Skip to content

startPrank

Signature

function startPrank(address msgSender) external;
function startPrank(address msgSender, bool delegateCall) external;
function startPrank(address msgSender, address txOrigin) external;
function startPrank(address msgSender, address txOrigin, bool delegateCall) external;

Description

  • startPrank(address msgSender): sets msg.sender for all subsequent calls until stopPrank is called.
  • startPrank(address msgSender, address txOrigin): sets msg.sender and tx.origin for all subsequent calls until stopPrank is called.
  • startPrank(address msgSender, bool delegateCall): if delegateCall value is true then sets msg.sender for all subsequent delegate calls until stopPrank is called.
  • startPrank(address msgSender, address txOrigin, bool delegateCall): if delegateCall value is true then sets msg.sender and tx.origin for all subsequent delegate calls until stopPrank is called.

ℹ️ Note

The delegate calls cannot be pranked from an EOA.

Examples

  • prank delegate call and record state diffs
contract ImplementationTest {
    uint public num;
    address public sender;
 
    function setNum(uint _num) public {
        num = _num;
    }
}
 
contract ProxyTest {
    uint public num;
    address public sender;
}
 
contract FoundryIssue is Script {
    function run() public {
        ProxyTest proxy = new ProxyTest();
        ImplementationTest impl = new ImplementationTest();
 
        vm.label(address(proxy), 'proxy');
        vm.label(address(impl), 'Impl');
 
        uint num = 42;
        vm.startPrank(address(proxy), true);
        vm.startStateDiffRecording();
        (bool successTwo,) = address(impl).delegatecall(abi.encodeWithSignature('setNum(uint256)', num));
 
        VmSafe.AccountAccess[] memory accountAccesses = vm.stopAndReturnStateDiff();
        console.log('accountAccesses.kind', uint8(accountAccesses[0].kind));
        console.log('accountAccesses.accessor', vm.getLabel(accountAccesses[0].accessor));
        console.log('accountAccesses.account', vm.getLabel(accountAccesses[0].account));
        console.logBytes(accountAccesses[0].data);
    }
}
== Logs ==
  accountAccesses.kind 1
  accountAccesses.accessor proxy
  accountAccesses.account Impl
  0xcd16ecbf000000000000000000000000000000000000000000000000000000000000002a

SEE ALSO

Forge Standard Library

startHoax, changePrank