@steemit/steem-js/lib/auth/serializer/src/precision.js

JavaScript library for the Steem blockchain

"use strict";

var _my;
var _internal;
var v = require('./validation');
var BigInteger = require('bigi');
module.exports = _my =
// Result may be used for int64 types (like transfer amount).  Asset's
// precision is used to convert the number to a whole number with an implied
// decimal place.

// "1.01" with a precision of 2 returns long 101
// See http://cryptocoinjs.com/modules/misc/bigi/#example
{
  to_bigint64(number_or_string, precision, error_info = "") {
    var long = _internal.to_long64(number_or_string, precision, error_info);
    return BigInteger(long.toString());
  },
  // 101 string or long with a precision of 2 returns "1.01" 
  to_string64(number_or_string, precision, error_info = "") {
    v.required(number_or_string, error_info);
    v.number(precision, error_info);
    var number_long = v.to_long(number_or_string, error_info);
    var string64 = _internal.decimal_precision_string(number_long, precision, error_info);
    v.no_overflow64(string64, error_info);
    return string64;
  }
};

// _internal is for low-level transaction code
module.exports._internal = _internal =
// Warning: Long operations may over-flow without detection
{
  to_long64(number_or_string, precision, error_info = "") {
    v.required(number_or_string, "number_or_string " + error_info);
    v.required(precision, "precision " + error_info);
    return v.to_long(_internal.decimal_precision_string(number_or_string, precision, error_info));
  },
  decimal_precision_string(number, precision, error_info = "") {
    v.required(number, "number " + error_info);
    v.required(precision, "precision " + error_info);
    var number_string = v.to_string(number);
    number_string = number_string.trim();
    precision = v.to_number(precision);

    // remove leading zeros (not suffixing)
    var number_parts = number_string.match(/^-?0*([0-9]*)\.?([0-9]*)$/);
    if (!number_parts) {
      throw new Error(`Invalid number: ${number_string} ${error_info}`);
    }
    var sign = number_string.charAt(0) === '-' ? '-' : '';
    var int_part = number_parts[1];
    var decimal_part = number_parts[2];
    if (!decimal_part) {
      decimal_part = "";
    }

    // remove trailing zeros
    while (/0$/.test(decimal_part)) {
      decimal_part = decimal_part.substring(0, decimal_part.length - 1);
    }
    var zero_pad_count = precision - decimal_part.length;
    if (zero_pad_count < 0) {
      throw new Error(`overflow, up to ${precision} decimals may be used ${error_info}`);
    }
    if (sign === "-" && !/[1-9]/.test(int_part + decimal_part)) {
      sign = "";
    }
    if (int_part === "") {
      int_part = "0";
    }
    for (var i = 0; 0 < zero_pad_count ? i < zero_pad_count : i > zero_pad_count; 0 < zero_pad_count ? i++ : i++) {
      decimal_part += "0";
    }
    return sign + int_part + decimal_part;
  }
};