Ethereum: Will upgrading a smart contract to inherit from a new base class cause potential storage conflicts with UUPS proxy pattern?

Ethereum: Will upgrading a smart contract to inherit from a new base class cause potential storage conflicts with the UUPS proxy pattern?

When building smart contracts for the Ethereum blockchain, developers must carefully consider the implications of upgrading a contract to inherit from a new base class. One such upgrade is to use the UUPS (Uniswap-Upgradeable) proxy pattern. In this article, we will explore whether upgrading a smart contract to inherit from a new base class will cause potential storage conflicts with the UUPS proxy pattern.

What is the UUPS proxy pattern?

The UUPS proxy pattern allows developers to create custom, reusable upgrade logic for their contracts. This pattern allows for the creation of upgrades that are more modular and flexible than traditional upgrades using UIMode. The UUPS proxy pattern provides several benefits, including:

• Improved Readability: The UUPS proxy pattern makes it easier to understand the contract upgrade logic.

• Increased flexibility: The UUPS proxy pattern allows developers to create upgrades that can be easily reused across different contracts.

Inheriting from a new base class

When upgrading a smart contract to inherit from a new base class, such as ERC20BurnableUpgradeable, you must consider the implications of using the UUPS proxy pattern. The UUPS proxy pattern is designed to work with upgrades that use traditional upgrade logic.

Potential storage conflicts

If an upgrade uses the UUPS proxy pattern and inherits from a new base class, it can cause potential storage conflicts. These conflicts can arise if the state of the contract is not managed properly or if there are data dependencies between different parts of the contract.

For example, consider the following code:

contract My contract is ERC20BurnableUpgradeable {
mapping(address => uint256) public totalSpent;
function addSpent(uint256 amount) internal {
// ...
totalSpent[msg.sender] += amount;
}
}

In this example, the addSpent function updates the totalSpent mapping using traditional upgrade logic. However, if another contract upgrades the same base class and uses the UUPS proxy pattern, this can cause a storage conflict with the original contract’s state.

Resolving storage conflicts

To resolve potential storage conflicts, developers can take several steps:

• Use UIMode instead: Instead of using the UUPS proxy pattern, developers can use traditional upgrade logic using UIMode. This approach is more flexible and allows for better control over the contract’s state.

• Use a different mapping: If necessary, developers can create a separate mapping to store additional data that is independent of the original mapping used by the UUPS proxy pattern.

Conclusion

Upgrading a smart contract to inherit from a new base class using the UUPS proxy pattern can introduce potential storage conflicts with traditional upgrade logic. By understanding these implications and taking steps to resolve storage conflicts, developers can build more flexible and scalable contracts for the Ethereum blockchain.

Recommendations

To avoid potential storage conflicts when upgrading to inherit from a new base class:

• Use UIMode instead: Consider using traditional upgrade logic instead of the UUPS proxy pattern.

• Create separate mappings

  

  : If necessary, create separate mappings to store additional data that is independent of the original mapping used by the UUPS proxy pattern.

By following these recommendations and understanding the implications of upgrading a contract to inherit from a new base class, developers can build more flexible and scalable contracts for the Ethereum blockchain.