Unity Find missing references

_readme.md

How to open: On Unity menu bar -> Tools -> Find Missing References

FindMissingEditor.cs

using System.Collections.Generic;
using UnityEditor;
using UnityEditor.UIElements;
using UnityEngine;
using UnityEngine.UIElements;

public class FindMissingEditor : EditorWindow
{
    private float _progress = 0f;
    private bool _canceled;
    private List<GameObject> _errorGameObjects = new List<GameObject>();


    [MenuItem(itemName: "Tools/Find Missing References")]
    public static void Open()
    {
        FindMissingEditor window = GetWindow<FindMissingEditor>("Find Missing Editor");

        Rect main = EditorGUIUtility.GetMainWindowPosition();
        Rect pos = window.position;
        float centerWidth = (main.width - pos.width) * 0.5f;
        float centerHeight = (main.height - pos.height) * 0.3f;
        pos.x = main.x + centerWidth;
        pos.y = main.y + centerHeight;
        window.position = new Rect(pos.position.x, pos.position.y, pos.width, window._errorGameObjects.Count > 0 ? Mathf.Max(50, pos.height) : 50);

        window.Show();
    }

    private void CreateGUI()
    {
        var hierarchyBtn = new Button()
        {
            name = "Hierarchy-Button",
            text = "Missing in Hierarchy...",
        };

        var prefabBtn = new Button()
        {
            name = "Prefab-Button",
            text = "Missing in Prefabs..."
        };

        var listView = new ListView()
        {
            makeNoneElement = () => new VisualElement(),
            makeItem = () =>
            {
                var objectField = new ObjectField();
                var selector = objectField.Q(className: "unity-object-field__selector");
                selector.RemoveFromClassList("unity-object-field__selector");
                return objectField;
            },

            bindItem = (v, i) =>
            {
                var objectField = (v as ObjectField);
                objectField.name = _errorGameObjects[i].name;
                objectField.value = _errorGameObjects[i];
            },
            itemsSource = _errorGameObjects,
            selectionType = SelectionType.None,

        };
        listView.style.minHeight = 0;
        listView.style.maxHeight = 1000;


        hierarchyBtn.clicked += () =>
        {
            _errorGameObjects.Clear();
            int sceneCount = UnityEngine.SceneManagement.SceneManager.sceneCount;
            _progress = 0f;
            EditorUtility.DisplayProgressBar("Finding Missing References", "Searching in Hierarchy...", _progress);
            listView.Q("unity-content-container").Clear();

            _canceled = false;
            int totalIterator = sceneCount;
            int currentIterator = 0;

            for (int i = 0; i < sceneCount; ++i)
            {
                var scene = UnityEngine.SceneManagement.SceneManager.GetSceneAt(i);
                var roots = scene.GetRootGameObjects();
                var rootLength = roots.Length;
                totalIterator += rootLength;
                foreach (var go in roots)
                {
                    currentIterator++;
                    FindMissing(go, Iterator, AddToList, AddToList);

                    void AddToList(GameObject go)
                    {
                        _errorGameObjects.Add(go);
                    }

                    void Iterator(GameObject gameObject)
                    {
                        _progress = (float)currentIterator / totalIterator;
                        _canceled = EditorUtility.DisplayCancelableProgressBar("Finding Missing References", $"Searching in Hierarchy...`{gameObject.name}`", _progress);
                    }
                    if (_canceled)
                        break;
                }
                if (_canceled)
                    break;
                currentIterator++;
            }

            EditorUtility.ClearProgressBar();

            UpdateUIAndAdjustWindowSize(listView);

        };

        rootVisualElement.Add(listView);
        rootVisualElement.Add(hierarchyBtn);

        prefabBtn.clicked += () =>
        {
            _errorGameObjects.Clear();
            string[] guids = AssetDatabase.FindAssets("t:prefab");
            _progress = 0f;
            _canceled = false;
            EditorUtility.DisplayProgressBar("Finding Missing References", "Searching in Prefabs...", _progress);

            var totalIterator = guids.Length;
            var currentIterator = 0;

            for (int i = 0; i < guids.Length; ++i)
            {
                var path = AssetDatabase.GUIDToAssetPath(guids[i]);
                var go = AssetDatabase.LoadAssetAtPath<GameObject>(path);

                currentIterator++;
                FindMissing(go, Iterator, AddToList, AddToList);


                void AddToList(GameObject go)
                {
                    _errorGameObjects.Add(go);
                }

                void Iterator(GameObject gameObject)
                {
                    _progress = (float)currentIterator / totalIterator;
                    _canceled = EditorUtility.DisplayCancelableProgressBar("Finding Missing References", $"Searching in Prefabs...`{gameObject.name}`", _progress);
                }
                if (_canceled)
                    break;
            }


            EditorUtility.ClearProgressBar();

            UpdateUIAndAdjustWindowSize(listView);
        };

        rootVisualElement.Add(prefabBtn);

    }

    private void FindMissing(GameObject go, System.Action<GameObject> iterator, System.Action<GameObject> missingScript, System.Action<GameObject> missingReference)
    {
        var transforms = go.GetComponentsInChildren<Transform>();
        foreach (var t in transforms)
        {
            iterator?.Invoke(t.gameObject);

            int missingScripts = GameObjectUtility.GetMonoBehavioursWithMissingScriptCount(t.gameObject);
            if (missingScripts > 0)
            {
                Debug.LogError($"{t.gameObject.name} has missing script(s)", t.gameObject);
                missingScript?.Invoke(t.gameObject);
            }

            var components = t.gameObject.GetComponents<MonoBehaviour>();
            foreach (var c in components)
            {
                if (c == null) { continue; }
                var serializedObject = new SerializedObject(c);
                var it = serializedObject.GetIterator();
                while (it.NextVisible(true))
                {
                    if (it.propertyType == SerializedPropertyType.ObjectReference)
                    {
                        if (it.objectReferenceValue == null && it.objectReferenceInstanceIDValue != 0)
                        {
                            Debug.LogError($"{t.gameObject.name}.{c.GetType().Name}.{it.displayName} has missing reference", c);
                            missingReference?.Invoke(t.gameObject);
                        }
                    }
                }
            }
        }
    }

    private void UpdateUIAndAdjustWindowSize(ListView listView)
    {
        var hasError = _errorGameObjects.Count > 0;
        if (hasError)
        {
            listView.style.minHeight = new StyleLength(Length.Auto());
            listView.style.paddingBottom = 8;
            listView.style.paddingTop = 8;
            listView.style.paddingLeft = 8;
            listView.style.paddingRight = 8;
        }
        else
        {
            listView.style.minHeight = 0;
            listView.style.paddingBottom = 0;
            listView.style.paddingTop = 0;
            listView.style.paddingLeft = 0;
            listView.style.paddingRight = 0;

        }

        listView.Rebuild();

        if (hasError)
        {
            var listViewCurrentHeight = _errorGameObjects.Count * 20;
            var maxWindowHeight = 200;
            listViewCurrentHeight = Mathf.Clamp(listViewCurrentHeight, 0, maxWindowHeight);
            position = new Rect(position.x, position.y, position.width, height: Mathf.Max(listViewCurrentHeight + 50, position.height));
        }
        else
        {
            position = new Rect(position.x, position.y, position.width, Mathf.Max(50, position.height));
        }
    }

}