This package includes several classes which extend ethers.js with explicit ways to convert between unit types.

Not sure which to use for values from smart contract calls? BigNumbers? BigNumberishes? Strings? Numbers? BNs? The Wei class bundles all those types under one roof.

Classes

Wei

A class representation of an unsigned integer returned from the EVM. Has getters that easily convert the value into different units with precision customized by decimal amounts.

parseWei(value, decimals) is a wrapper around the toBn function in evm-bn, it will multiply value by 10 ^ decimals and return a Wei instance.

Use raw when passing the value to a smart contract call.

Use float when a floating point number is needed, rather than the raw integer.

Use display when the value is being shown on a UI.

Check out Paul's evm-bn library to handle better conversion to BigNumbers from ethers.js.

FixedPointX64

Typescript representation of a signed 64x64 fixed point integer, a numerator with denominator 2^64, stored as an int128 in solidity.

parseFixedPointX64(value, decimals) will scale value up to decimals, then multiply it by 2^64, and return a FixedPointX64 instance.

Percentage

Simple class to represent a percentage unit, with a default precision of 4.

parsePercentage(value: number | string) will accept a raw percent in decimal format and multiply it by 10 ^ 4 to construct and return a Percentage instance.

Use bps to return the Percentage formatted in basis points.

Use points to return the Percentage formatted in points.

Use float to return a floating point percentage in decimal format.

Use display to return a percentage in point format, with a fixed amount of decimals.

The amount of decimals to display can be edited with displayDecimals(x: number), it defaults to 2 otherwise.

Time

Simple class to represent time units, with getters to return seconds or years.

Year units are used for javascript math, second units are used for solidity math because block.timestamp returns a UNIX timestamp in seconds.

Use float to return the timestamp.

Use years to return the amount of years the amount of seconds is equal to.

Use seconds to return the amount of seconds represented.

Use the static method Time.now to get a floored timestamp of Date.now(), in seconds.