Refactors astor usages

.importlinter

@@ -64,13 +64,15 @@ forbidden_modules =
   pycodestyle
   mccabe
   radon
+  astor
 
 ignore_imports =
   # These modules must import from flake8 to provide required API:
   wemake_python_styleguide.checker -> flake8
   wemake_python_styleguide.formatter -> flake8
-  wemake_python_styleguide.formatter -> pygments
   wemake_python_styleguide.options.config -> flake8
+  wemake_python_styleguide.formatter -> pygments
+  wemake_python_styleguide.logic.source -> astor
 
 
 [importlinter:contract:subapi-restrictions]

tests/test_visitors/test_ast/test_keywords/test_keyword_condition.py

@@ -61,7 +61,6 @@ def test_false_condition_keywords(
     '0.1',
     '"0"',
     '[None]',
-    '(0,)',
     '{1, 2, 3}',
     '{name: "0"}',
     'True',

wemake_python_styleguide/logic/compares.py

@@ -5,10 +5,11 @@
 from collections import defaultdict
 from typing import DefaultDict, Mapping, Set, Tuple, Type, Union
 
-import astor
 import attr
 from typing_extensions import Final, final
 
+from wemake_python_styleguide.logic import source
+
 
 @final
 @attr.dataclass(frozen=True, slots=True)
@@ -95,14 +96,11 @@ def _find_lower_upper_bounds(
                 self._mutate(
                     comparison_node,
                     operator,
-                    self._get_operand_name(operand),
+                    source.node_to_string(operand),
                     operand is left_operand,
                 )
             left_operand = right_operand
 
-    def _get_operand_name(self, operand: ast.AST) -> str:
-        return astor.to_source(operand)
-
     def _mutate(
         self,
         comparison_node: ast.Compare,

wemake_python_styleguide/logic/functions.py

@@ -3,8 +3,7 @@
 from ast import Call, Yield, YieldFrom, arg
 from typing import Container, List, Optional
 
-import astor
-
+from wemake_python_styleguide.logic import source
 from wemake_python_styleguide.logic.walk import is_contained
 from wemake_python_styleguide.types import (
     AnyFunctionDef,
@@ -25,7 +24,7 @@ def given_function_called(node: Call, to_check: Container[str]) -> str:
     ''
 
     """
-    function_name = astor.to_source(node.func).strip()
+    function_name = source.node_to_string(node.func)
     if function_name in to_check:
         return function_name
     return ''

wemake_python_styleguide/logic/source.py

@@ -0,0 +1,10 @@
+# -*- coding: utf-8 -*-
+
+import ast
+
+import astor
+
+
+def node_to_string(node: ast.AST) -> str:
+    """Returns the source code by doing ``ast`` to string convert."""
+    return astor.to_source(node).strip()

wemake_python_styleguide/visitors/ast/builtins.py

@@ -5,12 +5,11 @@
 from contextlib import suppress
 from typing import ClassVar, DefaultDict, Iterable, List, Sequence, Union
 
-import astor
 from typing_extensions import final
 
 from wemake_python_styleguide import constants
 from wemake_python_styleguide.compat.aliases import FunctionNodes
-from wemake_python_styleguide.logic import safe_eval
+from wemake_python_styleguide.logic import safe_eval, source
 from wemake_python_styleguide.logic.naming.name_nodes import extract_name
 from wemake_python_styleguide.logic.operators import (
     get_parent_ignoring_unary,
@@ -257,8 +256,8 @@ def _check_set_elements(
             real_item = unwrap_unary_node(set_item)
             if isinstance(real_item, self._elements_in_sets):
                 # Similar look:
-                source = astor.to_source(set_item)
-                elements.append(source.strip().strip('(').strip(')'))
+                node_repr = source.node_to_string(set_item)
+                elements.append(node_repr.strip().strip('(').strip(')'))
 
             real_item = unwrap_starred_node(real_item)
 

wemake_python_styleguide/visitors/ast/classes.py

@@ -4,7 +4,6 @@
 from collections import defaultdict
 from typing import ClassVar, DefaultDict, FrozenSet, List, Optional, Tuple
 
-import astor
 from typing_extensions import final
 
 from wemake_python_styleguide import constants, types
@@ -15,6 +14,7 @@
     functions,
     nodes,
     prop_access,
+    source,
     strings,
     walk,
 )
@@ -306,7 +306,7 @@ def _slot_item_name(self, node: ast.AST) -> Optional[str]:
         if isinstance(node, ast.Str):
             return node.s
         if isinstance(node, ast.Starred):
-            return astor.to_source(node).strip()
+            return source.node_to_string(node)
         return None
 
     def _are_correct_slots(self, slots: List[ast.AST]) -> bool:

wemake_python_styleguide/visitors/ast/compares.py

@@ -3,7 +3,6 @@
 import ast
 from typing import ClassVar, List, Optional, Sequence
 
-import astor
 from typing_extensions import final
 
 from wemake_python_styleguide.compat.aliases import AssignNodes
@@ -14,6 +13,7 @@
     ifs,
     nodes,
     operators,
+    source,
 )
 from wemake_python_styleguide.logic.naming.name_nodes import is_same_variable
 from wemake_python_styleguide.types import AnyIf, AnyNodes
@@ -299,7 +299,7 @@ def _is_simplifiable_assign(
         if len(targets) != 1:
             return None
 
