class GraphQL::StaticValidation::VariableUsagesAreAllowed

def non_null_levels_match(arg_type, var_type)
  if arg_type.kind.non_null? && !var_type.kind.non_null?
    false
  elsif arg_type.kind.wraps? && var_type.kind.wraps?
    # If var_type is a non-null wrapper for a type, and arg_type is nullable, peel off the wrapper
    # That way, a var_type of `[DairyAnimal]!` works with an arg_type of `[DairyAnimal]`
    if var_type.kind.non_null? && !arg_type.kind.non_null?
      var_type = var_type.of_type
    end
    non_null_levels_match(arg_type.of_type, var_type.of_type)
  else
    true
  end
end