chapter 4, service layer exercise, "decrement" should be "increment" in test names

[iamdbychkov]

In chapter 4, we are challenged to implement a deallocation service, given a link with some stubs for tests and some complete e2e tests.
There are some inaccuracies with the exercies which I have found:

1. code/test_services.py

   Line 58 in 7efebb6

   services.add_batch("b1", "BLUE-PLINTH", 100, None, repo, session)

   
   Test uses unexistent service add_batch. Shall we also implement it with tests? I would say yes. Maybe it worth to be included in the book itself?

2. code/test_services.py

   Line 59 in 7efebb6

   services.allocate("o1", "BLUE-PLINTH", 10, repo, session)

   
   Invalid call for a service.allocate() function.

Unclear cases:

code/test_services.py

Line 56 in 7efebb6

def test_deallocate_decrements_available_quantity():

code/test_services.py

Line 67 in 7efebb6

def test_deallocate_decrements_correct_quantity():

What is an expected outcome of such functions? My intertpretation is that in first test we can deallocate any line with matching orderid and sku which is allocated. In the second test we deallocate the line with matching orderid, sku and qty. Is it correct?

[hjwp]

Hello Dmitry! thanks very much for these questions, it's nice to know someone is having a go at the exercises.

I've pushed some clarifications/explanations as TODOs in the exercise code, let me know what you think?

https://github.com/cosmicpython/code/blob/chapter_04_service_layer_exercise/test_services.py#L58

[hjwp]

(PS cosmicpython/book@667b2fd)

[iamdbychkov]

I've found exercises quite challenging so I think it fits quite nicely :)
Also, great job on the book, have enjoyed it. Right now trying to employ DDD techniques in my day job project 👍

[hjwp]

good luck! hey and if you have a couple of secs to write a review on amazon or goodreads or wherever you like to do that, it'd be much appreciated 😊

[Xupeiyi]

I'm having a question with the tests' names. As allocate decrements the available qunatity, should deallocate actually "increment" the available quantity?

[hjwp]

oh yes! you're quite right sorry