Code Quality: Improve dashboard code and fix warnings

fenn/dashboard/app.py

@@ -126,7 +126,7 @@ def _require_login():
 
 
 @app.errorhandler(CSRFError)
-def _csrf_failed(e):
+def _csrf_failed(_e):
     return render_template(
         "connect.html",
         error_message="Form expired. Please try again.",
@@ -233,7 +233,7 @@ def api_sessions():
     default 0), sort (field, optionally ``-`` prefixed for descending).
     """
     try:
-        project = request.args.get("project") or None
+        project_name = request.args.get("project") or None
         status = request.args.get("status") or None
         sort = request.args.get("sort") or "-started"
         limit = _parse_int_arg(
@@ -243,7 +243,7 @@ def api_sessions():
 
         try:
             result = scanner.list_sessions(
-                project=project,
+                project=project_name,
                 status=status,
                 limit=limit,
                 offset=offset,
@@ -262,7 +262,7 @@ def api_sessions():
 
 
 @app.errorhandler(404)
-def not_found(e):
+def not_found(_e):
     return render_template("404.html", **scanner.get_overview()), 404
 
 
@@ -332,6 +332,7 @@ def logout():
 # --------------------------------------------------------------------------- #
 
 
+# TODO: Use 'debug' in logger
 def run(
     host: str = "127.0.0.1", port: int = 5000, debug: bool = False, log_dirs=None
 ) -> None:

fenn/dashboard/auth.py

@@ -3,7 +3,7 @@
 The dashboard is a localhost-only Flask app. To authenticate, the user
 generates a "dashboard token" on pyfenn.com, pastes it into the
 ``/connect`` page, and the server validates it once against
-``https://pyfenn.com/api/dashboard/me``. On success we store
+``https://pyfenn.com/api/dashboard/me``. On success, we store
 ``{user_id, email}`` in a signed Flask session cookie and discard the
 token — it is never written to disk or kept in memory.
 """

fenn/dashboard/scanner.py

@@ -4,7 +4,7 @@
 import time
 from pathlib import Path
 from typing import Any, Dict, List, Optional, Tuple
-from xml.etree import ElementTree as ET
+from xml.etree import ElementTree
 
 # Default directories to scan (resolved at runtime)
 _DEFAULT_DIRS = [
@@ -106,7 +106,7 @@ def find_fn_files(self) -> List[Path]:
             if f not in seen:
                 seen.add(f)
                 unique.append(f)
-        ordered = sorted(unique, key=lambda f: f.stat().st_mtime, reverse=True)
+        ordered = sorted(unique, key=lambda path: path.stat().st_mtime, reverse=True)
         self._files_cache = (now, ordered)
         return ordered
 
@@ -137,25 +137,23 @@ def parse_fn_file(self, path: Path) -> Optional[Dict[str, Any]]:
         self._parse_cache[key] = (mtime, parsed)
         return self._refresh_running_status(parsed, mtime)
 
-    def _parse_uncached(
-        self, path: Path, stat: os.stat_result
-    ) -> Optional[Dict[str, Any]]:
+    @staticmethod
+    def _parse_uncached(path: Path, stat: os.stat_result) -> Optional[Dict[str, Any]]:
         try:
             content = path.read_text(encoding="utf-8")
         except (OSError, PermissionError):
             return None
 
-        root = None
         status = "completed"
 
         try:
-            root = ET.fromstring(content)
-        except ET.ParseError:
+            root = ElementTree.fromstring(content)
+        except ElementTree.ParseError:
             # Session may still be running — try appending the closing tag
             try:
-                root = ET.fromstring(content + "\n</fenn-log>")
+                root = ElementTree.fromstring(content + "\n</fenn-log>")
                 status = "running"
-            except ET.ParseError:
+            except ElementTree.ParseError:
                 return None
 
         # Override status from <meta> if present
@@ -261,7 +259,9 @@ def _build_projects_list(sessions: List[Dict[str, Any]]) -> List[Dict[str, Any]]
                 p["running_count"] += 1
             elif s["status"] == "crashed":
                 p["crashed_count"] += 1
-        return sorted(projects.values(), key=lambda p: p["last_active"], reverse=True)
+        return sorted(
+            projects.values(), key=lambda project: project["last_active"], reverse=True
+        )
 
     def get_overview(self) -> Dict[str, Any]:
         """Aggregate stats for the dashboard home page."""
@@ -360,11 +360,12 @@ def list_sessions(
         if status:
             sessions = [s for s in sessions if s["status"] == status]
 
-        # Sentinel keeps None values consistently last (asc) / first (desc)
-        # without crashing the comparison on mixed types.
+        # Sorts None values last (ascending) / first (descending) without comparing None to
+        # non-None values, but may raise TypeError if non-None values are of different types
+        # (e.g., int vs str).
         def sort_key(s: Dict[str, Any]):
             v = s.get(field)
-            return (v is None, v if v is not None else "")
+            return v is None, v
 
         sessions.sort(key=sort_key, reverse=descending)
 
@@ -380,7 +381,8 @@ def sort_key(s: Dict[str, Any]):
             "offset": offset,
         }
 
-    def format_duration(self, seconds: Optional[int]) -> str:
+    @staticmethod
+    def format_duration(seconds: Optional[int]) -> str:
         if seconds is None:
             return "—"
         if seconds < 60:
@@ -391,7 +393,8 @@ def format_duration(self, seconds: Optional[int]) -> str:
         m = (seconds % 3600) // 60
         return f"{h}h {m}m"
 
-    def format_size(self, size_bytes: int) -> str:
+    @staticmethod
+    def format_size(size_bytes: int) -> str:
         if size_bytes < 1024:
             return f"{size_bytes} B"
         if size_bytes < 1024 * 1024: