[boot] Add check for SQLite driver missing in target folder (#2440)

## Motivation for the change, related issues

Context: 

By running `npx @wp-playground/cli@latest server server
--mount-before-install=.:/wordpress --skip-wordpress-setup
--skip-sqlite-setup` without:

1. Specifying a working WordPress
2. Specifying a SQLite working driver

The CLI crashed. Now, more safety checks take into consideration:

1. If the user did not pass `--skip-sqlite-setup`, it checks if the
mu-plugins folder exists in the target folder
2. If it skips everything, it does not crash but returns a more
insightful error to explain the situation

## Implementation details

## Testing Instructions (or ideally a Blueprint)

Choose a working WordPress folder, such as a WordPress Studio one. It
should work because the folder already has a sqlite driver inside:
```
npx nx run playground-cli:dev-node server --mount-before-install=~/Studio/your-test-site:/wordpress --skip-wordpress-setup --skip-sqlite-setup --debug
```

This should not crash, but tell you that "SQLite installation has been
skipped and no SQLite mu-plugin has been found".
```
npx nx run playground-cli:dev-node server --mount-before-install=./an-empty-folder:/wordpress --skip-wordpress-setup --skip-sqlite-setup --debug
```

This should work. Notice the `skip-sqlite-setup` missing:
```
npx nx run playground-cli:dev-node server --mount-before-install=./a-test-site:/wordpress --skip-wordpress-setup --debug
```

Other combinations should work as well.

---------

Co-authored-by: Adam Zieliński <[email protected]>

Author: zaerl

packages/playground/cli/src/blueprints-v1/blueprints-v1-handler.ts

@@ -154,7 +154,7 @@ export class BlueprintsV1Handler {
 			mountsAfterWpInstall,
 			wordPressZip: wordPressZip && (await wordPressZip!.arrayBuffer()),
 			sqliteIntegrationPluginZip:
-				await sqliteIntegrationPluginZip!.arrayBuffer(),
+				await sqliteIntegrationPluginZip?.arrayBuffer(),
 			firstProcessId: 0,
 			processIdSpaceLength: this.processIdSpaceLength,
 			followSymlinks,

packages/playground/cli/src/run-cli.ts

@@ -571,7 +571,7 @@ export async function runCLI(args: RunCLIArgs): Promise<RunCLIServer> {
 					throw error;
 				}
 				let phpLogs = '';
-				if (await playground.fileExists(errorLogPath)) {
+				if (await playground?.fileExists(errorLogPath)) {
 					phpLogs = await playground.readFileAsText(errorLogPath);
 				}
 				throw new Error(phpLogs, { cause: error });

packages/playground/wordpress/src/boot.ts

@@ -182,11 +182,44 @@ export async function bootWordPress(options: BootOptions) {
 
 	if (!options.dataSqlPath) {
 		if (!(await isWordPressInstalled(php))) {
+			// Install WordPress if it's not installed.
 			await installWordPress(php);
 		}
 
 		if (!(await isWordPressInstalled(php))) {
-			throw new Error('WordPress installation has failed.');
+			// Check if the database connection (MySQL or SQLite) is up and running.
+			const validConnection = await isDatabaseConnectionValid(php);
+
+			if (validConnection) {
+				// The database connection is valid, but WordPress installation has failed.
+				// Throw a generic error, not related to the database connection.
+				throw new Error('WordPress installation has failed.');
+			} else {
+				if (php.isFile('/internal/shared/preload/0-sqlite.php')) {
+					// The core SQLite integration has been installed, but the database connection is not valid.
+					throw new Error('Error connecting to the SQLite database.');
+				}
+
+				// Check if a SQLite integration plugin has not been provided.
+				if (!options.sqliteIntegrationPluginZip) {
+					const sqlitePluginPath = joinPaths(
+						requestHandler.documentRoot,
+						'wp-content/mu-plugins/sqlite-database-integration'
+					);
+
+					if (php.isDir(sqlitePluginPath)) {
+						// The mu-plugin has been installed, but the database connection is not valid.
+						throw new Error(
+							'Error connecting to the SQLite database.'
+						);
+					}
+				}
+
+				// 1. No core SQLite integration has been installed.
+				// 2. No valid SQLite integration plugin has been provided.
+				// The MySQL database connection is not valid.
+				throw new Error('Error connecting to the MySQL database.');
+			}
 		}
 	}
 
