Make RailsEventStore::Client#inspect more useful

[mostlyobvious]

By default when you inspect RES::Client in console it returns a lot of unreadable stuff (ivars):

irb(main):001:0> Rails.configuration.event_store
=> #<RailsEventStore::Client:0x000000010923c4e0 @repository=#<RubyEventStore::InstrumentedRepository:0x0000000106e0b2b0 @repository=#<RailsEventStoreActiveRecord::EventRepository:0x000000010923c4b8 @repo_reader=#<RailsEventStoreActiveRecord::EventRepositoryReader:0x000000010923c328>>, @instrumentation=ActiveSupport::Notifications>, @mapper=#<RubyEventStore::Mappers::Default:0x000000010923c300 @serializer=Psych, @events_class_remapping={}>, @broker=#<RubyEventStore::PubSub::Broker:0x0000000106e0acc0 @subscriptions=#<RubyEventStore::PubSub::Subscriptions:0x000000010923c2b0 @local=#<RubyEventStore::PubSub::Subscriptions::LocalSubscriptions:0x000000010923c288 @subscriptions={}>, @global=#<RubyEventStore::PubSub::Subscriptions::GlobalSubscriptions:0x000000010923c1e8 @subscriptions=[]>, @thread=#<RubyEventStore::PubSub::Subscriptions::ThreadSubscriptions:0x000000010923c198 @local=#<RubyEventStore::PubSub::Subscriptions::ThreadLocalSubscriptions:0x000000010923c170 @subscriptions=#<Concurrent::ThreadLocalVar:0x000000010923c148 @default_block=#<Proc:0x000000010923c0f8@/Users/pawelpacana/.rubies/ruby-2.5.1/lib/ruby/gems/2.5.0/gems/ruby_event_store-0.32.0/lib/ruby_event_store/pub_sub/subscriptions.rb:79>, @default=nil, @index=0>>, @global=#<RubyEventStore::PubSub::Subscriptions::ThreadGlobalSubscriptions:0x000000010923c008 @subscriptions=#<Concurrent::ThreadLocalVar:0x0000000106e0b648 @default_block=nil, @default=[], @index=1>>>>, @dispatcher=#<RubyEventStore::InstrumentedDispatcher:0x0000000106e0b238 @dispatcher=#<RubyEventStore::ComposedDispatcher:0x0000000106e0b378 @dispatchers=[#<RubyEventStore::ImmediateAsyncDispatcher:0x0000000106e0b468 @scheduler=#<RailsEventStore::ActiveJobScheduler:0x0000000106e0b4b8>>, #<RubyEventStore::PubSub::Dispatcher:0x0000000106e0b418>]>, @instrumentation=ActiveSupport::Notifications>>, @clock=#<Proc:0x0000000106e0ad38@/Users/pawelpacana/.rubies/ruby-2.5.1/lib/ruby/gems/2.5.0/gems/ruby_event_store-0.32.0/lib/ruby_event_store/client.rb:10 (lambda)>, @metadata=#<Concurrent::ThreadLocalVar:0x0000000106e0abf8 @default_block=nil, @default=nil, @index=2>, @request_metadata=#<Proc:0x0000000106e0b2d8@/Users/pawelpacana/.rubies/ruby-2.5.1/lib/ruby/gems/2.5.0/gems/rails_event_store-0.32.0/lib/rails_event_store/client.rb:28 (lambda)>>

First we could tame most of this noise by presenting the bare minimum — class and object_id.

Next we could extend it with more useful, nicely formatted information, including:

• chosen configuration of repository, dispatcher, etc.
• number of known event subscribers

WDYT?

[mostlyobvious]

Related: https://ruby-doc.org/core-2.5.0/Object.html#method-i-inspect

[mpraglowski]

Next we could extend it with more useful, nicely formatted information, including: ...

Then we shall "force" inspect for all classes implementing subscriptions, dispatcher, repository * mapper. Then RailsEventStore::Client#inspect could look like:

RailsEventStore::Client (Instance id: 0x3fc8ab033c6c)
- repository: <respository.inspect>
- mapper: <mapper.inspect>
- subscriptions: <subscribtions.inspect>
- dispatcher: <dispatcher.inspect>