add feature on token transfer invoke contractFallback silently

contracts/ERC677BridgeToken.sol

@@ -26,11 +26,24 @@ contract ERC677BridgeToken is
     function transferAndCall(address _to, uint _value, bytes _data)
         external validRecipient(_to) returns (bool)
     {
-        require(transfer(_to, _value));
-        emit Transfer(msg.sender, _to, _value, _data);
+        require(_value <= balances[msg.sender]);
+
+        balances[msg.sender] = balances[msg.sender].sub(_value);
+        balances[_to] = balances[_to].add(_value);
         if (isContract(_to)) {
             require(contractFallback(_to, _value, _data));
         }
+        emit Transfer(msg.sender, _to, _value);
+        emit Transfer(msg.sender, _to, _value, _data);
+        return true;
+    }
+
+    function transfer(address _to, uint256 _value) public returns (bool)
+    {
+        require(super.transfer(_to, _value));
+        if (isContract(_to)) {
+            contractFallback(_to, _value, new bytes(0));
+        }
         return true;
     }
 
@@ -38,8 +51,7 @@ contract ERC677BridgeToken is
         private
         returns(bool)
     {
-        ERC677Receiver receiver = ERC677Receiver(_to);
-        return receiver.onTokenTransfer(msg.sender, _value, _data);
+        return _to.call(abi.encodeWithSignature("onTokenTransfer(address,uint256,bytes)",  msg.sender, _value, _data));
     }
 
     function isContract(address _addr)

package.json

@@ -10,8 +10,8 @@
     "flatten": "bash flatten.sh",
     "watch-tests": "./node_modules/.bin/nodemon ./node_modules/.bin/truffle test --network test"
   },
-  "author": "",
-  "license": "ISC",
+  "author": "POA network",
+  "license": "GPLv3",
   "dependencies": {
     "ganache-cli": "^6.1.0",
     "openzeppelin-solidity": "^1.10.0",

test/poa20_test.js

@@ -115,4 +115,34 @@ contract('ERC677BridgeToken', async (accounts) => {
 
     })
   })
+  describe('#transfer', async () => {
+    it('if transfer called on contract, onTokenTransfer is also invoked', async () => {
+      const receiver = await ERC677ReceiverTest.new();
+      (await receiver.from()).should.be.equal('0x0000000000000000000000000000000000000000');
+      (await receiver.value()).should.be.bignumber.equal('0');
+      (await receiver.data()).should.be.equal('0x');
+      (await receiver.someVar()).should.be.bignumber.equal('0');
+
+      await token.mint(user, 1, {from: owner }).should.be.fulfilled;
+      const {logs} = await token.transfer(receiver.address, 1, {from: user}).should.be.fulfilled;
+
+      (await token.balanceOf(receiver.address)).should.be.bignumber.equal(1);
+      (await token.balanceOf(user)).should.be.bignumber.equal(0);
+      (await receiver.from()).should.be.equal(user);
+      (await receiver.value()).should.be.bignumber.equal(1);
+      (await receiver.data()).should.be.equal('0x');
+      logs[0].event.should.be.equal("Transfer")
+    })
+    it('if transfer called on contract, still works even if onTokenTransfer doesnot exist', async () => {
+      const someContract = await POA20.new("Some", "Token", 18);
+      await token.mint(user, 2, {from: owner }).should.be.fulfilled;
+      const tokenTransfer = await token.transfer(someContract.address, 1, {from: user}).should.be.fulfilled;
+      const tokenTransfer2 = await token.transfer(accounts[0], 1, {from: user}).should.be.fulfilled;
+      (await token.balanceOf(someContract.address)).should.be.bignumber.equal(1);
+      (await token.balanceOf(user)).should.be.bignumber.equal(0);
+      tokenTransfer.logs[0].event.should.be.equal("Transfer")
+      tokenTransfer2.logs[0].event.should.be.equal("Transfer")
+
+    })
+  })
 })

test/testContracts/ERC677ReceiverTest.sol

@@ -9,11 +9,11 @@ contract ERC677ReceiverTest is ERC677Receiver {
     bytes public data;
     uint public someVar = 0;
 
-    function onTokenTransfer(address _from, uint _value, bytes _data) external returns(bool) {
+    function onTokenTransfer(address _from, uint256 _value, bytes _data) external returns(bool) {
         from = _from;
         value = _value;
         data = _data;
-        require(address(this).call(_data));
+        address(this).call(_data);
         return true;
     }