Merge pull request #4 from AugustoL/add-proxy-proposal

Add ERC827 with proxy proposal

contracts/ERC827/proposals/ERC827AllowedCallbacksProxy.sol

@@ -0,0 +1,71 @@
+/* solium-disable security/no-low-level-calls */
+
+pragma solidity ^0.4.24;
+
+import "./ERC827TokenMockAllowedCallbacks.sol";
+
+/**
+ * @title ERC827AllowedCallbacksProxy
+ *
+ * @dev Proxy to forward tokens balance and allowance with arbitrary calls
+ */
+contract ERC827AllowedCallbacksProxy {
+
+  ERC827TokenAllowedCallbacks public token;
+
+  /**
+   * @dev Constructor
+   */
+  constructor(ERC827TokenAllowedCallbacks _token) public {
+    token = _token;
+    bytes4 makeCallSig = bytes4(keccak256('makeCall(address,bytes)'));
+    token.allowCallback(address(0), makeCallSig,
+      ERC827TokenAllowedCallbacks.FunctionType.Approve
+    );
+    token.allowCallback(address(0), makeCallSig,
+      ERC827TokenAllowedCallbacks.FunctionType.Transfer
+    );
+    token.allowCallback(address(0), makeCallSig,
+      ERC827TokenAllowedCallbacks.FunctionType.TransferFrom
+    );
+  }
+
+  /**
+   * @dev Fallback function that give back all tokens received
+   */
+  function() {
+    forwardTokens(msg.sender);
+  }
+
+  /**
+   * @dev Forward arbitary calls with token balance or allowance
+   * @param _target address The address which you want to transfer to
+   * @param _data bytes The data to be executed in the call
+   */
+  function makeCall(address _target, bytes _data) public returns (bool) {
+    require(msg.sender == address(token));
+
+    forwardTokens(_target);
+
+    // solium-disable-next-line security/no-call-value
+    return _target.call.value(msg.value)(_data);
+  }
+
+  /**
+   * @dev Give back all tokens balance and allowance to address
+   * @param to address The address which you want to transfer to
+   */
+  function forwardTokens(address to) internal {
+    uint256 callerBalance = token.balanceOf(address(this));
+    uint256 callerAllowance = token.allowance(to, address(this));
+
+    // Give back token balance
+    if (callerBalance > 0)
+      token.transfer(to, callerBalance);
+
+    // Give back token allowance
+    if (callerAllowance > 0)
+      token.transferFrom(address(this), to, callerAllowance);
+  }
+
+}

contracts/ERC827/proposals/ERC827Proxy.sol

@@ -2,7 +2,6 @@
 
 pragma solidity ^0.4.24;
 
-import "./ERC827TokenMockAllowedCallbacks.sol";
 
 /**
  * @title ERC827Proxy
@@ -11,61 +10,26 @@ import "./ERC827TokenMockAllowedCallbacks.sol";
  */
 contract ERC827Proxy {
 
-  ERC827TokenAllowedCallbacks public token;
+  address public token;
+  bytes4 public makeCallSig = bytes4(keccak256('makeCall(address,bytes)'));
 
   /**
-   * @dev Constructor
+   * @dev constructor
    */
-  constructor(ERC827TokenAllowedCallbacks _token) public {
-    token = _token;
-    bytes4 makeCallSig = bytes4(keccak256('makeCall(address,bytes)'));
-    token.allowCallback(address(0), makeCallSig,
-      ERC827TokenAllowedCallbacks.FunctionType.Approve
-    );
-    token.allowCallback(address(0), makeCallSig,
-      ERC827TokenAllowedCallbacks.FunctionType.Transfer
-    );
-    token.allowCallback(address(0), makeCallSig,
-      ERC827TokenAllowedCallbacks.FunctionType.TransferFrom
-    );
+  constructor() public {
+    token = address(msg.sender);
   }
 
   /**
-   * @dev Fallback function that give back all tokens received
-   */
-  function() {
-    forwardTokens(msg.sender);
-  }
-
-  /**
-   * @dev Forward arbitary calls with token balance or allowance
+   * @dev Forward arbitary calls
    * @param _target address The address which you want to transfer to
    * @param _data bytes The data to be executed in the call
    */
-  function makeCall(address _target, bytes _data) public returns (bool) {
+  function makeCall(address _target, bytes _data) public payable returns (bool) {
     require(msg.sender == address(token));
 
