How to check for nullable reference type in C#

C# 8.0 introduced nullable reference types. Since .NET 6 we are able to easily retreive nullability info through reflection.

Let's assume the following class.

class Person
{
    public required string FirstName { get; init; }
    public string? MiddleName { get; init; }
    public required string LastName { get; init; }
}

To retreive nullability info we use the new NullabilityInfoContext.

// Program.cs - Top-level statements

var personType = typeof(Person);
var middleNameProperty = personType.GetProperty("MiddleName")!;

var nullabilityInfo = new NullabilityInfoContext().Create(middleNameProperty);
Assert.Equal(nullabilityInfo.ReadState, NullabilityState.Nullable);

That's it!