ioredis-mock/lib/commands/srandmember.js

This library emulates ioredis by performing all operations in-memory.

'use strict';

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

var _lodash = require('lodash');

var _es6Set = require('es6-set');

var _es6Set2 = _interopRequireDefault(_es6Set);

var _arrayFrom = require('array-from');

var _arrayFrom2 = _interopRequireDefault(_arrayFrom);

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

function srandmember(key, count) {
  if (this.data.has(key) && !(this.data.get(key) instanceof _es6Set2.default)) {
    throw new Error('Key ' + key + ' does not contain a set');
  }

  var set = this.data.get(key) || new _es6Set2.default();
  var list = (0, _arrayFrom2.default)(set);
  var total = list.length;

  if (total === 0) {
    return null;
  }

  var shouldReturnArray = count !== undefined;
  var max = shouldReturnArray ? Math.abs(count) : 1;
  var skipDuplicates = shouldReturnArray && count > -1;

  if (skipDuplicates) {
    return (0, _lodash.shuffle)(list.splice(0, max));
  }

  var items = [];
  var results = 0;
  while (results < max) {
    var item = list[(0, _lodash.random)(0, total - 1)];
    items.push(item);

    results += 1;
  }

  return shouldReturnArray ? items : items[0];
}