private async ValueTask <RuleResult[]> HandleAsync(IValidationRule <T> rule, T[] items, CancellationToken cancellationToken)
{
// Creates final handler that executes the rule itself.
async ValueTask <ValidationResult[]> finalHandler()
{
return(await rule.ValidateAsync(items, cancellationToken));
}
// Creates the handler chain by reversing the original list of handlers then aggregating them with the final handler as the seed.
var handlerChain = _handlers
.Reverse()
.Aggregate((ValidationRuleHandlerDelegate)finalHandler,
(next, handler) => () => handler.HandleAsync(rule.GetType(), items, next, cancellationToken));
var validationResult = await handlerChain();
return(validationResult
.Select(result => new RuleResult(rule.GetType(), result))
.ToArray());
}
