check the arity of #document_partial_name before calling the new 2-ar…

…g form

app/helpers/blacklight/blacklight_helper_behavior.rb

@@ -472,7 +472,12 @@ def render_document_partials(doc, partials = [], locals ={})
   # @param [String] base name for the partial
   # @param [Hash] locales to pass through to the partials
   def render_document_partial(doc, base_name, locals = {})
-    format = document_partial_name(doc, base_name)
+    format = if method(:document_partial_name).arity == 1
+      Deprecation.warn self, "The #document_partial_name with a single argument is deprecated. Update your override to include a second argument for the 'base name'"
+      document_partial_name(doc)
+    else
+      document_partial_name(doc, base_name)
+    end
 
     document_partial_path_templates.each do |str|
       # XXX rather than handling this logic through exceptions, maybe there's a Rails internals method

spec/helpers/blacklight_helper_spec.rb

@@ -445,6 +445,27 @@ def mock_document_app_helper_url *args
       expect(helper.should_show_spellcheck_suggestions? response).to be_false
     end
   end
+
+  describe "#render_document_partials" do
+    let(:doc) { double }
+    before do
+      helper.stub(document_partial_path_templates: [])
+    end
+
+    it "should get the document format from document_partial_name" do
+      helper.should_receive(:document_partial_name).with(doc, :xyz)
+      helper.render_document_partial(doc, :xyz)    
+    end
+
+    context "with a 1-arg form of document_partial_name" do
+      it "should only call the 1-arg form of the document_partial_name" do
+        helper.should_receive(:method).with(:document_partial_name).and_return(double(arity: 1))
+        helper.should_receive(:document_partial_name).with(doc)
+        Deprecation.should_receive(:warn)
+        helper.render_document_partial(doc, nil)
+      end
+    end
+  end
 
   describe "#document_partial_name" do
     let(:blacklight_config) { Blacklight::Configuration.new }