brain-game/dist/games/brain-progression.js

simple game

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _ = require('../');

var _2 = _interopRequireDefault(_);

var _utils = require('../utils');

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

const description = 'What number is missing in this progression?\n';

const generate = () => {
  const start = (0, _utils.getCustomRandomInt)();
  const step = (0, _utils.getRandomInt)(0, 10);
  const points = (0, _utils.getRandomInt)(2, 9);
  const seq = [start];
  for (let i = 0; i < 10; i += 1) {
    seq.push(seq[seq.length - 1] + step);
  }
  seq[points] = '..';
  return seq.slice();
};

const target = array => {
  const indexLast = array.findIndex(item => item === '..') - 1;
  const indexFirst = indexLast - 1;
  const step = array[indexLast] - array[indexFirst];
  return array[indexLast] + step;
};

const toString = array => array.toString().split(',').join(' ');

exports.default = () => (0, _2.default)(description, generate, target, toString);