[Haml] Abstract away RAILS_ROOT.

Closes gh-48

doc-src/HAML_CHANGELOG.md

@@ -27,6 +27,12 @@
   This is consistent with the behavior of multiple ids
   when one is specified as a standard attribute.
 
+### Edge Rails Compatibility
+
+* Don't use `RAILS_ROOT` directly.
+  This no longer exists in Rails 3.0.
+  Instead abstract this out as `Haml::Util.rails_root`.
+
 ## [2.2.10](http://github.com/nex3/haml/commit/2.2.10)
 
 * Fixed a bug where elements with dynamic attributes and no content

doc-src/SASS_CHANGELOG.md

@@ -14,6 +14,12 @@
 
 * Fixed `css2sass`'s generation of pseudo-classes so that they're backslash-escaped.
 
+### Edge Rails Compatibility
+
+* Don't use `RAILS_ROOT` directly.
+  This no longer exists in Rails 3.0.
+  Instead abstract this out as `Haml::Util.rails_root`.
+
 ## [2.2.10](http://github.com/nex3/haml/commit/2.2.10)
 
 * Add support for attribute selectors with spaces around the `=`.

lib/haml/template.rb

@@ -61,14 +61,14 @@ else
   Haml::Template.try_enabling_xss_integration
 end
 
-if defined?(RAILS_ROOT)
+if Haml::Util.rails_root
   # Update init.rb to the current version
   # if it's out of date.
   #
   # We can probably remove this as of v1.9,
   # because the new init file is sufficiently flexible
   # to not need updating.
-  rails_init_file = File.join(RAILS_ROOT, 'vendor', 'plugins', 'haml', 'init.rb')
+  rails_init_file = File.join(Haml::Util.rails_root, 'vendor', 'plugins', 'haml', 'init.rb')
   haml_init_file = Haml::Util.scope('init.rb')
   begin
     if File.exists?(rails_init_file)
@@ -79,7 +79,7 @@ if defined?(RAILS_ROOT)
     warn <<END
 HAML WARNING:
 #{rails_init_file} is out of date and couldn't be automatically updated.
-Please run `haml --rails #{File.expand_path(RAILS_ROOT)}' to update it.
+Please run `haml --rails #{File.expand_path(Haml::Util.rails_root)}' to update it.
 END
   end
 end

lib/haml/util.rb

@@ -122,6 +122,19 @@ module Haml
       end
     end
 
+    ## Cross Rails Version Compatibility
+
+    # Returns the root of the Rails application,
+    # if this is running in a Rails context.
+    # Returns `nil` if no such root is defined.
+    #
+    # @return [String, nil]
+    def rails_root
+      return Rails.root if defined?(Rails.root)
+      return RAILS_ROOT if defined?(RAILS_ROOT)
+      return nil
+    end
+
     ## Rails XSS Safety
 
     # Whether or not ActionView's XSS protection is available and enabled,

lib/sass/plugin/rails.rb

@@ -1,9 +1,9 @@
 unless defined?(Sass::RAILS_LOADED)
   Sass::RAILS_LOADED = true
 
-  Sass::Plugin.options.merge!(:template_location => RAILS_ROOT + '/public/stylesheets/sass',
-                              :css_location      => RAILS_ROOT + '/public/stylesheets',
-                              :cache_location    => RAILS_ROOT + '/tmp/sass-cache',
+  Sass::Plugin.options.merge!(:template_location => Haml::Util.rails_root + '/public/stylesheets/sass',
+                              :css_location      => Haml::Util.rails_root + '/public/stylesheets',
+                              :cache_location    => Haml::Util.rails_root + '/tmp/sass-cache',
                               :always_check      => RAILS_ENV != "production",
                               :full_exception    => RAILS_ENV != "production")
 

test/test_helper.rb

@@ -9,12 +9,6 @@ require 'sass'
 
 Sass::RAILS_LOADED = true unless defined?(Sass::RAILS_LOADED)
 
-# required because of Sass::Plugin
-unless defined? RAILS_ROOT
-  RAILS_ROOT = '.'
-  MERB_ENV = RAILS_ENV  = 'testing'
-end
-
 class Test::Unit::TestCase
   def munge_filename(opts)
     return if opts[:filename]