[Feat] Generic Way to trigger a light bulb for a code action on PyLint issues

[dciborow]

I would like a generic way to specify per linter per error code to trigger a light bulb for a code action that is provided in a configuration file. Before finding a truely global way to achieve, this since PyLint handles the majority of my Python static code analysis, I would like to begin here. A subset of PyLint's suggestions could contain a suggested fix. In easy cases, this can be done by triggering a preexisting function in VSCode.

Here are some example PyLint Warnings.

Code	VS Action	Issue	Description
C0301	Format Document	line-too-long	Line too long (%s/%s)
C0303	Format Document	trailing-whitespace	Trailing whitespace
C0304	Format Document	missing-final-newline	Final newline missing
C0305	Format Document	trailing-newlines	Trailing newlines
C0321	Format Document	multiple-statements	More than one statement on a single line
C0410	Sort Imports	multiple-imports	Multiple imports on one line (%s)
C0411	Sort Imports	wrong-import-order	%s should be placed before %s
C0412	Sort Imports	ungrouped-imports	Imports from package %s are not grouped
C0413	Sort Imports	wrong-import-position	Import "%s" should be placed at the top of the module

Here is an example of some slightly more complex Fixes and Actions.

Code	VS Action	Issue	Description
W0611	Delete Line	unused-import	Unused %s
W0612	Delete Line	unused-variable	Unused variable %r
W0613	Refactor Function Signature - Remove %r	unused-argument	The argument in the function definition is deleted, then, anywhere in the code base that the argument was present, it is also removed
W0621	Refactor Variable Name - %r to _%r	redefined-outer-name	This is a simple opinionated auto-fix suggestion, that should be further configurable by the user
W0622	Refactor Variable Name - %r to my_%r	redefined-builtin	This is a simple opinionated auto-fix suggestion, that should be further configurable by the user

The HOOK into PyLint, would read the configuration file containing the list of PyLint Codes, and descriptions of the actions in VS Code.

In the above examples the following actions would be used.

1. Format Document
2. Sort Imports
3. Delete Line
4. Refactor Function Signature
5. Refactor Variable Name

Some may use a sed like REGEX to perform a transformation, use case camelCase -> snake_case.

1. Refactor Variable Name /[.][^][.]/(0)_(1)(2)/

If there is interest in developing the hook, I will continue to generate maps between PyLint Codes and VS actions. But I leave no suggested way to format the file, or hook declaration, and look for advice for that from the project owners.

[brettcannon]

And even if we don't decide to have some generic way for all linters, we should probably discuss whether we want to accept changes to this extension directly to provide quick fixes.

[dciborow]

One option to consider would be supporting sarif. https://sarifweb.azurewebsites.net/
But, most Python Linters do not support this out of the box.

Or, even just the more generic "GitHub" logging sytle:
%f:%l:%c: %m

%f = filename
%l = line number
%c = column number
%m = message

And within the message, a suggestion can be placed between ``` like this

```suggestion
RUN conda install -y python=3.8 \
` ``

(space added to ` `` to display properly)

[DanielNoord]

If supporting a more commonly used standard is indeed preferred (instead of something only VS Code can use) it might make more sense to build this into pylint directly so others can also benefit from this.

[brettcannon]

Standardized output formats isn't going to be what helps here. The critical piece would be some mechanism to make it so you can hook into the linter results that we provide to get the quick fixes. Basically quick fixes are given the diagnostics, so you're already passed caring about how we got the diagnostic.

[ketozhang]

I'm suggesting an additional action: to ignore the pylint rule for that line by adding the inline comment # pylint: disable=<issue>.

[ketozhang]

Additionally a second code action option for #pylint: disable-next=<issue>. The use case often being adding a comment will cause line-too-long.

Thoughts? I can work on this. @karthiknadig @luabud

[gilmarGNJ]

Any news on this?

[karthiknadig]

@gilmarGNJ The extension now supports code actions. The first set of code actions (based on existing commands) is already done. The one that needed text change, can also be implemented. This is unblocked for community contributions.

[dciborow]

I'm able to create #300

[karthiknadig]

Verification:

1. Install the latest pylint extension.
2. create a python file with following content:

class MyObject(object):
    """Test class"""
    pass

1. In the problems window it should show: useless-object-inheritance
2. Click on the quickfix provided for that problem.
3. Code should be updated to:

class MyObject:
    """Test class"""
    pass