js-runtime-triage

name	js-runtime-triage
description	Triage JavaScript runtime issues by isolating the first failing execution stage and applying focused fixes.

Skill: js-runtime-triage

Use when:

• JS execution throws
• runtime behavior diverges
• a feature fails after script execution
• console/runtime traces point to engine-side scripting behavior

Goal

Determine whether the failure is in:

• parser/AST lowering
• bytecode generation
• VM/runtime execution
• host API binding
• event-loop / task timing
• DOM integration triggered by script

Workflow

1. Capture the smallest repro:
   • page/script fragment
   • stack/error
   • visible symptom
2. Identify whether the failure is:
   • parse-time
   • compile-time
   • runtime
   • host-API contract
3. Inspect only the owning scripting/runtime area first.
4. Prefer spec-shaped behavior over ad hoc compatibility patches.
5. Verify with the smallest focused test slice or repro.

Do not

• blame JS for a layout-only bug without evidence
• widen changes across runtime and DOM if only one side is broken
• dump long execution traces back to the user

Output contract

1. failure class
2. root cause
3. touched files
4. minimal fix
5. verification

Token discipline

• summarize error shape
• keep discussion at the failing layer