Using FluentValidation

FluentValidation gives you full control when creating data validation. Hence, it is very useful for all validation scenarios:

1. Let's add the FluentValidation package to our application:

   dotnet add package FluentValidation

   This preceding command installs the popular validation library for .NET. The package uses a fluent interface to build strongly typed rules.

2. The following command installs the dependency injection extensions for FluentValidation:

   dotnet add package FluentValidation.DependencyInjectionExtensions

Now we can create another behavior, and this will be for validation. The following code validates the requests inside PipeLineBehavior by using IValidator, which defines a validator for a specific type, and ValidationContext, which creates an instance of the new validation context, from the FluentValidation namespace:

// ValidationBehavior.cs

using FluentValidation;
using MediatR;
using ValidationException = Travel.Application...