Appease RUF lints

flatpak_builder_lint/appstream.py

@@ -64,7 +64,7 @@ def parse_xml(path: str) -> etree._ElementTree:
     try:
         return etree.parse(path)
     except etree.XMLSyntaxError as e:
-        raise RuntimeError(f"XML syntax error in file {path}: {str(e)}") from None
+        raise RuntimeError(f"XML syntax error in file {path}: {e!s}") from None
 
 
 def components(path: str) -> list[etree._Element]:

flatpak_builder_lint/checks/__init__.py

@@ -1,3 +1,5 @@
+from typing import ClassVar
+
 from .. import ostree
 
 ALL = []
@@ -13,12 +15,12 @@ def __init__(cls, *args, **kwargs) -> None:  # type: ignore
 
 
 class Check(metaclass=CheckMeta):
-    warnings: set[str] = set()
-    errors: set[str] = set()
-    jsonschema: set[str] = set()
-    appstream: set[str] = set()
-    desktopfile: set[str] = set()
-    info: set[str] = set()
+    warnings: ClassVar[set[str]] = set()
+    errors: ClassVar[set[str]] = set()
+    jsonschema: ClassVar[set[str]] = set()
+    appstream: ClassVar[set[str]] = set()
+    desktopfile: ClassVar[set[str]] = set()
+    info: ClassVar[set[str]] = set()
     repo_primary_ref: str | None = None
 
     def _populate_ref(self, repo: str) -> None:

flatpak_builder_lint/checks/finish_args.py

@@ -62,7 +62,7 @@ def _validate(self, appid: str | None, finish_args: dict[str, set[str]]) -> None
 
                 mode_suffix = "rw"
                 if fs.startswith(xdgdirs) and fs.endswith(modes):
-                    mode_src = [i for i in modes if fs.endswith(i)][0]
+                    mode_src = next(i for i in modes if fs.endswith(i))
                     mode_suffix = mode_src.split(":", 1)[1]
 
                 if re.match(regexp_arbitrary, fs):

flatpak_builder_lint/checks/flathub_json.py

@@ -5,7 +5,7 @@
 
 
 class FlathubJsonCheck(Check):
-    arches: set[str] = {"x86_64", "aarch64"}
+    arches: tuple[str] = ("x86_64", "aarch64")
 
     def _check_if_extra_data(self, modules: list) -> bool:
         for module in modules: