Implement proper reset settings for adapters

spec/gson_adapter_spec.rb

@@ -7,4 +7,4 @@
 
 describe MultiJson::Adapters::Gson do
   it_behaves_like 'an adapter', described_class
-end
+end

spec/oj_adapter_spec.rb

@@ -10,13 +10,11 @@
 
   describe '.dump' do
     describe '#dump_options' do
-      before{ MultiJson.use :oj }
-      before{ MultiJson.dump_options = MultiJson.adapter.dump_options = {} }
-      after{ MultiJson.dump_options = MultiJson.adapter.dump_options = {} }
+      around{ |example| with_default_options(&example) }
 
       it 'ensures indent is a Fixnum' do
-        expect { MultiJson.dump(42, :indent => '')}.not_to raise_error
+        expect{ MultiJson.dump(42, :indent => '')}.not_to raise_error
       end
     end
   end
-end
+end

spec/spec_helper.rb

@@ -79,3 +79,11 @@ def get_exception(exception_class = StandardError)
     exception
   end
 end
+
+def with_default_options
+  adapter = MultiJson.adapter
+  adapter.load_options = adapter.dump_options = MultiJson.load_options = MultiJson.dump_options = nil
+  yield
+ensure
+  adapter.load_options = adapter.dump_options = MultiJson.load_options = MultiJson.dump_options = nil
+end