def test_checkout_basket_with_empty_basket():
basket = Basket()
subtotal, discount, total = checkout_basket(basket, catalogue)
assert subtotal == 0
assert discount == 0
assert total == 0
def test_calculate_percentage_discount_for_one_item():
# Discount tomato by 25%
offers = {"BuyXGetY": {"": []}, "PercentageDiscount": {"tomato": 0.25}}
basket = Basket()
basket.add_item("tomato", 1)
subtotal, discount, total = checkout_basket(basket, catalogue, offers)
assert subtotal == 0.60
assert discount == 0.15
assert total == 0.45
def test_calculate_buy_x_get_y_for_one_item_type():
# Buy 2 Get 1 Free on peaches
offers = {
"BuyXGetY": {
"peach": [2, 1]
},
"PercentageDiscount": {
"cornflakes": 0.25
}
}
basket = Basket()
basket.add_item("peach", 3)
subtotal, discount, total = checkout_basket(basket, catalogue, offers)
assert subtotal == 4.59
assert discount == 1.53
assert total == 3.06
def test_calculate_percentage_discount_for_multiple_items():
# Discount tomato by 25% and cornflakes by 50%
offers = {
"BuyXGetY": {
"": []
},
"PercentageDiscount": {
"tomato": 0.25,
"cornflakes": 0.50
},
}
basket = Basket()
basket.add_item("tomato", 1)
basket.add_item("cornflakes", 2)
subtotal, discount, total = checkout_basket(basket, catalogue, offers)
assert subtotal == 5.30
assert discount == 2.50
assert total == 2.80
def test_both_offers_being_used_on_seperate_items():
# Buy 3 Get 1 Free on peaches && 25% off cornflakes
offers = {
"BuyXGetY": {
"peach": [3, 1],
"tomato": [3, 2]
},
"PercentageDiscount": {
"cornflakes": 0.25
},
}
basket = Basket()
basket.add_item("peach", 4)
basket.add_item("cornflakes", 5)
subtotal, discount, total = checkout_basket(basket, catalogue, offers)
assert subtotal == 17.87
assert discount == 4.47
assert total == 13.40
def test_buy_three_get_two_and_buy_four_get_one():
# Buy 4 Get 1 Free on peaches && Buy 3 Get 2 Free on tomatos
offers = {
"BuyXGetY": {
"peach": [4, 1],
"tomato": [3, 2]
},
"PercentageDiscount": {
"cornflakes": 0.25
},
}
basket = Basket()
basket.add_item("peach", 16)
basket.add_item("tomato", 23)
subtotal, discount, total = checkout_basket(basket, catalogue, offers)
assert subtotal == 38.28
assert discount == 9.39
assert total == 28.89
def test_calculate_buy_x_get_y_for_multiple_items():
# Buy 2 Get 1 Free on peaches && Buy 3 Get 2 Free on tomatos
offers = {
"BuyXGetY": {
"peach": [2, 1],
"tomato": [3, 2]
},
"PercentageDiscount": {
"cornflakes": 0.25
},
}
basket = Basket()
basket.add_item("peach", 3)
basket.add_item("tomato", 15)
subtotal, discount, total = checkout_basket(basket, catalogue, offers)
assert subtotal == 13.59
assert discount == 5.13
assert total == 8.46
def test_multiple_buy_x_get_y_offers_with_excess_and_inelegible_quantities():
# Buy 3 Get 1 Free on peaches && Buy 3 Get 2 Free on tomatos
offers = {
"BuyXGetY": {
"peach": [3, 1],
"tomato": [3, 2]
},
"PercentageDiscount": {
"cornflakes": 0.25
},
}
basket = Basket()
basket.add_item("peach", 23)
basket.add_item("tomato", 4)
basket.add_item("corn", 5)
subtotal, discount, total = checkout_basket(basket, catalogue, offers)
assert subtotal == 37.59
assert discount == 7.65
assert total == 29.94