Implement source keyword feature for recipes

features/recipe.feature

@@ -8,3 +8,16 @@ Feature: recipe evaluation
     When I execute the recipe
     Then the exit status must be 0
     And the output must contain "hello from recipe"
+
+  Scenario: source keyword, requires a recipe file
+    Given a recipe with:
+      """
+      source 'sourced_recipe'
+      """
+    And a file named "sourced_recipe.rb" with:
+      """
+      puts 'sourced recipe'
+      """
+    When I execute the recipe
+    Then the exit status must be 0
+    And the output must contain "sourced recipe"

lib/producer/core/recipe.rb

@@ -24,6 +24,13 @@ module Producer
             instance_eval &block
           end
         end
+
+
+        private
+
+        def source(filepath)
+          instance_eval File.read("./#{filepath}.rb")
+        end
       end
     end
   end

spec/fixtures/recipes/error.rb

@@ -0,0 +1 @@
+raise 'error from recipe'

spec/producer/core/recipe_spec.rb

@@ -45,6 +45,15 @@ module Producer::Core
           expect { dsl }.to raise_error(RuntimeError, 'error from recipe')
         end
       end
+
+      describe '#source' do
+        let(:code)  { "source '#{fixture_path_for 'recipes/error'}'" }
+        let(:dsl)   { Recipe::DSL.new code }
+
+        it 'evaluates its code' do
+          expect { dsl }.to raise_error(RuntimeError, 'error from recipe')
+        end
+      end
     end
   end
 end