Merge pull request #323 from adrienthebo/maint/master/settings-contai…

…ner-inheritance

Add Settings::Container#reset!, set up inheritance relationship

lib/r10k/settings/container.rb

@@ -74,6 +74,12 @@ def valid_key?(key)
     end
   end
 
+  # Clear all existing settings in this container. Valid settings are left alone.
+  # @return [void]
+  def reset!
+    @settings = {}
+  end
+
   private
 
   def validate_key!(key)

lib/r10k/settings/mixin.rb

@@ -41,5 +41,14 @@ def defaults
     def settings
       @settings ||= R10K::Settings::Container.new(defaults)
     end
+
+    # Allow subclasses to use the settings of the parent class as default values
+    #
+    # @return [void]
+    def inherited(subclass)
+      subclass.instance_eval do
+        @settings = R10K::Settings::Container.new(superclass.settings)
+      end
+    end
   end
 end

spec/unit/settings/container_spec.rb

@@ -65,4 +65,21 @@
       end
     end
   end
+
+  describe "resetting" do
+    before do
+      subject.add_valid_key :v
+    end
+
+    it "unsets all settings" do
+      subject[:v] = "hi"
+      subject.reset!
+      expect(subject[:v]).to be_nil
+    end
+
+    it "doesn't remove valid values" do
+      subject.reset!
+      expect(subject.valid_key?(:v)).to be_truthy
+    end
+  end
 end