ArbSys does not work on Arbitrum Fork

[Archethect]

Version of Hardhat

2.18.1

What happened?

It seems it is not possible to use ArbSys(100) contract methods on Arbitrum forks. While testing ArbSys(address(100)).arbBlockNumber() it reverts without a reason. It would be cool to make forks work with all Arbitrum Precompiles: https://docs.arbitrum.io/for-devs/dev-tools-and-resources/precompiles

Minimal reproduction steps

• Fork Arbitrum on an existing block
• Test some solidity code containing ArbSys(address(100)).arbBlockNumber() (or any other method in that contract)

Search terms

Arbitrum, Fork, ArbSys

[fvictorio]

Hey @Archethect, thanks for opening this. We are in the middle of a big refactor of the Hardhat network, but after that we want (at some point) to have some mechanism for adding custom precompiles, which should help with this.

[islishude]

I'd like to have following api to support the precompile contracts

const precompiles = [
  {
    address: "0x...",
    gas(input) {
      return 100; // gas required for the call
    },
    run(input) {
      return [0x1, 0x2]; // return bytes or throw an error
    },
  },
];

await hardhat.addPrecompiles(...precompiles);

[escottalexander]

Any progress on this?

[kanej]

For Hardhat 3 we are building out better support for layer 2s, including precompiles and predeploys.

We are still in early Alpha - Optimism is currently the only supported L2 chain type, but hopefully that will give some insight into the general approach:

https://hardhat.org/hardhat3-alpha