I’m trying to start using null state analysis in our application: https://learn.microsoft.com/en-us/dotnet/csharp/nullable-references

I’ve run in to the following issue: (with a new C# console app)

public interface ITester
{
    string GetString();
}

public class Test(ITester t)
{
    public void TestMethod()
    {
        var x = t.GetString();
    }
}

When I hover over “var x” it is shown as being of type string? whereas I want the interace to enforce nullability, so that the return object of GetString really is string, not string?.

This is the same behaviour for other returned types too, the example here is just to keep it simple.

I expected the compiler to know the object returned via the interface cannot be null (because I have <Nullable>enable</Nullable> set), but it doesn’t seem to.

What would I need to change here for it to realise that the “var x” variable is string instead of string?: