Fix pylint warnings: logging, globals, exceptions, imports, duplicates

Agent-Logs-Url: https://github.com/christianlouis/dmarq/sessions/576427d4-4f6a-46d2-b75f-6862ecbcf526

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

backend/app/utils/domain_validator.py

@@ -56,7 +56,7 @@ def _validate_domain_labels(
     return True, None, None
 
 
-def validate_domain(
+def validate_domain(  # pylint: disable=too-many-return-statements
     domain_name: str, check_dns: bool = True
 ) -> Tuple[bool, Optional[str], Optional[str]]:
     """
@@ -103,7 +103,6 @@ def validate_domain(
     if check_dns:
         try:
             socket.gethostbyname(domain_name)
-            return True, None, None
         except socket.gaierror:
             # We could consider this valid if we don't require DNS resolution,
             # but since DMARC requires valid DNS, we'll mark it as warning
@@ -133,7 +132,7 @@ def validate_domain_config(domain_data: Dict) -> Dict[str, Union[bool, str]]:
     # Validate domain name
     if "name" in domain_data:
         # Don't check DNS for domain config validation
-        is_valid, error_msg, error_code = validate_domain(domain_data["name"], check_dns=False)
+        is_valid, error_msg, _ = validate_domain(domain_data["name"], check_dns=False)
         if not is_valid:
             errors["name"] = error_msg
     else:

backend/app/utils/stats_summarizer.py

@@ -63,10 +63,10 @@ class StatsSummarizer:
                 return None
 
             # Read cache file
-            with open(cache_file, "r") as f:
+            with open(cache_file, "r", encoding="utf-8") as f:
                 return json.load(f)
-        except Exception as e:
-            logger.warning(f"Error reading cache file {cache_file}: {str(e)}")
+        except Exception as e:  # pylint: disable=broad-exception-caught
+            logger.warning("Error reading cache file %s: %s", cache_file, str(e))
             return None
 
     def save_summary(self, stats: Dict[str, Any], domain_id: Optional[str] = None) -> bool:
@@ -87,12 +87,12 @@ class StatsSummarizer:
             stats["cached_at"] = datetime.now().isoformat()
 
             # Write to cache file
-            with open(cache_file, "w") as f:
+            with open(cache_file, "w", encoding="utf-8") as f:
                 json.dump(stats, f)
 
             return True
-        except Exception as e:
-            logger.error(f"Error writing cache file {cache_file}: {str(e)}")
+        except Exception as e:  # pylint: disable=broad-exception-caught
+            logger.error("Error writing cache file %s: %s", cache_file, str(e))
             return False
 
     def invalidate_cache(self, domain_id: Optional[str] = None) -> None:
@@ -126,12 +126,13 @@ class StatsSummarizer:
         """
         if domain_id is None:
             return os.path.join(self.cache_dir, "global_summary.json")
-        else:
-            # Sanitize domain_id to use as filename
-            safe_domain = domain_id.replace(".", "_").replace("/", "_")
-            return os.path.join(self.cache_dir, f"domain_{safe_domain}.json")
+        # Sanitize domain_id to use as filename
+        safe_domain = domain_id.replace(".", "_").replace("/", "_")
+        return os.path.join(self.cache_dir, f"domain_{safe_domain}.json")
 
-    def calculate_summary_statistics(self, db, domain_id: Optional[str] = None) -> Dict[str, Any]:
+    def calculate_summary_statistics(
+        self, _db, domain_id: Optional[str] = None
+    ) -> Dict[str, Any]:
         """
         Calculate summary statistics from the database