README

Evm Bn

Convert fixed-point numbers to ethers big numbers and vice-versa. This is useful for EVM-related projects, since 1 ETH is 1e18 wei.

Accepts scientific notation.
Limits the precision to 78 digits.
Enforces 60 integer digits and 18 fractional digits.
Designed to be used alongside @ethersproject/bignumber.
Slices the fractional digits automatically at position n + 1 and above, with n the number of decimals, rounding down in the process.

Install

With yarn:

$ yarn add evm-bn

Or npm:

$ npm install evm-bn

Usage

To Bn

import type { BigNumber } from "@ethersproject/bignumber";
import { toBn } from "evm-bn";

// 3141500000000000000
const foo: BigNumber = toBn("3.1415");

// 115792089237316195423570985008687907853269984665640564039457584007913129639935
const bar: BigNumber = toBn("115792089237316195423570985008687907853269984665640564039457.584007913129639935");

// 100000000000000
const baz: BigNumber = toBn("100e6", 6);

From Bn

import type { BigNumber } from "@ethersproject/bignumber";
import { fromBn } from "evm-bn";

// 3.1415
const foo: BigNumber = fromBn(BigNumber.from("3141500000000000000"));

// 115792089237316195423570985008687907853269984665640564039457.584007913129639935
const bar: BigNumber = fromBn(
  BigNumber.from("115792089237316195423570985008687907853269984665640564039457584007913129639935"),
);

// 100000000
const baz: BigNumber = fromBn(BigNumber.from("100000000000000"), 6);

Contributing

Feel free to dive in! Open an issue, start a discussion or submit a PR.

Set Up

Install the dependencies:

$ yarn install

evm-bn

Usage no npm install needed!