test(item-sliding): add test for side issue with CDN (#30469)

Adds test for https://github.com/ionic-team/ionic-framework/pull/29845

Must be merged after the fix in that PR is released. The test will fail
while using the older version of the CDN.

---------

Co-authored-by: Brandy Smith <6577830+brandyscarney@users.noreply.github.com>

core/src/components/item-sliding/test/async/item-sliding.e2e.ts

@@ -1,6 +1,9 @@
 import { expect } from '@playwright/test';
 import { configs, test } from '@utils/test/playwright';
 
+/**
+ * This behavior does not vary across modes/directions
+ */
 configs({ modes: ['ios'], directions: ['ltr'] }).forEach(({ title, config }) => {
   test.describe(title('item-sliding: async'), () => {
     test.beforeEach(async ({ page }) => {
@@ -35,5 +38,85 @@ configs({ modes: ['ios'], directions: ['ltr'] }).forEach(({ title, config }) =>
 
       await expect(itemSlidingEl).toHaveClass(/item-sliding-active-slide/);
     });
+
+    // NOTE: This test uses the CDN version of Ionic.
+    // If this test fails, it is likely due to a regression in the published package.
+    test('should not throw errors when adding multiple items with side="end" using the Ionic CDN', async ({
+      page,
+    }, testInfo) => {
+      testInfo.annotations.push({
+        type: 'issue',
+        description: 'https://github.com/ionic-team/ionic-framework/issues/29499',
+      });
+
+      const errors: string[] = [];
+      page.on('console', (msg) => {
+        if (msg.type() === 'error') {
+          errors.push(msg.text());
+        }
+      });
+      page.on('pageerror', (error) => {
+        errors.push(error.message);
+      });
+
+      // This issue only happens when using a CDN version of Ionic
+      // so we need to use the CDN by passing the `importIonicFromCDN` option
+      // to setContent.
+      await page.setContent(
+        `
+        <ion-header>
+          <ion-toolbar>
+            <ion-title>Item Sliding</ion-title>
+            <ion-buttons slot="end">
+              <ion-button id="addItem" onclick="addItem()">ADD ITEM</ion-button>
+            </ion-buttons>
+          </ion-toolbar>
+        </ion-header>
+        <ion-content>
+          <ion-list id="list"></ion-list>
+        </ion-content>
+
+        <script>
+          let itemList = [];
+          function generateItem() {
+            const currentItem = itemList.length + 1;
+            const item = \`
+              <ion-item-sliding>
+                <ion-item>
+                  <ion-label>Sliding Item \${currentItem}</ion-label>
+                </ion-item>
+                <ion-item-options side="end">
+                  <ion-item-option>Delete</ion-item-option>
+                </ion-item-options>
+              </ion-item-sliding>
+            \`;
+            itemList.push(item);
+            return item;
+          }
+          function addItem() {
+            const list = document.getElementById('list');
+            list.innerHTML += generateItem();
+            const currentItem = itemList.length;
+          }
+        </script>
+      `,
+        { ...config, importIonicFromCDN: true }
+      );
+
+      // Click the button enough times to reproduce the issue
+      const addButton = page.locator('#addItem');
+      await addButton.click();
+      await addButton.click();
+      await addButton.click();
+
+      await page.waitForChanges();
+
+      // Check that the items have been added
+      const items = page.locator('ion-item-sliding');
+      expect(await items.count()).toBe(3);
+
+      // Check that no errors have been logged
+      expect(errors.length).toBe(0);
+    });
   });
 });

core/src/utils/test/playwright/page/utils/set-content.ts

@@ -33,6 +33,26 @@ export const setContent = async (page: Page, html: string, testInfo: TestInfo, o
 
   const baseUrl = process.env.PLAYWRIGHT_TEST_BASE_URL;
 
+  // The Ionic bundle is included locally by default unless the test
+  // config passes in the importIonicFromCDN option. This is useful
+  // when testing with the CDN version of Ionic.
+  let ionicCSSImports = `
+    <link href="${baseUrl}/css/ionic.bundle.css" rel="stylesheet" />
+  `;
+  let ionicJSImports = `
+    <script type="module" src="${baseUrl}/dist/ionic/ionic.esm.js"></script>
+  `;
+
+  if (options?.importIonicFromCDN) {
+    ionicCSSImports = `
+      <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@ionic/core/css/ionic.bundle.css" />
+    `;
+    ionicJSImports = `
+      <script type="module" src="https://cdn.jsdelivr.net/npm/@ionic/core/dist/ionic/ionic.esm.js"></script>
+      <script nomodule src="https://cdn.jsdelivr.net/npm/@ionic/core/dist/ionic/ionic.js"></script>
+    `;
+  }
+
   const output = `
     <!DOCTYPE html>
     <html dir="${direction}" lang="en">
@@ -40,11 +60,11 @@ export const setContent = async (page: Page, html: string, testInfo: TestInfo, o
         <title>Ionic Playwright Test</title>
         <meta charset="UTF-8" />
         <meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0" />
-        <link href="${baseUrl}/css/ionic.bundle.css" rel="stylesheet" />
+        ${ionicCSSImports}
         <link href="${baseUrl}/scripts/testing/styles.css" rel="stylesheet" />
         ${palette !== 'light' ? `<link href="${baseUrl}/css/palettes/${palette}.always.css" rel="stylesheet" />` : ''}
         <script src="${baseUrl}/scripts/testing/scripts.js"></script>
-        <script type="module" src="${baseUrl}/dist/ionic/ionic.esm.js"></script>
+        ${ionicJSImports}
         <script>
           window.Ionic = {
             config: {

core/src/utils/test/playwright/playwright-declarations.ts

@@ -31,6 +31,12 @@ interface PageOptions {
    * - `'commit'` - consider operation to be finished when network response is received and the document started loading.
    */
   waitUntil?: 'load' | 'domcontentloaded' | 'networkidle' | 'commit';
+
+  /**
+   * If true, the default Ionic imports will be included
+   * via the CDN instead of the local bundle.
+   */
+  importIonicFromCDN?: boolean;
 }
 
 export interface E2EPage extends Page {