Add e2e test for maintenance mode and other edge cases

src/wp-includes/functions.php

@@ -3862,6 +3862,9 @@ function _default_wp_die_handler( $message, $title = '', $args = array() ) {
 		<?php
 		if ( function_exists( 'wp_robots' ) && function_exists( 'wp_robots_no_robots' ) && function_exists( 'add_filter' ) ) {
 			add_filter( 'wp_robots', 'wp_robots_no_robots' );
+			// Prevent warnings because of $wp_query not existing.
+			remove_filter( 'wp_robots', 'wp_robots_noindex_embeds' );
+			remove_filter( 'wp_robots', 'wp_robots_noindex_search' );
 			wp_robots();
 		}
 		?>

tests/e2e/specs/fatal-error-handler.test.js

@@ -0,0 +1,46 @@
+/**
+ * External dependencies
+ */
+import { existsSync, mkdirSync, writeFileSync, unlinkSync } from 'node:fs';
+import { join } from 'node:path';
+
+/**
+ * WordPress dependencies
+ */
+import { test, expect } from '@wordpress/e2e-test-utils-playwright';
+
+test.describe( 'Fatal error handler', () => {
+	const muPlugins = join(
+		process.cwd(),
+		process.env.LOCAL_DIR ?? 'src',
+		'wp-content/mu-plugins'
+	);
+	const muPluginFile = join( muPlugins, 'fatal-error.php' );
+
+	test.beforeAll( async () => {
+		const muPluginCode = `<?php new NonExistentClass();`;
+
+		if ( ! existsSync( muPlugins ) ) {
+			mkdirSync( muPlugins, { recursive: true } );
+		}
+		writeFileSync( muPluginFile, muPluginCode );
+	} );
+
+	test.afterAll( async () => {
+		unlinkSync( muPluginFile );
+	} );
+
+	test( 'should display fatal error notice', async ( { admin, page } ) => {
+		await admin.visitAdminPage( '/' );
+
+		await expect(
+			page.getByText( /Fatal error:/ ),
+			'should display PHP error message'
+		).toBeVisible();
+
+		await expect(
+			page.getByText( /There has been a critical error on this website/ ),
+			'should display WordPress fatal error handler message'
+		).toBeVisible();
+	} );
+} );

tests/e2e/specs/install.test.js

@@ -0,0 +1,85 @@
+/**
+ * External dependencies
+ */
+import { writeFileSync, readFileSync } from 'node:fs';
+import { join } from 'node:path';
+
+/**
+ * WordPress dependencies
+ */
+import { test, expect } from '@wordpress/e2e-test-utils-playwright';
+
+let wpConfigOriginal;
+
+test.describe( 'WordPress installation process', () => {
+	const wpConfig = join(
+		process.cwd(),
+		'wp-config.php',
+	);
+
+
+	test.beforeEach( async () => {
+		wpConfigOriginal = readFileSync( wpConfig, 'utf-8' );
+		// Changing the table prefix tricks WP into new install mode.
+		writeFileSync(
+			wpConfig,
+			wpConfigOriginal.replace( `$table_prefix = 'wp_';`, `$table_prefix = 'wp_e2e_';` )
+		);
+	} );
+
+	test.afterEach( async () => {
+		writeFileSync( wpConfig, wpConfigOriginal );
+	} );
+
+	test( 'should install WordPress with pre-existing database credentials', async ( { page } ) => {
+		await page.goto( '/' );
+
+		await expect(
+			page,
+			'should redirect to the installation page'
+		).toHaveURL( /wp-admin\/install\.php$/ );
+
+		await expect(
+			page.getByText( /WordPress database error/ ),
+			'should not have any database errors'
+		).not.toBeVisible();
+
+		// First page: language selector. Keep default English (US).
+		await page.getByRole( 'button', { name: 'Continue' } ).click();
+
+		// Second page: enter site name, username & password.
+
+		await expect( page.getByRole( 'heading', { name: 'Welcome' } ) ).toBeVisible();
+
+		// This information matches tools/local-env/scripts/install.js.
+
+		await page.getByLabel( 'Site Title' ).fill( 'WordPress Develop' );
+		await page.getByLabel( 'Username' ).fill( 'admin' );
+		await page.getByLabel( 'Password', { exact: true } ).fill( '' );
+		await page.getByLabel( 'Password', { exact: true } ).fill( 'password' );
+		await page.getByLabel( /Confirm use of weak password/ ).check()
+		await page.getByLabel( 'Your Email' ).fill( 'test@test.com' );
+
+		await page.getByRole( 'button', { name: 'Install WordPress' } ).click();
+
+		// Installation finished, can now log in.
+
+		await expect( page.getByRole( 'heading', { name: 'Success!' } ) ).toBeVisible();
+
+		await page.getByRole( 'link', { name: 'Log In' } ).click();
+
+		await expect(
+			page,
+			'should redirect to the login page'
+		).toHaveURL( /wp-login\.php$/ );
+
+		await page.getByLabel( 'Username or Email Address' ).fill( 'admin' );
+		await page.getByLabel( 'Password', { exact: true } ).fill( 'password' );
+
+		await page.getByRole( 'button', { name: 'Log In' } ).click();
+
+		await expect(
+			page.getByRole( 'heading', { name: 'Welcome to WordPress', level: 2 })
+		).toBeVisible();
+	} );
+} );

tests/e2e/specs/maintenance-mode.test.js

@@ -0,0 +1,33 @@
+/**
+ * External dependencies
+ */
+import { writeFileSync, unlinkSync } from 'node:fs';
+import { join } from 'node:path';
+
+/**
+ * WordPress dependencies
+ */
+import { test, expect } from '@wordpress/e2e-test-utils-playwright';
+
+test.describe( 'Maintenance mode', () => {
+	const documentRoot = join(
+		process.cwd(),
+		process.env.LOCAL_DIR ?? 'src',
+	);
+	const maintenanceLockFile = join( documentRoot, '.maintenance' );
+
+	test.beforeAll( async () => {
+		writeFileSync( maintenanceLockFile, '<?php $upgrading = 10000000000; ?>' ); // Year 2286.
+	} );
+
+	test.afterAll( async () => {
+		unlinkSync( maintenanceLockFile );
+	} );
+
+	test( 'should display maintenance mode page', async ( { page } ) => {
+		await page.goto( '/' );
+		await expect(
+			page.getByText( /Briefly unavailable for scheduled maintenance\. Check back in a minute\./ )
+		).toBeVisible();
+	} );
+} );