Aave aaveLendingPool.withdraw() return value validation

Question

I am writing a pull payment function and, as with any external call it is good practice validate the result and check successful execution. I am using the following interface:

    interface IAaveLendingPool {
    function deposit(
        address asset,
        uint256 amount,
        address onBehalfOf,
        uint16 referralCode
    ) external;

    function withdraw(
        address asset,
        uint256 amount,
        address to
    ) external;

    function getReservesList() external view returns (address[] memory);
}

aAveLendingPool= IAaveLendingPool(0x0543958349aAve_pooladdress)

The interface provided by Aave doesn't specify a return either. The withdraw function of the LendingPool.sol contract returns external override whenNotPaused returns (uint256).

The question: Can I use the returned uint to validate successful execution or aAveLendingPool.withdraw() returns a boolean? Will the following work as expected?

    ///@notice assigns dai to caller
    require( aaveLendingPool.withdraw(
                address(dai),
                amount,
                msg.sender), "Error, contract does not have enough DAI")

 

Please provide a solidity docs link to external function call return value, if any.

Answer 1

According to the Consensys Diligence Aave V2 audit:

ERC20 implementations are not always consistent. Some implementations of transfer and transferFrom could return ‘false’ on failure instead of reverting. It is safer to wrap such calls into require() statements to these failures.

Therefore, wrapping the transfer call in a require check is safe and sufficient.

require( aaveLendingPool.withdraw(
                address(dai),
                amount,
                msg.sender), "Error, contract does not have enough DAI")