Rulesets & Linting

AST Metrics allows you to enforce rules on your codebase (Linting). You can check complexity, coupling, volume, and more.

Managing Rulesets (CLI)

The easiest way to add rules is to use the ruleset command. It allows you to import pre-defined sets of rules.

Available Rulesets

You can list available rulesets with:

ast-metrics ruleset list

Ruleset	Description
architecture	Architecture-related constraints (e.g., coupling)
volume	Volume metrics (e.g., lines of code)
complexity	Complexity metrics (e.g., cyclomatic complexity)
golang	Golang-specific best practices and API hygiene

Installing a Ruleset

To add a ruleset to your configuration:

ast-metrics ruleset add architecture
ast-metrics ruleset add volume

Detailed Rules

🏗️ Architecture Ruleset

ast-metrics ruleset add architecture

Rule Name	Description
coupling	Checks for forbidden coupling between packages
max_afferent_coupling	Checks the afferent coupling of files/classes
max_efferent_coupling	Checks the efferent coupling of files/classes
min_maintainability	Checks the maintainability of the code
no_circular_dependencies	Detect circular dependencies between classes
max_responsibilities	Maximum number of responsibilities (LCOM) per class
no_god_class	Avoid God Classes (too many methods/properties)

📏 Volume Ruleset

ast-metrics ruleset add volume

Rule Name	Description
max_loc	Checks the lines of code in a file
max_logical_loc	Checks the logical lines of code in a file
max_loc_by_method	Checks the lines of code by method/function
max_logical_loc_by_method	Checks the logical lines of code by method/function
max_methods_per_class	Maximum number of methods per class
max_switch_cases	Maximum number of cases in switch statements
max_parameters_per_method	Maximum number of parameters per method
max_nested_blocks	Maximum nesting depth of blocks
max_public_methods	Maximum number of public methods per class

🧠 Complexity Ruleset

ast-metrics ruleset add complexity

Rule Name	Description
max_cyclomatic	Checks the cyclomatic complexity of functions

🐹 Golang Ruleset

ast-metrics ruleset add golang

Rule Name	Description
no_package_name_in_method	Do not include the package name in exported function or method identifiers
max_nesting	Limit nested depth of control structures (if/for/switch)
max_file_size	Limit file size (LOC)
max_files_per_package	Limit number of source files per package (excluding doc.go)
slice_prealloc	Check if slice preallocation is used
context_missing	Check if context is missing in function arguments
context_ignored	Check if context is ignored

---

Manual Configuration

You can also manually edit the .ast-metrics.yaml file at the root of your project.

sources:
  - ./internal
exclude: []
reports:
  html: ./build/report
  markdown: ./build/report.md
requirements:
  rules:
    architecture:
      coupling:
        forbidden:
          - from: Controller
            to: Repository
          - from: Repository
            to: Service
      max_afferent_coupling: 10
      max_efferent_coupling: 10
      min_maintainability: 70
    volume:
      max_loc: 1000
      max_logical_loc: 600
      max_loc_by_method: 30
      max_logical_loc_by_method: 20
    complexity:
      max_cyclomatic: 10
    golang:
      no_package_name_in_method: true
      max_nesting: 4
      max_file_size: 1000
      max_files_per_package: 50
      slice_prealloc: true
      context_missing: true
      context_ignored: true

Run the analysis with:

ast-metrics analyze