index.js

'use strict';

const assert = require('assert');
const Events = require('events');
const utils = require('./lib/utils');

/**
 * Create an instance of `Enquirer`.
 *
 * ```js
 * const Enquirer = require('enquirer');
 * const enquirer = new Enquirer();
 * ```
 * @name Enquirer
 * @param {Object} `options` (optional) Options to use with all prompts.
 * @param {Object} `answers` (optional) Answers object to initialize with.
 * @api public
 */

class Enquirer extends Events {
  constructor(options, answers) {
    super();
    this.options = utils.merge({}, options);
    this.answers = { ...answers };
  }

  /**
   * Register a custom prompt type.
   *
   * ```js
   * const Enquirer = require('enquirer');
   * const enquirer = new Enquirer();
   * enquirer.register('customType', require('./custom-prompt'));
   * ```
   * @name register()
   * @param {String} `type`
   * @param {Function|Prompt} `fn` `Prompt` class, or a function that returns a `Prompt` class.
   * @return {Object} Returns the Enquirer instance
   * @api public
   */

  register(type, fn) {
    if (utils.isObject(type)) {
      for (let key of Object.keys(type)) this.register(key, type[key]);
      return this;
    }
    assert.equal(typeof fn, 'function', 'expected a function');
    let name = type.toLowerCase();
    if (fn.prototype instanceof this.Prompt) {
      this.prompts[name] = fn;
    } else {
      this.prompts[name] = fn(this.Prompt, this);
    }
    return this;
  }

  /**
   * Prompt function that takes a "question" object or array of question objects,
   * and returns an object with responses from the user.
   *
   * ```js
   * const Enquirer = require('enquirer');
   * const enquirer = new Enquirer();
   *
   * const response = await enquirer.prompt({
   *   type: 'input',
   *   name: 'username',
   *   message: 'What is your username?'
   * });
   * console.log(response);