- Added relevant test for car rentals

test/rent_cars/rentals/create_rental_test.exs

@@ -0,0 +1,12 @@
+defmodule RentCars.Rentals.CreateRentalTest do
+  use RentCars.DataCase
+  import RentCars.CarsFixtures
+  alias RentCars.Rentals.CreateRental
+
+  describe "create rentals" do
+    test "throw error when car is not available" do
+      car = car_fixture(%{available: false})
+      assert {:error, "Car is unavailable"} == CreateRental.execute(car.id)
+    end
+  end
+end