setup-ruby/src/main.ts

import * as core from '@actions/core';
import * as cache from './cache';

export async function run() {
  try {
    core.info('Please note: this action is deprecated and will not be maintained in future by GitHub engineers. Please, migrate to https://github.com/ruby/setup-ruby from official Ruby community.');
    let versionSpec = core.getInput('ruby-version', {required: true});
    if (!versionSpec) {
      // deprecated
      versionSpec = core.getInput('version');
    }

    // check in the VMs cache first
    let toolPath: string = await cache.find(versionSpec);

    // TODO: download JIT and/or ruby-build

    if (!toolPath) {
      core.setFailed(`Version ${versionSpec} not found`);
      return;
    }

    core.addPath(toolPath);
  } catch (error) {
    // unhandled
    core.setFailed(error.message);
  }
}