def _one_of_check()

in core/config/base_config.py [0:0]

• 6 lines of code
• 4 McCabe index (conditional complexity)

  def _one_of_check(cls, values):
    """Validate that all 'one of' fields are appear exactly once."""
    one_of_map = cls._field_data_map("one_of")
    for one_of, field_names in one_of_map.items():
      if sum([values.get(n, None) is not None for n in field_names]) != 1:
        raise ValueError(f"Exactly one of {','.join(field_names)} required.")
    return values