faker/lib/datatype.js

Generate massive amounts of fake contextual data

/**
 *
 * @namespace faker.datatype
 */
function Datatype (faker, seed) {
  // Use a user provided seed if it is an array or number
  if (Array.isArray(seed) && seed.length) {
    faker.mersenne.seed_array(seed);
  }
  else if(!isNaN(seed)) {
    faker.mersenne.seed(seed);
  }

  /**
     * returns a single random number based on a max number or range
     *
     * @method faker.datatype.number
     * @param {mixed} options {min, max, precision}
     */
  this.number = function (options) {

    if (typeof options === "number") {
      options = {
        max: options
      };
    }

    options = options || {};

    if (typeof options.min === "undefined") {
      options.min = 0;
    }

    if (typeof options.max === "undefined") {
      options.max = 99999;
    }
    if (typeof options.precision === "undefined") {
      options.precision = 1;
    }

    // Make the range inclusive of the max value
    var max = options.max;
    if (max >= 0) {
      max += options.precision;
    }

    var randomNumber = Math.floor(
      faker.mersenne.rand(max / options.precision, options.min / options.precision));
    // Workaround problem in Float point arithmetics for e.g. 6681493 / 0.01
    randomNumber = randomNumber / (1 / options.precision);

    return randomNumber;

  };

  /**
     * returns a single random floating-point number based on a max number or range
     *
     * @method faker.datatype.float
     * @param {mixed} options
     */
  this.float = function (options) {
    if (typeof options === "number") {
      options = {
        precision: options
      };
    }
    options = options || {};
    var opts = {};
    for (var p in options) {
      opts[p] = options[p];
    }
    if (typeof opts.precision === 'undefined') {
      opts.precision = 0.01;
    }
    return faker.datatype.number(opts);
  };

  /**
     * method returns a Date object using a random number of milliseconds since 1. Jan 1970 UTC
     * Caveat: seeding is not working
     *
     * @method faker.datatype.datetime
     * @param {mixed} options, pass min OR max as number of milliseconds since 1. Jan 1970 UTC
     */
  this.datetime = function (options) {
    if (typeof options === "number") {
      options = {
        max: options
      };
    }

    var minMax = 8640000000000000;

    options = options || {};

    if (typeof options.min === "undefined" || options.min < minMax*-1) {
      options.min = new Date().setFullYear(1990, 1, 1);
    }

    if (typeof options.max === "undefined" || options.max > minMax) {
      options.max = new Date().setFullYear(2100,1,1);
    }

    var random = faker.datatype.number(options);
    return new Date(random);
  };

  /**
     * Returns a string, containing UTF-16 chars between 33 and 125 ('!' to '}')
     *
     *
     * @method faker.datatype.string
     * @param { number } length: length of generated string, default = 10, max length = 2^20
     */
  this.string = function (length) {
    if(length === undefined ){
      length = 10;
    }

    var maxLength = Math.pow(2, 20);
    if(length >= (maxLength)){
      length = maxLength;
    }

    var charCodeOption = {
      min: 33,
      max: 125
    };

    var returnString = '';

    for(var i = 0; i < length; i++){
      returnString += String.fromCharCode(faker.datatype.number(charCodeOption));
    }
    return returnString;
  };

  /**
     * uuid
     *
     * @method faker.datatype.uuid
     */
  this.uuid = function () {
    var RFC4122_TEMPLATE = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx';
    var replacePlaceholders = function (placeholder) {
      var random = faker.datatype.number({ min: 0, max: 15 });
      var value = placeholder == 'x' ? random : (random &0x3 | 0x8);
      return value.toString(16);
    };
    return RFC4122_TEMPLATE.replace(/[xy]/g, replacePlaceholders);
  };

  /**
     * boolean
     *
     * @method faker.datatype.boolean
     */
  this.boolean = function () {
    return !!faker.datatype.number(1);
  };


  /**
     * hexaDecimal
     *
     * @method faker.datatype.hexaDecimal
     * @param {number} count defaults to 1
     */
  this.hexaDecimal = function hexaDecimal(count) {
    if (typeof count === "undefined") {
      count = 1;
    }

    var wholeString = "";
    for(var i = 0; i < count; i++) {
      wholeString += faker.random.arrayElement(["0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f", "A", "B", "C", "D", "E", "F"]);
    }

    return "0x"+wholeString;
  };

  /**
     * returns json object with 7 pre-defined properties
     *
     * @method faker.datatype.json
     */
  this.json = function json() {

    var properties = ['foo', 'bar', 'bike', 'a', 'b', 'name', 'prop'];

    var returnObject = {};
    properties.forEach(function(prop){
      returnObject[prop] = faker.datatype.boolean() ?
        faker.datatype.string() : faker.datatype.number();
    });

    return JSON.stringify(returnObject);
  };

  /**
     * returns an array with values generated by faker.datatype.number and faker.datatype.string
     *
     * @method faker.datatype.array
     * @param { number } length of the returned array
     */

  this.array = function array(length) {


    if(length === undefined){
      length = 10;
    }
    var returnArray = new Array(length);
    for(var i = 0; i < length; i++){
      returnArray[i] = faker.datatype.boolean() ?
        faker.datatype.string() : faker.datatype.number();
    }
    return returnArray;

  };

  return this;
}

module['exports'] = Datatype;