-    forwardTokens(_target);
-
     // solium-disable-next-line security/no-call-value
-    return _target.call.value(msg.value)(_data);
-  }
-
-  /**
-   * @dev Give back all tokens balance and allowance to address
-   * @param to address The address which you want to transfer to
-   */
-  function forwardTokens(address to) internal {
-    uint256 callerBalance = token.balanceOf(address(this));
-    uint256 callerAllowance = token.allowance(to, address(this));
-
-    // Give back token balance
-    if (callerBalance > 0)
-      token.transfer(to, callerBalance);
-
-    // Give back token allowance
-    if (callerAllowance > 0)
-      token.transferFrom(address(this), to, callerAllowance);
+    require(_target.call.value(msg.value)(_data));
   }
 
 }

contracts/ERC827/proposals/ERC827TokenWithProxy.sol

@@ -0,0 +1,191 @@
+/* solium-disable security/no-low-level-calls */
+
+pragma solidity ^0.4.24;
+
+import "../ERC827.sol";
+import "../../ERC20/StandardToken.sol";
+import "./ERC827Proxy.sol";
+
+/**
+ * @title ERC827, an extension of ERC20 token standard
+ *
+ * @dev Implementation the ERC827, following the ERC20 standard with extra
+ * methods to transfer value and data and execute calls in transfers and
+ * approvals. Uses OpenZeppelin StandardToken and ERC827Proxy.
+ */
+contract ERC827TokenWithProxy is ERC827, StandardToken {
+
+  ERC827Proxy public proxy;
+
+  /**
+   * @dev Constructor
+   */
+  constructor() public {
+    proxy = new ERC827Proxy();
+  }
+
+  /**
+   * @dev Addition to ERC20 token methods. It allows to
+   * approve the transfer of value and execute a call with the sent data.
+   * Beware that changing an allowance with this method brings the risk that
+   * someone may use both the old and the new allowance by unfortunate
+   * transaction ordering. One possible solution to mitigate this race condition
+   * is to first reduce the spender's allowance to 0 and set the desired value
+   * afterwards:
+   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
+   * @param _spender The address that will spend the funds.
+   * @param _value The amount of tokens to be spent.
+   * @param _data ABI-encoded contract call to call `_spender` address.
+   * @return true if the call function was executed successfully
+   */
+  function approveAndCall(
+    address _spender,
+    uint256 _value,
+    bytes _data
+  )
+    public
+    payable
+    returns (bool)
+  {
+    require(_spender != address(this));
+
+    super.approve(_spender, _value);
+
+    // solium-disable-next-line security/no-call-value
+    require(address(proxy).call.value(msg.value)(
+      abi.encodeWithSelector(proxy.makeCallSig(), _spender, _data))
+    );
+    return true;
+  }
+
+  /**
+   * @dev Addition to ERC20 token methods. Transfer tokens to a specified
+   * address and execute a call with the sent data on the same transaction
+   * @param _to address The address which you want to transfer to
+   * @param _value uint256 the amout of tokens to be transfered
+   * @param _data ABI-encoded contract call to call `_to` address.
+   * @return true if the call function was executed successfully
+   */
+  function transferAndCall(
+    address _to,
+    uint256 _value,
+    bytes _data
+  )
+    public
+    payable
+    returns (bool)
+  {
+    require(_to != address(this));
+
+    super.transfer(_to, _value);
+
+    // solium-disable-next-line security/no-call-value
+    require(address(proxy).call.value(msg.value)(
+      abi.encodeWithSelector(proxy.makeCallSig(), _to, _data))
+    );
+    return true;
+  }
+
+  /**
+   * @dev Addition to ERC20 token methods. Transfer tokens from one address to
+   * another and make a contract call on the same transaction
+   * @param _from The address which you want to send tokens from
+   * @param _to The address which you want to transfer to
+   * @param _value The amout of tokens to be transferred
+   * @param _data ABI-encoded contract call to call `_to` address.
+   * @return true if the call function was executed successfully
+   */
+  function transferFromAndCall(
+    address _from,
+    address _to,
+    uint256 _value,
+    bytes _data
+  )
+    public payable returns (bool)
+  {
+    require(_to != address(this));
+
+    super.transferFrom(_from, _to, _value);
+
+    // solium-disable-next-line security/no-call-value
+    require(address(proxy).call.value(msg.value)(
+      abi.encodeWithSelector(proxy.makeCallSig(), _to, _data))
+    );
+    return true;
+  }
+
+  /**
+   * @dev Addition to StandardToken methods. Increase the amount of tokens that
+   * an owner allowed to a spender and execute a call with the sent data.
+   * approve should be called when allowed[_spender] == 0. To increment
+   * allowed value is better to use this function to avoid 2 calls (and wait until
+   * the first transaction is mined)
+   * From MonolithDAO Token.sol
+   * @param _spender The address which will spend the funds.
+   * @param _addedValue The amount of tokens to increase the allowance by.
+   * @param _data ABI-encoded contract call to call `_spender` address.
+   */
+  function increaseApprovalAndCall(
+    address _spender,
+    uint _addedValue,
+    bytes _data
+  )
+    public
+    payable
+    returns (bool)
+  {
+    require(_spender != address(this));
+
+    super.increaseApproval(_spender, _addedValue);
+
+    // solium-disable-next-line security/no-call-value
+    require(address(proxy).call.value(msg.value)(
+      abi.encodeWithSelector(proxy.makeCallSig(), _spender, _data))
+    );
+    return true;
+  }
+
+  /**
+   * @dev Addition to StandardToken methods. Decrease the amount of tokens that
+   * an owner allowed to a spender and execute a call with the sent data.
+   * approve should be called when allowed[_spender] == 0. To decrement
+   * allowed value is better to use this function to avoid 2 calls (and wait until
+   * the first transaction is mined)
+   * From MonolithDAO Token.sol
+   * @param _spender The address which will spend the funds.
+   * @param _subtractedValue The amount of tokens to decrease the allowance by.
+   * @param _data ABI-encoded contract call to call `_spender` address.
+   */
+  function decreaseApprovalAndCall(
+    address _spender,
+    uint _subtractedValue,
+    bytes _data
+  )
+    public
+    payable
+    returns (bool)
+  {
+    require(_spender != address(this));
+
+    super.decreaseApproval(_spender, _subtractedValue);
+
+    // solium-disable-next-line security/no-call-value
+    require(address(proxy).call.value(msg.value)(
+      abi.encodeWithSelector(proxy.makeCallSig(), _spender, _data))
+    );
+    return true;
+  }
+
+}
+
+// mock class using ERC827 Token with proxy
+contract ERC827TokenWithProxyMock is ERC827TokenWithProxy {
+
+  constructor(
+    address initialAccount, uint256 initialBalance
+  ) public {
+    balances[initialAccount] = initialBalance;
+    totalSupply_ = initialBalance;
+  }
+
+}

