1. import functools
  2. import inspect
  4. def validate_url_params(func):
  5. """
  6. Decorator to validate URL parameters and wrap errors for diagnostics.
  7. """
  8. @functools.wraps(func)
  9. def wrapper(*args, **kwargs):
  10. """Wrapper function to validate URL parameters."""
  11. sig = inspect.signature(func)
  12. params = sig.parameters
  14. # Extract URL parameters from kwargs
  15. url_params = {
  16. p.name: kwargs.get(p.name)
  17. for p in params.values()
  18. if p.name in kwargs
  19. }
  21. # Validate parameters based on function signature
  22. for name, param in params.items():
  23. if param.default is inspect.Parameter.empty and name in url_params:
  24. try:
  25. # Perform validation logic here. Example: convert to int
  26. if param.annotation == int:
  27. int(url_params[name])
  28. # Add other validation logic based on param.annotation
  29. # ...
  30. except ValueError:
  31. raise ValueError(f"Invalid value for URL parameter '{name}'. Expected {param.annotation}, got '{url_params[name]}'")
  32. except TypeError:
  33. raise TypeError(f"Invalid type for URL parameter '{name}'. Expected {param.annotation}, got {type(url_params[name])}")
  35. # Call the original function if validation passes
  36. return func(*args, **kwargs)
  38. return wrapper
  40. if __name__ == '__main__':
  41. @validate_url_params
  42. def my_function(id: int, name: str = "default"):
  43. """
  44. Example function that accepts URL parameters.
  45. """
  46. print(f"ID: {id}, Name: {name}")
  48. # Test cases
  49. try:
  50. my_function(123, name="Alice") # Valid
  51. my_function(123) # Valid, uses default for name
  52. my_function("abc", name="Bob") # Raises ValueError
  53. except (ValueError, TypeError) as e:
  54. print(f"Error: {e}")

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