UNT0013 Invalid or redundant SerializeField attribute

The SerializeField attribute is redundant for public non-dictionary fields, and invalid for static/readonly fields.

Examples of patterns that are flagged by this analyzer

using System.Collections.Generic;
using UnityEngine;

public class SerializedAttributes : MonoBehaviour
{
    [SerializeField] // correct usage
    private string privateField;
    
    [SerializeField] // redundant usage
    public string publicField;

    [SerializeField] // correct usage for public dictionary fields
    public Dictionary<string, string> publicDictionary;

    [SerializeField] // invalid usage
    static string staticField;

    [SerializeField] // invalid usage
    readonly field readonlyField;
}

Solution

Remove the SerializeField attribute when it is redundant or invalid:

using System.Collections.Generic;
using UnityEngine;

public class SerializedAttributes : MonoBehaviour
{
    [SerializeField] // correct usage
    private string privateField;
    
    public string publicField;

    [SerializeField] // correct usage for public dictionary fields
    public Dictionary<string, string> publicDictionary;

    static string staticField;

    readonly field readonlyField;
}

A code fix is offered for this diagnostic to automatically apply this change.