1 files changed, 44 insertions, 0 deletions
diff --git a/railties/lib/rails_generator/spec.rb b/railties/lib/rails_generator/spec.rb
new file mode 100644
index 0000000000..ad609b8fe3
--- /dev/null
+++ b/railties/lib/rails_generator/spec.rb
@@ -0,0 +1,44 @@
+module Rails
+  module Generator
+    # A spec knows where a generator was found and how to instantiate it.
+    # Metadata include the generator's name, its base path, and the source
+    # which yielded it (PathSource, GemSource, etc.)
+    class Spec
+      attr_reader :name, :path, :source
+
+      def initialize(name, path, source)
+        @name, @path, @source = name, path, source
+      end
+
+      # Look up the generator class.  Require its class file, find the class
+      # in ObjectSpace, tag it with this spec, and return.
+      def klass
+        unless @klass
+          require class_file
+          @klass = lookup_class
+          @klass.spec = self
+        end
+        @klass
+      end
+
+      def class_file
+        "#{path}/#{name}_generator.rb"
+      end
+
+      def class_name
+        "#{name.camelize}Generator"
+      end
+
+      private
+        # Search for the first Class descending from Rails::Generator::Base
+        # whose name matches the requested class name.
+        def lookup_class
+          ObjectSpace.each_object(Class) do |obj|
+            return obj if obj.ancestors.include?(Rails::Generator::Base) and
+                          obj.name.split('::').last == class_name
+          end
+          raise NameError, "Missing #{class_name} class in #{class_file}"
+        end
+    end
+  end
+end