text: // Asserts that environment variable is set and returns its value.
  // When not set, the application will exit
  
  const assert = envName => _assert(process, console, envName)
  
  const _assert = (process, console, envName) => {
    var env
    if (!(env = process.env[envName])) {
      console.error('Error: Environment variable \'' + envName + '\' not set.')
      return process.exit(1)
    } else {
      return env
    }
  }
  
  const get = (envName, deflt) => { return process.env[envName] || deflt }
  
  module.exports = { assert, _assert, get }
  