Test bitemporal behavior

1. it should be possible to set valid_at
2. valid_at should be set to created_at if valid_at is null

Author: lukaszreszke

contrib/ruby_event_store-sequel/lib/ruby_event_store/sequel/event_repository.rb

@@ -168,7 +168,7 @@ def record(h)
             data: h[:data],
             metadata: h[:metadata],
             timestamp: h[:created_at].iso8601(TIMESTAMP_PRECISION),
-            valid_at: h[:valid_at].iso8601(TIMESTAMP_PRECISION)
+            valid_at: (h[:valid_at].nil? ? h[:created_at] : h[:valid_at]).iso8601(TIMESTAMP_PRECISION)
           )
           .deserialize(@serializer)
       end

contrib/ruby_event_store-sequel/spec/event_repository_spec.rb

@@ -59,16 +59,56 @@ module Sequel
         expect do
           expect do
             repository.link_to_stream(
-              %w[
-                72922e65-1b32-4e97-8023-03ae81dd3a27
-                d9f6d02a-05f0-4c27-86a9-ad7c4ef73042
-              ],
+              %w[72922e65-1b32-4e97-8023-03ae81dd3a27 d9f6d02a-05f0-4c27-86a9-ad7c4ef73042],
               Stream.new("flow"),
               ExpectedVersion.none
             )
           end.to raise_error(EventNotFound)
         end.to match_query /SELECT .*event_store_events.*event_id.* FROM .*event_store_events.* WHERE .*event_store_events.*.event_id.* IN \('72922e65-1b32-4e97-8023-03ae81dd3a27', 'd9f6d02a-05f0-4c27-86a9-ad7c4ef73042'\).*/
       end
+
+      specify "with post-valid-at appended record" do
+        helper.sequel[:event_store_events].insert(
+          event_id: id = SecureRandom.uuid,
+          data: "{}",
+          metadata: "{}",
+          event_type: "TestDomainEvent",
+          created_at: t1 = with_precision(Time.now.utc),
+          valid_at: t2 = with_precision(Time.at(0))
+        )
+
+        helper.sequel[:event_store_events_in_streams].insert(
+          stream: "stream",
+          position: 1,
+          event_id: id,
+          created_at: t1
+        )
+
+        record = repository.read(specification.result).first
+        expect(record.timestamp).to eq(t1)
+        expect(record.valid_at).to eq(t2)
+      end
+
+      specify "with pre-valid-at appended record" do
+        helper.sequel[:event_store_events].insert(
+          event_id: id = SecureRandom.uuid,
+          data: "{}",
+          metadata: "{}",
+          event_type: "TestDomainEvent",
+          created_at: t = with_precision(Time.now.utc),
+          valid_at: nil
+        )
+
+        record = repository.read(specification.result).first
+        expect(record.timestamp).to eq(t)
+        expect(record.valid_at).to eq(t)
+      end
+
+      private
+
+      def with_precision(time)
+        time.round(TIMESTAMP_PRECISION)
+      end
     end
   end
 end