Module: Sequent::Test::CommandHandlerHelpers

Defined in:
lib/sequent/test/command_handler_helpers.rb

Overview

Use in tests

This provides a nice DSL for event based testing of your CommandHandler like

given_events InvoiceCreatedEvent.new(args) when_command PayInvoiceCommand.new(args) then_events InvoicePaidEvent.new(args)

Example for Rspec config

RSpec.configure do |config|

config.include Sequent::Test::CommandHandlerHelpers

end

Then in a spec

describe InvoiceCommandHandler do

before :each do
  Sequent.configuration.event_store = Sequent::Test::CommandHandlerHelpers::FakeEventStore.new
  Sequent.configuration.command_handlers = [] # add your command handlers here
  Sequent.configuration.event_handlers = [] # add you event handlers (eg, workflows) here
end

it "marks an invoice as paid" do
  given_events InvoiceCreatedEvent.new(args)
  when_command PayInvoiceCommand(args)
  then_events InvoicePaidEvent(args)
end

end

Defined Under Namespace

Classes: FakeEventStore

Instance Method Summary collapse

Instance Method Details

#given_events(*events) ⇒ Object 



143
144
145
 
# File 'lib/sequent/test/command_handler_helpers.rb', line 143

def given_events(*events)
  Sequent.configuration.event_store.given_events(events.flatten(1))
end

#then_events(*expected_events) ⇒ Object 



151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
 
# File 'lib/sequent/test/command_handler_helpers.rb', line 151

def then_events(*expected_events)
  expected_classes = expected_events.flatten(1).map { |event| event.instance_of?(Class) ? event : event.class }
  expect(Sequent.configuration.event_store.stored_events.map(&:class)).to eq(expected_classes)

  Sequent
    .configuration
    .event_store
    .stored_events
    .zip(expected_events.flatten(1))
    .each_with_index do |(actual, expected), index|
      next if expected.instance_of?(Class)

      actual_hash = Sequent::Core::Oj.strict_load(Sequent::Core::Oj.dump(actual.payload))
      expected_hash = Sequent::Core::Oj.strict_load(Sequent::Core::Oj.dump(expected.payload))
      next unless expected

      # rubocop:disable Layout/LineLength
      expect(actual_hash)
        .to eq(expected_hash),
            "#{index + 1}th Event of type #{actual.class} not equal\nexpected: #{expected_hash.inspect}\n     got: #{actual_hash.inspect}"
      # rubocop:enable Layout/LineLength
    end
end

#then_no_events ⇒ Object 



175
176
177
 
# File 'lib/sequent/test/command_handler_helpers.rb', line 175

def then_no_events
  then_events
end

#when_command(command) ⇒ Object 



147
148
149
 
# File 'lib/sequent/test/command_handler_helpers.rb', line 147

def when_command(command)
  Sequent.configuration.command_service.execute_commands command
end