update cPool

.travis.yml

@@ -1,14 +0,0 @@
-dist: trusty
-language: node_js
-node_js:
-  - '11'
-install:
-  - npm ci
-  - cp .env.example .env
-  - travis_wait 30 npm run build
-  - npx ganache-cli > /dev/null &
-  - npm run migrate:dev
-script:
-  - npm run test
-  - npm run eslint
-  - node cli.js test

contracts/ERC20Tornado.sol

@@ -13,23 +13,26 @@
 pragma solidity ^0.6.0;
 
 import "./Tornado.sol";
+import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
 
 contract ERC20Tornado is Tornado {
-  address public token;
+  using SafeERC20 for IERC20;
+  IERC20 public immutable token;
 
   constructor(
     IVerifier _verifier,
     IHasher _hasher,
     uint256 _denomination,
     uint32 _merkleTreeHeight,
-    address _token
+    IERC20 _token
   ) public Tornado(_verifier, _hasher, _denomination, _merkleTreeHeight) {
     token = _token;
   }
 
   function _processDeposit() internal override {
     require(msg.value == 0, "ETH value is supposed to be 0 for ERC20 instance");
-    _safeErc20TransferFrom(msg.sender, address(this), denomination);
+    token.safeTransferFrom(msg.sender, address(this), denomination);
   }
 
   function _processWithdraw(
@@ -40,9 +43,9 @@ contract ERC20Tornado is Tornado {
   ) internal override {
     require(msg.value == _refund, "Incorrect refund amount received by the contract");
 
-    _safeErc20Transfer(_recipient, denomination - _fee);
+    token.safeTransfer(_recipient, denomination - _fee);
     if (_fee > 0) {
-      _safeErc20Transfer(_relayer, _fee);
+      token.safeTransfer(_relayer, _fee);
     }
 
     if (_refund > 0) {
@@ -53,47 +56,4 @@ contract ERC20Tornado is Tornado {
       }
     }
   }
-
-  function _safeErc20TransferFrom(
-    address _from,
-    address _to,
-    uint256 _amount
-  ) internal {
-    (bool success, bytes memory data) =
-      token.call(
-        abi.encodeWithSelector(
-          0x23b872dd, /* transferFrom */
-          _from,
-          _to,
-          _amount
-        )
-      );
-    require(success, "not enough allowed tokens");
-
-    // if contract returns some data lets make sure that is `true` according to standard
-    if (data.length > 0) {
-      require(data.length == 32, "data length should be either 0 or 32 bytes");
-      success = abi.decode(data, (bool));
-      require(success, "not enough allowed tokens. Token returns false.");
-    }
-  }
-
-  function _safeErc20Transfer(address _to, uint256 _amount) internal {
-    (bool success, bytes memory data) =
-      token.call(
-        abi.encodeWithSelector(
-          0xa9059cbb, /* transfer */
-          _to,
-          _amount
-        )
-      );
-    require(success, "not enough tokens");
-
-    // if contract returns some data lets make sure that is `true` according to standard
-    if (data.length > 0) {
-      require(data.length == 32, "data length should be either 0 or 32 bytes");
-      success = abi.decode(data, (bool));
-      require(success, "not enough tokens. Token returns false.");
-    }
-  }
 }

contracts/cPool.sol

@@ -12,28 +12,27 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.6.0;
 
-interface IComptroller {
+import "./ERC20Tornado.sol";
-    function claimComp(address holder) external;
+import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
-}
 
-interface IComptroller {
+contract cPool is ERC20Tornado {
-    function transfer(address dst, uint rawAmount) external returns (bool);
-    function balanceOf(address owner) external;
-}
-
-contract ERC20Tornado is Tornado {
-  IComptroller public comptroller;
   address public immutable governance = 0x5efda50f22d34F262c29268506C5Fa42cB56A1Ce;
-  ICOMP public immutable COMP = 0xc00e94Cb662C3520282E6f5717214004A7f26888;
+  IERC20 public immutable comp;
 
-  constructor(IComptroller _comptroller, ICOMP _comp) public {
+  constructor(
-    comptroller = _comptroller;
+    IERC20 _comp,
-    COMP = _comp;
+    IVerifier _verifier,
+    IHasher _hasher,
+    uint256 _denomination,
+    uint32 _merkleTreeHeight,
+    IERC20 _token
+  ) ERC20Tornado(_verifier, _hasher, _denomination, _merkleTreeHeight, _token) public {
+    comp = _comp;
   }
 
-  function moveYeild() {
+  /// @dev Moves earned yield of the COMP token to the tornado governance contract
-    comp.claimComp(address(this));
+  /// To make it work you may need to call `comptroller.claimComp(cPoolAddress)` before
-    uint balance = COMP.balanceOf(address(this));
+  function claimComp() external {
-    COMP.transfer(governance, balance);
+    comp.transfer(governance, comp.balanceOf(address(this)));
   }
 }