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 need to carefully consider the implications of upgrading a contract to inherit from a new base class. One such innovation is the use of 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 their own, reusable upgrade logic for their contracts. This pattern allows them to create 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.

• More 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 need to consider the implications of using the UUPS proxy pattern. The UUPS proxy pattern is designed to work with updates that use traditional update logic.

Potential storage conflicts

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

For example, consider the following code:

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

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

Overcoming storage conflicts

There are several steps that developers can take to overcome potential storage conflicts:

• Use UIMode instead: Instead of using the UUPS proxy pattern, developers can use traditional update 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 update logic. By understanding these implications and taking steps to overcome storage conflicts, developers can create 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 update logic instead of the UUPS proxy pattern.

• Create separate mappings: If necessary, create separate mappings to store additional data that are not dependent on 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 create more flexible and scalable contracts for the Ethereum blockchain.