pattern-debug_skill

Overview

This skill helps you debug pattern-related errors in TypeScript projects systematically. It provides a focused workflow to identify, reproduce, and fix issues related to patterns, handlers, actions, and type mismatches. Use it to accelerate root-cause analysis and verify fixes with tests.

How this skill works

The skill guides you through a five-step debugging process: run a type check, match the error to documented cases, verify common gotchas, reduce the code to a minimal repro, and apply a fix then run tests. It highlights specific checks for handler placement, writable/default type usage, and action triggering semantics so you can quickly pinpoint mistakes. Follow each step in sequence to move from error to verified resolution.

When to use it

• A TypeScript type error appears in a pattern or component file
• An action or output is not firing as expected in a pattern
• You suspect a handler is incorrectly scoped inside a pattern body
• You need to produce a minimal reproducible example for a tricky bug
• Before opening an issue or submitting a patch to confirm root cause

Best practices

• Run a full type check (no-run) on the pattern file before debugging runtime behavior
• Consult documented error cases and gotchas that match your error message first
• Move handler functions to module scope and bind them in the pattern body
• Use Writable<> for fields that require write access and Default<T, value> for possibly undefined fields
• When testing actions, ensure the Output type uses Stream<void> and invoke .send() to trigger

Example use cases

• Resolve a TS error caused by a handler function defined inside a pattern body by relocating the handler to module scope
• Fix a failing action by updating the Output type to include the action as Stream<void> and switching .get() to .send()
• Diagnose a type mismatch where a field should be writable or have a default value and apply Writable<> or Default<> accordingly
• Create a minimal reproduction by commenting out code sections until the error disappears, then add parts back to isolate the cause