unit tests and application.rb

Am fairly new to Rails so this may be an obvious question but I would
appreciate any help I can get.

I am working on an existing application and trying to add some unit
tests (there aren't any tests to date).

Firstly When I run a unit test I notice that it calls app/controller/
application.rb which is not something I was expecting. This is
something I see happening even in a freshly generated rails project
running the default generated unit tests. I am guessing this is
correct behaviour but am curious as to why running a unit test on a
model class results in application.rb being called.

Other than wanting to get a better understanding of Rails the other
reason I am asking the question is that it is causing the tests to
fail. This is because in application.rb someone has added the
following code:

class ApplicationController < ActionController::Base

  layout "application"
  include BasicAuth

  $currentsite = Site.find(1)
  $sitefooter=$currentsite.footer
  $sitename=$currentsite.name
  $buttons=Button.find(:all, :order => "position")

   .......
end

There is no Site with an ID of 1 as it has been created. I have
attempted to create a Sites fixture to solve this problem and
referencing it in the unit test. This did not work so I tried adding
it to the test_helper.rb class again this did not work. Looking at the
stack trace the reason seems to be the order of execution.

In my unit test class I have the following

require File.dirname(__FILE__) + '/../test_helper'

class PollTest < ActiveSupport::TestCase

  fixture :sites

  # Replace this with your real tests.
  def test_truth
    assert true
  end
end

this calls test_helper.rb which in has the following lines

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

class Test::Unit::TestCase

.......
end

It is the third line which seems to result in application.rb being
called. This happens before my fixtures are loaded and the test blows
up.

I have included the static trace below for addition information:

/Library/Ruby/Gems/1.8/gems/activerecord-2.0.2/lib/active_record/
base.rb:1267:in `find_one': Couldn't find Site with ID=1
(ActiveRecord::RecordNotFound)
  from /Library/Ruby/Gems/1.8/gems/activerecord-2.0.2/lib/active_record/
base.rb:1250:in `find_from_ids'
  from /Library/Ruby/Gems/1.8/gems/activerecord-2.0.2/lib/active_record/
base.rb:504:in `find'
  from /Users/rich/Documents/Dev/firework/app/controllers/
application.rb:14
  from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require'
  from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/
ruby/1.8/rubygems/custom_require.rb:27:in `require'
  from /Library/Ruby/Gems/1.8/gems/activesupport-2.0.2/lib/
active_support/dependencies.rb:496:in `require'
  from /Library/Ruby/Gems/1.8/gems/activesupport-2.0.2/lib/
active_support/dependencies.rb:342:in `new_constants_in'
  from /Library/Ruby/Gems/1.8/gems/activesupport-2.0.2/lib/
active_support/dependencies.rb:496:in `require'
   ... 8 levels...
  from /Library/Ruby/Gems/1.8/gems/activesupport-2.0.2/lib/
active_support/dependencies.rb:496:in `require'
  from ./test/unit/../test_helper.rb:3
  from test/unit/poll_test.rb:1:in `require'
  from test/unit/poll_test.rb:1

How can I load the fixtures first to ensure there is a Site by the
time application.rb gets called. The other option is to re-factor
application.rb. Is the code I have above bad practise?

Many thanks in advance for any help.

ma6rl wrote:

I am working on an existing application and trying to add some unit
tests (there aren't any tests to date).

Sometimes a rewrite is in order. Start a new project, write tests-first, and each time a test fails for the correct reason, copy in a line of the old program.

Firstly When I run a unit test I notice that it calls app/controller/
application.rb which is not something I was expecting. This is
something I see happening even in a freshly generated rails project
running the default generated unit tests. I am guessing this is
correct behaviour but am curious as to why running a unit test on a
model class results in application.rb being called.

Firstly, "unit test" does not necessarily mean "model test". Both verbiages are just a Rails opinion, as a prod to help remind you to isolate and decouple tests and business logic.

I added this to my nearest application.rb...

class ApplicationController < ActionController::Base
   def initialize(*args)
     raise 'wtf?'
     super
   end

...and found that not all tests call the application. The ones that do are using test/helper_testcase.rb:27: That's a system that tests helper files. Did you install such a system?

If you do the same experiment, do you get that file? What's on your stack trace?

Other than wanting to get a better understanding of Rails the other
reason I am asking the question is that it is causing the tests to
fail. This is because in application.rb someone has added the
following code:

class ApplicationController < ActionController::Base

  layout "application"
  include BasicAuth

  $currentsite = Site.find(1)
  $sitefooter=$currentsite.footer
  $sitename=$currentsite.name
  $buttons=Button.find(:all, :order => "position")

Someone is writing Perl-style Ruby here. Take out as many $ as you can, and add another point to the argument that a rewrite might be necessary.

Next, all that code runs when the ApplicationController compiles, not when it first invokes. Look up "before_filter", and put your (crappy) startup code inside it. Then it will only invoke when someone fetches a page - not necessarily when every danged test runs!