test(e2e): wait for navigation to be ready to avoid flaky failures

Ensure tests wait for navigation/UI readiness before proceeding to assertions, reducing flakiness.

Author: tijmenbruggeman

test/integration/utils.ts

@@ -3,13 +3,17 @@ import { Page } from '@playwright/test';
 
 export const BASE_URL = `http://localhost:${process.env.WORDPRESS_PORT}`;
 
-export async function uploadMedia(page: Page, file: string) {
+export async function uploadMedia(page: Page, file: string): Promise<string> {
   await page.goto('/wp-admin/media-new.php?browser-uploader');
   const fileChooserPromise = page.waitForEvent('filechooser');
   await page.getByLabel('Upload').click();
   const fileChooser = await fileChooserPromise;
   await fileChooser.setFiles(path.join(__dirname, `../fixtures/${file}`));
-  await page.locator('#html-upload').click();
+  await Promise.all([
+    page.waitForURL('**/wp-admin/upload.php**', { waitUntil: 'load' }),
+    page.locator('#html-upload').click(),
+  ]);
+  
   await page.goto('/wp-admin/upload.php?mode=list');
 
   const row = await page.locator('table.wp-list-table tbody > tr').first();
@@ -19,10 +23,12 @@ export async function uploadMedia(page: Page, file: string) {
 
   const rowID = await row.getAttribute('id');
   const attachmentID = rowID?.split('-')[1];
-  await page.goto(`/wp-admin/post.php?post=${attachmentID}&action=edit`);
+  await Promise.all([
+    page.waitForURL(new RegExp(`/wp-admin/post\\.php\\?post=${attachmentID}&action=edit$`), { waitUntil: 'load' }),
+    page.goto(`/wp-admin/post.php?post=${attachmentID}&action=edit`),
+  ]);
 
-  const imageURL = await page.locator('input[name="attachment_url"]').inputValue();
-  return imageURL;
+  return page.locator('input[name="attachment_url"]').inputValue();
 }
 
 export async function clearMediaLibrary(page: Page) {