Check for TMP materials shared between scene and GUI

_TextMeshPro_macOS_material_bug_test.md

My solution to error reported here: https://forum.unity.com/threads/text-does-not-show-in-build-with-macos-metal.571345

AssetUtility.cs

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

namespace Feed.Editor {
  public static class AssetUtility {
    public static IEnumerable<string> AllAssetsPathsInDirectory(string directoryPath) {
      var guids = AssetDatabase.FindAssets("", new [] { directoryPath });
      foreach (var guid in guids) {
        yield return AssetDatabase.GUIDToAssetPath(guid);
      }
    }

    public static IEnumerable<T> LoadAllAssetsInDirectory<T>(string directoryPath) where T : Object {
      var paths = AllAssetsPathsInDirectory(directoryPath);
      foreach (var path in paths) {
        var asset = AssetDatabase.LoadAssetAtPath<T>(path);
        if (asset) yield return asset;
      }
    }
  }
}

TextMeshProBugTest.cs

using Feed.Editor;
using NUnit.Framework;
using System.Collections.Generic;
using UnityEditor.SceneManagement;
using UnityEngine;
using UnityEditor;
using System.Linq;
using TMPro;

namespace Feed.Tests {
  public class TextMeshProBugTest {
    static string[] GetAllAssetPaths<T>(string directory) where T : Object =>
      AssetUtility
        .LoadAllAssetsInDirectory<T>(directory)
        .Select(s => AssetDatabase.GetAssetPath(s)).ToArray();

    static string[] GetScenePaths() =>
      GetAllAssetPaths<SceneAsset>(SceneEditorUtility.SceneDirectory);

    static string[] GetPrefabPaths() =>
      GetAllAssetPaths<GameObject>("Assets/_Game/Prefabs");

    static List<T> FindObjectsIncludingInactive<T>() where T : Object {
      var scene = EditorSceneManager.GetActiveScene();
      var result = new List<T>();
      var batch = new List<T>();
      foreach (var root in scene.GetRootGameObjects()) {
        root.GetComponentsInChildren<T>(includeInactive: true, batch);
        result.AddRange(batch);
      }
      return result;
    }

    static void AuditTexts(IReadOnlyCollection<TextMeshPro> texts) {
      var wrongMaterial = new List<TextMeshPro>();
      var richText = new List<TextMeshPro>();

      foreach (var text in texts) {
        if (!text.fontSharedMaterial.name.Contains("SCENE_ONLY")) {
          wrongMaterial.Add(text);
        }
        const FontStyles disallowedStyles = FontStyles.Bold | FontStyles.Italic;
        if (text.richText || (text.fontStyle & disallowedStyles) != 0) {
          richText.Add(text);
        }
      }

      void AssertEmpty(List<TextMeshPro> ts, string complaint) {
        if (ts.Count > 0) {
          var items = ts.Select(t => $"- object: '{t.name}', material: '{t.fontSharedMaterial.name}'");
          Assert.Fail(
            $"TextMeshPro instances found with {complaint}:\n{string.Join("\n", items)}"
          );
        }
      }

      AssertEmpty(wrongMaterial, "non-scene material");
      AssertEmpty(richText, "richText enabled or not regular style");
    }

    [TestCaseSource(nameof(GetScenePaths))]
    public void CheckScene(string scenePath) {
      EditorSceneManager.OpenScene(scenePath);
      var sceneTexts = FindObjectsIncludingInactive<TextMeshPro>();
      AuditTexts(sceneTexts);
    }

    [TestCaseSource(nameof(GetPrefabPaths))]
    public void CheckPrefab(string path) {
      var prefab = AssetDatabase.LoadAssetAtPath<GameObject>(path);
      var texts = prefab.GetComponentsInChildren<TextMeshPro>(includeInactive: true);
      AuditTexts(texts);
    }
  }
}