Ensuring that Traject::SolrJsonWriter::MaxSkippedRecordsExceeded erro…

…rs are only logged and not raised during indexing (#707)

config/traject/dataspace_research_data_config.rb

@@ -14,6 +14,30 @@
   provide 'logger', Logger.new($stderr, level: Logger::ERROR)
   provide "nokogiri.each_record_xpath", "//items/item"
   provide "dataspace_communities", DataspaceCommunities.new('./spec/fixtures/files/dataspace_communities.json')
+
+  provide "mapping_rescue", lambda { |context, exception|
+    if exception.is_a?(Traject::SolrJsonWriter::MaxSkippedRecordsExceeded)
+      context.logger.error("Encountered exception: #{exception}")
+    else
+
+      # This is the implementation from Traject::Indexer#default_mapping_rescue
+      # @see https://github.com/traject/traject/blob/main/lib/traject/indexer.rb#L483
+      msg = "Unexpected error on record #{context.record_inspect}\n"
+      msg += "    while executing #{context.index_step.inspect}\n"
+
+      msg += begin
+        "\n    Record: #{context.source_record}\n"
+             rescue StandardError => to_s_exception
+               "\n    (Could not log record, #{to_s_exception})\n"
+      end
+
+      msg += Traject::Util.exception_to_log_message(exception)
+
+      context.logger.error(msg) if context.logger
+
+      raise exception
+    end
+  }
 end
 
 each_record do |record, context|

spec/lib/dspace_indexer_spec.rb

@@ -38,6 +38,44 @@
         response = Blacklight.default_index.connection.get 'select', params: { q: '*:*' }
         expect(response["response"]["numFound"]).to eq 38
       end
+
+      context "when an error is raised" do
+        before do
+          indexer.traject_indexer.configure do
+            to_field 'id' do |_, _, _|
+              raise(StandardError, "I just like raising errors")
+            end
+          end
+
+          allow(indexer.traject_indexer.logger).to receive(:error)
+        end
+
+        it "propagates StandardError instances" do
+          expect { indexer.index }.to raise_error(StandardError, "I just like raising errors")
+
+          expect(indexer.traject_indexer.logger).not_to be_falsy
+          expect(indexer.traject_indexer.logger).to have_received(:error).with(/Unexpected error on record/).at_least(:once)
+        end
+      end
+
+      context "when a max skipped records error is raised" do
+        before do
+          indexer.traject_indexer.configure do
+            to_field 'id' do |_, _, _|
+              raise(Traject::SolrJsonWriter::MaxSkippedRecordsExceeded)
+            end
+          end
+
+          allow(indexer.traject_indexer.logger).to receive(:error)
+        end
+
+        it "only logs an error message" do
+          indexer.index
+
+          expect(indexer.traject_indexer.logger).not_to be_falsy
+          expect(indexer.traject_indexer.logger).to have_received(:error).with("Encountered exception: Traject::SolrJsonWriter::MaxSkippedRecordsExceeded").at_least(:once)
+        end
+      end
     end
 
     context 'invoking from CLI' do