Bug fixer

Skill Nembie/claude-code-skills/agents/bug-fixer

Reusable skills and intelligent agents for Claude Code. Production-grade, self-verifying, configurable.

Install

npx -y skills add Nembie/claude-code-skills --skill bug-fixer

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

One thing to look at

3 stars3 stars. Stars are a popularity signal and not a quality one, but at this level it is likely that nobody has read this closely except its author, and you would be relying on your own review.

What its author says it does

Copied from the file, not written here

Diagnose bugs through iterative investigation, apply a type-safe fix, and generate a regression test. Use when asked to fix a bug, debug an error, diagnose a crash, investigate a failing test, or resolve an exception.

SKILL.md

2.8 KB, as published. Nobody here has run it

Bug Fixer Agent

Before generating any output, read config/defaults.md and adapt all patterns, imports, and code examples to the user's configured stack.

This agent diagnoses and fixes bugs through iterative investigation. Follow this process:

Step 1: Intake

Read the error message, stack trace, or bug description. Identify the entry point file and line number if available.

Step 2: First Pass

Read the identified file and its immediate imports. Form a hypothesis about the root cause.

Step 3: Decision Point

If root cause is clear → proceed to step 5.
If root cause is unclear → WIDEN SEARCH. Read files upstream (who calls this function?) and downstream (what does this function call?). Check recent git changes in the affected area with git log -10 --oneline -- <file> if available. Reform hypothesis.
If still unclear after widening → ask the user for reproduction steps or additional context. Do not guess.

Step 4: Validate Hypothesis

Before fixing, explain the root cause to the user and ask for confirmation. A wrong diagnosis leads to a wrong fix.

Step 5: Apply Fix

Use typescript-refactorer principles to apply a type-safe fix:

Fix addresses the root cause, not just the symptom
Types are correct and narrowed (no any, no unsafe casts)
Null/undefined cases are handled with proper guards
No new code smells introduced

If the fix touches Prisma queries, validate with prisma-query-optimizer principles.

If the fix changes a function signature, check all call sites for compatibility.

Step 6: Generate Test

Use test-generator principles to create a regression test that:

Reproduces the exact original bug scenario (should fail without the fix)
Verifies the fix works (should pass with the fix)
Covers edge cases around the bug

Step 7: Run Test

Execute the regression test. If it fails, re-examine the fix. Repeat up to 3 times.

Step 8: Report

## Bug Fix Report

### Root Cause
[One-paragraph explanation]

### Fix Applied
**File**: `path/to/file.ts`
[Code diff or before/after]

### Regression Test
**File**: `path/to/file.test.ts`
[Generated test code]

### Confidence: [high/medium/low]
- high: root cause confirmed, test passes, fix is minimal
- medium: root cause likely, test passes, fix touches multiple files
- low: root cause uncertain, ask user to verify behavior

Skill Dependencies

skills/code-reviewer — root cause analysis patterns
skills/typescript-refactorer — type-safe fix
skills/prisma-query-optimizer — query-related bugs (conditional)
skills/test-generator — regression test generation