Enhance database initialization and improve command handling

- Added `__all__` declaration in `db/__init__.py` for better module export management.
- Simplified command text formatting in `handlers/commands.py` for improved readability.
- Refactored error handler function signature in `handlers/errors.py` for better code style.
- Introduced comprehensive tests for API duties and Telegram authentication in new test files.

handlers/commands.py

@@ -48,9 +48,7 @@ async def start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
 async def help_cmd(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
     if update.message:
         await update.message.reply_text(
-            "Доступные команды:\n"
-            "/start — Начать\n"
-            "/help — Показать эту справку"
+            "Доступные команды:\n/start — Начать\n/help — Показать эту справку"
         )
 
 

handlers/errors.py

@@ -8,7 +8,9 @@ from telegram.ext import ContextTypes
 logger = logging.getLogger(__name__)
 
 
-async def error_handler(update: Update | None, context: ContextTypes.DEFAULT_TYPE) -> None:
+async def error_handler(
+    update: Update | None, context: ContextTypes.DEFAULT_TYPE
+) -> None:
     logger.exception("Exception while handling an update")
     if isinstance(update, Update) and update.effective_message:
         await update.effective_message.reply_text("Произошла ошибка. Попробуйте позже.")