rails active record issue

gistfile1.rb

require "rubygems"
gem "minitest"
gem 'debugger'

# Activate the gem you are reporting the issue against.
gem 'activerecord', '3.2.15'

require 'active_record'
require 'minitest/autorun'
require 'logger'
require 'debugger'

# Ensure backward compatibility with Minitest 4
Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test)

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ':memory:')
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :posts do |t|
    t.string :title
    t.text :article
  end

  create_table :comments do |t|
    t.integer :post_id
    t.text :comment
  end
end

class Post < ActiveRecord::Base
  has_many :comments, autosave: :true
  validates :article, presence: :true, on: :my_context
end

class Comment < ActiveRecord::Base
  belongs_to :post
  validates :comment, presence: :true, on: :my_context
end

class BugTest < Minitest::Test
  def test_association_stuff
    post = Post.new
    post.comments << comment = Comment.new

    assert_equal post.valid?, true    
    assert_equal post.valid?(:my_context), false    
    assert_includes post.errors.messages, :article

    # mistakes start here
    assert_includes post.comments[0].errors.messages, :comment, "not validated comment when validate in context"
    
  end
end