chore: fix types (#2679)

Author: tlouisse

packages/ui/components/core/test-helpers/getCachedFixture.js

@@ -3,7 +3,15 @@ import { LitElement, nothing } from 'lit';
 import { cache } from 'lit/directives/cache.js';
 import { createRef } from 'lit/directives/ref.js';
 
-export async function getCachedFixture(render) {
+/**
+ * Helper to get a fixture with a cached render function and show/hide methods.
+ * @template T
+ * @param {(ref: import('lit/directives/ref.js').Ref<T>) => import('lit').TemplateResult} render - The render function
+ * @returns {Promise<{ wrapper: LitElement, el: T | undefined, show: () => Promise<void>, hide: () => Promise<void> }>}
+ */
+export async function getCachedFixture(
+  /** @type {(ref: import('lit/directives/ref.js').Ref<any>) => import('lit').TemplateResult} */ render,
+) {
   class CachingWrapper extends LitElement {
     static properties = {
       _show: { type: Boolean },
@@ -33,7 +41,10 @@ export async function getCachedFixture(render) {
   const customElementName = defineCE(CachingWrapper);
   const customTag = unsafeStatic(customElementName);
 
-  const wrapper = await fixture(html`<${customTag}></${customTag}>`);
+  const wrapper =
+    /** @type {LitElement & { ref: import('lit/directives/ref.js').Ref<any>, show(): Promise<void>, hide(): Promise<void> }} */ (
+      await fixture(html`<${customTag}></${customTag}>`)
+    );
 
   return {
     wrapper,

packages/ui/components/listbox/test-suites/ListboxMixin.suite.js

@@ -1792,10 +1792,13 @@ export function runListboxMixinSuite(customConfig = {}) {
       });
 
       it('does not calls "_onListboxContentChanged" during connect and disconnected', async () => {
-        const renderEl = refObj => html`<${wrappingTag} ${ref(refObj)}></${wrappingTag}>`;
+        const renderEl = /** @param {import('lit/directives/ref.js').Ref<any>} refObj */ refObj =>
+          html`<${wrappingTag} ${ref(refObj)}></${wrappingTag}>`;
         const { el, show, hide } = await getCachedFixture(renderEl);
-        await el.listbox.registrationComplete;
-        const spy = sinon.spy(el.listbox, '_onListboxContentChanged');
+        const typedEl = /** @type {MyEl} */ (el);
+        await typedEl?.listbox.registrationComplete;
+        // @ts-ignore [allow-protected] in test
+        const spy = sinon.spy(typedEl.listbox, '_onListboxContentChanged');
         await hide();
         await show();