1 files changed, 30 insertions, 0 deletions
diff --git a/testing/web-platform/tests/hr-time/window-worker-timeOrigin.window.js b/testing/web-platform/tests/hr-time/window-worker-timeOrigin.window.js
new file mode 100644
index 0000000000..1e5ef1cdff
--- /dev/null
+++ b/testing/web-platform/tests/hr-time/window-worker-timeOrigin.window.js
@@ -0,0 +1,30 @@
+"use strict"
+// https://w3c.github.io/hr-time/#time-origin
+
+async_test(function(test) {
+    // Cache global time before starting worker
+    const globalTimeOrigin = performance.timeOrigin;
+    const globalNowBeforeWorkerStart = performance.now();
+
+    // Start worker and retrieve time
+    const workerScript = "postMessage({timeOrigin: performance.timeOrigin, now: performance.now()})";
+    const blob = new Blob([workerScript]);
+    let worker = new Worker(URL.createObjectURL(blob));
+
+    worker.addEventListener("message", test.step_func_done(function(event) {
+        const workerTimeOrigin = event.data.timeOrigin;
+        const workerNow = event.data.now;
+
+        assert_not_equals(workerTimeOrigin, 0, "worker timeOrigin must not be 0");
+        assert_not_equals(performance.timeOrigin, 0, "Document timeOrigin must not be 0");
+
+        assert_equals(globalTimeOrigin, performance.timeOrigin, "timeOrigin should not be changed in same document mode");
+        assert_less_than(globalTimeOrigin, workerTimeOrigin, "Document timeOrigin must be earlier than worker timeOrigin");
+
+        // Document and worker's now() start from their respective timeOrigins.
+        const timeDiff = workerTimeOrigin - globalTimeOrigin; // convert worker's time to Document time.
+        assert_less_than(globalTimeOrigin + globalNowBeforeWorkerStart, globalTimeOrigin + timeDiff + workerNow, "Document old now is earlier than worker now.");
+
+        // Comparing timing between Document and worker threads could be delicate as it relies on the thread implementation and could be subject to race conditions.
+    }));
+}, 'timeOrigin and now() should be correctly ordered between window and worker');