Enable flake8-return in ruff (#10988)

flake8-return rule that flags a local variable assigned only to be returned on the next line.

Author: Pierre-Sassoulas

pylint/checkers/format.py

@@ -614,11 +614,10 @@ def check_line_length(self, line: str, i: int, checker_off: bool) -> None:
     def remove_pylint_option_from_lines(options_pattern_obj: Match[str]) -> str:
         """Remove the `# pylint ...` pattern from lines."""
         lines = options_pattern_obj.string
-        purged_lines = (
+        return (
             lines[: options_pattern_obj.start(1)].rstrip()
             + lines[options_pattern_obj.end(1) :]
         )
-        return purged_lines
 
     @staticmethod
     def is_line_length_check_activated(pylint_pattern_match_object: Match[str]) -> bool:

pylint/checkers/imports.py

@@ -1022,14 +1022,12 @@ def _get_out_of_order_string(
         )
         delimiter_first_party2 = ("and " if local else "") if first_party else ""
         delimiter_first_party = f"{delimiter_first_party1}{delimiter_first_party2}"
-        msg = (
+        return (
             f"{third_party}{delimiter_third_party}"
             f"{first_party}{delimiter_first_party}"
             f'{local if local else ""}'
         )
 
-        return msg
-
     def _get_full_import_name(self, importNode: ImportNode) -> str:
         # construct a more descriptive name of the import
         # for: import X, this returns X

pylint/pyreverse/diadefslib.py

@@ -64,15 +64,14 @@ def get_leaf_nodes(self) -> list[str]:
 
         A leaf node is one that is not a prefix (with an extra dot) of any other node.
         """
-        leaf_nodes = [
+        return [
             module
             for module in self.args
             if not any(
                 other != module and other.startswith(module + ".")
                 for other in self.args
             )
         ]
-        return leaf_nodes
 
     def _set_option(self, option: bool | None) -> bool:
         """Activate some options if not explicitly deactivated."""

pylint/pyreverse/dot_printer.py

@@ -143,9 +143,7 @@ def _build_label_for_node(self, properties: NodeProperties) -> str:
     def _escape_annotation_label(self, annotation_label: str) -> str:
         # Escape vertical bar characters to make them appear as a literal characters
         # otherwise it gets treated as field separator of record-based nodes
-        annotation_label = annotation_label.replace("|", r"\|")
-
-        return annotation_label
+        return annotation_label.replace("|", r"\|")
 
     def emit_edge(
         self,

pylint/pyreverse/mermaidjs_printer.py

@@ -35,8 +35,7 @@ def _open_graph(self) -> None:
 
     def _escape_mermaid_text(self, text: str) -> str:
         """Escape characters that conflict with Markdown formatting."""
-        text = text.replace("__", r"\_\_")  # Double underscore → escaped
-        return text
+        return text.replace("__", r"\_\_")  # Double underscore → escaped
 
     def emit_node(
         self,

pylint/pyreverse/writer.py

@@ -185,14 +185,13 @@ def get_package_properties(self, obj: PackageEntity) -> NodeProperties:
 
     def get_class_properties(self, obj: ClassEntity) -> NodeProperties:
         """Get label and shape for classes."""
-        properties = NodeProperties(
+        return NodeProperties(
             label=obj.title,
             attrs=obj.attrs if not self.config.only_classnames else None,
             methods=obj.methods if not self.config.only_classnames else None,
             fontcolor="red" if is_exception(obj.node) else "black",
             color=self.get_shape_color(obj) if self.config.colorized else "black",
         )
-        return properties
 
     def get_shape_color(self, obj: DiagramEntity) -> str:
         """Get shape color."""

pylint/testutils/configuration_test.py

@@ -151,5 +151,4 @@ def run_using_a_configuration_file(
     # in `_msg_states`, used by `is_message_enabled`.
     check = "pylint.lint.pylinter.check_parallel"
     with unittest.mock.patch(check):
-        runner = Run(args, exit=False)
-    return runner
+        return Run(args, exit=False)

pylint/utils/utils.py

@@ -84,8 +84,7 @@ def cmp(a: float, b: float) -> int:
 def diff_string(old: float, new: float) -> str:
     """Given an old and new value, return a string representing the difference."""
     diff = abs(old - new)
-    diff_str = f"{CMPS[cmp(old, new)]}{(diff and f'{diff:.2f}') or ''}"
-    return diff_str
+    return f"{CMPS[cmp(old, new)]}{(diff and f'{diff:.2f}') or ''}"
 
 
 def get_module_and_frameid(node: nodes.NodeNG) -> tuple[str, str]:

pyproject.toml

@@ -128,6 +128,7 @@ lint.select = [
   "PIE", # flake8-pie
   "PTH", # flake8-pathlib
   "PYI", # flake8-pyi
+  "RET", # flake8-return
   "RUF", # ruff
   "UP",  # pyupgrade
   "W",   # pycodestyle

tests/pyreverse/conftest.py

@@ -92,7 +92,6 @@ def _astroid_wrapper(
             return func(modname)
 
         with augmented_sys_path([discover_package_path(module, [])]):
-            project = project_from_files([module], _astroid_wrapper, project_name=name)
-        return project
+            return project_from_files([module], _astroid_wrapper, project_name=name)
 
     return _get_project