Merge pull request #518 from AugustoL/add-smart-token

Add ERC827 Token

contracts/mocks/ERC827TokenMock.sol

@@ -0,0 +1,15 @@
+pragma solidity ^0.4.13;
+
+
+import "../token/ERC827Token.sol";
+
+
+// mock class using ERC827 Token
+contract ERC827TokenMock is ERC827Token {
+
+  function ERC827TokenMock(address initialAccount, uint256 initialBalance) public {
+    balances[initialAccount] = initialBalance;
+    totalSupply = initialBalance;
+  }
+
+}

contracts/mocks/MessageHelper.sol

@@ -0,0 +1,23 @@
+pragma solidity ^0.4.11;
+
+contract MessageHelper {
+
+  event Show(bytes32 b32, uint256 number, string text);
+
+  function showMessage( bytes32 message, uint256 number, string text ) public returns (bool) {
+    Show(message, number, text);
+    return true;
+  }
+
+  function fail() public {
+    require(false);
+  }
+
+  function call(address to, bytes data) public returns (bool) {
+    if (to.call(data))
+      return true;
+    else
+      return false;
+  }
+
+}

contracts/token/ERC827.sol

@@ -0,0 +1,20 @@
+pragma solidity ^0.4.13;
+
+
+import "./ERC20.sol";
+
+
+/**
+   @title ERC827 interface, an extension of ERC20 token standard
+
+   Interface of a ERC827 token, following the ERC20 standard with extra
+   methods to transfer value and data and execute calls in transfers and
+   approvals.
+ */
+contract ERC827 is ERC20 {
+
+  function approve( address _spender, uint256 _value, bytes _data ) public returns (bool);
+  function transfer( address _to, uint256 _value, bytes _data ) public returns (bool);
+  function transferFrom( address _from, address _to, uint256 _value, bytes _data ) public returns (bool);
+
+}

contracts/token/ERC827Token.sol

@@ -0,0 +1,126 @@
+pragma solidity ^0.4.13;
+
+import "./ERC827.sol";
+import "./StandardToken.sol";
+
+/**
+   @title ERC827, an extension of ERC20 token standard
+
+   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.
+ */
+contract ERC827Token is ERC827, StandardToken {
+
+  /**
+     @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 `_to` address.
+
+     @return true if the call function was executed successfully
+   */
+  function approve(address _spender, uint256 _value, bytes _data) public returns (bool) {
+    require(_spender != address(this));
+
+    super.approve(_spender, _value);
+
+    require(_spender.call(_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 transfer(address _to, uint256 _value, bytes _data) public returns (bool) {
+    require(_to != address(this));
+
+    super.transfer(_to, _value);
+
+    require(_to.call(_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 transferFrom(address _from, address _to, uint256 _value, bytes _data) public returns (bool) {
+    require(_to != address(this));
+
+    super.transferFrom(_from, _to, _value);
+
+    require(_to.call(_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 increaseApproval(address _spender, uint _addedValue, bytes _data) public returns (bool) {
+    require(_spender != address(this));
+
+    super.increaseApproval(_spender, _addedValue);
+
+    require(_spender.call(_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 decreaseApproval(address _spender, uint _subtractedValue, bytes _data) public returns (bool) {
+    require(_spender != address(this));
+
+    super.decreaseApproval(_spender, _subtractedValue);
+
+    require(_spender.call(_data));
+
+    return true;
+  }
+
+}

package.json

@@ -56,6 +56,7 @@
     "truffle-hdwallet-provider": "0.0.3"
   },
   "dependencies": {
-    "dotenv": "^4.0.0"
+    "dotenv": "^4.0.0",
+    "ethjs-abi": "^0.2.1"
   }
 }

