Fix/memory leak popup (#2274)

* fix(popup): start positioner only if active

* test(popup): add test for positioning behavior on active state change

* fix(popup): ensure positioner starts only when active and anchor is present

src/components/popup/popup.component.ts

@@ -272,8 +272,8 @@ export default class SlPopup extends ShoelaceElement {
   }
 
   private start() {
-    // We can't start the positioner without an anchor
-    if (!this.anchorEl) {
+    // We can't start the positioner without an anchor or when the popup is inactive
+    if (!this.anchorEl || !this.active) {
       return;
     }
 

src/components/popup/popup.test.ts

@@ -1,10 +1,33 @@
 import '../../../dist/shoelace.js';
 import { expect, fixture, html } from '@open-wc/testing';
+import type SlPopup from './popup.js';
 
 describe('<sl-popup>', () => {
+  let element: SlPopup;
+
   it('should render a component', async () => {
     const el = await fixture(html` <sl-popup></sl-popup> `);
 
     expect(el).to.exist;
   });
+
+  it('should properly handle positioning when active changes', async () => {
+    element = await fixture('<sl-popup></sl-popup>');
+
+    element.active = true;
+    await element.updateComplete;
+
+    // SImulate a scroll event
+    const event = new Event('scroll');
+    window.dispatchEvent(event);
+
+    element.active = false;
+    await element.updateComplete;
+
+    // The component should not throw an error when the window is scrolled
+    expect(() => {
+      element.active = true;
+      window.dispatchEvent(event);
+    }).not.to.throw();
+  });
 });