BigDecimal

This library was made to simplify the Web3 development by extending BigNumber package from ethers.js with Decimals property and overriding the corresponding math.

Put simply - now you don't need parseEthers, formatEthers, and convert numbers/strings/bignumbers to each other.

BigDecimal structure/features:

1. inheriting BigNumber - so you don't need to change anything in your code - and can pass BigDecimal wherever you had BigNumber before
2. BigDecimal.decimals property - stores how many decimals this number has. Default is 18
3. BigDecimal.value property - stores the numeric value of the bignumber with decimals applied - for human-readable display and use anywhere where you would use a simple number

Usage

You can look in the test folder for all possible use-cases of BigDecimal.

And the source code src.ts/BigDecimal.ts also has very verbose comments on usage.

For now it only supports multiplication, division, addition and subtraction.

// You can create BigDecimal with Number, with string, or with BigNumber.
// You can pass the number of decimals as the second argument. If nothing is passed - default is assumed to be 18

// When creating BigDecimal from a number - it is converted to 18 decimals and stored as a BigNumber with 18 zeroes
const fiveEthers = new BigDecimal(5) // Same as BigNumber.from(5 with 18 zeroes) or parseEther(5)

// When creating with a BigNumber - it's assumed that decimals are already included:
const hundredUSDC = new BigDecimal(BigNumber.from("100000000"), 6) // Same as parseUnits(100, 6)

// When creating with a string - there are two ways:
// 1) same as BigNumber, where the decimals are assumed to be included:
const hundredUSDC = new BigDecimal("100000000", 6) // Same as parseUnits(100, 6)

// 1) set parseString to true - then the string will be parsed and treated as a number:
const hundredUSDC = new BigDecimal("100", 6, true) // Same as parseUnits("100", 6)

const meaning = new BigDecimal(BigNumber.from(42), 0) // 42 with 0 decimals

const half = hundredUSDC.mul(0.5) // equals hundredUSDC * 0.5 = 50 USDC with 6 decimals

const fivePercent = new Bigdecimal(0.05) // equals 0.05 * 1e18

const multiplication = hundredUSDC.mul(fivePercent) // equals 5 USDC with 6 decimals

const division = hundredUSDC.div(half) // equals 200 USDC with 6 decimals

console.log(hundredUSDC) // outputs 100 - human readable number with decimals applied to it

hundredUSDC.decimals // equals 6

License

MIT License