GuardClauses VS CH.CleanArchitecture

You could also use the Ardalis Guard Clause, Ardalis Result and Fluent Validation

Here is an example how one would make sure our order total is valid. For this purpose I use an amazing library called GuardClauses.

GuardClauses

I'm guessing it's just a port of Ardalis' Guard class since he helped a lot with Microsoft's web projects.

The Guard Clauses are from: https://github.com/ardalis/GuardClauses

In terms of readability concerns, I definitely hear you on that. Using something like this can cut down on code bloat that comes with param validation and help with readability.

It's made by Ardalis, who wrote Microsoft's architectural guide for ASP.NET Core Web APIs. I like his GuardClauses library too.

The IAggregateRoot interface is pretty specific to the overall architecture, as you may notice from the few domain-event-related functions in there. For more information regarding this, take a look at my earlier post Designing the domain model to support multiple persistence methods. Despite that, the point of this is to distinguish between data entities and domain entities so you should adjust this interface properly to your needs.

The repository for the source code of this solution can be found here. The solution includes an extremely basic domain model for an online shop application, as an example. The UI part for this is not included however. The order domain exists to simply showcase the different elements of the architecture.