Add total burned method

python/erc20_demurrage_token/token.py

@@ -167,6 +167,21 @@ class DemurrageToken(ERC20):
         return tx
 
 
+    def total_burned(self, contract_address, sender_address=ZERO_ADDRESS, id_generator=None):
+        j = JSONRPCRequest(id_generator)
+        o = j.template()
+        o['method'] = 'eth_call'
+        enc = ABIContractEncoder()
+        enc.method('totalBurned')
+        data = add_0x(enc.get())
+        tx = self.template(sender_address, contract_address)
+        tx = self.set_code(tx, data)
+        o['params'].append(self.normalize(tx))
+        o['params'].append('latest')
+        o = j.finalize(o)
+        return o
+
+
     def to_base_amount(self, contract_address, value, sender_address=ZERO_ADDRESS, id_generator=None):
         j = JSONRPCRequest(id_generator)
         o = j.template()
@@ -538,6 +553,7 @@ class DemurrageToken(ERC20):
     def parse_supply_cap(self, v):
         return abi_decode_single(ABIContractType.UINT256, v)
 
+
     @classmethod
     def parse_grow_by(self, v):
         return abi_decode_single(ABIContractType.UINT256, v)
@@ -561,3 +577,8 @@ class DemurrageToken(ERC20):
     @classmethod
     def parse_resolution_factor(self, v):
         return abi_decode_single(ABIContractType.UINT256, v)
+
+
+    @classmethod
+    def parse_total_burned(self, v):
+        return abi_decode_single(ABIContractType.UINT256, v)

python/tests/test_burn.py

@@ -37,7 +37,7 @@ class TestBurn(TestDemurrageDefault):
 
         nonce_oracle = RPCNonceOracle(self.accounts[1], self.rpc)
         c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        (tx_hash, o) = c.burn(self.address, self.accounts[1], 500000)
+        (tx_hash, o) = c.burn(self.address, self.accounts[1], 600000)
         r = self.rpc.do(o)
         o = receipt(tx_hash)
         r = self.rpc.do(o)
@@ -50,7 +50,7 @@ class TestBurn(TestDemurrageDefault):
 
         nonce_oracle = RPCNonceOracle(self.accounts[1], self.rpc)
         c = DemurrageToken(self.chain_spec, signer=self.signer, nonce_oracle=nonce_oracle)
-        (tx_hash, o) = c.burn(self.address, self.accounts[1], 500000)
+        (tx_hash, o) = c.burn(self.address, self.accounts[1], 600000)
         r = self.rpc.do(o)
         o = receipt(tx_hash)
         r = self.rpc.do(o)
@@ -59,7 +59,12 @@ class TestBurn(TestDemurrageDefault):
         o = c.total_supply(self.address, sender_address=self.accounts[0])
         r = self.rpc.do(o)
         new_supply = c.parse_total_supply(r)
-        self.assertEqual(new_supply, 500000)
+        self.assertEqual(new_supply, 400000)
+
+        o = c.total_burned(self.address, sender_address=self.accounts[0])
+        r = self.rpc.do(o)
+        burned = c.parse_total_burned(r)
+        self.assertEqual(burned, 600000)
 
 
     def test_burned_redistribution(self):

solidity/DemurrageTokenSingleNocap.sol

@@ -509,6 +509,11 @@ contract DemurrageTokenSingleCap {
 		return supply - burned;
 	}
 
+	// Return total number of burned tokens
+	function totalBurned() public view returns (uint256) {
+		return burned;
+	}
+
 	// Implements EIP165
 	function supportsInterface(bytes4 _sum) public pure returns (bool) {
 		if (_sum == 0xc6bb4b70) { // ERC20