Wrong type of event's timestamp when using some mappers

[mpraglowski]

When using RubyEventStore::Event class it is expected that metadata should be either Time instance or nil (see https://github.com/RailsEventStore/rails_event_store/blob/master/ruby_event_store/lib/ruby_event_store/event.rb#L39 ) and that works for default setup (mapper):

store = RubyEventStore::InMemoryRepository.new
mapper = RubyEventStore::Mappers::Default.new
es = RubyEventStore::Client.new(repository: store, mapper: mapper)
FooEvent = Class.new(RubyEventStore::Event)
es.publish(FooEvent.new(data: {some: :value}))
es.read.last.timestamp.class
# => Time

but timestamp is String when using JSON serializer:

store = RubyEventStore::InMemoryRepository.new
mapper = RubyEventStore::Mappers::Default.new(serializer: JSON)
es = RubyEventStore::Client.new(repository: store, mapper: mapper)
FooEvent = Class.new(RubyEventStore::Event)
es.publish(FooEvent.new(data: {some: :value}))
es.read.last.timestamp.class
# => String

[mostlyobvious]

Why would we allow nil?

[mostlyobvious]

Does the bug exist in #674 as well?

[mpraglowski]

Why would we allow nil?

because not published events does not have a timestamp:

FooEvent.new.timestamp
# => nil

[mostlyobvious]

No longer a case after merging #674:

mapper = RubyEventStore::Mappers::Default.new
store = RubyEventStore::InMemoryRepository.new(serializer: JSON)
es = RubyEventStore::Client.new(repository: store, mapper: mapper)
FooEvent = Class.new(RubyEventStore::Event)
es.publish(FooEvent.new(data: {some: :value}))
es.read.last.timestamp.class
=> Time