import {E2E_PORT} from '../../playwright.config'; import {MOCKED_SITE_URL, MockedApi} from '../utils/e2e'; import {expect, test} from '@playwright/test'; test.describe('Lazy loading', async () => { test('delays loading of content until scrolled into view', async ({page}) => { const mockedApi = new MockedApi({}); mockedApi.setMember({}); mockedApi.addComment({ html: '
This is comment 1
' }); const sitePath = MOCKED_SITE_URL; await page.route(sitePath, async (route) => { await route.fulfill({ status: 200, // include a div at the top of the body that's 1.5x viewport height // to force the need to scroll to see the comments body: `` }); }); const url = `http://localhost:${E2E_PORT}/comments-ui.min.js`; await page.setViewportSize({width: 1000, height: 1000}); await page.goto(sitePath); await mockedApi.listen({page, path: sitePath}); const options = { publication: 'Publisher Weekly', count: true, title: 'Title', ghostComments: MOCKED_SITE_URL, postId: mockedApi.postId }; await page.evaluate((data) => { const scriptTag = document.createElement('script'); scriptTag.src = data.url; for (const option of Object.keys(data.options)) { scriptTag.dataset[option] = data.options[option]; } document.body.appendChild(scriptTag); }, {url, options}); await page.locator('iframe[title="comments-frame"]').waitFor({state: 'attached'}); const commentsFrameSelector = 'iframe[title="comments-frame"]'; const adminFrameSelector = 'iframe[data-frame="admin-auth"]'; const commentsFrame = page.frameLocator(commentsFrameSelector); // wait for a little bit to ensure we're not loading comments until scrolled await page.waitForTimeout(250); // check that we haven't loaded comments or admin-auth yet await expect(commentsFrame.getByTestId('loading')).toHaveCount(1); await expect(page.locator(adminFrameSelector)).toHaveCount(0); // scroll the iframe into view const iframeHandle = await page.locator(commentsFrameSelector); iframeHandle.scrollIntoViewIfNeeded(); // loading state should be gone and admin-auth frame should be present await expect(commentsFrame.getByTestId('loading')).toHaveCount(0); await expect(page.locator(adminFrameSelector)).toHaveCount(1); }); });