Static analysis tool for checking Ruby code for Sandi Metz' rules.
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Static analysis tool for checking your Ruby code for Sandi Metz' four rules.

  • 100 lines per class
  • 5 lines per method
  • 4 params per method call (and don't even try cheating with hash params)
  • 1 instance variable per controller action

CLI mode

gem install sandi_meter

sandi_meter --help
    -d, --details                    CLI mode. Show details (path, line number)
    -g, --graph                      HTML mode. Create folder, log data and output stats to HTML file.
        --json                       Output as JSON
    -l, --log                        Show syntax error and indentation log output
    -o, --output-path PATH           Path for storing generated output files (default: ./sandi_meter/)
    -p, --path PATH                  Path to folder or file to analyze
    -q, --quiet                      Do not open HTML report for graph option in browser.
    -t, --thresholds THRESHOLD       Thresholds for each rule (default: "90,90,90,90" or in config.yml)
    -r, --rules                      Show rules
    -v, --version                    Gem version
    -h, --help                       Help

cd ~/your/ruby/or/rails/project
sandi_meter -d

1. 85% of classes are under 100 lines.
2. 45% of methods are under 5 lines.
3. 99% of method calls accepted are less than 4 parameters.
4. 66% of controllers have one instance variable per action.

Classes with 100+ lines
  Class name                 | Size  | Path
  SandiMeter::Analyzer       | 219   | ./lib/sandi_meter/analyzer.rb:7
  SandiMeter::Calculator     | 172   | ./lib/sandi_meter/calculator.rb:2
  SandiMeter::HtmlGenerator  | 135   | ./lib/sandi_meter/html_generator.rb:5
  Valera                     | 109   | ./spec/test_classes/12.rb:1

Misindented classes
  Class name        | Path
  MyApp::TestClass  | ./spec/test_classes/1.rb:2
  OneLinerClass     | ./spec/test_classes/5.rb:1

Methods with 5+ lines
  Class name                          | Method name                   | Size  | Path
  SandiMeter::Analyzer                | initialize                    | 10    | ./lib/sandi_meter/analyzer.rb:10
  SandiMeter::Analyzer                | analyze                       | 13    | ./lib/sandi_meter/analyzer.rb:22

Misindented methods
  Class name        | Method name  | Path
  MyApp::TestClass  | blah         | ./spec/test_classes/1.rb:3

Method calls with 4+ arguments
  # of arguments  | Path
  5               | ./lib/sandi_meter/html_generator.rb:55
  5               | ./lib/sandi_meter/html_generator.rb:71

Controllers with 1+ instance variables
  Controller name         | Action name  | Instance variables
  AnotherUsersController  | index        | @users, @excess_variable

HTML mode

Try using gem with -g (--graph) option, so it will create a folder with beautiful html output and log file with results of any scan.

SandiMeter HTML mode pie charts SandiMeter HTML mode details

Add ignore files and folders in sandi_meter/.sandi_meter file.

Ruby script mode

require 'sandi_meter/file_scanner'
require 'pp'

scanner =
data = scanner.scan(PATH_TO_PROJECT)
pp data
# {:first_rule=>
#   {:small_classes_amount=>916,
#    :total_classes_amount=>937,
#    :misindented_classes_amount=>1},
#  :second_rule=>
#   {:small_methods_amount=>1144,
#    :total_methods_amount=>1833,
#    :misindented_methods_amount=>0},
#  :third_rule=>{:proper_method_calls=>5857, :total_method_calls=>5894},
#  :fourth_rule=>{:proper_controllers_amount=>17, :total_controllers_amount=>94}}