Delegate DSL method values to their superclass

When inheriting from +Resource::LWRPBase+, the +default_action+ and +actions+
attributes are set as class instance variables. In Ruby's object model, class
instance variables are **not** shared with children. So subclassing a resource
that extended from +Resource::LWRPBase+ would result in some unexplainable
side-effects:

  class Chef::Resource::Parent < Chef::Resource::LWRPBase
    actions :execute
    default_action :execute
  end

  class Child::Resource::Child < Chef::Resource::Parent
    # In here, +actions+ and +default_action+ are **not** inherited so they
    # are +nil+!
  end

This commit tells resources that inherit from LWRPBase to check their
superclasses for values if they do not have one on their own.

This commit also deprecate +valid_actions+ in favor of just using +actions+ in
the LWRP DSL.

2 files changed, 92 insertions, 7 deletions

diff --git a/lib/chef/resource/lwrp_base.rb b/lib/chef/resource/lwrp_base.rb
index b7bb7d08fd..5e5b05e3ce 100644
--- a/lib/chef/resource/lwrp_base.rb
+++ b/lib/chef/resource/lwrp_base.rb
@@ -92,19 +92,32 @@ class Chef
       # Sets the default action
       def self.default_action(action_name=NULL_ARG)
         unless action_name.equal?(NULL_ARG)
-          valid_actions.push(action_name)
-          @default_action = action_name
+          action = action_name.to_sym
+          actions.push(action) unless actions.include?(action)
+          @default_action = action
         end
-        @default_action
+
+        @default_action ||= from_superclass(:default_action)
       end
 
       # Adds +action_names+ to the list of valid actions for this resource.
       def self.actions(*action_names)
-        valid_actions.push(*action_names)
+        if action_names.empty?
+          @actions || from_superclass(:actions, []).dup
+        else
+          # BC-compat way for checking if actions have already been defined
+          if @actions
+            @actions.push(*action_names)
+          else
+            @actions = action_names
+          end
+        end
       end
 
-      def self.valid_actions
-        @valid_actions ||= []
+      # @deprecated
+      def self.valid_actions(*args)
+        Chef::Log.warn("`valid_actions' is deprecated, please use actions `instead'!")
+        actions(*args)
       end
 
       # Set the run context on the class. Used to provide access to the node
@@ -125,6 +138,17 @@ class Chef
         DelayedEvaluator.new(&block)
       end
 
+      private
+
+      # Get the value from the superclass, if it responds, otherwise return
+      # +nil+. Since class instance variables are **not** inherited upon
+      # subclassing, this is a required check to ensure Chef pulls the
+      # +default_action+ and other DSL-y methods when extending LWRP::Base.
+      def self.from_superclass(m, default = nil)
+        return default if superclass == Chef::Resource::LWRPBase
+        superclass.respond_to?(m) ? superclass.send(m) : default
+      end
+
       # Default initializer. Sets the default action and allowed actions.
       def initialize(name, run_context=nil)
         super(name, run_context)
@@ -137,7 +161,7 @@ class Chef
 
         @resource_name = self.class.resource_name.to_sym
         @action = self.class.default_action
-        allowed_actions.push(self.class.valid_actions).flatten!
+        allowed_actions.push(self.class.actions).flatten!
       end
 
     end
diff --git a/spec/unit/lwrp_spec.rb b/spec/unit/lwrp_spec.rb
index eaa58bf48c..bffec9cace 100644
--- a/spec/unit/lwrp_spec.rb
+++ b/spec/unit/lwrp_spec.rb
@@ -180,6 +180,67 @@ describe "LWRP" do
       end
     end
 
+    describe "when inheriting from LWRPBase" do
+      let(:parent) do
+        Class.new(Chef::Resource::LWRPBase) do
+          actions :eat, :sleep
+          default_action :eat
+        end
+      end
+
+      context "when the child does not defined the methods" do
+        let(:child) do
+          Class.new(parent)
+        end
+
+        it "delegates #actions to the parent" do
+          expect(child.actions).to eq([:eat, :sleep])
+        end
+
+        it "delegates #default_action to the parent" do
+          expect(child.default_action).to eq(:eat)
+        end
+      end
+
+      context "when the child does define the methods" do
+        let(:child) do
+          Class.new(parent) do
+            actions :dont_eat, :dont_sleep
+            default_action :dont_eat
+          end
+        end
+
+        it "does not delegate #actions to the parent" do
+          expect(child.actions).to eq([:dont_eat, :dont_sleep])
+        end
+
+        it "does not delegate #default_action to the parent" do
+          expect(child.default_action).to eq(:dont_eat)
+        end
+      end
+
+      context "when actions are already defined" do
+        let(:child) do
+          Class.new(parent) do
+            actions :eat
+            actions :sleep
+            actions :drink
+          end
+        end
+
+        def raise_if_deprecated!
+          if Chef::VERSION.split('.').first.to_i > 11
+            raise "This test should be removed and the associated code should be removed!"
+          end
+        end
+
+        it "ammends actions when they are already defined" do
+          raise_if_deprecated!
+          expect(child.actions).to eq([:eat, :sleep, :drink])
+        end
+      end
+    end
+
   end
 
   describe "Lightweight Chef::Provider" do