Sorry the delay replying...
Right now the code uses a rollback test to verify the new implementation has upgrade capabilities.
/**
* @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
*
* Emits an {Upgraded} event.
*/
function _upgradeToAndCallSecure(
address newImplementation,
bytes memory data,
bool forceCall
) internal {
address oldImplementation = _getImplementation();
// Initial upgrade and setup call
_setImplementation(newImplementation);
if (data.length > 0 || forceCall) {
_functionDelegateCall(newImplementation, data);
}
// Perform rollback test if not already in progress
StorageSlotUpgradeable.BooleanSlot storage rollbackTesting = StorageSlotUpgradeable.getBooleanSlot(_ROLLBACK_SLOT);
if (!rollbackTesting.value) {
// Trigger rollback using upgradeTo from the new implementation
rollbackTesting.value = true;
_functionDelegateCall(
newImplementation,
abi.encodeWithSignature("upgradeTo(address)", oldImplementation)
);
rollbackTesting.value = false;
// Check rollback was effective
require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
// Finally reset to the new implementation and log the upgrade
_upgradeTo(newImplementation);
}
}
I'm not sure if this can be better replaced with supportsInterface(IUUPSUpgradreable), but anyway having that interface and supporting ERC165 in UUPSUpgradeable will help to recognize if the implementation contract has upgrade capabilities or not.