Debugging for Developers

In this hands-on meetup activity, participants will explore four complementary debugging tools such as WP_DEBUG, Query Monitor, browser DevTools, and Xdebug to eliminate guesswork and resolve code issues efficiently. Running primarily within the browser-based WordPress Playground, attendees will learn how to configure error logs, isolate database and hook execution data, and catch frontend or block editor JavaScript failures. Finally, participants will witness a facilitator-led live demonstration using the Playground CLI to watch PHP code execute in real-time using Xdebug step-debugging.

Learning Objectives

By the end of this activity, participants will be able to:

• Configure Safe Debugging Environments: Set up WP_DEBUG, WP_DEBUG_LOG, and WP_DEBUG_DISPLAY within wp-config.php to capture runtime activity without exposing stack traces to site visitors.
• Interpret Core PHP Errors: Correctly analyze PHP errors, warnings, and notices from a generated debug.log file to identify the precise file, line, and root cause of a fault.
• Utilize Query Monitor for Optimization: Navigate the Query Monitor interface to uncover slow database queries, trace mis-ordered hook priority conflicts, and monitor outbound HTTP API failures.
• Diagnose Client-Side Script Failures: Inspect and debug JavaScript errors or failed REST API traffic across the front end and the block editor using browser DevTools.
• Analyze Real-Time Code Execution: Explain the mechanics of Xdebug breakpoints and differentiate the visibility of step-by-step variable evaluation from standard log-based debugging.
• Evaluate and Select Debugging Tools: Match specific problem types—such as logic bugs, layout crashes, or loading delays—to the most effective debugging tool for the job.