MCP GitLab Server

"""Validation utilities for tool arguments.""" import functools import logging from typing import Any, Callable, Dict, Optional, TypeVar, Union from mcp import types logger = logging.getLogger(__name__) T = TypeVar('T', bound=Callable[..., Any]) def validate_tool_args( required_args: Optional[Dict[str, type]] = None, optional_args: Optional[Dict[str, type]] = None, ) -> Callable[[T], T]: """ Decorator to validate tool arguments at runtime. Args: required_args: Dict mapping required argument names to their expected types optional_args: Dict mapping optional argument names to their expected types Returns: Decorated function that validates arguments before execution """ required_args = required_args or {} optional_args = optional_args or {} def decorator(func: T) -> T: @functools.wraps(func) async def wrapper(request: types.CallToolRequest) -> types.CallToolResult: arguments = request.params.arguments or {} # Validate required arguments for arg_name, expected_type in required_args.items(): if arg_name not in arguments: return types.CallToolResult( content=[ types.TextContent( type="text", text=f"Missing required argument: {arg_name}" ) ] ) value = arguments[arg_name] if not isinstance(value, expected_type): return types.CallToolResult( content=[ types.TextContent( type="text", text=f"Invalid type for argument '{arg_name}': expected {expected_type.__name__}, got {type(value).__name__}" ) ] ) # Validate optional arguments if present for arg_name, expected_type in optional_args.items(): if arg_name in arguments: value = arguments[arg_name] if not isinstance(value, expected_type): return types.CallToolResult( content=[ types.TextContent( type="text", text=f"Invalid type for argument '{arg_name}': expected {expected_type.__name__}, got {type(value).__name__}" ) ] ) # Validate no unexpected arguments all_valid_args = set(required_args.keys()) | set(optional_args.keys()) unexpected_args = set(arguments.keys()) - all_valid_args if unexpected_args: return types.CallToolResult( content=[ types.TextContent( type="text", text=f"Unexpected arguments: {', '.join(unexpected_args)}" ) ] ) # All validation passed, call the original function return await func(request) return wrapper return decorator def validate_gitlab_id(value: Union[str, int]) -> bool: """Validate GitLab project/user/group ID.""" if isinstance(value, int): return value > 0 if isinstance(value, str): return value.strip() != "" and (value.isdigit() or "/" in value) return False def validate_pagination_params(arguments: Dict[str, Any]) -> Optional[str]: """ Validate pagination parameters. Returns: Error message if validation fails, None if validation passes """ page = arguments.get('page') per_page = arguments.get('per_page') if page is not None: if not isinstance(page, int) or page < 1: return "Page must be a positive integer" if per_page is not None: if not isinstance(per_page, int) or per_page < 1 or per_page > 100: return "Per page must be an integer between 1 and 100" return None