Pattern Debug

What it does

The Pattern Debug skill assists in identifying and resolving recurring test failures stemming from underlying code patterns within a development environment. It provides a structured debugging process, including checking for TypeScript errors, matching errors to documentation, simplifying issues to minimal reproductions, and verifying fixes. The skill also offers runtime debugging utilities accessible through the browser console or automated testing via agent-browser.

When to use it

• When encountering recurring test failures that seem related but have unclear root causes.
• During development when TypeScript errors arise during compilation (ct check pattern.tsx).
• To diagnose unexpected behavior in a deployed application, particularly when patterns are involved.
• For automated testing scenarios using agent-browser to inspect cell values, VDOM trees, and identify performance issues like non-idempotent computations.
• When handlers aren't triggering or computed properties exhibit broken conditional rendering.

Key capabilities

• TypeScript error checking via ct check pattern.tsx.
• Error matching against a reference matrix (docs/development/debugging/README.md).
• Guidance on common debugging gotchas (e.g., handler placement, Writable/Default type errors).
• Techniques for simplifying issues to minimal reproductions by commenting out code.
• Runtime debugging utilities accessible via browser console and agent-browser commands.
• Tools for inspecting cell values, VDOM trees, detecting non-idempotent computations, and checking action schema mismatches.

Example prompts

• "Run TypeScript checks on the pattern."
• "What are common errors related to handlers defined inside patterns?"
• "Inspect the current VDOM tree using agent-browser."
• "Detect any non-idempotent computations in the UI."

Tips & gotchas

• The debugging process is outlined in docs/development/debugging/workflow.md. Refer to this for a step-by-step guide.
• Be aware of common pitfalls like handlers defined inside pattern bodies, and incorrect usage of Writable or Default types.
• When using agent-browser, remember that commands are executed asynchronously.