Dispose stray validation scenes after every test

Apps/Playground/Scripts/validation_native.js

@@ -58,8 +58,8 @@
         "undeclared-name": "declare `name` for the example code",
         // Example captures effect-layer output before its render targets were submitted once.
         "prime-effect-layers": "render one extra frame before capture when effect layers exist",
-        // Example leaves scenes, textures, or Draco state behind for later tests.
-        "leak-cleanup": "dispose leaked scenes and textures and reset Draco after the test",
+        // Example leaves textures or Draco state behind for later tests.
+        "leak-cleanup": "release leaked textures and reset Draco after the test",
         // Example starts an async model load in createScene without awaiting it.
         "wait-for-import": "wait for loader promises started by createScene before rendering",
         // Example clears opaque but writes alpha < 1 that the browser would composite.
@@ -245,13 +245,6 @@
     function cleanupLeaks(test) {
         let leaked = false;
 
-        // Async loads may leave additional scenes registered on the engine.
-        const strayScenes = engine.scenes.slice();
-        leaked = leaked || strayScenes.length > 0;
-        for (let i = 0; i < strayScenes.length; ++i) {
-            try { strayScenes[i].dispose(); } catch (e) { console.error(e); }
-        }
-
         // Cache keys omit load-time options; leaked textures can change later tests.
         const leakedTextures = engine.getLoadedTexturesCache();
         leaked = leaked || leakedTextures.length > 0;
@@ -287,6 +280,13 @@
             return;
         }
 
+        // Async loads may leave additional scenes registered on the engine, including when a
+        // failed test never assigned currentScene, so dispose them for every test.
+        const strayScenes = engine.scenes.slice();
+        for (let i = 0; i < strayScenes.length; ++i) {
+            try { strayScenes[i].dispose(); } catch (e) { console.error(e); }
+        }
+
         if (hasWorkaround(test, "leak-cleanup")) {
             cleanupLeaks(test);
         }

Documentation/AddingNewValidationTests.md

@@ -53,7 +53,7 @@ TSV column. When a workaround changes what the runner does for a test, the runne
 | `wait-for-readiness` | Renders before utility-layer scenes, GUI images, or material effects are ready | Waits for those as described below |
 | `undeclared-name` | Reads the browser-only global `name` (`window.name`) | Declares `var name = ""` for the example code |
 | `prime-effect-layers` | Captures effect-layer (glow/highlight) output on the first frame | Renders one extra frame before counting frames |
-| `leak-cleanup` | Leaves scenes, textures, or Draco state behind after disposal | Disposes stray scenes, releases leaked textures, and resets Draco after the test |
+| `leak-cleanup` | Leaves textures or Draco state behind after disposal | Releases leaked textures and resets Draco after the test (stray scenes are disposed after every test) |
 | `wait-for-import` | Starts `ImportMeshAsync`/`AppendSceneAsync`/`LoadAssetContainerAsync` in `createScene` without awaiting it | Waits for loader promises started before the scene is returned |
 | `opaque-clear-alpha` | Clears opaque but leaves alpha < 1 in the final image | Skips canvas-background compositing unless the test sets `canvasBackgroundColor`, the scene uses a frame graph, or `clearColor.a < 1` |