Build/Test Tools: Add end-to-end (e2e) tests for edit posts page.

Adds e2e tests for 'Edit Posts':
* No posts found
* Shows a single post after publishing
* Edit existing post via Edit button
* Quick edit existing post via Quick Edit button
* Delete post

Props isabel_brison, azaozz, hellofromTonya, justinahinon, talldanwp, youknowriad.
Fixes #49507.

git-svn-id: https://develop.svn.wordpress.org/trunk@51990 602fd350-edb4-49c9-b593-d223f7449a82

tests/e2e/specs/edit-posts.test.js

@@ -0,0 +1,135 @@
+import {
+	createNewPost,
+	pressKeyTimes,
+	publishPost,
+	trashAllPosts,
+	visitAdminPage,
+} from '@wordpress/e2e-test-utils';
+
+describe( 'Edit Posts', () => {
+	beforeEach( async () => {
+		await trashAllPosts();
+	} );
+
+	it( 'displays a message in the posts table when no posts are present', async () => {
+		await visitAdminPage( '/edit.php' );
+		const noPostsMessage = await page.$x(
+			'//td[text()="No posts found."]'
+		);
+		expect( noPostsMessage.length ).toBe( 1 );
+	} );
+
+	it( 'shows a single post after one is published with the correct title', async () => {
+		const title = 'Test Title';
+		await createNewPost( { title } );
+		await publishPost();
+		await visitAdminPage( '/edit.php' );
+
+		await page.waitForSelector( '#the-list .type-post' );
+
+		// Expect there to be one row in the post list.
+		const posts = await page.$$( '#the-list .type-post' );
+		expect( posts.length ).toBe( 1 );
+
+		const [ firstPost ] = posts;
+
+		// Expect the title of the post to be correct.
+		const postTitle = await firstPost.$x(
+			`//a[contains(@class, "row-title")][contains(text(), "${ title }")]`
+		);
+		expect( postTitle.length ).toBe( 1 );
+	} );
+
+	it( 'allows an existing post to be edited using the Edit button', async () => {
+		const title = 'Test Title';
+		await createNewPost( { title } );
+		await publishPost();
+		await visitAdminPage( '/edit.php' );
+
+		await page.waitForSelector( '#the-list .type-post' );
+
+		// Click the post title (edit) link
+		const [ editLink ] = await page.$x(
+			`//a[contains(@class, "row-title")][contains(text(), "${ title }")]`
+		);
+		await editLink.click();
+
+		// Edit the post.
+		await page.waitForNavigation();
+
+		// Wait for title field to render onscreen.
+		await page.waitForSelector( '.editor-post-title__input' );
+
+		// Expect to now be in the editor with the correct post title shown.
+		const editorPostTitleInput = await page.$x(
+			`//textarea[contains(@class, "editor-post-title__input")][contains(text(), "${ title }")]`
+		);
+		expect( editorPostTitleInput.length ).toBe( 1 );
+	} );
+
+	it( 'allows an existing post to be quick edited using the Quick Edit button', async () => {
+		const title = 'Test Title';
+		await createNewPost( { title } );
+		await publishPost();
+		await visitAdminPage( '/edit.php' );
+
+		await page.waitForSelector( '#the-list .type-post' );
+
+		// Focus on the post title link.
+		const [ editLink ] = await page.$x(
+			`//a[contains(@class, "row-title")][contains(text(), "${ title }")]`
+		);
+		await editLink.focus();
+
+		// Tab to the Quick Edit button and press Enter to quick edit.
+		await pressKeyTimes( 'Tab', 2 );
+		await page.keyboard.press( 'Enter' );
+
+		// Type in the currently focused (title) field to modify the title, testing that focus is moved to the input.
+		await page.keyboard.type( ' Edited' );
+
+		// Update the post.
+		await page.click( '.button.save' );
+
+		// Wait for the quick edit button to reappear.
+		await page.waitForSelector( 'button.editinline', { visible: true } );
+
+		// Expect there to be one row in the post list.
+		const posts = await page.$$( '#the-list tr.type-post' );
+		expect( posts.length ).toBe( 1 );
+
+		const [ firstPost ] = posts;
+
+		// Expect the title of the post to be correct.
+		const postTitle = await firstPost.$x(
+			`//a[contains(@class, "row-title")][contains(text(), "${ title } Edited")]`
+		);
+		expect( postTitle.length ).toBe( 1 );
+	} );
+	it( 'allows an existing post to be deleted using the Trash button', async () => {
+		const title = 'Test Title';
+		await createNewPost( { title } );
+		await publishPost();
+		await visitAdminPage( '/edit.php' );
+
+		await page.waitForSelector( '#the-list .type-post' );
+
+		// Focus on the post title link.
+		const [ editLink ] = await page.$x(
+			`//a[contains(@class, "row-title")][contains(text(), "${ title }")]`
+		);
+		await editLink.focus();
+
+		// Tab to the Trash button and press Enter to delete the post.
+		await pressKeyTimes( 'Tab', 3 );
+		await page.keyboard.press( 'Enter' );
+
+		const noPostsMessage = await page.waitForSelector(
+			'#the-list .no-items td'
+		);
+
+		expect(
+			await noPostsMessage.evaluate( ( element ) => element.innerText )
+		).toBe( 'No posts found.' );
+	} );
+} );