Use short circuiting can save gas

[code423n4]

Handle

WatchPug

Vulnerability details

When tokenAddress == address(0), it's unnecessary to create the variable token as it will not be used.

Furthermore, since the variable token is only used in one place, making it inline will make the code simpler.

https://github.com/code-423n4/2021-10-union/blob/4176c366986e6d1a6b3f6ec0079ba547b040ac0f/contracts/asset/PureTokenAdapter.sol#L90-L93

function _supportsToken(address tokenAddress) internal view returns (bool) {
    IERC20Upgradeable token = IERC20Upgradeable(tokenAddress);
    return tokenAddress != address(0) && token.balanceOf(address(this)) >= 0; // simple check if the token is ERC20 compatible
}

Recommendation

Change to:

function _supportsToken(address tokenAddress) internal view returns (bool) {
    return tokenAddress != address(0) && IERC20Upgradeable(tokenAddress).balanceOf(address(this)) >= 0; // simple check if the token is ERC20 compatible
}

[GalloDaSballo]

Agree with the finding