Create an interactive adapter

To create new token adapter, one has to implement InteractiveAdapter interface. It inherits ProtocolAdapter, so one has to implement it, too.

InteractiveAdapters should implement 2 main functions: deposit() and withdraw().

function deposit(TokenAmount[] calldata tokenAmounts, bytes calldata data)
        external
        payable
        override
        returns (address[] memory tokensToBeWithdrawn)

tokenAmounts — tokens that will be used in the action (e.g. DAI in case of deposit to Compound).

Usually, tokenAmounts are decomposed in token and amount like that:

address token = tokenAmounts[0].token;
uint256 amount = getAbsoluteAmountDeposit(tokenAmounts[0]);

If tokens are required to be approved, use the following function:

ERC20(token).safeApproveMax(APPROVE_RECEIVER, amount, ABBR_OF_NAME);

Get additional data (e.g. user address or the desired derivative address) required for the interaction from bytes data using abi.decode like that:

address userAddress = abi.decode(data, (address));

Interact with the protocol using try-catch syntax:

try
    Interface(callee).foo{ value: value }(arg1, arg2)
returns (returntype1, returntype2) {} catch Error(string memory reason) {
    // solhint-disable-previous-line no-empty-blocks
    revert(reason);
} catch {
    revert("ABBR_OF_NAME: deposit fail");
}

Fill in tokensToBeWithdrawn array. It should consist of tokens returning to the user (e.g. cDAI in case of deposit to Compound).

Remove names of unused arguments.

Use npx prettier ./contracts/**/*.sol --write to fix linter issues.

Add tests for interactions it test/ directory, use Uniswap, Weth, and other required adapters.