Allow null-forgiving operator for injected services in Blazor Components

[mwasson74]

When Requesting a service in a component, Microsoft's note suggests:

ℹ️ Note
Since injected services are expected to be available, don't mark injected services as nullable. Instead, assign a default literal with the null-forgiving operator (default!). For example:

[Inject]
private IExampleService ExampleService { get; set; } = default!;

Since I have never worked with analyzers before, would you be able to allow the null-forgiving operator in this case? Or do you have any other suggestions for me to allow this in my code in conjunction with your NuGet package?

Thanks!!

[tom-englert]

I'm not sure what you want to do here - what exactly is your problem? Did you read the manual?

[mwasson74]

Hello, thanks for getting back to me!

I did read the manual. Since using default!; on injected services to a .razor/blazor component is a recommended practice, I was wanting to have the analyzer completely ignore this when/if it sees that the [Inject] attribute is being used at the same time in a .razor.cs file. I would like this to be ignored because this is a common practice and I have 100+ instances of this in my Blazor project. I want to set your diagnostic code to error so it cannot be used without justification in all other scenarios. Having to justify 100+ instances on a recommended practice seems rather unnecessary.

Thanks again for your time!!

Matt

[tom-englert]

OK, now I see what you mean.
But wouldn't it be better to fix the root cause, and have a suppression analyzer that suppresses CS8618 for items that have the [Inject] attribute, so you don't have to explicitly use null forgiving?

[mwasson74]

That does sound like the best option. Since I haven't the slightest idea how to begin doing that, do you have any suggestions and/or documentation that you could share to help me begin?

Thanks again!!

[tom-englert]

Best is to start here:
https://learn.microsoft.com/en-us/dotnet/csharp/roslyn-sdk/tutorials/how-to-write-csharp-analyzer-code-fix
Then this is a sample for a diagnostic suppressor
https://github.com/tom-englert/Nullable.Extended/blob/master/src/Nullable.Extended.Analyzer/Nullable.Extended.Analyzer/NullableDiagnosticSuppressor.cs

[mwasson74]

Thank you, I will see what I can come up with!! 🙏

[tom-englert]

A better example for a suppression analyzer is this, it better matches your use case:
https://github.com/tom-englert/Lazy.Fody

[mwasson74]

Oh, perfect, even better!!