How to create types for structs that have contract types instead of address?

[HareemSaad]

The struct I want to sign using ether's v5.7 (or 6) is as following,

struct Order {
  ...
  IERC20 token,
  uint256 tokenAmount,
  ...

Now if I change IERC20 to address in the struct and the typehash on the contract side ether's seems to generate correct signatures, but with IERC20 it generates incorrect signatures.

(cross checked it with foundry vm.sign produces the correct signature which ercrecover accepts but the library does not)

I am more inclined to find out a way to somehow make it work without changing the contract, so is there a way it will work with IERC20 instead of address?

Basic implementation here -> https://github.com/HareemSaad/Hashv4-Typed-Singing-Discussion

P.S I know there was a similar discussion before but that did not revolve around ways to make it work or if it could work for that matter.

[ricmoo]

You’re correct, the struct in ethers (and what Solidity does internally) should just be "address" for a contract type.

Can you provide an example with simple code that shows what is generated that is incorrect against what is correct?

[HareemSaad]

@ricmoo

0x765423b5ddf6552c2653d535f7a48c2182a531989dc6c66b68ac4fb1c8195478

this was the hash (not typed hash) created by the library with address instead of IERC20 , the contract generated the same hash after changing the type

0x765423b5ddf6552c2653d535f7a48c2182a531989dc6c66b68ac4fb1c8195478

this was the has created by the contract with IERC20

ovbiously i cannot share the actual code

[HareemSaad]

@ricmoo

I created this repo https://github.com/HareemSaad/Hashv4-Typed-Singing-Discussion it contains the basic code / smart contract

i am running this on foundry and ethers and i get a different out put if address is typecasted to IERC20