2. Method Steps

Write pytest cases once and inherit them for different providers.

Source

"""Write pytest cases once and inherit them for different providers."""

import pytest

from fastsprout.core import Field, dataclass
from fastsprout.testing.core import given, then, when


@dataclass
class Cart:
    products: Field[list[str]] = Field(default_factory=list)

    def add(self, name: str) -> None:
        self.products.append(name)


class CheckedCart(Cart):
    def add(self, name: str) -> None:
        if not name:
            raise ValueError("A product needs a name")
        super().add(name)


class CartCases:
    cart_type: type[Cart] = Cart

    @given("the user has an empty cart")
    def cart(self) -> Cart:
        return self.cart_type()

    @when('the user adds "{product_name}"')
    async def added(self, cart: Cart, product_name: str) -> Cart:
        cart.add(product_name)
        return cart

    @then("the cart contains {count:d} products")
    @pytest.mark.steps(
        ('the user adds "book"', "the cart contains 1 products"),
        ('the user adds "pen"', "the cart contains 1 products"),
        ids=("book", "pen"),
    )
    def test_cart_count(self, added: Cart, count: int) -> None:
        assert len(added.products) == count


class TestCart(CartCases):
    pass


class TestCheckedCart(CartCases):
    cart_type = CheckedCart

Result

examples/testing/01_core/02_method_steps.py::TestCart::test_cart_count[book] PASSED [ 25%]
examples/testing/01_core/02_method_steps.py::TestCart::test_cart_count[pen] PASSED [ 50%]
examples/testing/01_core/02_method_steps.py::TestCheckedCart::test_cart_count[book] PASSED [ 75%]
examples/testing/01_core/02_method_steps.py::TestCheckedCart::test_cart_count[pen] PASSED [100%]