Fix for #483 and jestjs/jest#14549

src/fake-timers-src.js

@@ -1578,6 +1578,8 @@ function withGlobal(_global) {
                     function doRun() {
                         originalSetTimeout(function () {
                             try {
+                                runJobs(clock);
+
                                 let numTimers;
                                 if (i < clock.loopLimit) {
                                     if (!clock.timers) {
@@ -1633,6 +1635,7 @@ function withGlobal(_global) {
                         try {
                             const timer = lastTimer(clock);
                             if (!timer) {
+                                runJobs(clock);
                                 resolve(clock.now);
                             }
 

test/issue-483-test.js

@@ -0,0 +1,34 @@
+"use strict";
+
+const FakeTimers = require("../src/fake-timers-src");
+const sinon = require("sinon");
+const assert = require("assert");
+
+function myFn(cb) {
+    queueMicrotask(() => cb());
+}
+
+describe("async time skippers should run microtasks", function () {
+    let clock;
+    const timers = ["runAllAsync", "runToLastAsync"];
+
+    afterEach(function () {
+        clock.uninstall();
+    });
+
+    beforeEach(function setup() {
+        clock = FakeTimers.install({ toFake: ["queueMicrotask"] });
+    });
+
+    // eslint-disable-next-line mocha/no-setup-in-describe
+    timers.forEach((fastForward) => {
+        it(`should advance past queued microtasks using ${fastForward}`, async function () {
+            const cb = sinon.fake();
+            myFn(cb);
+            myFn(cb);
+            myFn(cb);
+            await clock[fastForward]();
+            assert.equal(cb.callCount, 3);
+        });
+    });
+});