<!DOCTYPE HTML> <script src="/tests/SimpleTest/SimpleTest.js"></script> <link rel="stylesheet" href="/tests/SimpleTest/test.css"> <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1538622">Mozilla Bug 1538622</a> <script> SimpleTest.waitForExplicitFinish(); let o1 = new ImageData(25, 1), o2 = new ImageData(50, 1), o3 = new ImageData(75, 1), o4 = new ImageData(100, 1); let data = { img1: o1, img2: o2, img3: o3, img4: o4, img5: o4, }; window.addEventListener("message", windowMessage); window.postMessage(data); function windowMessage(e) { let dataCopied = e.data; ok(dataCopied.img5 instanceof ImageData, "backref ImageData should still be an ImageData"); is(dataCopied.img5, dataCopied.img4, "backref ImageData should be the referenced one"); SimpleTest.finish(); } </script>