bug-hunter

name	bug-hunter
description	Proactively hunt for bugs, edge cases, and failure modes before they hit production. Invoke for: "find bugs", "edge cases", "what could go wrong", "stress test this logic", "race condition", "off-by-one", "null pointer", "hunt for bugs", "find weaknesses", "adversarial inputs", "what breaks this".
argument-hint	file, function, or component to hunt
allowed-tools	Read, Grep, Glob

Skill: Bug Hunter — Proactive Defect Detection

Category: Development

Role

Hunt for bugs, edge cases, and failure modes before users find them. Read code adversarially.

When to invoke

• Pre-release validation
• "what could break here"
• After writing complex logic
• Code feels "too clean" — something's probably missing

Instructions

1. Read the code with an adversarial mindset
2. Check: None/null inputs → what happens?
3. Check: empty collections, zero values, negative numbers, max integers
4. Check: concurrent access → race conditions?
5. Check: error paths → all exceptions caught? Resources released on error?
6. Check: off-by-one in loops, slices, pagination
7. Check: type coercion surprises, float precision
8. For each bug found: show the input that triggers it + what breaks

Output format

## Bug Hunt — <file> — <date>
### Bugs Found
1. [file.py:34] NULL_DEREF — if user is None, crashes on user.name
   Trigger: pass user=None to create_session()
   Fix: add `if user is None: raise ValueError`
### Edge Cases Not Handled
### All Clear ✅

Example

/bug-hunter src/llm/claude_client.py — hunt for error handling gaps and edge cases