How do I implement async validators in Fluent Validation?

How do I implement async validators in Fluent Validation?

To implement async validators in Fluent Validation, you can use the MustAsync method. This allows you to define a validation rule that performs an asynchronous operation.

Can you give me an example of using MustAsync?

Sure! Here's a simple example:

RuleFor(x => x.Email)
    .MustAsync(async (email, cancellation) => await EmailIsUnique(email))
    .WithMessage("Email must be unique.");

What is the purpose of using async validators?

Async validators are useful for operations that require I/O, like checking a database for existing records, without blocking the main thread.

Are there any performance considerations I should be aware of?

Yes, while async validators can improve responsiveness, ensure that the operations they perform are efficient to avoid slowing down the validation process.