haste-server/lib/key_generators/dictionary.js

const fs = require('fs');

module.exports = class DictionaryGenerator {

  constructor(options, readyCallback) {
    // Check options format
    if (!options)      throw Error('No options passed to generator');
    if (!options.path) throw Error('No dictionary path specified in options');

    // Load dictionary
    fs.readFile(options.path, 'utf8', (err, data) => {
      if (err) throw err;

      this.dictionary = data.split(/[\n\r]+/);

      if (readyCallback) readyCallback();
    });
  }

  // Generates a dictionary-based key, of keyLength words
  createKey(keyLength) {
    let text = '';

    for (let i = 0; i < keyLength; i++) {
      const index = Math.floor(Math.random() * this.dictionary.length);
      text += this.dictionary[index];
    }

    return text;
  }

};