PLANET-5419 Add Playwright test for Articles block

This is to increase our test coverage

tests/e2e/articles.spec.js

@@ -0,0 +1,48 @@
+import {test, expect} from './tools/lib/test-utils.js';
+import {publishPostAndVisit} from './tools/lib/post.js';
+
+const TEST_TITLE = 'All Articles';
+const TEST_DESCRIPTION = 'All articles in date order';
+const TEST_BUTTON_TEXT = 'Load';
+
+test.useAdminLoggedIn();
+
+test('Test Articles block', async ({page, admin, editor}) => {
+  await admin.createNewPost({postType: 'page', title:'Test Articles', legacyCanvas: true});
+
+  // Add Articles block.
+  await editor.canvas.getByRole('button', {name: 'Add default block'}).click();
+  await page.keyboard.type('/articles');
+  await page.getByRole('option', {name: 'Articles'}).click();
+
+  // Check that the default texts for the title and button are applied.
+  const editorTitle = page.getByRole('textbox', {name: 'Enter title'});
+  const editorDescription = page.getByRole('textbox', {name: 'Enter description'});
+  const editorButton = page.getByRole('textbox', {name: 'Enter text'});
+  await expect(editorTitle).toHaveText('Related Articles');
+  await expect(editorButton).toHaveText('Load more');
+
+  // Change title, description and button text.
+  await editorTitle.click();
+  await editorTitle.fill(TEST_TITLE);
+  await editorDescription.click();
+  await editorDescription.fill(TEST_DESCRIPTION);
+  await editorButton.click();
+  await editorButton.fill(TEST_BUTTON_TEXT);
+
+  // Change amount of articles from 3 to 4.
+  await page.getByLabel('Articles count').fill('4');
+
+  // Publish page.
+  await publishPostAndVisit({page, editor});
+
+  // Test that the block is displayed as expected in the frontend.
+  const frontendTitle = await page.innerHTML('.page-section-header');
+  const frontendDescription = await page.innerHTML('.page-section-description');
+  const frontendButton = await page.innerHTML('.article-load-more');
+  expect(frontendTitle).toBe(TEST_TITLE);
+  expect(frontendDescription).toBe(TEST_DESCRIPTION);
+  expect(frontendButton).toBe(TEST_BUTTON_TEXT);
+  await expect(page.locator('.article-list-item')).toHaveCount(4);
+});
+