fix ruff checks (mostly documentation and dead code)

flupdt/flake_eval.py

@@ -1,14 +1,23 @@
+"""Provides components to evaluate nix components and process the result."""
+
 from __future__ import annotations
 
 import logging
-from typing import Optional
-from flupdt.common import bash_wrapper
 import re
 
+from flupdt.common import bash_wrapper
+
 drv_re = re.compile(r".*(/nix/store/.*\.drv).*")
 
 
-def evaluate_output(path: str, output: str) -> Optional[str]:
+def evaluate_output(path: str, output: str) -> str | None:
+    """Evaluates a given output in a flake.
+
+    :param path: path to flake
+    :param output: flake output to be evaluated
+    :returns the .drv path on success or None on failure
+    :raises RuntimeError: evaluation succeeds but no derivation is found
+    """
     logging.info(f"evaluating {output}")
     out = bash_wrapper(f"nix eval {path}#{output}")
     logging.debug(out[0])
@@ -17,10 +26,9 @@ def evaluate_output(path: str, output: str) -> Optional[str]:
     if out[2] != 0:
         logging.warning(f"output {output} did not evaluate correctly")
         return None
-    else:
-        drv_match = drv_re.match(out[0])
-        if drv_match is None:
-            out_msg = "derivation succeeded but output derivation does not contain a derivation"
-            raise RuntimeError(out_msg)
-        drv = drv_match.group(1)
-        logging.debug(f"derivation evaluated to {drv}")
+    drv_match = drv_re.match(out[0])
+    if drv_match is None:
+        out_msg = "derivation succeeded but output derivation does not contain a derivation"
+        raise RuntimeError(out_msg)
+    drv = drv_match.group(1)
+    logging.debug(f"derivation evaluated to {drv}")