Module: Yes::Core::TestSupport::EventHelpers

Defined in:
lib/yes/core/test_support/event_helpers.rb

Overview

Helpers for working with PgEventstore events in tests.

Examples:

Include in RSpec

RSpec.configure do |config|
  config.include Yes::Core::TestSupport::EventHelpers
end

Instance Method Summary collapse

Instance Method Details

#append_and_reload_event(stream, event) ⇒ Yes::Core::Event

Appends an event to a stream and reloads it

Parameters:

Returns:



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# File 'lib/yes/core/test_support/event_helpers.rb', line 27

def append_and_reload_event(stream, event)
  append_event(stream, event)
  PgEventstore.client.read(stream, options: { max_count: 1, direction: :desc }).first
end

#append_event(stream, event) ⇒ void

This method returns an undefined value.

Appends an event to a stream

Parameters:



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# File 'lib/yes/core/test_support/event_helpers.rb', line 18

def append_event(stream, event)
  PgEventstore.client.append_to_stream(stream, event)
end

#event_instance(event_attrs) ⇒ Yes::Core::Event

Builds a Yes::Core::Event from a hash of event attributes

Parameters:

  • event_attrs (Hash) —

    event attributes with :context, :aggregate, :event, :data keys

Returns:



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# File 'lib/yes/core/test_support/event_helpers.rb', line 67

def event_instance(event_attrs)
  Yes::Core::Event.new(
    type: event_type(event_attrs),
    data: (event_attrs[:data] || {}).with_indifferent_access
  )
end

#event_stream(event_attrs) ⇒ PgEventstore::Stream

Builds a PgEventstore::Stream from event attributes

Parameters:

  • event_attrs (Hash) —

    event attributes with :context, :aggregate, :data keys

Returns:

  • (PgEventstore::Stream) 


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# File 'lib/yes/core/test_support/event_helpers.rb', line 78

def event_stream(event_attrs)
  return event_attrs[:stream] if event_attrs[:stream]

  PgEventstore::Stream.new(
    context: event_attrs[:context],
    stream_name: event_attrs[:aggregate],
    stream_id: event_attrs[:data].first.last
  )
end

#event_type(event_attrs) ⇒ String

Constructs an event type string from event attributes

Parameters:

  • event_attrs (Hash) —

    event attributes with :context, :aggregate/:subject, :event keys

Returns:

  • (String) 


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# File 'lib/yes/core/test_support/event_helpers.rb', line 92

def event_type(event_attrs)
  aggregate_or_subject = event_attrs[:aggregate] || event_attrs[:subject]
  "#{event_attrs[:context]}::#{aggregate_or_subject}#{event_attrs[:event]}"
end

#given_events { ... } ⇒ void

This method returns an undefined value.

Creates events from a block and appends them to the eventstore

Examples:

given_events do
  [{ context: 'MyContext', aggregate: 'MyAggregate', event: 'Created', data: { id: '123' } }]
end

Yields:

  • block that returns an array of event attribute hashes

Yield Returns:

  • (Array<Hash>) —

    each hash should have :context, :aggregate, :event, :data keys



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# File 'lib/yes/core/test_support/event_helpers.rb', line 54

def given_events(&)
  events_data = yield
  events_data.each do |event_data|
    event = event_instance(event_data)
    stream = event_stream(event_data)
    append_event(stream, event)
  end
end

#safe_read(stream) ⇒ Array<Yes::Core::Event> Also known as: read_events

Reads eventstore and returns events from the stream or an empty array if stream does not exist

Parameters:

  • stream (PgEventstore::Stream)

Returns:



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# File 'lib/yes/core/test_support/event_helpers.rb', line 36

def safe_read(stream)
  PgEventstore.client.read(stream)
rescue PgEventstore::StreamNotFoundError
  []
end