C#8 Nullable References

[SeriousM]

Hi! Your article was very nice, ty for that.
We're using the new feature from c# to annotate nullable reference types with poco classes.
Since the new feature requires properties to be initialized if not mentioned in a constructor we came up with this pattern:

public class ModelPoco
{
  public User CurrentUser { get; set; } = default!;
}

This way the adaption on legacy code is quite simple by just appending ` = default!;" to each property.

Could your extension help to avoid this additional code?

Best, Bernhard

[cezarypiatek]

If you are going to use [InitOnly] or [InitRequired] with non-nullable fields then it's perfectly fine to disable CS8618 rule. You can do that via .editorconfig with the following entry

[*.cs]
#CS8618: Non-nullable property ‘PropertyName’ is uninitialized.
dotnet_diagnostic.CS8618.severity = none

[SeriousM]

Hmm, well, our codebase is quite large and the disabling the rule CS8618 would be counter-intuitive. Could your analyser disable this rule just for types/members that have your attribute applied?

[cezarypiatek]

It looks like Roslyn support such scenario thanks to DiagnosticSuppressor https://docs.microsoft.com/en-us/dotnet/api/microsoft.codeanalysis.diagnostics.diagnosticsuppressor?view=roslyn-dotnet

I will try to implement it. Thanks for reporting this suggestion.

[SeriousM]

Thank you for investigating it!

[cezarypiatek]

I have a working POC. I will try to finish it and publish it today afternoon.

[cezarypiatek]

@SeriousM I've just released version 2.1.31 with the requested feature. Please let me know if it works as expected.

[cezarypiatek]

@SeriousM I've introduced another attribute [assembly:InitRequiredForNotNull] which works on assembly level. Everything described on my blog https://cezarypiatek.github.io/post/better-non-nullable-handling/

[stijnherreman]

For anyone trying out this library with VS Code: DiagnosticSuppressor is not yet supported by OmniSharp (OmniSharp/omnisharp-roslyn#1711) so the Problems panel will still show the warnings.