add ERC20Receiver+tests

config/contracts.json

@@ -15,6 +15,9 @@
     ],
     "gas": "auto",
     "contracts": {
+      "ERC20Receiver": {
+        "deploy": false
+      }
     }
   }
 }

contracts/token/ERC20Receiver.sol

@@ -0,0 +1,90 @@
+pragma solidity ^0.4.23;
+
+import "./ERC20Token.sol";
+
+contract ERC20Receiver {
+
+    event TokenDeposited(address indexed token, address indexed sender, uint256 amount);
+    event TokenWithdrawn(address indexed token, address indexed sender, uint256 amount);
+
+    mapping (address => mapping(address => uint256)) tokenBalances;
+
+    constructor() public {
+        
+    }
+
+    function depositToken(
+        ERC20Token _token
+    )
+        external
+    {
+        _depositToken(
+            msg.sender,
+            _token,
+            _token.allowance(
+                msg.sender, 
+                address(this)
+            )
+        );
+    }
+
+    function withdrawToken(
+        ERC20Token _token,
+        uint256 _amount
+    )
+        external 
+    {
+        _withdrawToken(msg.sender, _token, _amount);
+    }
+
+    function depositToken(
+        ERC20Token _token,
+        uint256 _amount
+    ) 
+        external
+    {
+        require(_token.allowance(msg.sender, address(this)) >= _amount);
+        _depositToken(msg.sender, _token, _amount);
+    }
+
+    function tokenBalanceOf(
+        ERC20Token _token,
+        address _from
+    )
+        external 
+        view 
+        returns(uint256 fromTokenBalance) 
+    {
+        return tokenBalances[address(_token)][_from];
+    }
+
+    function _depositToken(
+        address _from,
+        ERC20Token _token,
+        uint256 _amount
+    )
+        private 
+    {
+        require(_amount > 0);
+        if (_token.transferFrom(_from, address(this), _amount)) {
+            tokenBalances[address(_token)][_from] += _amount;
+            emit TokenDeposited(address(_token), _from, _amount);
+        }
+    }
+
+    function _withdrawToken(
+        address _from,
+        ERC20Token _token,
+        uint256 _amount
+    )
+        private
+    {
+        require(_amount > 0);
+        require(tokenBalances[address(_token)][_from] >= _amount);
+        tokenBalances[address(_token)][_from] -= _amount;
+        require(_token.transfer(_from, _amount));
+        emit TokenWithdrawn(address(_token), _from, _amount);
+    }
+
+    
+}

test/erc20token.js

@@ -5,14 +5,14 @@ describe("ERC20Token", async function() {
   before(function(done) {
     this.timeout(0);
     var contractsConfig = {
-      "TestToken": {
-      }
+      "TestToken": { },
+      "ERC20Receiver": { }
     };
     EmbarkSpec.deployAll(contractsConfig, async function(accounts) { 
       ERC20Token = TestToken;
       accountsArr = accounts; 
       for(i=0;i<accountsArr.length;i++){
-        await ERC20Token.methods.mint(100).send({from: accountsArr[i]})
+        await ERC20Token.methods.mint(7 * 10 ^ 18).send({from: accountsArr[i]})
       }
       done()
     });
@@ -61,6 +61,21 @@ describe("ERC20Token", async function() {
     assert.equal(result, 0);
   });
 
+  it("should deposit approved amount to contract ERC20Receiver", async function() {
+    await ERC20Token.methods.approve(ERC20Receiver.address,10).send({from: accountsArr[0]});
+    await ERC20Receiver.methods.depositToken(ERC20Token.address).send({from: accountsArr[0]});
+    let result = await ERC20Receiver.methods.tokenBalanceOf(ERC20Token.address, accountsArr[0]).call();
+    assert.equal(result, 10, "ERC20Receiver.tokenBalanceOf("+ERC20Token.address+","+accountsArr[0]+") wrong");
+  });
+
+  it("should witdraw approved amount from contract ERC20Receiver", async function() {
+    let tokenBalance = await ERC20Receiver.methods.tokenBalanceOf(ERC20Token.address, accountsArr[0]).call();
+    await ERC20Receiver.methods.withdrawToken(ERC20Token.address, tokenBalance).send({from: accountsArr[0]});
+    tokenBalance = await ERC20Receiver.methods.tokenBalanceOf(ERC20Token.address, accountsArr[0]).call();
+    assert.equal(tokenBalance, 0, "ERC20Receiver.tokenBalanceOf("+ERC20Token.address+","+accountsArr[0]+") wrong");
+  });
+
   //TODO: include checks for expected events fired
 
+
 });