bugmagnet

name	bugmagnet
description	Discover edge cases and test coverage gaps through systematic analysis. Use when analysing TEST coverage, hunting for edge cases, or when code-reviewer identifies test gaps. Triggers on "find holes in my tests", "what could go wrong", "is this well tested", "what edge cases am I missing". When to pick bugmagnet vs alternatives: - find-bugs → branch-diff bug scan (uses git diff, scoped to recent changes) - security-review → OWASP-categorised vulnerability audit - code-review → PR-style review with comment threads - ct:bugmagnet → test-gap edge-case discovery (THIS one) If the question is "are my TESTS missing cases?", use bugmagnet. Otherwise pick one of the three above.
credit	Adapted from channingwalton/dotfiles (https://github.com/channingwalton/dotfiles)

BugMagnet

Systematic test coverage analysis and bug discovery.

Based on gojko/bugmagnet-ai-assistant.

Workflow

🔍 ANALYSE  → Understand code and existing tests
📊 GAP      → Identify missing coverage
✍️ WRITE    → Implement tests iteratively
🔬 ADVANCED → Deep edge case exploration (optional)
📋 SUMMARY  → Document findings and bugs

Interactive mode (default): STOP and wait for user confirmation between phases. Autonomous mode: When invoked by another agent (e.g. code-reviewer), skip all STOP points and proceed through all phases automatically. Present the full summary at the end instead of pausing for input.

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Phase 1: Analysis (🔍 ANALYSE)

1. Detect language and testing conventions
2. Read implementation — public API, parameters, state, dependencies
3. Locate test file — if none exists, ask user about creating one
4. Run baseline coverage if tools available
5. Read existing tests — understand current coverage and patterns
6. Ask user: "Are there additional files I should review?"

STOP — Wait for user input. (Skip in autonomous mode.)

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Phase 2: Gap Analysis (📊 GAP)

Evaluate missing coverage using edge-cases.md:

• Boundary conditions, error paths, state transitions
• Complex interactions, domain-specific edge cases
• Violated domain constraints

Categorise: High (core, errors, boundaries) → Medium (interactions, state) → Low (rare, performance). Present analysis with specific examples.

STOP — Ask user which tests to implement. (Skip in autonomous mode — implement all high-priority tests.)

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Phase 3: Test Implementation (✍️ WRITE)

For each test, highest priority first: write single test (or 2-3 related), name describes outcome ("returns X when Y"), run immediately. Maximum 3 attempts per test — document and move on.

→ While writing tests, actual bug discovered in implementation → STOP. Do NOT fix the bug.

1. Create minimal reproduction test.
2. Explore 2-3 adjacent code areas (bugs cluster).
3. Document in skipped test: brief description, root cause, code location, expected vs actual, proposed fix. → Return to test writing.

STOP — Ask user if they want advanced coverage. (Skip in autonomous mode — proceed to advanced if high-priority gaps remain.)

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Phase 4: Advanced Coverage (🔬 ADVANCED)

Create separate test suite: "bugmagnet session <date>"

Work through edge-cases.md comprehensively — complex interactions, error handling, numeric/date/string/collection edge cases, state transitions, domain-specific cases.

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Phase 5: Summary (📋 SUMMARY)

Keep summary under 30 lines. No preamble.

## Test Coverage Summary

**Tests Added:** X total (Y passing, Z skipped/bugs)

**Bugs Discovered:**
1. Bug name — file:line — root cause — proposed fix

Reference Files

• Edge Case Checklist