Enforce ruff rule RUF012

RUF012 Mutable class attributes should be annotated with `typing.ClassVar`

Author: DimitriPapadopoulos

fsspec/gui.py

@@ -169,8 +169,17 @@ def show(self, threads=False):
 class SingleSelect(SigSlot):
     """A multiselect which only allows you to select one item for an event"""
 
-    signals = ["_selected", "selected"]  # the first is internal
-    slots = ["set_options", "set_selection", "add", "clear", "select"]
+    signals: ClassVar[Sequence[str]] = [
+        "_selected",
+        "selected",
+    ]  # the first is internal
+    slots: ClassVar[Sequence[str]] = [
+        "set_options",
+        "set_selection",
+        "add",
+        "clear",
+        "select",
+    ]
 
     def __init__(self, **kwargs):
         self.kwargs = kwargs
@@ -212,7 +221,7 @@ class FileSelector(SigSlot):
     them as the output of a cell,  or in a separate browser tab using ``.show()``.
     """
 
-    signals = [
+    signals: ClassVar[Sequence[str]] = [
         "protocol_changed",
         "selection_changed",
         "directory_entered",
@@ -221,7 +230,7 @@ class FileSelector(SigSlot):
         "go_clicked",
         "filters_changed",
     ]
-    slots = ["set_filters", "go_home"]
+    slots: ClassVar[Sequence[str]] = ["set_filters", "go_home"]
 
     def __init__(self, url=None, filters=None, ignore=None, kwargs=None):
         """

fsspec/implementations/memory.py

@@ -5,7 +5,7 @@
 from errno import ENOTEMPTY
 from io import BytesIO
 from pathlib import PurePath, PureWindowsPath
-from typing import Any, ClassVar
+from typing import Any, ClassVar, Sequence
 
 from fsspec import AbstractFileSystem
 from fsspec.implementations.local import LocalFileSystem
@@ -22,7 +22,7 @@ class MemoryFileSystem(AbstractFileSystem):
     """
 
     store: ClassVar[dict[str, Any]] = {}  # global, do not overwrite!
-    pseudo_dirs = [""]  # global, do not overwrite!
+    pseudo_dirs: ClassVar[Sequence[str]] = [""]  # global, do not overwrite!
     protocol = "memory"
     root_marker = "/"
 

fsspec/implementations/tests/conftest.py

@@ -10,7 +10,7 @@
 
 
 class MultiProtocolFileSystem(LocalFileSystem):
-    protocol = ["file", "other"]
+    protocol = ("file", "other")
 
 
 FILESYSTEMS = {

fsspec/implementations/tests/test_archive.py

@@ -214,14 +214,14 @@ class TestAnyArchive:
     will adhere to the same specification.
     """
 
-    scenarios = [
+    scenarios = (
         scenario_zip,
         scenario_tar,
         scenario_targz,
         scenario_tarbz2,
         scenario_tarxz,
         scenario_libarchive,
-    ]
+    )
 
     def test_repr(self, scenario: ArchiveTestScenario):
         with scenario.provider() as archive:

fsspec/tests/conftest.py

@@ -6,6 +6,7 @@
 from collections import ChainMap
 from http.server import BaseHTTPRequestHandler, HTTPServer
 from types import SimpleNamespace
+from typing import ClassVar
 
 import pytest
 
@@ -45,7 +46,7 @@ def reset_files():
 
 
 class HTTPTestHandler(BaseHTTPRequestHandler):
-    static_files = {
+    static_files: ClassVar[dict[str, bytes]] = {
         "/index/realfile": data,
         "/index/otherfile": data,
         "/index": _make_index_listing,
@@ -55,7 +56,7 @@ class HTTPTestHandler(BaseHTTPRequestHandler):
         "/simple/dir/": _make_listing("/simple/dir/file"),
         "/simple/dir/file": data,
     }
-    dynamic_files = {}
+    dynamic_files: ClassVar[dict[str, bytes]] = {}
 
     files = ChainMap(dynamic_files, static_files)
 

pyproject.toml

@@ -178,6 +178,7 @@ select = [
     # "PT", enable in later PR
     "PYI",
     "RUF006",
+    "RUF012",
     "RUF015",
     "RUF024",
     "SIM",