1 files changed, 31 insertions, 0 deletions
diff --git a/testing/web-platform/tests/scheduler/task-controller-setPriority-delayed-task.any.js b/testing/web-platform/tests/scheduler/task-controller-setPriority-delayed-task.any.js
new file mode 100644
index 0000000000..43d24c8f92
--- /dev/null
+++ b/testing/web-platform/tests/scheduler/task-controller-setPriority-delayed-task.any.js
@@ -0,0 +1,31 @@
+// META: title=Scheduler: Change Delayed Task Priority
+// META: global=window,worker
+'use strict';
+
+promise_test(t => {
+  let taskCount = 0;
+  const start = performance.now();
+  const controller = new TaskController({priority: 'background'});
+
+  const task1 = scheduler.postTask(() => {
+    assert_equals(++taskCount, 1);
+    controller.setPriority('user-blocking');
+  }, {priority: 'user-blocking', delay: 10});
+
+  const task2 = scheduler.postTask(() => {
+    assert_equals(++taskCount, 2);
+
+    const elapsed = performance.now() - start;
+
+    if(navigator.userAgent.toLowerCase().indexOf('firefox') > -1){
+      // Firefox returns the timings with different precision,
+      // so we put 19 here.
+      assert_greater_than_equal(elapsed, 19);
+    } else {
+      assert_greater_than_equal(elapsed, 20);
+    }
+  }, {signal: controller.signal, delay: 20});
+
+  return Promise.all([task1, task2]);
+
+}, "Tests delay when changing a delayed task's priority");