Added source_paths to rails generators. If a template is added to RAILS_ROOT/lib/templates/base/generator it will be used. For example, to customize edit.html.erb template on scaffold, just add a customized copy at RAILS_ROOT/lib/templates/erb/scaffold.

railties/lib/generators/base.rb

@@ -6,15 +6,16 @@ module Rails
     end
 
     class Base < Thor::Group
+      include Thor::Actions
+      include Rails::Generators::Actions
+
       # Automatically sets the source root based on the class name.
       #
       def self.source_root
-        File.expand_path(File.join(File.dirname(__FILE__), base_name, generator_name, 'templates'))
+        @_rails_source_root ||= File.expand_path(File.join(File.dirname(__FILE__),
+                                                 base_name, generator_name, 'templates'))
       end
 
-      include Thor::Actions
-      include Rails::Generators::Actions
-
       # Tries to get the description from a USAGE file one folder above the source
       # root otherwise uses a default description.
       #
@@ -148,6 +149,19 @@ module Rails
         super(name, options)
       end
 
+      # Cache source root and add lib/generators/base/generator/templates to
+      # source paths.
+      #
+      def self.inherited(base) #:nodoc:
+        super
+        base.source_root # Cache source root
+
+        if defined?(RAILS_ROOT) && base.name !~ /Base$/
+          path = File.expand_path(File.join(RAILS_ROOT, 'lib', 'templates'))
+          base.source_paths << File.join(path, base.base_name, base.generator_name)
+        end
+      end
+
       protected
 
         # Check whether the given class names are already taken by user

railties/lib/vendor/thor-0.11.1/lib/thor/actions.rb

@@ -28,45 +28,27 @@ class Thor
     end
 
     module ClassMethods
-      # Hold source paths used by Thor::Actions.
+      # Hold source paths for one Thor instance. source_paths_for_search is the
+      # method responsible to gather source_paths from this current class,
+      # inherited paths and the source root.
       #
       def source_paths
-        @source_paths ||= from_superclass(:source_paths, [])
+        @source_paths ||= []
       end
 
-      # On inheritance, add source root to source paths so dynamic source_root
-      # (that depends on the class name, for example) are cached properly.
+      # Returns the source paths in the following order:
       #
-      def inherited(base) #:nodoc:
-        super
-        base.source_paths
-        if base.respond_to?(:source_root) && !base.source_paths.include?(base.source_root)
-          base.source_paths.unshift(base.source_root)
-        end
-      end
-
-      # Deal with source root cache in source_paths. source_paths in the
-      # inheritance chain are tricky to implement because:
+      #   1) This class source paths
+      #   2) Source root
+      #   3) Parents source paths
       #
-      # 1) We have to ensure that paths from the parent class appears later in
-      #    the source paths array.
-      #
-      # 2) Whenever source_root is added, it has to be cached because __FILE__
-      #    in ruby returns relative locations.
-      #
-      # 3) If someone wants to add source paths dinamically, added paths have
-      #    to come before the source root.
-      #
-      # This method basically check if source root was added and put it between
-      # the inherited paths and the user added paths.
-      #
-      def singleton_method_added(method) #:nodoc:
-        if method == :source_root
-          inherited_paths = from_superclass(:source_paths, [])
-
-          self.source_paths.reject!{ |path| inherited_paths.include?(path) }
-          self.source_paths.push(*self.source_root)
-          self.source_paths.concat(inherited_paths)
+      def source_paths_for_search
+        @source_paths_for_search ||= begin
+          paths = []
+          paths += self.source_paths
+          paths << self.source_root if self.respond_to?(:source_root)
+          paths += from_superclass(:source_paths, [])
+          paths
         end
       end
     end
@@ -132,14 +114,14 @@ class Thor
     #
     def find_in_source_paths(file)
       relative_root = relative_to_original_destination_root(destination_root, false)
-      source_file   = nil
+      paths = self.class.source_paths_for_search
 
-      self.class.source_paths.each do |source|
+      paths.each do |source|
         source_file = File.expand_path(file, File.join(source, relative_root))
         return source_file if File.exists?(source_file)
       end
 
-      if self.class.source_paths.empty?
+      if paths.empty?
         raise Error, "You don't have any source path defined for class #{self.class.name}. To fix this, " <<
                      "you can define a source_root in your class."
       else

railties/test/generators_test.rb

@@ -84,7 +84,7 @@ class GeneratorsTest < GeneratorsTestCase
     assert_equal "Others: active_record:fixjour, fixjour, mspec, rails:javascripts, wrong.", output
   end
 
-  def test_warning_is_raised_if_generator_cant_be_loaded
+  def test_warning_is_shown_if_generator_cant_be_loaded
     output = capture(:stderr){ Rails::Generators.find_by_namespace(:wrong) }
     assert_match /\[WARNING\] Could not load generator at/, output
     assert_match /Error: uninitialized constant Rails::Generator/, output
@@ -96,4 +96,22 @@ class GeneratorsTest < GeneratorsTestCase
   ensure
     Thor::Base.shell = Thor::Shell::Color
   end
+
+  def test_rails_root_templates
+    template = File.join(RAILS_ROOT, "lib", "templates", "active_record", "model", "model.rb")
+
+    # Create template
+    mkdir_p(File.dirname(template))
+    File.open(template, 'w'){ |f| f.write "empty" }
+
+    output = capture(:stdout) do
+      Rails::Generators.invoke :model, ["user"], :destination_root => destination_root
+    end
+
+    assert_file "app/models/user.rb" do |content|
+      assert_equal "empty", content
+    end
+  ensure
+    rm_rf File.dirname(template)
+  end
 end