rails nested resources no route matches missing required key [:id]

I have a very simple case of nested resources but I am having trouble to get them to work.

My models:

class TodoList < ActiveRecord::Base
    has_many :todo_items, dependent: :destroy

class TodoItem < ActiveRecord::Base
  belongs_to :todo_list

My controller:

class TodoItemsController < ApplicationController
  before_action :set_todo_list
  before_action :set_todo_item, only: [:show, :edit, :update, :destroy]

  def show
  end

  private
    def set_todo_item
      @todo_item = @todo_list.todo_items.find(params[:id])
    end

    def set_todo_list
      @todo_list = TodoList.find(params[:todo_list_id])
    end

My show.html.erb:

<%= link_to 'Edit', edit_todo_list_todo_item_path([@todo_item.todo_list, @todo_item]) %> 

I got the error

"No route matches {:action=>"edit", :controller=>"todo_items", :id=>nil, ...,  missing required keys: [:id].

I know the todo_item_id is missing, but I couldn't figure out why. When I debug, I saw that both @todo_list and @todo_item were getting values. But as soon as the @todo_item was assigned, this error would rise. What did I do wrong? How can I correct this? Any insights will be appreciated.

Try this:

<%= link_to 'Edit', edit_todo_list_todo_item_path(@todo_item.todo_list, @todo_item) %>

or:

<%= link_to 'Edit', edit_todo_list_todo_item_path(todo_list_id: @todo_item.todo_list.id, id: @todo_item.id) %>