GetBookByIdHandler.cs

namespace MediatRExploration.Application.BookApplication.GetBookById
{
    public class GetBookByIdRequestHandler:IRequestHandler<GetBookByIdRequest,Book>
    {
        private readonly IBookRepository _bookRepository;

        public GetBookByIdRequestHandler(IBookRepository bookRepository)
        {
            _bookRepository = bookRepository;
        }

        public Task<Book> Handle(GetBookByIdRequest request, CancellationToken cancellationToken)
        {
            return Task.FromResult(_bookRepository.GetBookById(request.BookId));
        }
    }
}