-        return astor.to_source(targets[0]).strip()
+        return source.node_to_string(targets[0])
 
     def _check_constant_condition(self, node: AnyIf) -> None:
         real_node = operators.unwrap_unary_node(node.test)

wemake_python_styleguide/visitors/ast/complexity/overuses.py

@@ -4,12 +4,11 @@
 from collections import defaultdict
 from typing import ClassVar, DefaultDict, List, Union
 
-import astor
 from typing_extensions import final
 
 from wemake_python_styleguide.compat.aliases import FunctionNodes
 from wemake_python_styleguide.constants import SPECIAL_ARGUMENT_NAMES_WHITELIST
-from wemake_python_styleguide.logic import nodes, walk
+from wemake_python_styleguide.logic import nodes, source, walk
 from wemake_python_styleguide.types import AnyNodes
 from wemake_python_styleguide.violations import complexity
 from wemake_python_styleguide.visitors import base
@@ -122,7 +121,7 @@ def _add_expression(self, node: ast.AST) -> None:
         if any(ignore(node) for ignore in ignore_predicates):
             return
 
-        source_code = astor.to_source(node).strip()
+        source_code = source.node_to_string(node)
         self._module_expressions[source_code].append(node)
 
         maybe_function = walk.get_closest_parent(node, FunctionNodes)
@@ -175,12 +174,12 @@ def _post_visit(self) -> None:
                 )
 
         for function_contexts in self._function_expressions.values():
-            for source, function_nodes in function_contexts.items():
+            for src, function_nodes in function_contexts.items():
                 if len(function_nodes) > self.options.max_function_expressions:
                     self.add_violation(
                         complexity.OverusedExpressionViolation(
                             function_nodes[0],
-                            text=self._msg.format(source, len(function_nodes)),
+                            text=self._msg.format(src, len(function_nodes)),
                         ),
                     )
 

wemake_python_styleguide/visitors/ast/conditions.py

@@ -5,10 +5,9 @@
 from functools import reduce
 from typing import ClassVar, DefaultDict, Dict, List, Set, Type
 
-import astor
 from typing_extensions import final
 
-from wemake_python_styleguide.logic import ifs
+from wemake_python_styleguide.logic import ifs, source
 from wemake_python_styleguide.logic.compares import CompareBounds
 from wemake_python_styleguide.logic.functions import given_function_called
 from wemake_python_styleguide.logic.nodes import get_parent
@@ -41,7 +40,7 @@ def _duplicated_isinstance_call(node: ast.BoolOp) -> List[str]:
         if not given_function_called(call, {'isinstance'}):
             continue
 
-        isinstance_object = astor.to_source(call.args[0]).strip()
+        isinstance_object = source.node_to_string(call.args[0])
         counter[isinstance_object] += 1
 
     return [
@@ -192,7 +191,7 @@ def _get_all_names(
             if isinstance(operand, ast.BoolOp):
                 names.extend(self._get_all_names(operand))
             else:
-                names.append(astor.to_source(operand))
+                names.append(source.node_to_string(operand))
         return names
 
     def _check_same_elements(self, node: ast.BoolOp) -> None:
@@ -247,7 +246,7 @@ def _check_implicit_in(self, node: ast.BoolOp) -> None:
             if not isinstance(compare.ops[0], allowed_ops[node.op.__class__]):
                 return
 
-            variables.append({astor.to_source(compare.left)})
+            variables.append({source.node_to_string(compare.left)})
 
         for duplicate in _get_duplicate_names(variables):
             self.add_violation(

wemake_python_styleguide/visitors/ast/exceptions.py

@@ -4,9 +4,9 @@
 from collections import Counter
 from typing import ClassVar, List, Tuple
 
-import astor
 from typing_extensions import final
 
+from wemake_python_styleguide.logic import source
 from wemake_python_styleguide.logic.walk import is_contained
 from wemake_python_styleguide.types import AnyNodes
 from wemake_python_styleguide.violations.best_practices import (
@@ -105,10 +105,10 @@ def _check_duplicate_exceptions(self, node: ast.Try) -> None:
             # There might be complex things hidden inside an exception type,
             # so we want to get the string representation of it:
             if isinstance(exc_handler.type, ast.Name):
-                exceptions.append(astor.to_source(exc_handler.type).strip())
+                exceptions.append(source.node_to_string(exc_handler.type))
             elif isinstance(exc_handler.type, ast.Tuple):
                 exceptions.extend([
-                    astor.to_source(node).strip()
+                    source.node_to_string(node)
                     for node in exc_handler.type.elts
                 ])
 

wemake_python_styleguide/visitors/ast/keywords.py

@@ -103,15 +103,14 @@ def _check_last_return_in_function(self, node: ast.Return) -> None:
             walk.get_subnodes_by_type(parent, ast.Return),
         )))
 
-        if node is parent.body[-1]:
-            last_value_return = (
-                len(parent.body) > 1 and
-                returns < 2 and
-                isinstance(node.value, ast.NameConstant) and
-                node.value.value is None
-            )
-            if node.value is None or last_value_return:
-                self.add_violation(InconsistentReturnViolation(node))
+        last_value_return = (
+            len(parent.body) > 1 and
+            returns < 2 and
+            isinstance(node.value, ast.NameConstant) and
+            node.value.value is None
+        )
+        if node.value is None or last_value_return:
+            self.add_violation(InconsistentReturnViolation(node))
 
     def _iterate_returning_values(
         self,