Empirical

(adjective) based on what is experienced or seen rather than on theory
(noun) enhancements for Ruby with a runtime type system

Empirical catches bugs early and makes your code self-documenting by enhancing Ruby with beautiful syntax to define runtime type assertions.

fun word_frequency(text: String) => _Hash(String, Integer) do
  text
    .downcase
    .scan(/\w+/)
    .tally
    .sort_by { |word, count| -count }
    .first(10)
    .to_h
end

(see below).

Setup

Install the gem by adding it to your Gemfile and running bundle install. You’ll probably want to set it to require: false here because you should require it manually at precisely the right moment.

gem "empirical", require: false

Now the gem is installed, you should require and initialize the gem as early as possible in your boot process. Ideally, this should be right after Bootsnap is set up. In Rails, this will be in your boot.rb file.

require "empirical"

You can pass an array of globs to Empirical.init as include: and exclude:

Empirical.init(include: ["#{Dir.pwd}/**/*"], exclude: ["#{Dir.pwd}/vendor/**/*"])