Analyzes cyclomatic and cognitive complexity, identifies overly complex functions. Use when assessing code complexity or identifying functions that need simplification.
View on GitHubarmanzeroeight/fastagent-plugins
code-quality-toolkit
plugins/code-quality-toolkit/skills/complexity-analyzer/SKILL.md
January 21, 2026
Select agents to install to:
npx add-skill https://github.com/armanzeroeight/fastagent-plugins/blob/main/plugins/code-quality-toolkit/skills/complexity-analyzer/SKILL.md -a claude-code --skill complexity-analyzerInstallation paths:
.claude/skills/complexity-analyzer/# Complexity Analyzer
## Quick Start
Analyze complexity with tools:
```bash
# JavaScript
npx eslint --plugin complexity --rule 'complexity: [error, 10]' src/
# Python
pip install radon
radon cc src/ -a -nb
# General
npx complexity-report src/
```
## Instructions
### Step 1: Calculate Cyclomatic Complexity
Count decision points + 1:
- if, else, elif
- for, while loops
- case statements
- && and || operators
- ternary operators
- catch blocks
**Example:**
```javascript
function example(x) { // +1 (base)
if (x > 0) { // +1
return x;
} else if (x < 0) { // +1
return -x;
}
return 0;
}
// Complexity: 3
```
### Step 2: Identify Complex Functions
| Complexity | Rating | Action |
|------------|--------|--------|
| 1-10 | Simple | No action needed |
| 11-20 | Moderate | Consider refactoring |
| 21-50 | Complex | Should refactor |
| 50+ | Very Complex | Must refactor |
### Step 3: Analyze Cognitive Complexity
Cognitive complexity considers:
- Nesting depth (each level adds to complexity)
- Breaks in linear flow (if, loops, catch)
- Recursion
```javascript
// Cyclomatic: 4, Cognitive: 7
function sumOfPrimes(max) { // +0
let total = 0;
for (let i = 2; i <= max; i++) { // +1 (loop)
let isPrime = true;
for (let j = 2; j < i; j++) { // +2 (nested loop)
if (i % j === 0) { // +3 (nested if)
isPrime = false;
break; // +1 (break)
}
}
if (isPrime) { // +1 (if)
total += i;
}
}
return total;
}
```
### Step 4: Generate Report
```markdown
## Complexity Report
### High Complexity (>20)
**processOrder()** - src/orders.js:45
- Cyclomatic: 28
- Cognitive: 35
- Lines: 127
- Recommendation: Extract validation, calculation, and persistence logic
**validateUser()** - src/auth.js:12
- Cyclomatic: 22
- Cognitive: 28
- Lines: 89
- Recommendation: Extract individual validation rules
### Moderate Complexity (11-20)
[List functions with complex