Fix EventTarget comparison with wildcard

[jeffschoner-stripe]

Motivation

During registration, the Dispatcher places all dispatch targets into a hash keyed on target. Before #111, event targets were always of type EventTarget. With that change, event targets could also be of type String (i.e., "*"). In the implementation of Hash, objects of these two types can be compared using the eql? method when they end up in the same bucket behind the scenes. EventTarget.eql? can only compare objects that have an id and type field like itself. Because a String does not have these fields, it sometimes fails with a specific error while trying to register a dispatch handler:

Failure/Error: id == other.id && type == other.type

     NoMethodError:
       undefined method `id' for "*":String
     # ./lib/temporal/workflow/history/event_target.rb:65:in `=='
     # ./lib/temporal/workflow/history/event_target.rb:70:in `eql?'
     # ./spec/unit/lib/temporal/workflow/dispatcher_spec.rb:89:in `block (4 levels) in <top (required)>'

Summary

• Modifies EventTarget.eql? to return false when called with an object that is not of its own type
• Separates TARGET_WILDCARD from WILDCARD to more clearly indicate their separate functions
• The dispatcher unit tests have been updated to use EventTarget objects rather than Strings to reflect the actual type used in the implementation outside of the tests
• A new unit test has been added to ensure EventType can be compared against TARGET_WILDCARD

Testing

Updated and new tests can all be run with,

rspec spec/unit/lib/temporal/workflow/dispatcher_spec.rb

[antstorm]

Great catch! Thank you for noticing and quickly fixing it