オブジェクト指向設計実践ガイド 9章 ダックタイプをテストする

ch9_trip.rb

# frozen_string_literal: true

class Trip
  def prepare(preparers)
    # ...

    preparers.each do |preparer|
      preparer.prepare_trip(foo: self)
    end

    # ...
  end
end

# Chapter 9: Designing Cost-Effective Tests
# Testing Duck Type
require 'minitest/autorun'

class TripTest < Minitest::Test
  def test_requests_trip_preparation
    @preparer = Minitest::Mock.new
    @trip = Trip.new
    @preparer.expect(:prepare_trip, nil, [foo: @trip])

    @trip.prepare([@preparer])
    @preparer.verify
  end
end