`compare-to-empty-string` false positive when the type is a union

[dotkrnl]

Bug description

a: str | int = "" if some_condition else 0
if a == "":
    print("some_condition")

Configuration

load-plugins = "pylint.extensions.emptystring"

Command used

pylint

Pylint output

C1901: "a == ''" can be simplified to "not a" as an empty string is falsey (compare-to-empty-string)

Expected behavior

No output as a == '' can not be simplified to not a in this case. Note that a is int | str.

I know that using a datatype of int | str is a bad practice but apparently someone in our team decided to do this anyhow. In making the code compliant to pylint, this causes the behavior of the code to change.

I would suggest pylint to take type analysis into account when suggesting the falsey replacement, as can be simplified is misleading somehow. If this is not feasible, I feel that adding can be simplified if the type of "a" is "str" to the message, or adding a warning to the pylint.extensions.emptystring plugin would be helpful.

Pylint version

pylint 2.17.2
astroid 2.15.3
Python 3.10.10 (main, Feb  8 2023, 14:49:42) [GCC 7.5.0]

OS / Environment

No response

Additional dependencies

No response

[dotkrnl]

The same applies to compare-to-zero as well.

[DanielNoord]

We probably won't be taking the type annotation into account very soon and there are already issues open to track this in the tracker.
This specific case is just a limitation of this checker, which is also why it is a plugin. I'd suggest adding a disable in this case!

[dotkrnl]

Thanks, Daniel, and I agree. Just my two cents, it might be good to have a small mention of this limitation in the documentation.

[DanielNoord]

Would you want to contribute this?