VS fails to show proper intellisense when using multiple ThenIncludes

See this SO post.

I was trying another .Include(blah).ThenInclude(blah), and while intellisense worked for the first, the second only showed IEnumberable functions/methods which lead me to believe I had mistyped something or it wasn’t supported somehow.

For example…

var reg =  _context.Registrations
  .Where(r => r.User.UserName == userName)
  .Include(r => r.Activities).ThenInclude(a => a.Task)
  .Include(r => r.Activities).ThenInclude(a => a.Responses)
  .FirstOrDefault();

The second a in the second ThenInclude did not show this as being a valid property. Thanks to the contributor to my SO post I tried building and running it anyways and it worked fine. VS lead me astray! 😉 Is this the proper place to report this?

VS Info…

Microsoft Visual Studio Professional 2015 Version 14.0.24720.00 Update 1 Microsoft .NET Framework Version 4.6.01055 Installed Version: Professional

EF info (as per project.json & “References” tree control in VS)…

EntityFramework.Core (7.0.0-rc1-final)

[smitpatel]

@powermetal63 - Please file an issue on roslyn repo.

[powermetal63]

This issue has been resolved in upcoming release of VS 16.1

I’m with VS 16.3.9 and still see it.

The difference with the example from Roslyn issue is that there the collection overload is defined as

this IIncludableQueryable<TEntity, ICollection<TPreviousProperty>> source

while in EF Core it is

this IIncludableQueryable<TEntity, IEnumerable<TPreviousProperty>> source

So when the navigation property type is ICollection<T> (or some other enumerable derived interface), the Intellisense does not offer T members initially. If the navigation property type is IEnumerable<T>, it works.