Update data_request_spec.rb (#339)

update validation check: Rails 4 -> 5 changes validation message. It is enough to say that the validation has failed without checking for a specific error message. Especially if we did not customize the error message.

add version check to check correct worker is run after_commit. after_commit tests work differently from Rails 4 to Rails 5, do to commit callbacks not getting called in transactional tests in rails versions less than 5. (This bug gets fixed in Rails 5)

spec/models/data_request_spec.rb

@@ -8,7 +8,7 @@
   context 'validating' do
     it 'should require a user' do
       without_user = build :data_request, user: nil
-      expect(without_user).to fail_validation user: "can't be blank"
+      expect(without_user).to fail_validation
     end
 
     it 'should require a section' do
@@ -75,9 +75,19 @@
 
   describe '#spawn_worker' do
     it 'should run the worker' do
-      data_request = create :tags_data_request
-      expect(TagExportWorker).to receive(:perform_async).with data_request.id
-      data_request.run_callbacks :commit
+      # TODO: Once on Rails 5, Can Remove this Version Check
+      # In Rails Versions < 5, commit callbacks are not getting called in transactional tests.
+      # See https://stackoverflow.com/a/30901628/15768801 for more details.
+      if Rails.version.starts_with?('5')
+        allow(TagExportWorker).to receive(:perform_async)
+        data_request = build :tags_data_request
+        data_request.save!
+        expect(TagExportWorker).to have_received(:perform_async).with data_request.id
+      else
+        data_request = create :tags_data_request
+        expect(TagExportWorker).to receive(:perform_async).with data_request.id
+        data_request.run_callbacks :commit
+      end
     end
   end