main entrypoint.js to use with a GitHub Action to run action written in ruby

action.rb

# .github/actions/my-action/lib/action.rb

require 'json'

puts "I'm an action!"

event = JSON.parse(File.read(ENV['GITHUB_EVENT_PATH']))
puts event.inspect

action.yml

# .github/actions/my-action/action.yml

name: "My fabulous ruby action!"
description: ""
runs:
  using: 'node12'
  main: 'entrypoint.js'

base_entrypoint.js

// .github/actions/base_entrypoint.js

// NOTE: this script just runs the main action.rb file with the ruby
// installed by GitHub's actions/setup-ruby action.

const { existsSync } = require('fs')
const { spawnSync } = require('child_process')

function run(cmd, cwd) {
  try {
    const child = spawnSync(cmd, { shell: true, cwd })
    if (child.stdout) {
      console.log(child.stdout.toString())
    }
    if (child.stderr) {
      console.error(child.stderr.toString())
    }
    if (child.status != 0) {
      process.exit(child.status)
    }
  } catch (err) {
    console.error(err.message)
    process.exit(err.status)
  }
}

function main (cwd) {
  if (existsSync(`${cwd}/Gemfile`) || existsSync(`${pwd}/Gemfile.lock`)) {
    run('gem install bundler', cwd)
    run('bundle install', cwd)
  }

  run(`ruby ./lib/action.rb`, cwd)
}

module.exports = { main, run }

entrypoint.js

// .github/actions/my-action/entrypoint.js

const { main } = require('../base_entrypoint.js')

main(__dirname)

Gemfile

# .github/actions/my-action/Gemfile

# frozen_string_literal: true

source 'https://rubygems.org'

git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }

gem 'json'