linters.md

ConanCenterIndex Linters

Some linter configuration files are available in the folder linter, which are executed by Github Actions and are displayed during code review as annotations, to improve recipe quality. They consume python scripts which are executed to fit CCI rules. Those scripts use astroid and pylint classes to parse Conan recipe files and manage their warnings and errors.

Pylint by itself is not able to find ConanCenterIndex rules, so astroid is used to iterate over a conanfile's content and validate CCI requirements. Pylint uses an rcfile to configure plugins, warnings and errors which should be enabled or disabled.

Contents

• Understanding the different linters
• Running the linters locally
• Pylint configuration files
• Linter Warning and Errors
  • E9006 - conan-import-conanfile: ConanFile should be imported from conan
  • E9005 - conan-missing-name: Every conan recipe must contain the attribute name
  • E9004 - conan-package-name: Conan package names must be lower-case
  • E9007 - conan-test-no-name: Do not add name attribute in test package recipes
  • E9008 - conan-import-errors: Deprecated imports should be replaced by new imports
  • E9009 - conan-import-error-conanexception: conans.errors is deprecated and conan.errors should be used instead
  • E9010 - conan-import-error-conaninvalidconfiguration: conans.errors is deprecated and conan.errors should be used instead
  • E9011 - conan-import-tools: Importing conan.tools or conan.tools.xxx.zzz.yyy should be considered as private
  • E9012 - conan-attr-version: Recipe should not contain version attribute

Understanding the different linters

There's a three classes of linters currently in place for ConanCenterIndex

• ConanCenter Hook - these are responsible for validating the structure of the recipes and packages.
• Pylint Linter - these are used to ensure the code quality and conventions of a recipes (i.e conanfile.py)
• Yaml Checks - stylistic guidance and schema validation check for support files and best practices

Running the linters locally

Check the Developing Recipes for more information on each of the three linters.

Pylint configuration files

• Pylint Recipe: This rcfile lists plugins and rules to be executed over all recipes (not test package) and validate them.
• Pylint Test Package Recipe: This rcfile lists plugins and rules to be executed over all recipes in test package folders only:

Linter Warning and Errors

Here is the list of current warning and errors provided by pylint, when using CCI configuration.

E9006 - conan-import-conanfile: ConanFile should be imported from conan

from conans import ConanFile

Should be replaced by:

from conan import Conanfile

E9005 - conan-missing-name: Every conan recipe must contain the attribute name

The attribute name is always expected. On the other hand, version should not be listed.

def BazConanfile(ConanFile):
    name = "baz"

E9004 - conan-package-name: Conan package names must be lower-case

The package name is always lower-case, even when the upstream uses another format

def FoobarConanfile(ConanFile):
    name = "foobar"

E9007 - conan-test-no-name: Do not add name attribute in test package recipes

The test package is not a recipe, thus, it should not have a name

def TestPackageConanFile(ConanFile):
    name = "test_package" # Wrong!

E9008 - conan-import-errors: Deprecated imports should be replaced by new imports

Read v2_linter for a list of mappings of v1 to v2. Regular imports from conans.tools are now updated:

from conans import tools
...

tools.rmdir(os.path.join(self.package_folder, "shared"))

Should be replaced by specialized tools, prepared for Conan 2.0

from conan.tools.files import rmdir
...

rmdir(self, os.path.join(self.package_folder, "shared"))

E9009 - conan-import-error-conanexception: conans.errors is deprecated and conan.errors should be used instead

from conans.errors import ConanException

Should be replaced by:

from conan.errors import ConanException

Only the namespace conans has been replaced by conan.

E9010 - conan-import-error-conaninvalidconfiguration: conans.errors is deprecated and conan.errors should be used instead

from conans.errors import ConanInvalidConfiguration

Should be replaced by:

from conan.errors import ConanInvalidConfiguration

Only the namespace conans has been replaced by conan.

E9011 - conan-import-tools: Importing conan.tools or conan.tools.xxx.zzz.yyy should be considered as private

Documented on conanfile.tools: It's not allowed to use tools.xxx directly:

from conan import tools
...

tools.scm.Version(self.version)

Neither sub modules:

from conan.tools.apple.apple import is_apple_os

Only modules under conan.tools and conan.tools.xxx are allowed:

from conan.tools.files import rmdir
from conan.tools import scm

E9012 - conan-attr-version: Recipe should not contain version attribute

All recipes on CCI should be generic enough to support as many versions as possible, so enforcing a specific version as attribute will not allow to re-use the same recipe for multiple release versions.

from conan import ConanFile

class FooConanFile(ConanFile):
    version = "1.0.0"  # Wrong!

The package version should be passed as command argument, e.g:

conan create all/ 1.0.0@ -pr:h=default -pr:b=default

Or, if you are running Conan 2.0:

conan create all/ --version=1.0.0 -pr:h=default -pr:b=default

The only exception is when providing system packages, which are allowed.

from conan import ConanFile

class FooConanFile(ConanFile):
    version = "system"  # Okay!