Skip 3694 warnings on trivial resource cloning

Turns the 3694 warning into a debug message if the prior resource is
identical to the current resource.  Suggestion for opscode/chef-rfc#76

This also moves resource building out to its own class.

1 files changed, 75 insertions, 0 deletions

diff --git a/spec/unit/recipe_spec.rb b/spec/unit/recipe_spec.rb
index e8c1358ba2..22389a1a82 100644
--- a/spec/unit/recipe_spec.rb
+++ b/spec/unit/recipe_spec.rb
@@ -161,7 +161,82 @@ describe Chef::Recipe do
         zm_resource # force let binding evaluation
         expect { run_context.resource_collection.resources(:zen_master => "klopp") }.to raise_error(Chef::Exceptions::ResourceNotFound)
       end
+    end
+
+    describe "when cloning resources" do
+      def expect_warning
+        expect(Chef::Log).to receive(:warn).with(/3694/)
+        expect(Chef::Log).to receive(:warn).with(/Previous/)
+        expect(Chef::Log).to receive(:warn).with(/Current/)
+      end
+
+      it "should emit a 3694 warning when attributes change" do
+        recipe.zen_master "klopp" do
+          something "bvb"
+        end
+        expect_warning
+        recipe.zen_master "klopp" do
+          something "vbv"
+        end
+      end
+
+      it "should emit a 3694 warning when attributes change" do
+        recipe.zen_master "klopp" do
+          something "bvb"
+        end
+        expect_warning
+        recipe.zen_master "klopp" do
+          something "bvb"
+          peace true
+        end
+      end
 
+      it "should emit a 3694 warning when attributes change" do
+        recipe.zen_master "klopp" do
+          something "bvb"
+          peace true
+        end
+        expect_warning
+        recipe.zen_master "klopp" do
+          something "bvb"
+        end
+      end
+
+      it "should emit a 3694 warning for non-trivial attributes (unfortunately)" do
+        recipe.zen_master "klopp" do
+          something "bvb"
+        end
+        expect_warning
+        recipe.zen_master "klopp" do
+          something "bvb"
+        end
+      end
+
+      it "should not emit a 3694 warning for completely trivial resource cloning" do
+        recipe.zen_master "klopp"
+        expect(Chef::Log).to_not receive(:warn)
+        recipe.zen_master "klopp"
+      end
+
+      it "should not emit a 3694 warning when attributes do not change and the first action is :nothing" do
+        recipe.zen_master "klopp" do
+          action :nothing
+        end
+        expect(Chef::Log).to_not receive(:warn)
+        recipe.zen_master "klopp" do
+          action :score
+        end
+      end
+
+      it "should not emit a 3694 warning when attributes do not change and the second action is :nothing" do
+        recipe.zen_master "klopp" do
+          action :score
+        end
+        expect(Chef::Log).to_not receive(:warn)
+        recipe.zen_master "klopp" do
+          action :nothing
+        end
+      end
     end
 
     describe "creating resources via declare_resource" do