[FEATURE REQUEST] Blending and ignore

[sbrunner]

Issue

When we ignore a blended message, another one aspires

Create test environment

toto.py:

def main():
    a = 1

.prospector.yaml file:

pylint:
  run: true
  enable:
    - unused-variable
vulture:
  run: true
  enable:
    - unused-variable
pyflakes:
  run: true
  enable:
    - F841

Test blending => OK

prospector --no-blending --output-format=pylint toto.py:

...
toto.py:2: unused-variable(vulture): Unused variable 'a'
toto.py:2:4: [unused-variable(pylint), main]: Unused variable 'a'
toto.py:2:5: F841(pyflakes): local variable 'a' is assigned to but never used
...

prospector --output-format=pylint toto.py:

...
toto.py:2:4: [unused-variable(pylint), main]: Unused variable 'a'
...

=> the blending works correctly

Test Ignore

Ignore the error with # pylint: disable=unused-variable

=>

...
toto.py:2: unused-variable(vulture): Unused variable 'a'
...

=> We get another issue
=> It will be good if it will be completely ignored

Describe the solution you'd like

The solution I imagine:

• In the tools classes, add a function to parse the lines of code to get the ignored codes. This will be implemented in the Pylint, Mypy and Ruff, the other tolls can't ignore a specific code, and that is necessary for our usage. For Ruff we should be sure that it will not create some issue with other tools.
• Replace this part of code https://github.com/prospector-dev/prospector/blob/master/prospector/suppression.py#L144-L155 by one that uses the blending configuration and the parsed code by tools to generate the other ignores.

Describe alternatives you've considered

Create a profile that ignores the duplicated check, but it's in the opposition of blending, and the advantage of the proposed solution we are more safe do not ignore a check to replace it by as less safe one.

[sbrunner]

@Pierre-Sassoulas, @carlio What do you think about this?

[Pierre-Sassoulas]

It's probably going to be really painful to maintain, no ? (Check can be similar but not identical). But the feature would be amazing for sure.

[sbrunner]

The blender_combinations.yaml file can be painful to maintain, but he is already here.

What the behavior if the checks are similar but not identical, and we are on the “different” part:

• When the runs Prospector without any ignore => we get only the check who is triggered.
• When we ignore one of them => we will not have any issue reported.

For me, it's a coherent behavior :-)