Initial commit

skills/code-refactoring/SKILL.md

@@ -0,0 +1,62 @@
+# Code Refactoring
+
+Modify code with clean, secure, maintainable changes that precisely meet requirements.
+
+## Workflow
+
+1. **Discover:** Glob for files, Grep for patterns
+2. **Read:** Always read before modifying
+3. **Modify:** Edit existing (prefer over Write)
+4. **Verify:** Run tests
+
+## Rules
+
+| Rule | Details |
+|------|---------|
+| Read first | Never modify unread files |
+| Edit > Write | Use Edit for existing, Write only for new |
+| Delete completely | No `_unused` prefixes or `// removed` comments |
+| Match style | Follow existing conventions exactly |
+| Minimal changes | Only what's requested |
+
+## Security Checklist
+
+**Prevent:**
+- Command injection → Use arrays, not string interpolation: `exec('cmd', [args])`
+- XSS → Use `textContent`, not `innerHTML`
+- SQL injection → Use parameterized queries
+- Path traversal → Validate with `path.basename()`
+
+## Tool Usage
+
+```
+Glob: pattern: "**/*.js"           # Find files
+Grep: pattern: "func", output_mode: "files_with_matches"  # Search
+Read: file_path: "/path/file.js"   # Read before edit
+Edit: file_path, old_string, new_string  # Modify
+```
+
+Parallelize independent Read calls. Chain sequentially: Read → Edit → Bash (test).
+
+## Quality
+
+- Three similar lines > premature abstraction
+- Meaningful names, focused functions
+- Comments only where logic isn't obvious
+- Refactor only when explicitly requested
+
+## Example
+
+```javascript
+// Before: Bug - off-by-one error
+function getLastItem(arr) {
+  return arr[arr.length]  // Wrong: returns undefined
+}
+
+// After: Fix
+function getLastItem(arr) {
+  return arr[arr.length - 1]
+}
+```
+
+Change is minimal and targeted - only fix what's requested.