error_scope tests: break up awaits into chunks (#4324)

Author: kainino0x

src/webgpu/api/validation/error_scope.spec.ts

@@ -85,12 +85,8 @@ Tests that an error bubbles to the correct parent scope.
 
     // Cause the error and then pop all the unrelated filters.
     t.generateError(errorFilter);
-    const promises = [];
-    for (let i = 0; i < stackDepth; i++) {
-      promises.push(t.device.popErrorScope());
-    }
-    const errors = await Promise.all(promises);
-    t.expect(errors.every(e => e === null));
+
+    await t.chunkedPopManyErrorScopes(stackDepth);
 
     // Finally the actual error should have been caught by the parent scope.
     const error = await t.device.popErrorScope();
@@ -126,12 +122,7 @@ Tests that an error does not bubbles to parent scopes when local scope matches.
     t.expect(t.isInstanceOfError(errorFilter, error));
 
     // Remaining scopes shouldn't catch anything.
-    const promises = [];
-    for (let i = 0; i < stackDepth; i++) {
-      promises.push(t.device.popErrorScope());
-    }
-    const errors = await Promise.all(promises);
-    t.expect(errors.every(e => e === null));
+    await t.chunkedPopManyErrorScopes(stackDepth);
   });
 
 g.test('balanced_siblings')

src/webgpu/error_test.ts

@@ -80,6 +80,24 @@ export class ErrorTest extends Fixture {
     }
   }
 
+  /**
+   * Pop `count` error scopes, and assert they all return `null`. Chunks the
+   * awaits so we only `Promise.all` 200 scopes at a time, instead of stalling
+   * on a huge `Promise.all` all at once. This helps Chromium's "heartbeat"
+   * mechanism know that the test is still running (and not hung).
+   */
+  async chunkedPopManyErrorScopes(count: number) {
+    const promises = [];
+    for (let i = 0; i < count; i++) {
+      promises.push(this.device.popErrorScope());
+      if (promises.length >= 200) {
+        this.expect((await Promise.all(promises)).every(e => e === null));
+        promises.length = 0;
+      }
+    }
+    this.expect((await Promise.all(promises)).every(e => e === null));
+  }
+
   /**
    * Expect an uncapturederror event to occur. Note: this MUST be awaited, because
    * otherwise it could erroneously pass by capturing an error from later in the test.