/test/test_helper.rb

ENV["RAILS_ENV"] = "test"
require File.expand_path(File.dirname(__FILE__) + "/../config/environment")
require 'test_help'

class Test::Unit::TestCase
  # Transactional fixtures accelerate your tests by wrapping each test method
  # in a transaction that's rolled back on completion.  This ensures that the
  # test database remains unchanged so your fixtures don't have to be reloaded
  # between every test method.  Fewer database queries means faster tests.
  #
  # Read Mike Clark's excellent walkthrough at
  #   http://clarkware.com/cgi/blosxom/2005/10/24#Rails10FastTesting
  #
  # Every Active Record database supports transactions except MyISAM tables
  # in MySQL.  Turn off transactional fixtures in this case; however, if you
  # don't care one way or the other, switching from MyISAM to InnoDB tables
  # is recommended.
  self.use_transactional_fixtures = true

  # Instantiated fixtures are slow, but give you @david where otherwise you
  # would need people(:david).  If you don't want to migrate your existing
  # test cases which use the @david style and don't mind the speed hit (each
  # instantiated fixtures translates to a database query per test method),
  # then set this back to true.
  self.use_instantiated_fixtures  = false

  # Assert the form tag.
  def assert_form_tag(action)
    assert_tag "form", :attributes => { :action => action, 
                                        :method => "post" }
  end

  # Assert submit button with optional label.
  def assert_submit_button(button_label = nil)
    if button_label
      assert_tag "input", :attributes => { :type => "submit",
                                           :value => button_label }
    else 
      assert_tag "input", :attributes => { :type => "submit" }
    end
  end
  
  ERROR_DIV = { :tag => "div", :attributes => { :class => "fieldWithErrors" } }

  # Assert existence of form input field with attributes.
  def assert_input_field(name, value, field_type, size, maxlength, options = {})   
    attributes = { :name  => name,
                   :type  => field_type, 
                   :size  => size,
                   :maxlength => maxlength }
    # Surprisingly, attributes[:value] == nil is different from attributes
    # not having a :value key at all.
    attributes[:value] = value unless value.nil?
    tag = { :tag => "input", :attributes => attributes }
    # Merge tag hash with options, especially to handle :parent => ERROR_DIV
    # option in error tests.
    tag.merge!(options)
    assert_tag tag 
  end
  
  # Test the minimum or maximum length of an attribute.
  def assert_length(boundary, object, attribute, length, options = {})
    valid_char = options[:valid_char] || "a"
    barely_invalid = barely_invalid_string(boundary, length, valid_char)
    # Test one over the boundary.
    object[attribute] = barely_invalid
    assert !object.valid?,
           "#{object[attribute]} (length #{object[attribute].length}) " +
           "should raise a length error"
    assert_equal correct_error_message(boundary, length), 
                 object.errors.on(attribute) 

    # Test the boundary itself.
    barely_valid = valid_char * length 
    object[attribute] = barely_valid 
    assert object.valid?,
           "#{object[attribute]} (length #{object[attribute].length}) " +
           "should be on the boundary of validity"
  end
  
  # Create an attribute that is just barely invalid.
  def barely_invalid_string(boundary, length, valid_char)
    if boundary == :max 
      invalid_length = length + 1
    elsif boundary == :min
      invalid_length = length - 1
    else
      raise ArgumentError, "boundary must be :max or :min"
    end    
    valid_char * invalid_length
  end

  # Return the correct error message for the length test.
  def correct_error_message(boundary, length)
    error_messages = ActiveRecord::Errors.default_error_messages
    if boundary == :max
      sprintf(error_messages[:too_long], length)
    elsif boundary == :min
      sprintf(error_messages[:too_short], length)
    else
      raise ArgumentError, "boundary must be :max or :min"
    end
  end
  
  # Authorize a user.
  def authorize(user)
    @request.session[:user_id] = user.id
  end
  
  # Simulate an uploaded file.
  # From http://wiki.rubyonrails.org/rails/pages/HowtoUploadFiles
  def uploaded_file(filename, content_type)
    t = Tempfile.new(filename)
    t.binmode
    path = RAILS_ROOT + "/test/fixtures/" + filename
    FileUtils.copy_file(path, t.path)
    (class << t; self; end).class_eval do
      alias local_path path
      define_method(:original_filename) {filename}
      define_method(:content_type) {content_type}
    end
    return t
  end
end