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.

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 CheatcodesIssue 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)
    );

    Vm.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