🎯 What is Nullable reference type?
Nullable reference type explicitly specifies whether a variable must contain a value or may not.
Key Features
- Design-time analysis
- Explicit API contracts
- Search for potential locations with NullReference
📑 Software requirements
- .NET Standard 2.1+
- Unity 2021+
📃 How to turn on static analysis
To analyze the individual assemblies
Create a csc.rsp file next to the asmdef:
Add the nullable argument to the contents of csc.rsp:
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-nullable:enable
To analyze individual .cs files
Add the #nullable annotation context to the .cs content:
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#nullable enable
💻 Migration Guide
What to do with Unity UI bindings and DI Inject attributes?
Explicitly tell the analyzer that you guarantee their assignment and suppress the warnings using the ! null-forgiving operator.
Unity UI example:
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[SerializeField] private Image _image = null!;
VContainer DI example:
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namespace Sandbox.Domain
{
private MoveController _moveController = null!;
[Inject]
public void Init(MoveController moveController)
{
_moveController = moveController;
}
}
To exclude a separate part of the code from analysis, you can use the following annotation:
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#nullable disable
using System;
namespace Sandbox.Server.Responses
{
[Serializable]
public class UserResponse
{
public int Id;
public string Name;
}
}