arjancodes / 2022-test-existing-code

How To Write Unit Tests For Existing Python Code

In this two-part miniseries, I show you a practical example of adding unit tests to existing code. This first part focuses on adding tests while not changing the original code. There are also a few things in the test setup that are not ideal, like how dates are used in the test code, using a real API key and doing actual card charges. I address these things in part 2, where I also show how refactoring the code simplifies test writing while improving the design as well.

• Part 1: https://youtu.be/ULxMQ57engo.
• Part 2: https://youtu.be/NI5IGAim8XU.

2022-test-existing-code's Issues

test_api_key_invalid() does not raise a ValueError

Hi

First of all, thank You very much for this tutorial. I'm walking step by step and I suddenly stopped on: https://youtu.be/ULxMQ57engo?t=781 where this test does not throws me an error with empty API_KEY.
I'm getting an error like:

./before/tests/test_processor.py::test_api_key_invalid Failed: [undefined]Failed: DID NOT RAISE <class 'ValueError'>
def test_api_key_invalid() -> None:
>       with pytest.raises(ValueError):
E       Failed: DID NOT RAISE <class 'ValueError'>

before\tests\test_processor.py:8: Failed

I'm looking at the code of processor.py:PaymentProcessor class, and I can't see any code responsible for checking API_KEY which might throw an error. For a card number - yes there is a ValueError in charge() method, but nothing for API_KEY

Can I kindly ask You for some help/clarification? :) I just want to align your tutorial with my code

EDIT:
It's because on before/pay/processor.py class PaymentProcessor does not contain _check_api_key() method :) that's it.

TypeError: 'type' object is not subscriptable

collected 7 items / 3 errors

===================================================================================================== ERRORS ======================================================================================================
__________________________________________________________________________________ ERROR collecting pay/tests/test_line_item.py ___________________________________________________________________________________
pay/tests/test_line_item.py:1: in
from pay.order import LineItem
pay/order.py:22: in
class Order:
pay/order.py:23: in Order
line_items: list[LineItem] = field(default_factory=list)
E TypeError: 'type' object is not subscriptable
____________________________________________________________________________________ ERROR collecting pay/tests/test_order.py _____________________________________________________________________________________
pay/tests/test_order.py:1: in
from pay.order import LineItem, Order
pay/order.py:22: in
class Order:
pay/order.py:23: in Order
line_items: list[LineItem] = field(default_factory=list)
E TypeError: 'type' object is not subscriptable
___________________________________________________________________________________ ERROR collecting pay/tests/test_payment.py ____________________________________________________________________________________
pay/tests/test_payment.py:5: in
from pay.order import LineItem, Order, OrderStatus
pay/order.py:22: in
class Order:
pay/order.py:23: in Order
line_items: list[LineItem] = field(default_factory=list)
E TypeError: 'type' object is not subscriptable
============================================================================================= short test summary info =============================================================================================
ERROR pay/tests/test_line_item.py - TypeError: 'type' object is not subscriptable
ERROR pay/tests/test_order.py - TypeError: 'type' object is not subscriptable
ERROR pay/tests/test_payment.py - TypeError: 'type' object is not subscriptable
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 3 errors during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Can anyone please help, I am getting TypeError when I run pytest command from refactored code directory. thanks