1 files changed, 60 insertions, 0 deletions
diff --git a/testing/web-platform/tests/scheduler/task-controller-setPriority-repeated.any.js b/testing/web-platform/tests/scheduler/task-controller-setPriority-repeated.any.js
new file mode 100644
index 0000000000..fae3ec6c48
--- /dev/null
+++ b/testing/web-platform/tests/scheduler/task-controller-setPriority-repeated.any.js
@@ -0,0 +1,60 @@
+// META: title=Scheduler: TaskController.setPriority() repeated calls
+// META: global=window,worker
+'use strict';
+
+promise_test(async t => {
+  const controller = new TaskController();
+  const signal = controller.signal;
+
+  const tasks = [];
+  const runOrder = [];
+  const callback = id => { runOrder.push(id); };
+
+  tasks.push(scheduler.postTask(() => callback(0), {signal}));
+  tasks.push(scheduler.postTask(() => callback(1), {priority: 'user-blocking'}));
+  tasks.push(scheduler.postTask(() => callback(2), {priority: 'user-visible' }));
+
+  controller.setPriority('background');
+  assert_equals(signal.priority, 'background');
+
+  await Promise.all(tasks);
+  assert_equals(runOrder.toString(), '1,2,0');
+
+  while (tasks.length) { tasks.pop(); }
+  while (runOrder.length) { runOrder.pop(); }
+
+  tasks.push(scheduler.postTask(() => callback(3), {signal}));
+  tasks.push(scheduler.postTask(() => callback(4), {priority: 'user-blocking'}));
+  tasks.push(scheduler.postTask(() => callback(5), {priority: 'user-visible' }));
+
+  controller.setPriority('user-blocking');
+  assert_equals(signal.priority, 'user-blocking');
+
+  await Promise.all(tasks);
+  assert_equals(runOrder.toString(), '3,4,5');
+}, 'TaskController.setPriority() changes the priority of all associated tasks when called repeatedly');
+
+promise_test(async t => {
+  const controller = new TaskController();
+  const signal = controller.signal;
+
+  const tasks = [];
+  const runOrder = [];
+  const callback = id => { runOrder.push(id); };
+
+  tasks.push(scheduler.postTask(() => callback(0), {signal}));
+  tasks.push(scheduler.postTask(() => callback(1), {priority: 'user-blocking'}));
+  tasks.push(scheduler.postTask(() => callback(2), {priority: 'user-visible' }));
+
+  controller.setPriority('background');
+  assert_equals(signal.priority, 'background');
+
+  controller.setPriority('user-visible');
+  assert_equals(signal.priority, 'user-visible');
+
+  controller.setPriority('user-blocking');
+  assert_equals(signal.priority, 'user-blocking');
+
+  await Promise.all(tasks);
+  assert_equals(runOrder.toString(), '0,1,2');
+}, 'TaskController.setPriority() changes the priority of all associated tasks when called repeatedly before tasks run');