When should I use toQuantity?

[Oxbobby]

Ethers Version

6.3.0

Search Terms

toQuantity, hexlify

Describe the Problem

toQuantity method trims away the leading 0s from the hexlify result if it so happens to start with a 0. That makes it uncompatible with it's reverse method, getBytes(), as getBytes() requires a 66 length BytesLike value. A "invalid BytesLike value" error is thrown.

Code Snippet

const bytes = randomBytes(32)
const quantity = toQuantity(salt) // this sometimes returns a 66 length hex, sometimes a 65
const opposite = getBytes(quantity) // this sometimes passes, sometimes it does not

Contract ABI

No response

Errors

TypeError: invalid BytesLike value (argument="value", value="0xf03195ef369f204f7baeb48f909e6181cf661f4c5e92f8a6eef7683be5b103d", code=INVALID_ARGUMENT, version=6.3.0)

Environment

Ethereum (mainnet/ropsten/rinkeby/goerli), Hardhat

Environment (Other)

No response

[Oxbobby]

Answer is: just use hexlify instead of toQuantity. Still, I'm leaving this issue open to get an answer whether this is OK or not because using toQuantity instead of hexlify might cause serious random trouble in a production env

[ricmoo]

That is the purpose of toQuantity. It converts a numeric value into a JSON-RPC quantity. You should definitely not be using it for the purposes of converting things to a data hexstring, that is what hexlify is for.

A quantity must not have any leading zeros, with the exception of 0 (which is 0x0) so it will absolutely produce odd-length strings if the top nibble of a the most significant bytes value is 0.