RSpec DSL for stubbing services

services.rb

module Support
  module Services
    class HaveBeenCalledMatcher
      include RSpec::Mocks::Matchers::Matcher

      NotCalledYet = Class.new(StandardError)

      def initialize(&block)
        @matcher = RSpec::Mocks::Matchers::HaveReceived.new(:call, &block)
      end

      def matches?(actual, &block)
        until matcher.matches?(actual, &block)
          started ||= Time.now
          return false unless @eventually
          return false unless Time.now - started < @eventually
          sleep 0.1
        end
        true
      end

      def name
        'have_been_called'
      end

      delegate :failure_message, :failure_message_when_negated, to: :matcher

      def eventually(timeout = 5)
        @eventually = timeout
        self
      end

      private

      attr_reader :matcher

      def method_missing(name, *args, &block)
        super unless matcher.respond_to?(name)
        @matcher = matcher.__send__(name, *args, &block)
        self
      end

      def respond_to_missing?(name, priv = false)
        matcher.respond_to?(name, priv)
      end
    end

    def be_called(&block)
      receive(:call, &block)
    end

    def have_been_called(&block)
      HaveBeenCalledMatcher.new(&block)
    end

    def stub_services(*args)
      args.each do |klass|
        stub_service klass
      end
    end

    def spy_on_services(*args)
      args.each do |klass|
        spy_on_service klass
      end
    end

    def stub_service(klass, return_value = nil)
      allow(klass).to receive(:call).and_return return_value
    end

    def spy_on_service(klass)
      allow(klass).to receive(:call).and_call_original
    end

    def unstub_services(*args)
      args.each do |klass|
        allow(klass).to receive(:call).and_call_original
      end
    end

    RSpec.configure do |rspec|
      rspec.include self
    end
  end
end