text: 'use strict';
  var _ = {
    extend: require('lodash/extend'),
    omit: require('lodash/omit'),
  };
  var MuteStream = require('mute-stream');
  var readline = require('readline');
  
  /**
   * Base interface class other can inherits from
   */
  
  class UI {
    constructor(opt) {
      // Instantiate the Readline interface
      // @Note: Don't reassign if already present (allow test to override the Stream)
      if (!this.rl) {
        this.rl = readline.createInterface(setupReadlineOptions(opt));
      }
  
      this.rl.resume();
  
      this.onForceClose = this.onForceClose.bind(this);
  
      // Make sure new prompt start on a newline when closing
      process.on('exit', this.onForceClose);
  
      // Terminate process on SIGINT (which will call process.on('exit') in return)
      this.rl.on('SIGINT', this.onForceClose);
    }
  
    /**
     * Handle the ^C exit
     * @return {null}
     */
  
    onForceClose() {
      this.close();
      process.kill(process.pid, 'SIGINT');
      console.log('');
    }
  
    /**
     * Close the interface and cleanup listeners
     */
  
    close() {
      // Remove events listeners
      this.rl.removeListener('SIGINT', this.onForceClose);
      process.removeListener('exit', this.onForceClose);
  
      this.rl.output.unmute();
  
      if (this.activePrompt && typeof this.activePrompt.close === 'function') {
        this.activePrompt.close();
      }
  
      // Close the readline
      this.rl.output.end();
      this.rl.pause();
      this.rl.close();
    }
  }
  
  function setupReadlineOptions(opt) {
    opt = opt || {};
    // Inquirer 8.x:
    // opt.skipTTYChecks = opt.skipTTYChecks === undefined ? opt.input !== undefined : opt.skipTTYChecks;
    opt.skipTTYChecks = opt.skipTTYChecks === undefined ? true : opt.skipTTYChecks;
  
    // Default `input` to stdin
    var input = opt.input || process.stdin;
  
    // Check if prompt is being called in TTY environment
    // If it isn't return a failed promise
    if (!opt.skipTTYChecks && !input.isTTY) {
      const nonTtyError = new Error(
        'Prompts can not be meaningfully rendered in non-TTY environments'
      );
      nonTtyError.isTtyError = true;
      throw nonTtyError;
    }
  
    // Add mute capabilities to the output
    var ms = new MuteStream();
    ms.pipe(opt.output || process.stdout);
    var output = ms;
  
    return _.extend(
      {
        terminal: true,
        input: input,
        output: output,
      },
      _.omit(opt, ['input', 'output'])
    );
  }
  
  module.exports = UI;
  