Fix exercises on objects

[yakutovicha]

fixes #111

[edoardob90]

I've been thinking about this test all afternoon (mostly). And it can be faked easily because it doesn't really enforce you to define/use the class. One can build a tuple with (None, "<Properly formatted string>") and the test will pass.

I think it's trickier that it seems to perform some checks on the actual class. One way is to parse the AST as Simone did with some FP tests, but I didn't want to implement it for the time being.

Needs some more thoughts... 💭

[baffelli]

You could check whether there is a class with the name Scoop in the locals() of the function. Something like:

import inspect
import ast

def check_if_class_in_scope(class_name: str, scope: callable) -> bool:
    source = ast.parse(inspect.getsource(scope))
    for node in ast.walk(source):
        match node:
            case ast.ClassDef() as cd:
                return cd.name == class_name


def f1():
    class A:
        a = 1


is_a = check_if_class_in_scope("A", f1)  # True
is_b = check_if_class_in_scope("B", f1)  # True
print(f"A is {is_a}, B is {is_b}")

[edoardob90]

That's a good suggestion 👍🏻 We must change the solution and add the class inside the solution function. Or apply the same idea to the entire code of the cell.

[baffelli]

You could check whether there is a class with the name Scoop in the locals() of the function. Something like:

import inspect
import ast

def check_if_class_in_scope(class_name: str, scope: callable) -> bool:
    source = ast.parse(inspect.getsource(scope))
    for node in ast.walk(source):
        match node:
            case ast.ClassDef() as cd:
                return cd.name == class_name


def f1():
    class A:
        a = 1


is_a = check_if_class_in_scope("A", f1)  # True
is_b = check_if_class_in_scope("B", f1)  # True
print(f"A is {is_a}, B is {is_b}")

[edoardob90]

Don't know (yet) if we want to fix this issue before the next tutorial, but here's something we can do without changing anything substantially: add a test on the type (e.g. isinstance) of the return value of the solution function instead of only its content.

At the moment, we are only testing the content with test_solution = [string for _, string in function_to_test(flavors)]