Foundry Book

copyStorage

Signature

function copyStorage(address from, address to) external;

Description

Utility cheatcode to copy storage of from contract to another to contract. Cheatcode is not allowed if the target address has arbitrary storage set.

Examples

Given a contract

contract Counter {
    uint256 public count;

    function setCount(uint256 x) public {
        count = x;
    }
}

using copyStorage cheatcode copies the storage set on an instance to another address:

function testCopyStorage() public {
    Counter original = new Counter();
    original.setCount(1000);
    Counter copy = new Counter();
    copy.setCount(1);
    // Check initial count on copy.
    assertEq(copy.count(), 1);

    vm.copyStorage(address(original), address(copy));
    // Value is copied from first contract to copy.
    assertEq(copy.count(), 1000);
}