private void ValidateRequiredArguments(
ISyntaxNode parent,
IEnumerable <ArgumentNode> providedArguments,
IFieldCollection <IInputField> arguments)
{
ILookup <string, ArgumentNode> providedArgumentLookup =
providedArguments.ToLookup(t => t.Name.Value);
foreach (InputField requiredArgument in arguments
.Where(t => IsRequiredArgument(t)))
{
ArgumentNode providedArgument =
providedArgumentLookup[requiredArgument.Name]
.FirstOrDefault();
if (providedArgument == null ||
providedArgument.Value is NullValueNode)
{
Errors.Add(new ValidationError(
$"The argument `{requiredArgument.Name}` is required " +
"and does not allow null values.", parent));
}
}
}
