def test_pricer_calculates_sub_total_using_product_price():
catalogue_provider = CatalogueProvider({"APPLE": Decimal("5")})
offer_provider = OfferProvider({})
basket = {"APPLE": 1}
pricer = BasketPricer(catalogue_provider, offer_provider)
prices = pricer.calculate_basket_prices(basket)
assert prices["sub_total"] == Decimal("5")
def test_pricer_calculates_percentage_discount_for_product():
catalogue_provider = CatalogueProvider({"APPLE": Decimal("5")})
offer_provider = OfferProvider({"APPLE": [PercentageOffer(Decimal("10"))]})
basket = {"APPLE": 1}
pricer = BasketPricer(catalogue_provider, offer_provider)
prices = pricer.calculate_basket_prices(basket)
assert prices["discount"] == Decimal("0.5")
def test_pricer_calculates_sub_total_for_multi_quantity():
catalogue_provider = CatalogueProvider({"APPLE": Decimal("5")})
offer_provider = OfferProvider({})
basket = {"APPLE": 3}
pricer = BasketPricer(catalogue_provider, offer_provider)
prices = pricer.calculate_basket_prices(basket)
assert prices["sub_total"] == Decimal("15")
def test_pricer_calculated_total_cant_be_negative():
catalogue_provider = CatalogueProvider({"APPLE": Decimal("-5")})
offer_provider = OfferProvider({})
basket = {"APPLE": 1}
pricer = BasketPricer(catalogue_provider, offer_provider)
with pytest.raises(NegativeBasketPriceException):
pricer.calculate_basket_prices(basket)
def test_pricer_calculates_sub_total_for_multiple_products_in_basket():
catalogue_provider = CatalogueProvider({
"APPLE": Decimal("5"),
"CHEESE": Decimal("3")
})
offer_provider = OfferProvider({})
basket = {"APPLE": 2, "CHEESE": 1}
pricer = BasketPricer(catalogue_provider, offer_provider)
prices = pricer.calculate_basket_prices(basket)
assert prices["sub_total"] == Decimal("13")
def test_pricer_calculates_sub_total_from_basket_products():
catalogue_provider = CatalogueProvider({"APPLE": Decimal("5")})
offer_provider = OfferProvider({})
basket = {"APPLE": 1}
pricer = BasketPricer(catalogue_provider, offer_provider)
assert pricer.calculate_basket_prices(basket) == {
"sub_total": Decimal("5"),
"discount": Decimal("0"),
"total": Decimal("5"),
}
def test_pricer_returns_prices():
catalogue_provider = CatalogueProvider({})
offer_provider = OfferProvider({})
basket = {}
pricer = BasketPricer(catalogue_provider, offer_provider)
assert pricer.calculate_basket_prices(basket) == {
"sub_total": Decimal("0"),
"discount": Decimal("0"),
"total": Decimal("0"),
}
def test_pricer_calculates_chooses_highest_discount():
catalogue_provider = CatalogueProvider({"APPLE": Decimal("5")})
offer_provider = OfferProvider({
"APPLE":
[PercentageOffer(Decimal("10")),
PercentageOffer(Decimal("15"))],
})
basket = {"APPLE": 1}
pricer = BasketPricer(catalogue_provider, offer_provider)
prices = pricer.calculate_basket_prices(basket)
assert prices["discount"] == Decimal("0.75")
def test_pricer_returns_zero_prices_when_basket_is_empty():
catalogue_provider = CatalogueProvider({
"APPLE": Decimal("5"),
"CHEESE": Decimal("3")
})
offer_provider = OfferProvider({})
basket = {}
pricer = BasketPricer(catalogue_provider, offer_provider)
assert pricer.calculate_basket_prices(basket) == {
"sub_total": Decimal("0"),
"discount": Decimal("0"),
"total": Decimal("0"),
}
def test_pricer_calculates_correctly_total_value():
catalogue_provider = CatalogueProvider({
"APPLE": Decimal("5"),
"POTATO": Decimal("2")
})
offer_provider = OfferProvider({"APPLE": [PercentageOffer(Decimal("20"))]})
basket = {"APPLE": 4, "POTATO": 2, "NOT_IN_CATALOGUE_PRODUCT": 3}
pricer = BasketPricer(catalogue_provider, offer_provider)
assert pricer.calculate_basket_prices(basket) == {
"sub_total": Decimal("24"),
"discount": Decimal("4"),
"total": Decimal("20"),
}