test/ERC827Token.js

@@ -0,0 +1,374 @@
+
+import EVMRevert from './helpers/EVMRevert';
+var Message = artifacts.require('./mock/MessageHelper.sol');
+var ERC827TokenMock = artifacts.require('./mock/ERC827TokenMock.sol');
+
+var BigNumber = web3.BigNumber;
+var _ = require('lodash');
+var ethjsABI = require('ethjs-abi');
+require('chai')
+  .use(require('chai-as-promised'))
+  .use(require('chai-bignumber')(BigNumber))
+  .should();
+
+contract('ERC827 Token', function (accounts) {
+  let token;
+
+  function findMethod (abi, name, args) {
+    for (var i = 0; i < abi.length; i++) {
+      const methodArgs = _.map(abi[i].inputs, 'type').join(',');
+      if ((abi[i].name === name) && (methodArgs === args)) {
+        return abi[i];
+      }
+    }
+  }
+
+  beforeEach(async function () {
+    token = await ERC827TokenMock.new(accounts[0], 100);
+  });
+
+  it('should return the correct totalSupply after construction', async function () {
+    let totalSupply = await token.totalSupply();
+
+    assert.equal(totalSupply, 100);
+  });
+
+  it('should return the correct allowance amount after approval', async function () {
+    let token = await ERC827TokenMock.new();
+    await token.approve(accounts[1], 100);
+    let allowance = await token.allowance(accounts[0], accounts[1]);
+
+    assert.equal(allowance, 100);
+  });
+
+  it('should return correct balances after transfer', async function () {
+    await token.transfer(accounts[1], 100);
+    let balance0 = await token.balanceOf(accounts[0]);
+    assert.equal(balance0, 0);
+
+    let balance1 = await token.balanceOf(accounts[1]);
+    assert.equal(balance1, 100);
+  });
+
+  it('should throw an error when trying to transfer more than balance', async function () {
+    await token.transfer(accounts[1], 101).should.be.rejectedWith(EVMRevert);
+  });
+
+  it('should return correct balances after transfering from another account', async function () {
+    await token.approve(accounts[1], 100);
+    await token.transferFrom(accounts[0], accounts[2], 100, { from: accounts[1] });
+
+    let balance0 = await token.balanceOf(accounts[0]);
+    assert.equal(balance0, 0);
+
+    let balance1 = await token.balanceOf(accounts[2]);
+    assert.equal(balance1, 100);
+
+    let balance2 = await token.balanceOf(accounts[1]);
+    assert.equal(balance2, 0);
+  });
+
+  it('should throw an error when trying to transfer more than allowed', async function () {
+    await token.approve(accounts[1], 99);
+    await token.transferFrom(
+      accounts[0], accounts[2], 100,
+      { from: accounts[1] }
+    ).should.be.rejectedWith(EVMRevert);
+  });
+
+  it('should throw an error when trying to transferFrom more than _from has', async function () {
+    let balance0 = await token.balanceOf(accounts[0]);
+    await token.approve(accounts[1], 99);
+    await token.transferFrom(
+      accounts[0], accounts[2], balance0 + 1,
+      { from: accounts[1] }
+    ).should.be.rejectedWith(EVMRevert);
+  });
+
+  describe('validating allowance updates to spender', function () {
+    let preApproved;
+
+    it('should start with zero', async function () {
+      preApproved = await token.allowance(accounts[0], accounts[1]);
+      assert.equal(preApproved, 0);
+    });
+
+    it('should increase by 50 then decrease by 10', async function () {
+      const abiMethod = findMethod(token.abi, 'increaseApproval', 'address,uint256');
+      const increaseApprovalData = ethjsABI.encodeMethod(abiMethod,
+        [accounts[1], 50]
+      );
+      await token.sendTransaction(
+        { from: accounts[0], data: increaseApprovalData }
+      );
+      let postIncrease = await token.allowance(accounts[0], accounts[1]);
+      preApproved.plus(50).should.be.bignumber.equal(postIncrease);
+      await token.decreaseApproval(accounts[1], 10);
+      let postDecrease = await token.allowance(accounts[0], accounts[1]);
+      postIncrease.minus(10).should.be.bignumber.equal(postDecrease);
+    });
+  });
+
+  it('should increase by 50 then set to 0 when decreasing by more than 50', async function () {
+    await token.approve(accounts[1], 50);
+    await token.decreaseApproval(accounts[1], 60);
+    let postDecrease = await token.allowance(accounts[0], accounts[1]);
+    postDecrease.should.be.bignumber.equal(0);
+  });
+
+  it('should throw an error when trying to transfer to 0x0', async function () {
+    await token.transfer(0x0, 100).should.be.rejectedWith(EVMRevert);
+  });
+
+  it('should throw an error when trying to transferFrom to 0x0', async function () {
+    await token.approve(accounts[1], 100);
+    await token.transferFrom(accounts[0], 0x0, 100, { from: accounts[1] })
+      .should.be.rejectedWith(EVMRevert);
+  });
+
