SinachPat
0dae13cfd3
- wursor-precheck: router skill, entry point for non-trivial tasks - wursor-principles: 21 engineering principles adapted for Wursor - wursor-tdd, wursor-bug-fix, wursor-feature, wursor-investigation, wursor-review, wursor-decision-log: playbook skills - AGENTS.md: repo guide wiring the skill routing table - Fix: double-quote YAML frontmatter descriptions (colon-space in plain scalars broke Zed's skill loader)
2.7 KiB
2.7 KiB
name, description
| name | description |
|---|---|
| wursor-bug-fix | Reproduce a defect, root-cause it, and fix it with runtime evidence. Follow the repro-first discipline: never patch a symptom without proving the cause. For bugs in api/, web/, plugin/, infrastructure/, and e2e/. Adapted from pstack's bug-fix playbook. |
Wursor Bug Fix
Reproduce a defect, root-cause it, fix it, and prove the fix with runtime evidence.
When to use
Use this skill when:
- The user reports a symptom: "X is slow", "X crashes", "X returns the wrong value"
- A test fails and the failure is unexplained
- A behavior regressed
- A task involves fixing a defect rather than adding a feature
Playbook
Step 1 — Reproduce it first
Do not touch code until the defect is reproduced with a reliable, minimal repro.
- If there's a failing test, run it and confirm it fails for the stated reason
- If there's no test, write the smallest test or script that reproduces the symptom
- Capture the actual behavior: error message, stack trace, wrong value, timing
- The repro must be repeatable. "Sometimes it breaks" is not a repro; narrow it until it's deterministic
Step 2 — Root-cause it
Trace the symptom back to its cause. Ask "why" repeatedly:
- Why does this output appear? → Because module A does X
- Why does A do X? → Because B passed it the wrong input
- Why did B pass the wrong input? → Because the schema validation at the boundary is missing
Stop when the answer is a genuine defect, not another symptom. A root cause is a place where the code violates its own contract, not a place that "needs a guard."
Step 3 — State the root cause
Write it down before fixing. "The sandbox GC destroys a container while the deploy verifier is still polling it, because the verifier checks status once and the GC doesn't check the verifier's lease."
Step 4 — Fix the root cause
Apply the smallest change that fixes the cause at the point where it happens. Follow the principles:
- Fix root causes — no nil-check that silences a crash
- Laziness protocol — the smallest correct change
- Boundary discipline — the guard belongs at the boundary, not in every consumer
Step 5 — Prove the fix
- The repro from step 1 must now pass (the test, the script, the manual case)
- Run the surrounding test suite
- If the bug was a regression, add the repro as a permanent test so it cannot return silently
Step 6 — Report
## Root cause
[file.ts:42] — the verifier polls status without a lease; GC does not respect it
## Fix
[file.ts:52] — verifier now holds a short lease; GC skips leased containers
## Proof
- repro test added at [bug.test.ts] — passes before fix, fails after revert
- pnpm test:api — 412 passed, 0 failed