karolswdev/dotnet-useful-resources

A collection of useful resources for dotnet development

About

🔖 My curated list of useful resources for dotnet development.

---

🏆 Great NuGet packages

Noteworthy packages to consider picking up as a developer.

OneOf

This package enables you to write clean and reliable code. It ships with the Match method that is used to map outcomes.

Some of the benefits:

• Method signature describes all method outcomes:

  OneOf<User, InvalidName, NameTaken> CreateUser(string username)

• Consumer must always handle all outcomes:

  [HttpPost]
  public IActionResult Register(string username)
  {
      OneOf<User, InvalidName, NameTaken> createUserResult = CreateUser(username);
      return createUserResult.Match(
          user => new RedirectResult("/dashboard"),
          invalidName => {
              ModelState.AddModelError(nameof(username), $"Sorry, that is not a valid username.");
              return View("Register");
          },
          nameTaken => {
              ModelState.AddModelError(nameof(username), "Sorry, that name is already in use.");
              return View("Register");
          }
      );
  }

---

MediatR

MediatR is another tool that can be used to write clear and efficient code.

It is the most popular C# implementation of the mediator pattern.

It supports request/response, commands, queries, notifications and events.

I've used only used it in the Request/Response paradigm. I find that it makes the code much cleaner and easier to understand. It also helps massively with testing.

You can create Handlers for commands as follows:

public class PingHandler : IRequestHandler<Ping, string>
{
    public Task<string> Handle(Ping request, CancellationToken cancellationToken)
    {
        return Task.FromResult("Pong");
    }
}

You can then issue commands to the mediator and have them handled as follows:

var response = await mediator.Send(new Ping());
Debug.WriteLine(response); // "Pong"

---

FluentAssertions

We all love code that ANYBODY could understand, and FluentAssertions definitely helps with that!

It lets you write assertion statements in human readable format. This is usually the first package I install when creating a new project. A must have for your testing side.

To get an idea of how this looks like consider the following:

string actual = "ABCDEFGHI";
actual.Should().StartWith("AB").And.EndWith("HI").And.Contain("EF").And.HaveLength(9);

IEnumerable numbers = new[] { 1, 2, 3 };

numbers.Should().OnlyContain(n => n > 0);
numbers.Should().HaveCount(4, "because we thought we put four items in the collection");