UserManager.FindAsync not working with custom implementation of UserStore

Question

I am relatively new in ASP.NET Identity. To understand the things better I am doing a custom implementation of ASP.NET Identity. I am able to create user successfully using the custom code. However the FindAsync(username, password) functionality is not working.

Here is what I have done so far:

User: This is my User class that inherits from IUser<int>

public class User:IUser<int>
{
    public User(){ Id = 0; }

    public int Id { get; private set; }
    public string UserName { get; set; }
    public string PasswordHash { get; set; }
    public string SecurityStamp { get; set; }
}

UserStore: This is custom implementation of IUserStore' and 'IUserPasswordStore

public class UserStore : IUserStore<User, int>, IUserPasswordStore<User, int>
{
    private IdentityContext _context;
    public UserStore()
    {
        _context = new IdentityContext();
    }

    public void Dispose()
    {
        throw new NotImplementedException();
    }

    #region IUserStore<T,K> members
    public Task CreateAsync(User user)
    {
        _context.Users.Add(user);
        _context.SaveChangesAsync();
        return Task.FromResult(true);
    }

    public Task UpdateAsync(User user)
    {
        throw new NotImplementedException();
    }

    public Task DeleteAsync(User user)
    {
        throw new NotImplementedException();
    }

    public Task<User> FindByIdAsync(int userId)
    {
        return _context.Users.FirstOrDefaultAsync(user=>user.Id==userId);
    }

    public Task<User> FindByNameAsync(string userName)
    {
        var user = _context.Users.SingleOrDefaultAsync(u => u.UserName.Equals(userName));
        return user;
    }
    #endregion

    #region IUserPasswordStore<User,int>
    public Task SetPasswordHashAsync(User user, string passwordHash)
    {
        user.PasswordHash = passwordHash;
        return Task.FromResult(true);
    }

    public Task<string> GetPasswordHashAsync(User user)
    {
        return new Task<string>(() => user.PasswordHash);
    }

    public Task<bool> HasPasswordAsync(User user)
    {
        throw new NotImplementedException();
    }
    #endregion
}

In my MVC5 controller I have the following line that tries find the user by username and password:

var user = await UserManager.FindAsync("User1355436", "passw0rd");

The above line of code in turn sequentially invokes the following methods of UserStore:

public Task<User> FindByNameAsync(string userName) and public Task<string> GetPasswordHashAsync(User user).

And after that the code goes to waiting state perpetually and nothing happens, i.e. the control is never returned to the controller again.

What I am missing here?

Answer 1

The problem is likely with this line of code...

return new Task<string>(() => user.PasswordHash);

... this creates a task that is never started, so the code waiting for its continuation waits forever. For returning a value wrapped in a task, use Task.FromResult()...

return Task.FromResult(user.PasswordHash);