require_relative 'test_helper'
require_relative '../lib/casting.rb'

class TestPerson
  def name
    'name from TestPerson'
  end

  module Greeter
    def greet
      'hello'
    end
  end

  module Verbose
    def verbose(arg1, arg2)
      %w{arg1 arg2}.join(',')
    end
  end
end

class SubTestPerson < TestPerson
  def sub_method
    'sub'
  end
end

class Unrelated
end

describe Casting::Delegation do
  it 'initializes with method name and object' do
    assert Casting::Delegation.new('some_method', Object.new)
  end

  it 'raises an error when calling without an attendant object' do
    delegation = Casting::Delegation.new('some_method', Object.new)
    assert_raises(Casting::MissingAttendant){
      delegation.call
    }
  end

  it 'raises an error when setting an invalid attendant type' do
    delegation = Casting::Delegation.new('some_method', TestPerson.new)
    assert_raises(TypeError, 'poo'){
      delegation.to(Unrelated.new)
    }
  end

  it 'sets an attendant to an object of an ancestor class of the object class' do
    attendant = TestPerson.new
    client = SubTestPerson.new

    delegation = Casting::Delegation.new('name', client)
    assert delegation.to(attendant)
  end

  it 'calls a method defined on another object of the same type' do
    client = TestPerson.new
    attendant = TestPerson.new
    attendant.extend(TestPerson::Greeter)
    delegation = Casting::Delegation.new('greet', client).to(attendant)
    assert_equal 'hello', delegation.call
  end

  it 'passes arguments to a delegated method' do
    client = TestPerson.new
    attendant = TestPerson.new
    attendant.extend(TestPerson::Verbose)
    delegation = Casting::Delegation.new('verbose', client).to(attendant).with('arg1','arg2')
    assert_equal 'arg1,arg2', delegation.call
  end

  it 'delegates when given a module' do
    client = TestPerson.new
    delegation = Casting::Delegation.new('greet', client).to(TestPerson::Greeter)
    assert_equal 'hello', delegation.call
  end
end

describe Casting::Client do
  it 'adds a delegate method to call a method on an attendant' do
    client = TestPerson.new
    client.extend(Casting::Client)
    attendant = TestPerson.new
    attendant.extend(TestPerson::Greeter)

    assert_equal attendant.greet, client.delegate('greet', attendant)
  end
  
  it 'passes additional parameters to the attendant' do
    client = TestPerson.new
    client.extend(Casting::Client)
    attendant = TestPerson.new
    attendant.extend(TestPerson::Verbose)

    attendant_output = attendant.verbose('hello', 'goodbye')
    client_output = client.delegate('verbose', attendant, 'hello', 'goodbye')

    assert_equal attendant_output, client_output
  end
  
  it 'passes the object as the client for delegation' do
    client = Object.new
    client.extend(Casting::Client)

    delegation = client.delegation('id')
    
    assert_equal client, delegation.client
  end
end

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