Should I test pure CQRS Commands? - asp.net-mvc

Question

I'm coding an application using CQRS. I have my commands and my commandHandler. I do tests my commands handlers. But...should you recommend testing commands? What's the best strategy? Should I test all validation possibilities? How do you guys do?
using System;
using Flunt.Notifications;
using Flunt.Validations;
using Todo.Domain.Commands.Contracts;
namespace Todo.Domain.Commands
{
public class CreateTodoCommand : Notifiable, ICommand
{
public CreateTodoCommand() { }
public CreateTodoCommand(string title, string user, DateTime date)
{
Title = title;
User = user;
Date = date;
}
public string Title { get; set; }
public string User { get; set; }
public DateTime Date { get; set; }
public void Validate()
{
AddNotifications(
new Contract()
.Requires()
.HasMinLen(Title, 3, "Title", "Please, describe better your task!")
.HasMinLen(User, 6, "User", "Invalid User!")
);
}
}
}

Answer 1

should you recommend testing commands?
How often do you change commands?
How likely are you to introduce a mistake when changing a command?
How expensive is it for this mistake to escape into a release?
How expensive is it to test?
Commands are out near the input boundary, and one of the common problems that we have near the input boundary is parsing some general purpose data structure to ensure that it satisfies our bespoke constraints.
Does parsing need to be tested? Well, it is logic (more than one possible outcome), so it is certainly a candidate to consider.
Chances are: you don't have particularly specific answers to the questions above. In that case, I would err on the side of introducing tests: because the tests give you a way to collect data, which over time will improve your answers.