Summary

The entire contents here amounts to quite a chapter. Let's summarize the essential parts.

You have finally seen how to apply CQRS, MediatR, and Pipeline Behavior. The MediatR package makes the CQRS pattern easy to do in ASP.NET Core. The Pipeline Behavior package allows you to run a number of methods, such as validations or loggings, in a command before and after a handler processes it.

You learned how to use the FluentValidation package, a powerful library for validating your models.

You also learned how to use the AutoMapper package, a library that allows you to map an object to another object by writing a few lines of code.

Lastly, you saw how to use IServiceCollection to create a clean dependency injection in the Startup.cs file.

With this, we have made the ASP.NET Core 5 application more testable and scalable. In the next chapter, we will use Serilog for logging in ASP.NET Core 5, and we will also implement API versioning.