`Too-many-branches` scanning returns different values if directories to scan are explicitly specified.

[jackdewinter]

Bug description

In scanning my PyMarkdown project, a switch to pylint==2.13.5 caused some errors to show up with pylint. Specifically, when pipenv run pylint --rcfile=setup.cfg pymarkdown pymarkdown/plugins was executed, this was the response:

************* Module pymarkdown.plugins.rule_md_033
pymarkdown\plugins\rule_md_033.py:68:4: R0912: Too many branches (14/12) (too-many-branches)

--------------------------------------------------------------------
Your code has been rated at 10.00/10 (previous run: 10.00/10, +0.00)

However, upon using either pipenv run pylint --rcfile=setup.cfg --recursive=y pymarkdown or specifying the file directly, the errors were not reported.

Command used

Command to generate bad behavior:

pipenv run pylint --rcfile=setup.cfg pymarkdown pymarkdown/plugins

Commands that did not generate the bad behavior:

pipenv run pylint --rcfile=setup.cfg --recursive=y pymarkdown
pipenv run pylint --rcfile=setup.cfg --recursive=y pymarkdown/plugins/rule_md_021.py

Pylint output

Output for the bad case:

pymarkdown\plugins\rule_md_033.py:68:4: R0912: Too many branches (14/12) (too-many-branches)

No errors were output for the good cases.

Expected behavior

My expectations are that the same results should be generated, regardless of what form is used to get to that file.

Pylint version

pylint 2.13.5
astroid 2.11.2
Python 3.8.10 (tags/v3.8.10:3d8993a, May  3 2021, 11:48:03) [MSC v.1928 64 bit (AMD64)]

OS / Environment

Win10

[emcd]

I have also run into this bug. It is counting the number of branches for each way that the scanned file is being reached by Pylint. So, reaching the same module two different ways doubles the count of branches in each of its functions.

Here is a simple reproduction.

1. Assume that I have the following file, bugs/pylint_branches.py:

''' Simple reproducer for 'too-many-branches' bug. '''

def too_many_branches( lol ):
    ''' Each branch is counted once per file reference. '''
    aaa = 1
    if aaa > lol: aaa = lol
    else: aaa = 42

2. Running pylint --report n --score n --max-branches 1 bugs/pylint_branches.py bugs produces the following output:

************* Module pylint_branches
bugs/pylint_branches.py   3, 0 [too-many-branches] Too many branches (2/1)
bugs/pylint_branches.py   3, 0 [too-many-branches] Too many branches (4/1)

Environment:

$ pylint --version
pylint 2.15.5
astroid 2.12.12
Python 3.7.15 (default, Oct 15 2022, 11:29:20)
[GCC 9.4.0]

[Pierre-Sassoulas]

Thank you for investigating @emcd, do you want to contribute a fix ?

[emcd]

do you want to contribute a fix ?

@Pierre-Sassoulas : "Want to contribute" is a relative term, but, sure, I'll contribute. :) I've benefited from Pylint much over the years and Daniel and Tyler have fixed other issues I've filed. PR #7747 seems to fix this issue. I still need to consider whether I can do anything to validate it with the test suite, but it is otherwise ready.