cast works, but forge does not, against hardhat BSC mainnet fork

[aathan]

Any clue what I might be doing wrong here? cast successfully calls the BUSD contract address at a hardhat fork of BSC mainnet. If I try to do the same call from a Solidity test function the return values are empty.

$ cast call --rpc-url http://127.0.0.1:8545 0xe9e7CEA3DedcA5984780Bafc599bD69ADd087D56 "totalSupply()(uint256)"
4850999328629409465655005513


$ forge test -vvv --fork-url http://127.0.0.1:8545/ -m testTotalSupply
[⠆] Compiling...
Compiler run successful (with warnings)

Running 1 test for src/test/ReplaceTest.t.sol:ContractTest
[PASS] testTotalSupply() (gas: 182223)
Logs:
  success: 1
  data: 0x0000000000000000000000000000000000000000000000000000000000000000
  totalSupply: 0
  totalSupply Boo: 12345

Test result: ok. 1 passed; 0 failed; finished in 223.54ms

$ cat src/test/ReplaceTest.t.sol
import "ds-test/test.sol";

pragma solidity ^0.8.0;
interface I {
    function totalSupply() external view returns (uint256);
}

contract Boo {
    string _name;
    uint256 _totalSupply;
    constructor() {
        _name='foo';
        _totalSupply=12345;
    }
    function name() external view returns (string memory) {
        return _name;
    }
    function totalSupply() external view returns (uint256) {
        return _totalSupply;
    }
}
    
contract ContractTest is DSTest {
    function setUp() public {}

    address payable constant busd = payable(0xe9e7CEA3DedcA5984780Bafc599bD69ADd087D56);

    function testTotalSupply() public {
        I i = I(busd);
        uint t = i.totalSupply();
        (bool success, bytes memory data) = busd.call(abi.encodeWithSignature("totalSupply()"));
        emit log_named_uint('success',  (success ? 1:0));
        emit log_named_bytes('data', data);
        emit log_named_uint('totalSupply', t);

        Boo b=new Boo();
        emit log_named_uint('totalSupply Boo', b.totalSupply());
    }

}

[onbjerg]

Can you try just passing the BSC node as the fork RPC instead of going through Hardhat? If that does not work, can you post the output of RUST_LOG=trace forge test -vvv --fork-url http://127.0.0.1:8545/ -m testTotalSupply

[aathan]

forge 0.2.0 (64087b5 2022-04-13T00:10:42.429318924+00:00)

I guess I'll get in touch with the project and see what I can find out. The hardhat node command does not seem to have verbosity options.

[aathan]

By the way, it seems relevant that cast does work correctly, against the hardhat fork?

$ cast call --rpc-url http://127.0.0.1:8545 0xe9e7CEA3DedcA5984780Bafc599bD69ADd087D56 "totalSupply()(uint256)"
4850999328629409465655005513

RUST_LOG env seems to have no effect on cast.

[onbjerg]

These are different RPC calls: Forge will call stuff like eth_getCode/eth_getStorageAt/eth_balance etc. whereas Cast just performs an eth_call

[mds1]

Seems like the eth_getStorageAt request fails for Hardhat, but not for direct. Not sure why that would be the case - is there any logs you can inspect for Hardhat that may give clues? Anyhow, seems like a Hardhat issue.

This is an issue with Hardhat, see:

• forge: storage slot retrieval errors #385 (comment)
• Make eth_getStorageAt spec-compliant NomicFoundation/hardhat#2581

[onbjerg]

Great find, thanks!!!

[onbjerg]

Confirmed to be a Hardhat issue, see #1287 (reply in thread) (or just NomicFoundation/hardhat#2581)