Add approve, transferfrom

python/tests/test_basic.py

@@ -45,7 +45,7 @@ class Test(unittest.TestCase):
         provider = web3.Web3.EthereumTesterProvider(self.eth_tester)
         self.w3 = web3.Web3(provider)
         c = self.w3.eth.contract(abi=self.abi, bytecode=self.bytecode)
-        tx_hash = c.constructor('Foo Token', 'FOO', TAX_LEVEL, PERIOD).transact({'from': self.w3.eth.accounts[0]})
+        tx_hash = c.constructor('Foo Token', 'FOO', 6, TAX_LEVEL, PERIOD).transact({'from': self.w3.eth.accounts[0]})
 
         r = self.w3.eth.getTransactionReceipt(tx_hash)
         self.contract = self.w3.eth.contract(abi=self.abi, address=r.contractAddress)
@@ -56,14 +56,12 @@ class Test(unittest.TestCase):
         pass
 
 
-    @unittest.skip('test')
     def test_hello(self):
         self.assertEqual(self.contract.functions.actualPeriod().call(), 1)
         self.eth_tester.mine_blocks(PERIOD)
         self.assertEqual(self.contract.functions.actualPeriod().call(), 2)
 
 
-    @unittest.skip('test')
     def test_mint(self):
         tx_hash = self.contract.functions.mintTo(self.w3.eth.accounts[1], 1024).transact()
         r = self.w3.eth.getTransactionReceipt(tx_hash)
@@ -101,7 +99,32 @@ class Test(unittest.TestCase):
         self.assertEqual(r.status, 1)
         logg.debug('tx {}'.format(r))
 
-    @unittest.skip('test')
+
+    def test_transfer_from(self):
+        tx_hash = self.contract.functions.mintTo(self.w3.eth.accounts[1], 1024).transact()
+        r = self.w3.eth.getTransactionReceipt(tx_hash)
+        self.assertEqual(r.status, 1)
+
+        tx_hash = self.contract.functions.approve(self.w3.eth.accounts[2], 500).transact({'from': self.w3.eth.accounts[1]})
+        r = self.w3.eth.getTransactionReceipt(tx_hash)
+        self.assertEqual(r.status, 1)
+        logg.debug('tx {}'.format(r))
+
+        balance_alice = self.contract.functions.balanceOf(self.w3.eth.accounts[1]).call()
+        self.assertEqual(balance_alice, 1024)
+
+        tx_hash = self.contract.functions.transferFrom(self.w3.eth.accounts[1], self.w3.eth.accounts[3], 500).transact({'from': self.w3.eth.accounts[2]})
+        r = self.w3.eth.getTransactionReceipt(tx_hash)
+        self.assertEqual(r.status, 1)
+        logg.debug('tx {}'.format(r))
+
+        balance_alice = self.contract.functions.balanceOf(self.w3.eth.accounts[1]).call()
+        self.assertEqual(balance_alice, 524)
+
+        balance_alice = self.contract.functions.balanceOf(self.w3.eth.accounts[3]).call()
+        self.assertEqual(balance_alice, 500)
+
+
     def test_apply_tax(self):
         self.eth_tester.mine_blocks(PERIOD)
         tx_hash = self.contract.functions.applyTax().transact()
@@ -116,7 +139,6 @@ class Test(unittest.TestCase):
         self.assertEqual(self.contract.functions.demurrageModifier().call(), 960400)
 
 
-    @unittest.skip('test')
     def test_tax_balance(self):
         tx_hash = self.contract.functions.mintTo(self.w3.eth.accounts[1], 1000).transact()
         r = self.w3.eth.getTransactionReceipt(tx_hash)
@@ -131,7 +153,6 @@ class Test(unittest.TestCase):
         self.assertEqual(balance, 980)
 
     
-    @unittest.skip('test')
     def test_taxed_transfer(self):
         tx_hash = self.contract.functions.mintTo(self.w3.eth.accounts[1], 1000000).transact()
         r = self.w3.eth.getTransactionReceipt(tx_hash)

solidity/RedistributedDemurrageToken.sol

@@ -17,8 +17,9 @@ contract RedistributedDemurrageToken {
 	uint256 public demurrageModifier; // PPM
 
 	bytes32[] public redistributions; // uint1(usedDustSink) | uint1(isFractional) | uint38(participants) | uint160(value) | uint56(period)
-	mapping (address => bytes32) account; // uint12(period) | uint160(value)
+	mapping (address => bytes32) account; // uint20(unused) | uint56(period) | uint160(value)
 	mapping (address => bool) minter;
+	mapping (address => mapping (address => uint256 ) ) allowance; // holder -> spender -> amount (amount is subject to demurrage)
 
 	event Transfer(address indexed _from, address indexed _to, uint256 _value);
 	event Approval(address indexed _owner, address indexed _spender, uint256 _value);
@@ -27,7 +28,7 @@ contract RedistributedDemurrageToken {
 	event Taxed(uint256 indexed _period);
 	event Redistribution(address indexed _account, uint256 indexed _period, uint256 _value);
 
-	constructor(string memory _name, string memory _symbol, uint32 _taxLevel, uint256 _period) {
+	constructor(string memory _name, string memory _symbol, uint8 _decimals, uint32 _taxLevel, uint256 _period) {
 		owner = msg.sender;
 		minter[owner] = true;
 		periodStart = block.number;
@@ -35,7 +36,7 @@ contract RedistributedDemurrageToken {
 		taxLevel = _taxLevel;
 		name = _name;
 		symbol = _symbol;
-		decimals = 6;
+		decimals = _decimals;
 		demurrageModifier = 1000000;
 		bytes32 initialRedistribution = toRedistribution(0, 0, 1);
 		redistributions.push(initialRedistribution);
@@ -250,6 +251,11 @@ contract RedistributedDemurrageToken {
 		return true;
 	}
 
+	// Inflates the given amount according to the current demurrage modifier
+	function toBaseAmount(uint256 _value) public view returns (uint256) {
+		return (_value * 1000000) / demurrageModifier;
+	}
+
 	// ERC20, triggers tax and/or redistribution
 	function transfer(address _to, uint256 _value) public returns (bool) {
 		uint256 baseValue;
@@ -259,7 +265,7 @@ contract RedistributedDemurrageToken {
 		applyRedistributionOnAccount(msg.sender);
 
 		// TODO: Prefer to truncate the result, instead it seems to round to nearest :/
-		baseValue = (_value * 1000000) / demurrageModifier;
+		baseValue = toBaseAmount(_value);
 		result = transferBase(msg.sender, _to, baseValue);
 
 		return result;
@@ -281,4 +287,32 @@ contract RedistributedDemurrageToken {
 		}
 		return true;
 	}
+
+	// ERC20, triggers tax and/or redistribution
+	function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
+		uint256 baseValue;
+		bool result;
+
+		applyTax();
+		applyRedistributionOnAccount(msg.sender);
+
+		baseValue = toBaseAmount(_value);
+		require(allowance[_from][msg.sender] >= baseValue);
+
+		result = transferBase(_from, _to, baseValue);
+		return result;
+	}
+
+	// ERC20, triggers tax and/or redistribution
+	function approve(address _spender, uint256 _value) public returns (bool) {
+		uint256 baseValue;
+
+		applyTax();
+		applyRedistributionOnAccount(msg.sender);
+
+		baseValue = toBaseAmount(_value);
+		allowance[msg.sender][_spender] += baseValue;
+		emit Approval(msg.sender, _spender, _value);
+		return true;
+	}
 }