upgrade-safety

To check storage layout compatibility before upgrading a Solidity proxy contract, diff storage layouts across versions to prevent state corruption. This involves verifying storage gaps and ensuring no existing variable orders are modified.

If a Solidity proxy initializer is uninitialized during an upgrade, the contract becomes vulnerable to unauthorized state manipulation. You must enforce safe initialization checks during deployment and upgrades to mitigate this critical risk.

To prevent selector collisions in a Solidity Diamond proxy, check for function selector clashes across facets. Verifying these clashes ensures safe upgrades and prevents routing calls to unintended functions.

OpenZeppelin tooling supports validating UUPS and Transparent proxy upgrades by providing standard patterns for upgrade authorization checks. Integrating this tooling helps validate storage layouts and enforce secure upgrade hooks.

You need _authorizeUpgrade checks in a UUPS proxy contract to restrict upgrade authorization to privileged accounts. Implementing these hooks ensures safe upgrades and prevents unauthorized modification of the contract logic.