@@ -368,3 +401,24 @@ export function getFileNotFoundActionForWordPress(
 		uri: '/index.php',
 	};
 }
+
+async function isDatabaseConnectionValid(php: PHP) {
+	const result = await php.run({
+		code: `<?php
+			ob_start();
+			$wp_load = getenv('DOCUMENT_ROOT') . '/wp-load.php';
+			if (!file_exists($wp_load)) {
+				echo '-1';
+				exit;
+			}
+			require $wp_load;
+			ob_clean();
+			echo $wpdb->check_connection( false) ? '1' : '0';
+			ob_end_flush();
+		`,
+		env: {
+			DOCUMENT_ROOT: php.documentRoot,
+		},
+	});
+	return result.text === '1';
+}

packages/playground/wordpress/src/test/database.spec.ts

@@ -0,0 +1,86 @@
+import { createNodeFsMountHandler, loadNodeRuntime } from '@php-wasm/node';
+import { RecommendedPHPVersion } from '@wp-playground/common';
+import {
+	getWordPressModule,
+	MinifiedWordPressVersions,
+} from '@wp-playground/wordpress-builds';
+import { mkdirSync, rmdirSync } from 'fs';
+import { tmpdir } from 'os';
+import { join } from 'path';
+import { bootWordPress } from '../boot';
+import { getLoadedWordPressVersion } from '../version-detect';
+
+describe('Test database', () => {
+	let tempDir: string;
+
+	beforeAll(() => {
+		tempDir = join(tmpdir(), 'database-test');
+
+		try {
+			mkdirSync(
+				join(
+					tempDir,
+					'wp-content',
+					'mu-plugins',
+					'sqlite-database-integration'
+				),
+				{ recursive: true }
+			);
+		} catch {
+			// Ignore error if directory already exists
+		}
+	});
+
+	afterAll(() => {
+		rmdirSync(tempDir, { recursive: true });
+	});
+
+	it("should not start WordPress when SQLite ZIP not specified, the SQLite driver directory doesn't exist and MySQL can't be used", async () => {
+		await expect(async () => {
+			await bootWordPress({
+				createPhpRuntime: async () =>
+					await loadNodeRuntime(RecommendedPHPVersion),
+				siteUrl: 'http://playground-domain/',
+				wordPressZip: await getWordPressModule(),
+				sqliteIntegrationPluginZip: undefined,
+			});
+		}).rejects.toThrow('Error connecting to the MySQL database.');
+	});
+
+	it('hould install WordPress when SQL data path specified, even without SQLite ZIP path or SQLite driver directory', async () => {
+		const handler = await bootWordPress({
+			createPhpRuntime: async () =>
+				await loadNodeRuntime(RecommendedPHPVersion),
+			siteUrl: 'http://playground-domain/',
+			wordPressZip: await getWordPressModule(),
+			sqliteIntegrationPluginZip: undefined,
+			dataSqlPath: '/wordpress/wp-content/database/.ht.sqlite',
+		});
+
+		const loadedWordPressVersion = await getLoadedWordPressVersion(handler);
+		expect(loadedWordPressVersion).toBeTruthy();
+		expect(Object.keys(MinifiedWordPressVersions)).toContain(
+			loadedWordPressVersion
+		);
+	});
+
+	it("should fail when the SQLite driver directory exists, but doesn't contain a valid driver", async () => {
+		await expect(async () => {
+			await bootWordPress({
+				createPhpRuntime: async () =>
+					await loadNodeRuntime(RecommendedPHPVersion),
+				siteUrl: 'http://playground-domain/',
+				wordPressZip: await getWordPressModule(),
+				sqliteIntegrationPluginZip: undefined,
+				hooks: {
+					beforeWordPressFiles: async (php) => {
+						await php.mount(
+							'/wordpress',
+							createNodeFsMountHandler(tempDir)
+						);
+					},
+				},
+			});
+		}).rejects.toThrow('Error connecting to the SQLite database.');
+	});
+});