Provide pylint plugin to avoid warnings in IDE when working with conanfile.py

[ytimenkov]

Problem

When editing conanfile.py with editor which has linter support (VS Code with Python extension in my case) there are a bunch of errors related to dynamic fields (like self.copy is not callable or Instance of ConanFile doesn't have package_folder member).

Proposal

Conan has a built-in linting support for conanfile.py, but it deals with dynamic fields by post-processing json output.

It would be useful if this logic is moved to a pylint plugin which can be reused by editor/IDE or via command line options.

There are few tutorials on the Internet about how to do it.

[memsharded]

Yes, this is a good idea, thanks!
Actually, extracting the linting functionality to a conan plugin system (where other custom checkers can be provided by users) is something that we want to do.

We will check this when we do that, and will try to make this plugin reusable, not only for conan, but for editors too.

[ytimenkov]

I've created a prototype of pylint plugin: ytimenkov/conan@dd1c20e
Will try later today how it integrates with VS Code.

[sourcedelica]

Pycharm warns on self.settings.xxx (for example self.settings.compiler, where compiler is flagged). The reason is self.settings is an attribute with a tuple of strings (settings = "os", "compiler", "build_type", "arch"). The same thing goes for self.options.xxx.

I'm wondering if there could be a less dynamic alternative API that would be less confusing to IDEs.

[ytimenkov]

@sourcedelica ConanFile.settings actually has type of conans.model.settings.Settings

You may try using get_safe method, for example self.settings.get_safe("os.arch")

There could be a way to help IDE to infer the type. E.g. VS Code's plugin understands assert isinstance(x, type). See microsoft/PTVS#82

[sourcedelica]

That sounds just like what what I would like. I’ll give it a shot. Thanks!

On Wed, May 16, 2018 at 3:03 PM Yuri Timenkov ***@***.***> wrote: @sourcedelica <https://github.com/sourcedelica> ConanFile.settings actually has type of conans.model.settings.Settings You may try using get_safe method, for example self.settings.get_safe("os.arch") There could be a way to help IDE to infer the type. E.g. VS Code's plugin understands assert isinstance(x, type). See microsoft/PTVS#82 <microsoft/PTVS#82> — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#2706 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AEBjBIgPozbWX6wuVGgCq7lRq8P6HYj-ks5tzHf_gaJpZM4TEffg> .

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[mmatrosov]

@sourcedelica I can't even go that far, I have immediate error "[pylint] E0401:Unable to import 'conans'". How did you pass through that? :) (Note that I have conan installed with the stand-alone installer, not as python package, maybe this might be the problem?)

[ytimenkov]

@mmatrosov It works better if you install conan via pip. If you have standalone installer which provides python modules (not sure if the official one does, pyinstaller explicitly hides modules so they can't be imported) you can add it to sys.path. For example my .pylintrc looks like:

[MASTER]
init-hook='import sys; sys.path.extend(["/home/user/conan-install"])'

load-plugins=conans.client.conanfile_plugin

[MESSAGES CONTROL]
disable=C,R

(the plugin is in PR yet)

[memsharded]

Hi all!

Many thanks to @ytimenkov for implementing it! It will be released in next 1.6, keep tuned for testing it!