DefiRound Code Style Findings

DRD-01C: Data Location Optimization

Description:

The linked function is declared as external yet possesses a memory argument.

Example:

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192function getRates(address[] memory tokens) external view override returns (RateData[] memory rates) {
193    uint256 tokensLength = tokens.length;
194    rates = new RateData[](tokensLength);
195    for (uint256 i = 0; i < tokensLength; i++) {
196        rates[i] = tokenRates[tokens[i]];
197    }
198}

Recommendation:

We advise it to be set to calldata greatly optimizing the function's gas cost.

Alleviation:

The tokens member of getRates was set to calldata optimizing the codebase.

DRD-02C: Ineffectual Statement

Description:

The comment above the tokenAccountData assignment denotes that updates are not saved if the struct is not assigned to the mapping which is false as the tokenAccountData is declared as storage rather than memory.

Example:

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81AccountData storage tokenAccountData = accountData[msg.sender];
82
83if (tokenAccountData.token == address(0)) {
84    tokenAccountData.token = token;
85}
86
87require(tokenAccountData.token == token, "SINGLE_ASSET_DEPOSITS") ;
88
89tokenAccountData.initialDeposit = tokenAccountData.initialDeposit.add(tokenAmount);
90tokenAccountData.currentBalance = tokenAccountData.currentBalance.add(tokenAmount);
91
92require(tokenAccountData.currentBalance <= tokenSettings[token].maxLimit, "MAX_LIMIT_EXCEEDED");
93
94// set the data back in the mapping, otherwise updates are not saved
95accountData[msg.sender] = tokenAccountData;

Recommendation:

We advise either the struct to be declared as memory or the assignment to be omitted entirely as changes are reflected to the underlying struct when the storage attribute is specified in the in-memory declaration.

Alleviation:

The assignment was safely omitted from the codebase along with its accompanying comment.

DRD-03C: Redundant Assignment

Description:

All variables in Solidity are initialized to a default value which in most cases is equivalent to the "0" of the respective type.

Example:

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221function accountBalance(address account) external view override returns (uint256 value) {
222    value = 0;
223    uint256 tokenBalance = accountData[account].currentBalance;
224    value = value.add(getTokenValue(accountData[account].token, tokenBalance));   
225}

Recommendation:

We advise the linked assignment to be omitted from the codebase safely as it is ineffectual.

Alleviation:

The redundant assignment was safely omitted from the codebase.

DRD-04C: Variable Mutability Specifiers

Description:

The linked variables are assigned to only once during the contract's constructor.

Example:

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48constructor(
49    // solhint-disable-next-line
50    address _WETH,
51    address _treasury,
52    uint256 _maxTotalValue
53) public {
54    WETH = _WETH;
55    treasury = _treasury;
56    currentStage = STAGES.STAGE_1;
57    
58    maxTotalValue = _maxTotalValue;
59}

Recommendation:

We advise them to be set as immutable greatly optimizing their gas cost.

Alleviation:

Both variables were properly set to immutable greatly optimizing the codebase.