+  describe('Test ERC827 methods', function () {
+    it(
+      'should return correct balances after transfer (with data) and show the event on receiver contract'
+      , async function () {
+        const message = await Message.new();
+
+        const extraData = message.contract.showMessage.getData(
+          web3.toHex(123456), 666, 'Transfer Done'
+        );
+        const abiMethod = findMethod(token.abi, 'transfer', 'address,uint256,bytes');
+        const transferData = ethjsABI.encodeMethod(abiMethod,
+          [message.contract.address, 100, extraData]
+        );
+        const transaction = await token.sendTransaction(
+          { from: accounts[0], data: transferData }
+        );
+
+        assert.equal(2, transaction.receipt.logs.length);
+
+        new BigNumber(100).should.be.bignumber.equal(
+          await token.balanceOf(message.contract.address)
+        );
+      });
+
+    it(
+      'should return correct allowance after approve (with data) and show the event on receiver contract'
+      , async function () {
+        const message = await Message.new();
+
+        const extraData = message.contract.showMessage.getData(
+          web3.toHex(123456), 666, 'Transfer Done'
+        );
+
+        const abiMethod = findMethod(token.abi, 'approve', 'address,uint256,bytes');
+        const approveData = ethjsABI.encodeMethod(abiMethod,
+          [message.contract.address, 100, extraData]
+        );
+        const transaction = await token.sendTransaction(
+          { from: accounts[0], data: approveData }
+        );
+
+        assert.equal(2, transaction.receipt.logs.length);
+
+        new BigNumber(100).should.be.bignumber.equal(
+          await token.allowance(accounts[0], message.contract.address)
+        );
+      });
+
+    it(
+      'should return correct allowance after increaseApproval (with data) and show the event on receiver contract'
+      , async function () {
+        const message = await Message.new();
+
+        const extraData = message.contract.showMessage.getData(
+          web3.toHex(123456), 666, 'Transfer Done'
+        );
+
+        await token.approve(message.contract.address, 10);
+        new BigNumber(10).should.be.bignumber.equal(
+          await token.allowance(accounts[0], message.contract.address)
+        );
+
+        const abiMethod = findMethod(token.abi, 'increaseApproval', 'address,uint256,bytes');
+        const increaseApprovalData = ethjsABI.encodeMethod(abiMethod,
+          [message.contract.address, 50, extraData]
+        );
+        const transaction = await token.sendTransaction(
+          { from: accounts[0], data: increaseApprovalData }
+        );
+
+        assert.equal(2, transaction.receipt.logs.length);
+
+        new BigNumber(60).should.be.bignumber.equal(
+          await token.allowance(accounts[0], message.contract.address)
+        );
+      });
+
+    it(
+      'should return correct allowance after decreaseApproval (with data) and show the event on receiver contract'
+      , async function () {
+        const message = await Message.new();
+
+        await token.approve(message.contract.address, 100);
+
+        new BigNumber(100).should.be.bignumber.equal(
+          await token.allowance(accounts[0], message.contract.address)
+        );
+
+        const extraData = message.contract.showMessage.getData(
+          web3.toHex(123456), 666, 'Transfer Done'
+        );
+
+        const abiMethod = findMethod(token.abi, 'decreaseApproval', 'address,uint256,bytes');
+        const decreaseApprovalData = ethjsABI.encodeMethod(abiMethod,
+          [message.contract.address, 60, extraData]
+        );
+        const transaction = await token.sendTransaction(
+          { from: accounts[0], data: decreaseApprovalData }
+        );
+
+        assert.equal(2, transaction.receipt.logs.length);
+
+        new BigNumber(40).should.be.bignumber.equal(
+          await token.allowance(accounts[0], message.contract.address)
+        );
+      });
+
+    it(
+      'should return correct balances after transferFrom (with data) and show the event on receiver contract'
+      , async function () {
+        const message = await Message.new();
+
+        const extraData = message.contract.showMessage.getData(
+          web3.toHex(123456), 666, 'Transfer Done'
+        );
+
+        await token.approve(accounts[1], 100, { from: accounts[0] });
+
+        new BigNumber(100).should.be.bignumber.equal(
+          await token.allowance(accounts[0], accounts[1])
+        );
+
+        const abiMethod = findMethod(token.abi, 'transferFrom', 'address,address,uint256,bytes');
+        const transferFromData = ethjsABI.encodeMethod(abiMethod,
+          [accounts[0], message.contract.address, 100, extraData]
