From f84d7dde872bbb44fa7a482565c0046a06d7f55c Mon Sep 17 00:00:00 2001
From: Andrew Scott <atscott@google.com>
Date: Mon, 22 Apr 2024 12:31:30 -0700
Subject: [PATCH] test(core): Wait for zone stability before test completion
 (#55468)

Need to wait for microtaskEmty to emit or test will leak into others.

PR Close #55468
---
 packages/core/test/zone/ng_zone_spec.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/packages/core/test/zone/ng_zone_spec.ts b/packages/core/test/zone/ng_zone_spec.ts
index effa39e6b4df9..ff426b8b57ad5 100644
--- a/packages/core/test/zone/ng_zone_spec.ts
+++ b/packages/core/test/zone/ng_zone_spec.ts
@@ -9,6 +9,7 @@
 import {EventEmitter, NgZone} from '@angular/core';
 import {fakeAsync, flushMicrotasks, inject, waitForAsync} from '@angular/core/testing';
 import {Log} from '@angular/core/testing/src/testing_internal';
+import {firstValueFrom} from 'rxjs';
 
 import {scheduleCallbackWithRafRace as scheduler} from '../../src/util/callback_scheduler';
 import {global} from '../../src/util/global';
@@ -1193,10 +1194,13 @@ function commonTests() {
            });
          });
 
-      it('does not throw when apply args array has `undefined`', () => {
+      it('does not throw when apply args array has `undefined`', async () => {
         expect(() => {
           coalesceZone.run(function(this: any, arg: any) {}, undefined, [undefined]);
         }).not.toThrow();
+        // wait for the zone to stabilize after the task above. Needed to prevent this from leaking
+        // into a follow-up test
+        await firstValueFrom(coalesceZone.onMicrotaskEmpty);
       });
     });
   });