Remove the explicit superclass from monkey-patch

lib/active_fedora.rb

@@ -11,26 +11,23 @@
 # Monkey patching RDF::Literal::DateTime to support fractional seconds.
 # See https://github.com/samvera/active_fedora/issues/497
 # Also monkey patches in a fix for timezones to be stored properly.
-#
-# RDF 3.2.5 changes the superclass of DateTime to RDF::Temporal
-# TODO: Determine if this monkey-patch is needed even with RDF pre-3.2.5 (All the tests pass without it)
-if RDF::Literal::DateTime.superclass == RDF::Literal
-  module RDF
-    class Literal
-      class DateTime < Literal
-	ALTERNATIVE_FORMAT   = '%Y-%m-%dT%H:%M:%S'.freeze
-	DOT                  = '.'.freeze
-	EMPTY                = ''.freeze
-	TIMEZONE_FORMAT      = '%:z'.freeze
-
-	def to_s
-	  @string ||= begin
-	    # Show nanoseconds but remove trailing zeros
-	    nano = @object.strftime('%N').sub(/0+\Z/, EMPTY)
-	    nano = DOT + nano unless nano.blank?
-	    @object.strftime(ALTERNATIVE_FORMAT) + nano + @object.strftime(TIMEZONE_FORMAT)
-	  end
-	end
+# This is needed in both RDF <= 3.2.4 and RDF >= 3.2.5
+# TODO: Figure out how to contribute something upstream to avoid monkey-patching
+module RDF
+  class Literal
+    class DateTime
+      ALTERNATIVE_FORMAT   = '%Y-%m-%dT%H:%M:%S'.freeze
+      DOT                  = '.'.freeze
+      EMPTY                = ''.freeze
+      TIMEZONE_FORMAT      = '%:z'.freeze
+
+      def to_s
+        @string ||= begin
+          # Show nanoseconds but remove trailing zeros
+          nano = @object.strftime('%N').sub(/0+\Z/, EMPTY)
+          nano = DOT + nano unless nano.blank?
+          @object.strftime(ALTERNATIVE_FORMAT) + nano + @object.strftime(TIMEZONE_FORMAT)
+        end
       end
     end
   end

spec/integration/date_time_properties_spec.rb

@@ -33,9 +33,33 @@ class Foo < ActiveFedora::Base
 
   describe 'serializing' do
     let(:object) { Foo.new(date: [date]) }
-    let(:triple) { object.resource.query(predicate: ::RDF::Vocab::DC.date).to_a.first }
+    let(:triple) { object.resource.query(predicate: ::RDF::Vocab::DC.date).to_a.first.object }
     it 'time zone must have semicolin to be a cannonical XMLSchema#dateTime' do
       expect(triple.to_s).to match(/\+01:00/)
     end
+
+    context 'nanoseconds' do
+      let(:date) { DateTime.parse("2015-10-22T10:20:03.653991025+01:00") }
+
+      it 'includes nanosecond precision' do
+        expect(triple.to_s).to eq "2015-10-22T10:20:03.653991025+01:00"
+      end
+
+      context 'with trailing zeros' do
+        let(:date) { DateTime.parse("2015-10-22T15:34:20.97800000-11:00") }
+
+        it 'trims trailing zeros' do
+          expect(triple.to_s).to eq "2015-10-22T15:34:20.978-11:00"
+        end
+
+        context 'and only zero nanoseconds' do
+          let(:date) { DateTime.parse("2015-10-22T15:34:20.000000000-11:00") }
+
+          it 'trims trailing zeros and dot if nanoseconds are all 0' do
+            expect(triple.to_s).to eq "2015-10-22T15:34:20-11:00"
+          end
+        end
+      end
+    end
   end
 end