Python - Jak napisać testy jednostkowe do tego kodu?

pytanie zadane 4 czerwca 2023 w Python przez whiteman808 Obywatel (1,820 p.)

Witam

Mam taki kod i potrzebuję do niego napisać testy jednostkowe. Mam pytanie, co i jak powinienem testować? Mam utworzyć instancje zdefiniowanych klas i posprawdzać czy takie rzeczy jak liczba produktów, czy transakcja zaszła pomyślnie itd się zgadzają?

Będę wdzięczny za podpowiedzi

from users import User, Address
from products import Product
from typing import NamedTuple, Optional
from payments import PaymentMethod


class Order(NamedTuple):
    buyer: User
    products: list[Product]
    shipping_address: Address
    payment_method: PaymentMethod


class ShoppingCart:
    def __init__(self, owner: User, products: list[Product]):
        self.owner = owner
        self.products = products

    def add_product(self, product: Product, qty: int) -> None:
        if qty < 1:
            raise ValueError(f"expected qty to be a positive value, got {qty}")
        for _ in range(0, qty):
            self.products.append(product)

    def remove_product(self, product: Product) -> None:
        self.products.remove(product)

    def count_product(self, product: Product) -> int:
        return self.products.count(product)

    def __str__(self) -> str:
        return f"{self.owner}'s shopping cart"

    def __repr__(self) -> str:
        return f"{self.__class__.__name__}(owner={self.owner!r}, products={self.products!r})"


def make_order(shopping_cart: ShoppingCart,
               shipping_address: Optional[Address] = None,
               payment_method: Optional[PaymentMethod] = None) -> Order:
    customer = shopping_cart.owner
    if shipping_address is None:
        shipping_address = customer.shipping_address
    if payment_method is None:
        payment_method = customer.payment_method
    return Order(customer, shopping_cart.products, shipping_address, payment_method)