fix(config): return None if env var is empty or non-existent (#315)

* fix(config): return None if env var is empty or non-existent
* chore: fix pylint issues
* fix: add unit test for non-existent env vars

app/utils/config.py

@@ -69,23 +69,32 @@ class Config:
         return os.environ["N8N_WEBHOOK_URL"]
 
     @property
-    def approved_users(self) -> list:
+    def approved_users(self) -> list | None:
         """Returns a list of approved users."""
-        emails: list[str] = os.environ.get("APPROVED_USERS", "").split(",")
-        emails = [i.strip() for i in emails if validate_email_syntax(i.strip())]
+        _emails: list[str] = os.environ.get("APPROVED_USERS", "").split(",")
+        _emails: list[str] = [i.strip() for i in _emails if i]
+        if not _emails:
+            return None
+        emails = [i for i in _emails if validate_email_syntax(i)]
         return emails
 
     @property
-    def approved_rooms(self) -> list:
+    def approved_rooms(self) -> list | None:
         """Returns a list of approved rooms."""
-        rooms: list[str] = os.environ.get("APPROVED_ROOMS", "").split(",")
-        return [i.strip() for i in rooms]
+        _rooms: list[str] = os.environ.get("APPROVED_ROOMS", "").split(",")
+        rooms: list[str] = [i.strip() for i in _rooms if i]
+        if not rooms:
+            return None
+        return rooms
 
     @property
-    def approved_domains(self) -> list:
+    def approved_domains(self) -> list | None:
         """Returns a list of approved domains."""
-        domains: list[str] = os.environ.get("APPROVED_DOMAINS", "").split(",")
-        return [i.strip() for i in domains]
+        _domains: list[str] = os.environ.get("APPROVED_DOMAINS", "").split(",")
+        domains: list[str] = [i.strip() for i in _domains if i]
+        if not domains:
+            return None
+        return domains
 
 
 config: Config = Config()