`lint-fixme` comments not respected

[samueljsb]

lint-fixme comments on nodes in some cases are not respected.

comprehensions

In the following file (t.py), we would expect the violation to be reported for the first function, but not for either of the other two.

def f(l):
    return [
        i for i in l
        if isinstance(i, int) or isinstance(i, float)
    ]

def g(l):
    return [
        i for i in l
        # lint-fixme: CollapseIsinstanceChecks
        if isinstance(i, int) or isinstance(i, float)
    ]

def h(l):
    return [
        i for i in l
        if isinstance(i, int) or isinstance(i, float)  # lint-fixme: CollapseIsinstanceChecks
    ]

However, the violation is reported for all three:

$ fixit lint t.py
t.py@4:11 CollapseIsinstanceChecks: Multiple isinstance calls with the same target but different types can be collapsed into a single call with a tuple of types. (has autofix)
t.py@12:11 CollapseIsinstanceChecks: Multiple isinstance calls with the same target but different types can be collapsed into a single call with a tuple of types. (has autofix)
t.py@19:11 CollapseIsinstanceChecks: Multiple isinstance calls with the same target but different types can be collapsed into a single call with a tuple of types. (has autofix)
🛠️  1 file checked, 1 file with errors, 3 auto-fixes available 🛠️

lambdas

In the following file (t.py), we would expect the violation to be reported for the first list, but not for either of the other two.

operators = [
    int,
    str,
    lambda x: float(x),
]

operators = [
    int,
    str,
    # lint-fixme: NoRedundantLambda
    lambda x: float(x),
]

operators = [
    int,
    str,
    lambda x: float(x),  # lint-fixme: NoRedundantLambda
]

However, the violation is reported for all three:

$ fixit lint t.py
t.py@4:4 NoRedundantLambda: The lambda that is wrapping float is redundant. It can unwrapped safely and used purely. (has autofix)
t.py@11:4 NoRedundantLambda: The lambda that is wrapping float is redundant. It can unwrapped safely and used purely. (has autofix)
t.py@17:4 NoRedundantLambda: The lambda that is wrapping float is redundant. It can unwrapped safely and used purely. (has autofix)
🛠️  1 file checked, 1 file with errors, 3 auto-fixes available 🛠️

EDIT: the commit is respected if it is placed before the list:

# lint-fixme: NoRedundantLambda
operators = [
    int,
    str,
    lambda x: float(x),
]

$ fixit lint t.py
🧼 1 file clean 🧼

This is not expected, though, and means that multiple lines will be ignored rather than just the desired one.

methods

In the following file (t.py), we would expect the violation to be reported for the first class, but not for either of the other two.

class foo:
    @classmethod
    def nm(self, a, b, c):
        pass

class foo:
    @classmethod
    # lint-fixme: UseClsInClassmethod
    def nm(self, a, b, c):
        pass

class foo:
    @classmethod
    def nm(self, a, b, c):  # lint-fixme: UseClsInClassmethod
        pass

However, the violation is correctly silenced for the last case, but shown for the middle case that should be silenced:

$ fixit lint t.py
t.py@3:4 UseClsInClassmethod: When using @classmethod, the first argument must be `cls`. (has autofix)
t.py@9:4 UseClsInClassmethod: When using @classmethod, the first argument must be `cls`. (has autofix)
🛠️  1 file checked, 1 file with errors, 2 auto-fixes available 🛠️

supporting information

$ python --version
Python 3.11.5

$ fixit --version
fixit, version 2.1.0

I have also observed this behaviour on Python 3.10.11.

[samueljsb]

I've found another one that's causing us problems: decorators.

from dataclasses import dataclass

@dataclass()
class C:
    pass

# lint-fixme: ExplicitFrozenDataclass
@dataclass()
class C:
    pass

@dataclass()  # lint-fixme: ExplicitFrozenDataclass
class C:
    pass

We'd expect the first function to be reported, and the other two to be silenced.

t.py@4:0 ExplicitFrozenDataclass: When using dataclasses, explicitly specify a frozen keyword argument. Example: `@dataclass(frozen=True)` or `@dataclass(frozen=False)`. Docs: https://docs.python.org/3/library/dataclasses.html (has autofix)
t.py@10:0 ExplicitFrozenDataclass: When using dataclasses, explicitly specify a frozen keyword argument. Example: `@dataclass(frozen=True)` or `@dataclass(frozen=False)`. Docs: https://docs.python.org/3/library/dataclasses.html (has autofix)
🛠️  1 file checked, 1 file with errors, 2 auto-fixes available 🛠️

But we see the first two reported. The last one is correctly silenced.

[samueljsb]

I have written some failing tests to demonstrate these problems in #413. I haven't worked out how to demonstrate the function def problem yet, so I'd appreciate any advice you can offer there.

[samueljsb]

I have found another case. This looks superficially similar to the comprehensions case.

In the following file (t.py), we would expect the violation to be reported for the first function, but not for either of the other two.

def f(x):
    return (
        isinstance(x, int) or isinstance(x, float)
    )

def f(x):
    return (
        isinstance(x, int) or isinstance(x, float)  # lint-fixme: CollapseIsinstanceChecks
    )

def f(x):
    return (
        # lint-fixme: CollapseIsinstanceChecks
        isinstance(x, int) or isinstance(x, float)
    )

However, the violation is reported for all three:

$ fixit lint t.py
t.py@3:8 CollapseIsinstanceChecks: Multiple isinstance calls with the same target but different types can be collapsed into a single call with a tuple of types. (has autofix)
t.py@9:8 CollapseIsinstanceChecks: Multiple isinstance calls with the same target but different types can be collapsed into a single call with a tuple of types. (has autofix)
t.py@16:8 CollapseIsinstanceChecks: Multiple isinstance calls with the same target but different types can be collapsed into a single call with a tuple of types. (has autofix)
🛠️  1 file checked, 1 file with errors, 3 auto-fixes available 🛠️