is plain null.