Fixes multiple bugs, closes #332, closes #318

CHANGELOG.md

@@ -3,11 +3,12 @@
 We follow Semantic Versions since the `0.1.0` release.
 We used to have incremental versioning before `0.1.0`.
 
-## WIP
+## 0.5.1
 
-### Misc
+### Bugfixes
 
-- Fixes build failing on Windows
+- Fixes all possible error that happens 
+  because of unset `parent` and `function_type` nodes
 
 
 ## 0.5.0

tests/fixtures/noqa.py

@@ -178,7 +178,10 @@ class SomeClass(FirstParent, SecondParent, object):  # noqa: Z315
 
 
 class Example(object):
+    """Correct class docstring."""
+
     def __init__(self):  # noqa: Z439
+        """Correct function docstring."""
         yield 10
 
 

tests/fixtures/regression.py

@@ -0,0 +1,9 @@
+class MqttListener:
+    """MqttListener is a wrapper for (hb)mqtt connection."""
+
+    def __init__(self, user: str, password: str, topic: str):
+        """Init (hb)mqtt client."""
+        self.mqtt_client = MQTTClient()
+        self.user = user
+        self.password = password
+        self.topic = topic

tests/test_visitors/test_ast/conftest.py

@@ -4,49 +4,8 @@
 from textwrap import dedent
 
 import pytest
-from pep8ext_naming import NamingChecker
 
-
-class _ClassVisitor(ast.NodeVisitor):
-    def __init__(self, transformer: NamingChecker) -> None:
-        super().__init__()
-        self.transformer = transformer
-
-    def visit_ClassDef(self, node: ast.ClassDef) -> None:  # noqa: N802
-        self.transformer.tag_class_functions(node)
-        self.generic_visit(node)
-
-
-def _maybe_set_parent(tree: ast.AST) -> ast.AST:
-    """
-    Sets parents for all nodes that do not have this prop.
-
-    This step is required due to how `flake8` works.
-    It does not set the same properties as `ast` module.
-
-    This function was the cause of `issue-112`.
-
-    .. versionchanged:: 0.0.11
-
-    """
-    for statement in ast.walk(tree):
-        for child in ast.iter_child_nodes(statement):
-            setattr(child, 'parent', statement)
-    return tree
-
-
-def _maybe_set_function_type(tree: ast.AST) -> ast.AST:
-    """
-    Sets the function type for methods.
-
-    Can set: `method`, `classmethod`, `staticmethod`.
-
-    .. versionchanged:: 0.3.0
-
-    """
-    transformer = _ClassVisitor(NamingChecker(tree, 'stdin'))
-    transformer.visit(tree)
-    return tree
+from wemake_python_styleguide.transformation.ast_tree import transform
 
 
 @pytest.fixture(scope='session')
@@ -65,11 +24,6 @@ def parse_ast_tree():
 
     Order is important.
     """
-    transformation_pipeline = [
-        _maybe_set_parent,
-        _maybe_set_function_type,
-    ]
-
     def factory(code: str, do_compile: bool = True) -> ast.AST:
         code_to_parse = dedent(code)
 
@@ -78,10 +32,6 @@ def factory(code: str, do_compile: bool = True) -> ast.AST:
             # that are validated after the `ast` is processed:
             # like double arguments or `break` outside of loops.
             compile(code_to_parse, '<filename>', 'exec')  # noqa: Z421
-        tree = ast.parse(code_to_parse)
-
-        for transform in transformation_pipeline:
-            tree = transform(tree)
-        return tree
+        return transform(ast.parse(code_to_parse))
 
     return factory

wemake_python_styleguide/checker.py

@@ -64,6 +64,7 @@
 from wemake_python_styleguide import constants, types
 from wemake_python_styleguide import version as pkg_version
 from wemake_python_styleguide.options.config import Configuration
+from wemake_python_styleguide.transformation.ast_tree import transform
 from wemake_python_styleguide.visitors import base
 from wemake_python_styleguide.visitors.presets import (
     complexity,
@@ -127,7 +128,7 @@ def __init__(
             http://flake8.pycqa.org/en/latest/plugin-development/index.html
 
         """
-        self.tree = tree
+        self.tree = transform(tree)
         self.filename = filename
         self.file_tokens = file_tokens
 

wemake_python_styleguide/transformation/__init__.py

@@ -0,0 +1 @@
+# -*- coding: utf-8 -*-

wemake_python_styleguide/transformation/ast_tree.py

@@ -0,0 +1,63 @@
+# -*- coding: utf-8 -*-
+
+import ast
+
+from pep8ext_naming import NamingChecker
+
+
+class _ClassVisitor(ast.NodeVisitor):
+    def __init__(self, transformer: NamingChecker) -> None:
+        super().__init__()
+        self.transformer = transformer
+
+    def visit_ClassDef(self, node: ast.ClassDef) -> None:  # noqa: N802
+        self.transformer.tag_class_functions(node)
+        self.generic_visit(node)
+
+
+def _set_parent(tree: ast.AST) -> ast.AST:
+    """
+    Sets parents for all nodes that do not have this prop.
+
+    This step is required due to how `flake8` works.
+    It does not set the same properties as `ast` module.
+
+    This function was the cause of `issue-112`.
+
+    .. versionchanged:: 0.0.11
+
+    """
+    for statement in ast.walk(tree):
+        for child in ast.iter_child_nodes(statement):
+            setattr(child, 'parent', statement)
+    return tree
+
+
+def _set_function_type(tree: ast.AST) -> ast.AST:
+    """
+    Sets the function type for methods.
+
+    Can set: `method`, `classmethod`, `staticmethod`.
+
+    .. versionchanged:: 0.3.0
+
+    """
+    transformer = _ClassVisitor(NamingChecker(tree, 'stdin'))
+    transformer.visit(tree)
+    return tree
+
+
+def transform(tree: ast.AST) -> ast.AST:
+    """
+    Mutates the given ``ast`` tree.
+
+    Applies all possible tranformations.
+    """
+    pipeline = (
+        _set_parent,
+        _set_function_type,
+    )
+
+    for tranformation in pipeline:
+        tree = tranformation(tree)
+    return tree