liefery_spec.rb

  describe "#cancel_slot" do
    let(:courier_slot) do
      instance_double("CourierSlot", external_api_identifier: "api_identifier")
    end
    let(:cancel_slot) do
      instance_double("EasyPost::Carriers::CancelSlot", ez_shipment: ez_shipment)
    end
    let(:ez_shipment) do
      instance_double("EasyPost::Carriers::CancelSlot")
    end

    before do
      allow(EasyPost::Carriers::CancelSlot).to receive(:call) { cancel_slot }
    end

    it "delegates the carrier cancelation slot" do
      described_class.new.cancel_slot(courier_slot)

      expect(EasyPost::Carriers::CancelSlot).to have_received(:call)
        .with("api_identifier")
    end
  end