How to encode data for low level call? (Compound/Uniswap governence)

Question

I can't get the transaction to execute no matter how much I play with it. I know that it reverts during the secondary call because I always get this revert message: Timelock::executeTransaction: Transaction execution reverted.Here is the function I am calling:

function executeTransactions(address[] targets, uint[] values, string[] memory signatures, bytes[] memory data) public payable returns (bytes memory) 

    bytes memory callData;
    for(uint i = 0; i < targets.length; i++){
        
        if (bytes(signatures[i]).length == 0) {
            callData = data[i];
        } else {
            callData = abi.encodePacked(bytes4(keccak256(bytes(signatures[i]))), data[i]);
        }

        // solium-disable-next-line security/no-call-value
        (bool success, bytes memory returnData) = targets[i].call.value(values[i])(callData);
        require(success, "Timelock::executeTransaction: Transaction execution reverted.");

        return returnData;
    }
}

Here is how I'm calling it (with web3.eth.Contract):

      Contract.methods.executeTransactions(
        ["0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984"],//targets
        [0],//values
        [web3.eth.abi.encodeFunctionSignature("transfer(address,uint)")],//signatures
        [web3.eth.abi.encodeParameters(["address", "uint"], ["0xC722A3F999983325c611e7E1D967a3c27063F8b0", 5000000000000000000000000])]//calldata

      ).send({from: accounts[0], gas: 5000000})

Help is greatly appreciated as with my current setup I have to run through a simulation that takes ~15 mins per shot in the dark to test this :/

Answer 1

The function changes execution according to signature passed

    if (bytes(signatures[i]).length == 0) {
        callData = data[i];
    } else {
        callData = abi.encodePacked(bytes4(keccak256(bytes(signatures[i]))), data[i]);
    }

If it is empty it will assume the function call is contained in data[i]. You would have to use web3.eth.abi.encodeFunctionCall to encode the function call.

If it is not empty it will calculate the signature bytes4(keccak256(bytes(signatures[i]))), so it is expecting as signature parameter a string like "transfer(address,uint)".

One option is to pass signature as string

  Contract.methods.executeTransactions(
    ["0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984"],//targets
    [0],//values
    ["transfer(address,uint)"],//signatures
    [web3.eth.abi.encodeParameters(["address", "uint"], ["0xC722A3F999983325c611e7E1D967a3c27063F8b0", 5000000000000000000000000])]//calldata

  ).send({from: accounts[0], gas: 5000000})