```ruby
class FavoritesController < ApplicationController
  def create
    @topic = Topic.find(params[:topic_id])
    @post = @topic.posts.find(params[:post_id])

    authorize Favorite.new

    favorite = current_user.favorites.create(post: @post)
    
    if favorite.valid?
      flash[:notice] = "Favorited post"
      redirect_to [@topic, @post]
    else
      flash[:error] = "Unable to add favorite. Please try again."
      redirect_to [@topic, @post]
    end
  end

  def destroy
    @topic = Topic.find(params[:topic_id])
    @post = @topic.posts.find(params[:post_id])
    @favorite = current_user.favorites.find(params[:id])

    authorize @favorite

    if @favorite.destroy
      flash[:notice] = "Removed favorite."
      redirect_to [@topic, @post]
    else
      flash[:error] = "Unable to remove favorite. Please try again."
      redirect_to [@topic, @post]
    end
  end
end
```

Change favorites controller to be more in line with the roadmap text.
user
```ruby
class FavoritesController < ApplicationController
  def create
    @topic = Topic.find(params[:topic_id])
    @post = @topic.posts.find(params[:post_id])
    favorite = current_user.favorites.build(post: @post)

    authorize favorite

    if favorite.save
      flash[:notice] = "Favorited post"
      redirect_to [@topic, @post]
    else
      flash[:error] = "Unable to add favorite. Please try again."
      redirect_to [@topic, @post]
    end
  end

  def destroy
    @topic = Topic.find(params[:topic_id])
    @post = @topic.posts.find(params[:post_id])
    @favorite = current_user.favorites.find(params[:id])

    authorize @favorite

    if @favorite.destroy
      flash[:notice] = "Removed favorite."
      redirect_to [@topic, @post]
    else
      flash[:error] = "Unable to remove favorite. Please try again."
      redirect_to [@topic, @post]
    end
  end
end
```
assistant