test/proposals/ERC827Proxy.js → test/proposals/AllowedCallbacksProxy.js

@@ -2,7 +2,7 @@
 import EVMRevert from '../helpers/EVMRevert';
 var Message = artifacts.require('./mocks/MessageHelper');
 var ERC827TokenMock = artifacts.require('./ERC827/proposals/ERC827TokenMockAllowedCallbacks');
-var ERC827Proxy = artifacts.require('./ERC827/proposals/ERC827Proxy');
+var ERC827AllowedCallbacksProxy = artifacts.require('./ERC827/proposals/ERC827AllowedCallbacksProxy');
 
 var BigNumber = web3.BigNumber;
 require('chai')
@@ -23,8 +23,8 @@ contract('ERC827 Proxy for allowed callbacks', function (accounts) {
     token = await ERC827TokenMock.new(accounts[0], 100);
   });
 
-  it('should forward token balance correctly with ERC827Proxy', async function () {
-    let proxy = await ERC827Proxy.new(token.address);
+  it('should forward token balance correctly with ERC827AllowedCallbacksProxy', async function () {
+    let proxy = await ERC827AllowedCallbacksProxy.new(token.address);
 
     let makeCallData = proxy.contract.makeCall.getData(message.address, messageData);
     let makeCallSig = makeCallData.substring(0, 10);