title: test_helper don't load when I make a test
body: <p>I need make a test of a model, but when I do this:</p>
  
  <pre><code>ruby test/unit/user_test.rb 
  </code></pre>
  
  <p>I have also tried with other methods:</p>
  
  <pre><code>ruby -I test test/unit/user_test.rb
  rake test:units TEST=test/unit/user_test.rb
  </code></pre>
  
  <p>But anyone make the test and said:</p>
  
  <blockquote>
    <p>test/unit/user_test.rb:1:in `require': no such file to load -- test_helper (LoadError)</p>
  </blockquote>
  
  <p>Or like.</p>
  
  <p>This is part of the code (only the beginning):</p>
  
  <pre><code>require 'test_helper'
  
  class UserTest &lt; Test::Unit::TestCase
    self.use_instantiated_fixtures  = true
    fixtures :users
  
    def test_auth 
      #check that we can login we a valid user 
      assert_equal  @bob, User.authenticate("bob", "test")    
      #wrong username
      assert_nil    User.authenticate("nonbob", "test")
      #wrong password
      assert_nil    User.authenticate("bob", "wrongpass")
      #wrong login and pass
      assert_nil    User.authenticate("nonbob", "wrongpass")
    end
  </code></pre>
  
  <p>Yours sincerely</p>