demonstrates encoding bug in Rails4

rails4-emoji-bug

#!/usr/bin/env ruby

# Activate the gem you are reporting the issue against.
gem 'activerecord', '4.0.0' # NB: works fine with 3.2.13
gem 'mysql2'
require 'active_record'
require 'minitest/autorun'
require 'logger'

# This connection will do for database-independent bug reports.

# works fine w/ sqlite3
#ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ':memory:')
ActiveRecord::Base.establish_connection(adapter: 'mysql2', database: 'YOUR_MYSQL_DB', username: 'YOUR_MYSQL_USER', password: 'YOUR_MYSQL_PASSWORD', encoding: 'utf8')
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :posts do |t|
    t.text     "description"
  end

end

class Post < ActiveRecord::Base
end

class BugTest < MiniTest::Unit::TestCase

  # OK
  def test_yen
    post = Post.create!(description: "\u{A5}")
  end

  # fails
  def test_emoji
    post = Post.create!(description: "\u{1f525}")
  end

end