🔧 MAINTAIN: Add pylint_aiida plugin (#5182)

As discussed in #5176 and pylint-dev/pylint#1694,
pylint does not understand the `@classproperty` decorator,
and so mistakes the method as a function, rather than an attribute of the class.
This commit adds a pylint transform plugin, to remove false-positives.
(see: https://pylint.pycqa.org/en/latest/how_tos/transform_plugins.html)

aiida/common/utils.py

@@ -15,6 +15,7 @@
 import os
 import re
 import sys
+from typing import Any, Dict
 from uuid import UUID
 
 from .lang import classproperty
@@ -388,7 +389,7 @@ def _prettify_label_latex_simple(cls, label):
         return re.sub(r'(\d+)', r'$_{\1}$', label)
 
     @classproperty
-    def prettifiers(cls):  # pylint: disable=no-self-argument
+    def prettifiers(cls) -> Dict[str, Any]:  # pylint: disable=no-self-argument
         """
         Property that returns a dictionary that for each string associates
         the function to prettify a label
@@ -412,7 +413,7 @@ def get_prettifiers(cls):
 
         :return: a list of strings
         """
-        return sorted(cls.prettifiers.keys())  # pylint: disable=no-member
+        return sorted(cls.prettifiers.keys())
 
     def __init__(self, format):  # pylint: disable=redefined-builtin
         """

aiida/transports/transport.py

@@ -194,10 +194,10 @@ def get_valid_auth_params(cls):
         if cls._valid_auth_options is None:
             raise NotImplementedError
         else:
-            return cls.auth_options.keys()  # pylint: disable=no-member
+            return cls.auth_options.keys()
 
     @classproperty
-    def auth_options(cls):  # pylint: disable=no-self-argument
+    def auth_options(cls) -> OrderedDict:  # pylint: disable=no-self-argument
         """Return the authentication options to be used for building the CLI.
 
         :return: `OrderedDict` of tuples, with first element option name and second dictionary of kwargs

pyproject.toml

@@ -3,7 +3,7 @@ requires = ["setuptools>=40.8.0", "wheel", "fastentrypoints~=0.12"]
 build-backend = "setuptools.build_meta"
 
 [tool.pylint.master]
-load-plugins = "pylint_django"
+load-plugins = ["pylint_django", "utils.pylint_aiida"]
 # this currently fails with aiida.common.exceptions.ProfileConfigurationError: no profile has been loaded
 # we woud need a static settings module to use this
 # django-settings-module = "aiida.backends.djsite.settings"

utils/pylint_aiida.py

@@ -0,0 +1,57 @@
+# -*- coding: utf-8 -*-
+"""pylint plugin for ``aiida-core`` specific issues."""
+import astroid
+
+
+def register(linter):  # pylint: disable=unused-argument
+    """Register linters (unused)"""
+
+
+def remove_classprop_imports(import_from: astroid.ImportFrom):
+    """Remove any ``classproperty`` imports (handled in ``replace_classprops``)"""
+    import_from.names = [name for name in import_from.names if name[0] != 'classproperty']
+
+
+def replace_classprops(func: astroid.FunctionDef):
+    """Replace ``classproperty`` decorated methods.
+
+    As discussed in https://github.com/PyCQA/pylint/issues/1694, pylint does not understand the ``@classproperty``
+    decorator, and so mistakes the method as a function, rather than an attribute of the class.
+    If the method is annotated, this leads to pylint issuing ``no-member`` errors.
+
+    This transform replaces ``classproperty`` decorated methods with an annotated attribute::
+
+        from aiida.common.lang import classproperty
+
+        class MyClass:
+            @classproperty
+            def my_property(cls) -> AnnotatedType:
+                return cls.my_value
+
+        MyClass.my_property.attribute  # <-- pylint issues: Method 'my_property' has no 'attribute' member (no-member)
+
+        class MyClass:
+            my_property: AnnotatedType
+
+    """
+    # ignore methods without annotations or decorators
+    if not (func.returns and func.decorators and func.decorators.nodes):
+        return
+    # ignore methods that are specified as abstract
+    if any(isinstance(node, astroid.Name) and 'abstract' in node.name for node in func.decorators.nodes):
+        return
+    if any(isinstance(node, astroid.Attribute) and 'abstract' in node.attrname for node in func.decorators.nodes):
+        return
+    # convert methods with @classproperty decorator
+    if isinstance(func.decorators.nodes[0], astroid.Name) and func.decorators.nodes[0].name == 'classproperty':
+        assign = astroid.AnnAssign(lineno=func.lineno, col_offset=func.col_offset, parent=func.parent)
+        assign.simple = 1
+        assign.target = astroid.AssignName(func.name, lineno=assign.lineno, col_offset=assign.col_offset, parent=assign)
+        assign.annotation = func.returns
+        assign.annotation.parent = assign
+        func.parent.locals[func.name] = [assign.target]
+        return assign
+
+
+astroid.MANAGER.register_transform(astroid.ImportFrom, remove_classprop_imports)
+astroid.MANAGER.register_transform(astroid.FunctionDef, replace_classprops)