Refactor should handle primitive / object difference

[rentruewang]

See microsoft/vscode#198600

Steps to Reproduce:

1. Use the following code snippet

a = 0

for i in range(10):
    a += 1

2. Use extract method from refactoring tools on the for loop.
3. Get the following code

a = 0

def new_func(a):
    for i in range(10):
        a += 1

new_func(a)

This has no effect on primitive types.

[debonte]

This has no effect on primitive types.

To be clear, your point is that at the end of the original snippet a is 10, but at the end of the second snipet a is 0?

Is this what you were hoping to see?

a = 0

def new_func(a):
    for i in range(10):
        a += 1
    return a

a = new_func(a)

[rentruewang]

Hi, thanks for the response.

Answer to your question is yes. Since primitive types are copied by values, refactor should take care of that I think. Ideally it should also take care of assignment updates (where in the loop there are assignment statements).

For example, this is what i get if I changed the above line to a = a + 1 (used i instead of a but idea is the same)

[rentruewang]

Hi, I'm curious if there is an update on this? I see the 'user responded' label removed.

[StellaHuang95]

Hi @rentruewang, we've tagged the issue with the bug label, which means it's now in our backlog for fixing. The order in which we address backlog items depends on their priority and our current bandwidth. We will provide an update below this ticket once it's fixed. We appreciate your patience!

[rentruewang]

@StellaHuang95 Makes sense. Thanks.

[debonte]

Reopening as this has not been fixed yet. It still repros for me in 2024.5 103.

[rentruewang]

@debonte I closed it due to inactivity (and taking up space in my issue logger 😃), and it's not too big of an issue anyways. As I don't see it being worked on regardless, maybe close it as won't fix / not planned?

[heejaechang]

I think this is a bug.

first

a = 0

for i in range(10):
    a += 1

since there is no one using a after the for loop, we won't return a

but if you have

a = 0

for i in range(10):
    a += 1

print(a)

and extract method, for loop, it should have created return a but it didn't :), and that's a bug.

if you change it to

a = 0

for i in range(10):
    a = 1

print(a)

you will see it generate a = new_func(a)

it looks like we don't consider += as write of a