+        );
+        const transaction = await token.sendTransaction(
+          { from: accounts[1], data: transferFromData }
+        );
+
+        assert.equal(2, transaction.receipt.logs.length);
+
+        new BigNumber(100).should.be.bignumber.equal(
+          await token.balanceOf(message.contract.address)
+        );
+      });
+
+    it('should fail inside approve (with data)', async function () {
+      const message = await Message.new();
+
+      const extraData = message.contract.fail.getData();
+
+      const abiMethod = findMethod(token.abi, 'approve', 'address,uint256,bytes');
+      const approveData = ethjsABI.encodeMethod(abiMethod,
+        [message.contract.address, 10, extraData]
+      );
+      await token.sendTransaction(
+        { from: accounts[0], data: approveData }
+      ).should.be.rejectedWith(EVMRevert);
+
+      // approval should not have gone through so allowance is still 0
+      new BigNumber(0).should.be.bignumber
+        .equal(await token.allowance(accounts[1], message.contract.address));
+    });
+
+    it('should fail inside transfer (with data)', async function () {
+      const message = await Message.new();
+
+      const extraData = message.contract.fail.getData();
+
+      const abiMethod = findMethod(token.abi, 'transfer', 'address,uint256,bytes');
+      const transferData = ethjsABI.encodeMethod(abiMethod,
+        [message.contract.address, 10, extraData]
+      );
+      await token.sendTransaction(
+        { from: accounts[0], data: transferData }
+      ).should.be.rejectedWith(EVMRevert);
+
+      // transfer should not have gone through, so balance is still 0
+      new BigNumber(0).should.be.bignumber
+        .equal(await token.balanceOf(message.contract.address));
+    });
+
+    it('should fail inside transferFrom (with data)', async function () {
+      const message = await Message.new();
+
+      const extraData = message.contract.fail.getData();
+
+      await token.approve(accounts[1], 10, { from: accounts[2] });
+
+      const abiMethod = findMethod(token.abi, 'transferFrom', 'address,address,uint256,bytes');
+      const transferFromData = ethjsABI.encodeMethod(abiMethod,
+        [accounts[2], message.contract.address, 10, extraData]
+      );
+      await token.sendTransaction(
+        { from: accounts[1], data: transferFromData }
+      ).should.be.rejectedWith(EVMRevert);
+
+      // transferFrom should have failed so balance is still 0 but allowance is 10
+      new BigNumber(10).should.be.bignumber
+        .equal(await token.allowance(accounts[2], accounts[1]));
+      new BigNumber(0).should.be.bignumber
+        .equal(await token.balanceOf(message.contract.address));
+    });
+
+    it('should fail approve (with data) when using token contract address as receiver', async function () {
+      const message = await Message.new();
+
+      const extraData = message.contract.showMessage.getData(
+        web3.toHex(123456), 666, 'Transfer Done'
+      );
+
+      const abiMethod = findMethod(token.abi, 'approve', 'address,uint256,bytes');
+      const approveData = ethjsABI.encodeMethod(abiMethod,
+        [token.contract.address, 100, extraData]
+      );
+      await token.sendTransaction(
+        { from: accounts[0], data: approveData }
+      ).should.be.rejectedWith(EVMRevert);
+    });
+
+    it('should fail transfer (with data) when using token contract address as receiver', async function () {
+      const message = await Message.new();
+
+      const extraData = message.contract.showMessage.getData(
+        web3.toHex(123456), 666, 'Transfer Done'
+      );
+
+      const abiMethod = findMethod(token.abi, 'transfer', 'address,uint256,bytes');
+      const transferData = ethjsABI.encodeMethod(abiMethod,
+        [token.contract.address, 100, extraData]
+      );
+      await token.sendTransaction(
+        { from: accounts[0], data: transferData }
+      ).should.be.rejectedWith(EVMRevert);
+    });
+
+    it('should fail transferFrom (with data) when using token contract address as receiver', async function () {
+      const message = await Message.new();
+
+      const extraData = message.contract.showMessage.getData(
+        web3.toHex(123456), 666, 'Transfer Done'
+      );
+
+      await token.approve(accounts[1], 1, { from: accounts[0] });
+
+      const abiMethod = findMethod(token.abi, 'transferFrom', 'address,address,uint256,bytes');
+      const transferFromData = ethjsABI.encodeMethod(abiMethod,
+        [accounts[0], token.contract.address, 1, extraData]
+      );
+      await token.sendTransaction(
+        { from: accounts[1], data: transferFromData }
+      ).should.be.rejectedWith(EVMRevert);
+    });
+  });
+});