No struct defined in changeset

Hello,

I am trying to build a many to many relationship between users and comments using this blog post https://medium.com/coletiv-stories/ecto-elixir-many-to-many-relationships-66403933f8c1.

I am uisng the second method after the title The right way — Use Ecto powers.

This can be found in the middle of the blog post.

I have the following problem

My code

def changeset(user, attrs) do
    user
    |> cast(attrs, [:username, :email, :password, :role, :confirmed, :attempts, :locked])
    |> validate_required([:username, :email, :password, :role, :confirmed, :attempts, :locked])
  end

  def changeset_update_comments(%User{} = user, comment) do
    user
    |> cast(%{}, @required_fields)
    # associate projects to the user
    |> put_assoc(:comment, comment)
  end

Also getting this error:

** (CompileError) lib/medium_graphql_api/accounts/user.ex:25: User.__struct__/0 is undefined, cannot expand struct User
    lib/medium_graphql_api/accounts/user.ex:25: (module)
Elixir

What is the correct way to define my user struct?

Why is it undefined?

Why can’t I expand struct User?

The git with the full aplication is available here GitHub - wolfiton/medium_graphql_api at dao · GitHub

Thanks in advance