ethers.js/lib/units.js

79 lines
2.0 KiB
JavaScript

var utils = require('./utils.js');
var zero = new utils.BN(0);
var negative1 = new utils.BN(-1);
var tenPower18 = new utils.BN('1000000000000000000');
function formatEther(wei, options) {
if (typeof(wei) === 'number') {
// @TODO: Warn if truncation will occur?
wei = new utils.BN(wei);
} else if (utils.isHexString(wei)) {
wei = new utils.BN(wei.substring(2), 16);
}
if (!options) { options = {}; }
if (!(wei instanceof utils.BN)) { throw new Error('invalid wei'); }
var negative = wei.lt(zero);
if (negative) { wei = wei.mul(negative1); }
var fraction = wei.mod(tenPower18).toString(10);
while (fraction.length < 18) { fraction = '0' + fraction; }
if (!options.pad) {
fraction = fraction.match(/^([0-9]*[1-9]|0)(0*)/)[1];
}
var whole = wei.div(tenPower18).toString(10);
if (options.commify) {
whole = whole.replace(/\B(?=(\d{3})+(?!\d))/g, ",")
}
var value = whole + '.' + fraction;
if (negative) { value = '-' + value; }
return value;
}
function parseEther(ether) {
if (typeof(ether) !== 'string' || !ether.match(/^-?[0-9.]+$/)) {
throw new Error('invalid value');
}
// Is it negative?
var negative = (ether.substring(0, 1) === '-');
if (negative) { ether = ether.substring(1); }
if (ether === '.') { throw new Error('invalid value'); }
// Split it into a whole and fractional part
var comps = ether.split('.');
if (comps.length > 2) { throw new Error('too many decimal points'); }
var whole = comps[0], fraction = comps[1];
if (!whole) { whole = '0'; }
if (!fraction) { fraction = '0'; }
if (fraction.length > 18) { throw new Error('too many decimal places'); }
while (fraction.length < 18) { fraction += '0'; }
whole = new utils.BN(whole);
fraction = new utils.BN(fraction);
var wei = (whole.mul(tenPower18)).add(fraction);
if (negative) { wei = wei.mul(negative1); }
return wei;
}
module.exports = {
formatEther: formatEther,
parseEther: parseEther,
}