From fed4d061d501b955a260ca82738984f8056d02ea Mon Sep 17 00:00:00 2001
From: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>
Date: Fri, 6 Jun 2025 10:20:27 -0400
Subject: [PATCH 1/2] Change assert to warn for unneeded restriction around
 creating sub-applications

---
 .../views/lib/system/event_dispatcher.ts        |  4 ++--
 .../application/tests/application_test.js       | 17 +++++++++--------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/packages/@ember/-internals/views/lib/system/event_dispatcher.ts b/packages/@ember/-internals/views/lib/system/event_dispatcher.ts
index db3512393fc..35cd930e1e4 100644
--- a/packages/@ember/-internals/views/lib/system/event_dispatcher.ts
+++ b/packages/@ember/-internals/views/lib/system/event_dispatcher.ts
@@ -1,5 +1,5 @@
 import { getOwner } from '@ember/-internals/owner';
-import { assert } from '@ember/debug';
+import { assert, warn } from '@ember/debug';
 import { get, set } from '@ember/-internals/metal';
 import EmberObject from '@ember/object';
 import { getElementView } from './utils';
@@ -162,7 +162,7 @@ export default class EventDispatcher extends EmberObject {
       `You cannot use the same root element (${specifiedRootElement}) multiple times in an Ember.Application`,
       !rootElement.classList.contains(ROOT_ELEMENT_CLASS)
     );
-    assert(
+    warn(
       'You cannot make a new Ember.Application using a root element that is a descendent of an existing Ember.Application',
       (() => {
         let target = rootElement.parentNode;
diff --git a/packages/@ember/application/tests/application_test.js b/packages/@ember/application/tests/application_test.js
index 71fdd5c2fa7..e83e3c6a5a3 100644
--- a/packages/@ember/application/tests/application_test.js
+++ b/packages/@ember/application/tests/application_test.js
@@ -74,14 +74,15 @@ moduleFor(
       });
     }
 
-    [`@test you cannot make a new application that is a descendant of an existing application`]() {
-      expectAssertion(() => {
-        runTask(() =>
-          this.createSecondApplication({
-            rootElement: '#one-child',
-          })
-        );
-      });
+    [`@test you cannot make a new application that is a descendant of an existing application`](
+      assert
+    ) {
+      runTask(() =>
+        this.createSecondApplication({
+          rootElement: '#one-child',
+        })
+      );
+      assert.ok(true, 'should not raise');
     }
 
     [`@test you cannot make a new application that is a duplicate of an existing application`]() {

From af55f7e99379292572dad9a4e5d05abd8e959d3b Mon Sep 17 00:00:00 2001
From: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>
Date: Fri, 6 Jun 2025 13:09:14 -0400
Subject: [PATCH 2/2] expectWarning

---
 .../application/tests/application_test.js       | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/packages/@ember/application/tests/application_test.js b/packages/@ember/application/tests/application_test.js
index e83e3c6a5a3..36ce6cdf113 100644
--- a/packages/@ember/application/tests/application_test.js
+++ b/packages/@ember/application/tests/application_test.js
@@ -74,15 +74,14 @@ moduleFor(
       });
     }
 
-    [`@test you cannot make a new application that is a descendant of an existing application`](
-      assert
-    ) {
-      runTask(() =>
-        this.createSecondApplication({
-          rootElement: '#one-child',
-        })
-      );
-      assert.ok(true, 'should not raise');
+    [`@test you cannot make a new application that is a descendant of an existing application`]() {
+      expectWarning(() => {
+        runTask(() =>
+          this.createSecondApplication({
+            rootElement: '#one-child',
+          })
+        );
+      });
     }
 
     [`@test you cannot make a new application that is a duplicate of an existing application`]() {