Studio: Fix error connecting to external MySQL database

[gavande1]

Related issues

• Fixes STU-1203

Proposed Changes

• I propose to use do-not-attempt-installing WordPress installation mode when site is configured to use MySQL.
• Otherwise use install-from-existing-files-if-needed as it was configured before.
• The MySQL config is checked using existence of sqlite plugin directory and db.php.

Why

The actual error is originating from this line in playground CLI. Its part of assertValidDatabaseConnection function where some pre-test are done to make sure sqlite is configured correctly. This validation only runs if either install-from-existing-files-if-needed or download-and-install installation mode is used. You can check condition here. This PR updates WordPress installation mode based on sqlite plugin status to avoid these checks.

Testing Instructions

1. Create a new site or open an existing one in WordPress Studio
2. Configure wp-config.php to use an external MySQL database (127.0.0.1). Follow this guide to use Studio with MySQL server.
3. Start the server - it should attempt to connect to MySQL and server should start normally.
4. Verify the if site is using MySQL database. Goto Tools -> Site heath -> Info -> Database

5. Check for regression. Existing sites should start normally.

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

[wpmobilebot]

📊 Performance Test Results

Comparing c05a225 vs trunk

site-editor

Metric	trunk	c05a225	Diff	Change
load	2882.00 ms	2884.00 ms	+2.00 ms	🔴 0.1%

site-startup

Metric	trunk	c05a225	Diff	Change
siteCreation	8071.00 ms	8109.00 ms	+38.00 ms	🔴 0.5%
siteStartup	3943.00 ms	3943.00 ms	0.00 ms	⚪ 0.0%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change

[epeicher]

Thanks @gavande1 for solving this! I have tested it, and I can now connect to MySql database, while I have an error on trunk. Changes LGTM!

[wojtekn]

@gavande1 I merged trunk to this branch to run tests with the cli i2 changes.