Elixir Complexity Analyzer

A powerful CLI tool for analyzing cyclomatic and cognitive complexity in Elixir projects. Perfect for CI/CD pipelines and code quality monitoring.

Quick Start

# Analyze current directory (default: cyclomatic complexity)
mix complexity

# Analyze cognitive complexity with custom thresholds
mix complexity ./lib --type cognitive --error-threshold 15 --warning-threshold 10

# Generate detailed report
mix complexity ./lib --report complexity-report.json

# Or use the --default-report option
mix complexity ./lib --default-report

Features

Single Complexity Focus: Analyze either cyclomatic or cognitive complexity
CI/CD Ready: Exit codes for pipeline integration
Configurable Thresholds: Custom warning and error levels
Smart Filtering: Ignore patterns with glob support
Configuration File: JSON-based project configuration
Detailed Reports: JSON output for tracking over time
Fast Analysis: Parallel processing with Task.async_stream
AST-Powered: Uses Elixir's built-in Code.string_to_quoted for accurate parsing

CLI Options

Option	Description	Default
`--type <type>`	Complexity type to analyze (cyclomatic or cognitive)	cyclomatic
`--error-threshold <number>`	Error threshold for complexity	20
`--warning-threshold <number>`	Warning threshold for complexity	10
`--ignore <patterns>`	Comma-separated glob patterns to ignore	""
`--report <file>`	Save detailed JSON report to file	-
`--default-report`	Save report to default location (complexity-report.json)	-

Usage Examples

CI/CD Integration

# GitHub Actions example
- name: Check code complexity
  run: mix complexity ./lib --type cognitive --error-threshold 20

Local Development

# Quick check with default settings (cyclomatic complexity)
mix complexity ./lib

# Analyze cognitive complexity with strict thresholds
mix complexity ./lib --type cognitive --error-threshold 15 --warning-threshold 8

# Generate report for tracking
mix complexity ./lib --report "reports/complexity-$(date +%Y%m%d).json"

# Generate report to default location
mix complexity ./lib --default-report

Advanced Filtering

# Ignore test files and external libraries
mix complexity ./lib --ignore "**/test/**,**/*.spec.ex,**/vendor/**"

# Focus on specific file types (ignore test files)
mix complexity ./lib --ignore "**/*_test.exs,**/test_helper.exs"

Configuration File

Create a complexity.config.json file in the root of your analyzed directory:

{
  "type": "cognitive",
  "errorThreshold": 25,
  "warningThreshold": 15,
  "ignore": [
    "**/test/**",
    "**/*_test.exs",
    "**/vendor/**"
  ]
}

CLI options will override configuration file settings.

Exit Codes

0 - Success (no violations)
1 - Complexity thresholds exceeded
2 - Tool error (file not found, parse errors)

Output Examples

Success:

✓ No complexity threshold violations found

Warnings and Errors:

🟠 [12/10] parseComplexConfig @ lib/utils/parser.ex:45
🟠 [16/10] render_rows @ lib/components/data_table.ex:23
🔴 [25/20] process_data @ lib/legacy/processor.ex:156
🔴 [28/20] convert_legacy_data @ lib/legacy/converter.ex:89

The format shows: [actual_complexity/threshold] function_name @ file_path:line

🟠 indicates warnings (complexity ≥ warning threshold but < error threshold)
🔴 indicates errors (complexity ≥ error threshold)

Note: All violations are collected and displayed, then exits with code 1 if any errors exist