Gas Optimizations

[code423n4]

[G-01] ++variable costs less gas than variable++, especially in for loops

Saves about 5 gas per loop.

File: contracts/Project.sol
248: for (uint256 i = 0; i < _length; i++) {

603: for (; i < _changeOrderedTask.length; i++) {

625: _loopCount++;

710: for (uint256 _taskID = 1; _taskID <= _length; _taskID++) {

https://github.com/code-423n4/2022-08-rigor/blob/main/contracts/Project.sol

[G-02] The increment in for loop post condition can be made unchecked

The solidity compiler will apply arithmetic checks for the increment step during for loops. This can be disabled since the value being incremented won't surpass the upper bound that's checked on the break condition.

Adding uncheck can save 30-40 gas per loop.

File: contracts/Project.sol
248: for (uint256 i = 0; i < _length; i++) {

603: for (; i < _changeOrderedTask.length; i++) {

710: for (uint256 _taskID = 1; _taskID <= _length; _taskID++) {

https://github.com/code-423n4/2022-08-rigor/blob/main/contracts/Project.sol

[G-03] Array.length should not be computed on every interation during a loop

Instead of computing array.length for every iteration, the value for array.length should be cached before the loop to save gas.

File: contracts/Project.sol
603: for (; i < _changeOrderedTask.length; i++) {

https://github.com/code-423n4/2022-08-rigor/blob/main/contracts/Project.sol

[G-04] It costs more gas to initialize variables to zero than to let the default of zero be applied

File: contracts/Project.sol
248: for (uint256 i = 0; i < _length; i++) {

https://github.com/code-423n4/2022-08-rigor/blob/main/contracts/Project.sol

[G-05] != costs less gas than > in conditional contexts for uints

Saves about 6 gas.

File: contracts/Project.sol
195: require(_cost > 0, "Project::!value>0");

691: if (_loopCount > 0) emit TaskAllocated(_tasksAllocated);

https://github.com/code-423n4/2022-08-rigor/blob/main/contracts/Project.sol

[G-06] Use custom errors rather than revert()/require() to save gas

File: contracts/Project.sol
123: require(!contractorConfirmed, "Project::GC accepted");

132: require(_projectAddress == address(this), "Project::!projectAddress");

https://github.com/code-423n4/2022-08-rigor/blob/main/contracts/Project.sol

File: contracts/Community.sol
69: require(_address != address(0), "Community::0 address");

75: require(_msgSender() == homeFi.admin(), "Community::!admin");

81: require(

https://github.com/code-423n4/2022-08-rigor/blob/main/contracts/Community.sol

File: contracts/HomeFi.sol
142: require(!addrSet, "HomeFi::Set");

191: require(lenderFee != _newLenderFee, "HomeFi::!Change");

https://github.com/code-423n4/2022-08-rigor/blob/main/contracts/HomeFi.sol