1 files changed, 32 insertions, 0 deletions
diff --git a/testing/web-platform/tests/compute-pressure/compute_pressure_duplicate_updates.https.any.js b/testing/web-platform/tests/compute-pressure/compute_pressure_duplicate_updates.https.any.js
new file mode 100644
index 0000000000..04c5df5e57
--- /dev/null
+++ b/testing/web-platform/tests/compute-pressure/compute_pressure_duplicate_updates.https.any.js
@@ -0,0 +1,32 @@
+// META: script=/resources/test-only-api.js
+// META: script=resources/pressure-helpers.js
+// META: global=window,dedicatedworker,sharedworker
+
+'use strict';
+
+pressure_test(async (t, mockPressureService) => {
+  const pressureChanges = await new Promise(async resolve => {
+    const observer_changes = [];
+    let n = 0;
+    const observer = new PressureObserver(changes => {
+      observer_changes.push(changes);
+      if (++n === 2)
+        resolve(observer_changes);
+    }, {sampleInterval: 200});
+    observer.observe('cpu');
+    const updatesDelivered = mockPressureService.updatesDelivered();
+    mockPressureService.setPressureUpdate('cpu', 'critical');
+    mockPressureService.startPlatformCollector(/*sampleInterval*/ 200);
+    // Deliver 2 updates.
+    await t.step_wait(
+        () => mockPressureService.updatesDelivered() >= (updatesDelivered + 2),
+        'Wait for more than one update to be delivered to the observer');
+    mockPressureService.setPressureUpdate('cpu', 'nominal');
+    // Deliver more updates, |resolve()| will be called when the new pressure
+    // state reaches PressureObserver and its callback is invoked
+    // for the second time.
+  });
+  assert_equals(pressureChanges.length, 2);
+  assert_equals(pressureChanges[0][0].state, 'critical');
+  assert_equals(pressureChanges[1][0].state, 'nominal');
+}, 'Changes that fail the "has change in data" test are discarded.');