Class: Cucumber::Core::EventBus

Inherits:
Object
  • Object
show all
Defined in:
lib/cucumber/core/event_bus.rb

Overview

Event Bus

Implements an in-process pub-sub event broadcaster allowing multiple observers to subscribe to events that fire as your tests are executed.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(registry = self.class.registry) ⇒ EventBus

Returns a new instance of EventBus.

Parameters:

  • registry (Hash{Symbol => Class}) (defaults to: self.class.registry) —

    a hash of event types to use on the bus



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# File 'lib/cucumber/core/event_bus.rb', line 37

def initialize(registry = self.class.registry)
  @event_types = registry.freeze
  @handlers = {}
  @event_queue = []
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(event_id) ⇒ Object 



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# File 'lib/cucumber/core/event_bus.rb', line 59

def method_missing(event_id, *)
  event_class = event_types.fetch(event_id) { super }
  broadcast event_class.new(*)
end

Instance Attribute Details

#event_types ⇒ Object (readonly)

Returns the value of attribute event_types.



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# File 'lib/cucumber/core/event_bus.rb', line 12

def event_types
  @event_types
end

Class Method Details

.build_registry(*types) ⇒ Hash{Symbol => Class}

Build an event registry to be passed to the Cucumber::Core::EventBus constructor from a list of types. Each type must respond to event_id so that it can be added to the registry hash

Returns:

  • (Hash{Symbol => Class}) 


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# File 'lib/cucumber/core/event_bus.rb', line 32

def self.build_registry(*types)
  types.to_h { |type| [type.event_id, type] }
end

.registry ⇒ Object

The registry contains all the event registered in the core, that will be used by the Cucumber::Core::EventBus by default.



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# File 'lib/cucumber/core/event_bus.rb', line 15

def self.registry
  build_registry(
    Event::Envelope,
    Event::GherkinSourceParsed,
    Event::TestCaseCreated,
    Event::TestCaseStarted,
    Event::TestCaseFinished,
    Event::TestStepCreated,
    Event::TestStepStarted,
    Event::TestStepFinished
  )
end

Instance Method Details

#broadcast(event) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/cucumber/core/event_bus.rb', line 52

def broadcast(event)
  raise ArgumentError, "Event type #{event.class} is not registered. Try one of these:\n#{event_types.values.join("\n")}" unless registered_type?(event.class)

  handlers_for(event.class).each { |handler| handler.call(event) }
  @event_queue << event
end

#on(event_id, handler_object = nil, &handler_proc) ⇒ Object

Register for an event. The handler proc will be called back with each of the attributes of the event



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# File 'lib/cucumber/core/event_bus.rb', line 44

def on(event_id, handler_object = nil, &handler_proc)
  handler = handler_proc || handler_object
  validate_handler_and_event_id!(handler, event_id)
  event_class = event_types[event_id]
  handlers_for(event_class) << handler
  broadcast_queued_events_to handler, event_class
end

#respond_to_missing?(event_id, *args) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cucumber/core/event_bus.rb', line 64

def respond_to_missing?(event_id, *args)
  event_types.key?(event_id) || super
end