Add sourcedir accessor that holds the path to the extracted source

Fixes #142

lib/fpm/cookery/packager.rb

@@ -131,7 +131,9 @@ def dispense
               extracted_source = recipe.extracted_source
             end
 
-            recipe.run_lifecycle_hook(:after_source_extraction, recipe.builddir(extracted_source))
+            # Make the path to the extracted source available in the recipe.
+            recipe.sourcedir = recipe.builddir(extracted_source)
+            recipe.run_lifecycle_hook(:after_source_extraction, recipe.sourcedir)
 
             Log.info "Using source directory: #{extracted_source}"
 

lib/fpm/cookery/recipe.rb

@@ -184,7 +184,11 @@ def extracted_source
         self.class.extracted_source
       end
 
-      attr_reader :source_handler
+      def sourcedir=(sourcedir)
+        @sourcedir = sourcedir
+      end
+
+      attr_reader :source_handler, :sourcedir
 
       extend Forwardable
       def_delegator :@source_handler, :local_path

spec/recipe_spec.rb

@@ -280,6 +280,17 @@ def self.spec_recipe_attribute_list(name, list)
     end
   end
 
+  describe ".sourcedir" do
+    it "is not set by default" do
+      expect(recipe.sourcedir).to be_nil
+    end
+
+    it "can be set" do
+      recipe.sourcedir = '/tmp/foo/bar'
+      expect(recipe.sourcedir).to eq('/tmp/foo/bar')
+    end
+  end
+
   describe "#local_path" do
     it "returns the path to the local source file" do
       klass.class_eval do