nesfit / ics Goto Github PK

The problem

Let's say we want to extend CookBook with ingredient types and we want our user to input that ingredient type.

public record IngredientEntity : IEntity {
    public required string Name { get; set; }
    public required string Description { get; set; }
    // Add this
    public required IngridientTypeEntity Type { get; set; }
    public string? ImageUrl { get; set; }
    public required Guid Id { get; set; }
}

However, current implementation of IModelMapper and ModelMapperBase won't allow this kind of implementation:

public interface IModelMapper<TEntity, out TListModel, TDetailModel>;

So, in any case we are required to make a model even for the simplest of things that could just be solved with a list, text box and two buttons.

Workarounds

One of the workarounds would be creating dummy classes that just won't be used and changing ModelMapperBase.MapToEntity function signature to make it virtual and adding an overload that would allow mapping from TListModel. Or just using TListModel for TDetailModel.

The question

Was this intentional or did anyone just not consider the possibility of using something other than enum/string for this kind of problem?

The name of the test suggests that it is not supposed to throw any exceptions. However, you then assert that it does.

Link to test:

For a long time now, it was preferable to use int.Parse(string) over Convert.ToInt32(string). If you look at the implementation of ToInt32, you can see that it internally calls int.Parse(string), BUT returns 0 when input is null. This behaviour is rarely desirable. Even better than Parse is TryParse, since it is cleaner and performs better than handling exceptions with try catch. Parse is of course better when it comes to writing a simple code snippet for a lecture.

In modern .NET (version 7+) there is IParsable<TSelf> interface that reinforces the suggested pattern even further.

My suggested changes are to reflect these facts in lecture notes (and in related code examples).

The only relevant code example I could find with VS search was in CodeDemonstrations.cs:

Console.WriteLine("Waiting for input (number)...");
int input = Convert.ToInt32(Console.ReadLine());
Console.WriteLine($"Input: {input}");

So that's not too bad, but the lack of it in lecture notes is worse.