<!DOCTYPE html> <head> <link rel=author title="Aleks Totic" href="mailto:atotic@chromium.org"> <link rel=help href="https://html.spec.whatwg.org/#clean-up-after-running-script"> <script src="/resources/testharness.js"></script> <script src="/resources/testharnessreport.js"></script> <script src="resources/common.js"></script> </head> <body style="height:2000px;"> <script> /* promise 1, promise 2 execute immediately after rAF promise 1 child executes immediately after promise 2. Relevant specs: https://html.spec.whatwg.org/#clean-up-after-running-script If the JavaScript execution context stack is now empty, perform a microtask checkpoint. https://html.spec.whatwg.org/#perform-a-microtask-checkpoint "perform a microtask checkpoint" runs in a loop until all microtasks have been delivered. */ var test = async_test("Microtask execute immediately after script"); window.requestAnimationFrame( function() { var events = []; Promise.resolve() .then(function() { events.push("promise 1"); return Promise.resolve(); }) .then(function() { test.step(function() { events.push("promise 1 child"); assert_array_equals(events, ["promise 1", "promise 2", "promise 1 child"]); test.done(); }); }); Promise.resolve() .then(function() { events.push("promise 2"); }); // Set up events that must be executed after Promise. window.setTimeout(function() { events.push('timeout'); }, 0); window.addEventListener('scroll', function() { events.push('scroll'); }); window.scrollBy(0,10); }); </script> </body>