Ruby program giving TONS of errors!

require "./ToDoItem.rb"

def printSeparator(char = "-")
  puts char * 40
end

class ToDoList
  attr_reader :name
  attr_accessor :items

    def initialize(name)
      @name = name
      @items = []
    end

    def addItems(description)
      @items.push(ToDoItem.new(description))
    end

    def run
      choice = ""
      puts "To Do List: #{@name}"
      printSeparator()
      while choice != "quit"

        puts "add: Adds new items"
        puts "check: Check every task to see if it's complete"
        puts "print: Prints the to do list to the screen."
        puts "quit: Quits the program."

        print "What do you want to do? "
        choice = gets.chomp.downcase

        case choice
          when "add"
          print "What item do you want to add? "
          addItems(gets.chomp)

          when "print"
          printList()

          when "quit"
          exit
        end
      end
    end

    def isComplete?
      @items.each do |item|
        print "Is this item complete? (y/n) #{item.description} "
        choice = gets.chomp.downcase

        if choice == "n"
          puts "Okay. Be sure to complete it soon!"
        elsif choice == "y"
          item.complete
          puts "Good job! Onwards!"
        else
          puts "Invalid option selected. Try again"
        end
      end
    end

    def printList
      puts @name
      printSeparator()
      @items.each do |item|
        puts "To Do: #{item.description}"
      end
      printSeparator()
    end
end

toDoList = ToDoList.new("My list")

# toDoList.addItems("Get groceries")
# toDoList.addItems("Solve 3 papers")

# toDoList.printList

# toDoList.isComplete?

toDoList.run

class ToDoItem

  attr_reader :description
  attr_reader :complete

  def initialize(description)
    @description = description
    @complete = false
  end

  def complete
    @complete = true
  end
end