Audit token

contracts/generic/AugmintToken.sol

@@ -34,6 +34,7 @@ contract AugmintToken is AugmintTokenInterface {
         feeAccount = _feeAccount;
 
     }
+
     function transfer(address to, uint256 amount) external returns (bool) {
         _transfer(msg.sender, to, amount, "");
         return true;
@@ -193,21 +194,21 @@ contract AugmintToken is AugmintTokenInterface {
     }
 
     function _transferFrom(address from, address to, uint256 amount, string narrative) private {
-        require(balances[from] >= amount, "balance must >= amount");
-        require(allowed[from][msg.sender] >= amount, "allowance must be >= amount");
-        // don't allow 0 transferFrom if no approval:
-        require(allowed[from][msg.sender] > 0, "allowance must be >= 0 even with 0 amount");
+        uint fee = feeAccount.calculateTransferFee(from, to, amount);
+        uint amountWithFee = amount.add(fee);
 
-        /* NB: fee is deducted from owner. It can result that transferFrom of amount x to fail
-                when x + fee is not availale on owner balance */
-        _transfer(from, to, amount, narrative);
+        /* NB: fee is deducted from owner, so transferFrom could fail
+            if amount + fee is not available on owner balance, or allowance */
+        require(balances[from] >= amountWithFee, "balance must be >= amount + fee");
+        require(allowed[from][msg.sender] >= amountWithFee, "allowance must be >= amount + fee");
+
+        _transfer(from, to, amount, narrative, fee);
 
-        allowed[from][msg.sender] = allowed[from][msg.sender].sub(amount);
+        allowed[from][msg.sender] = allowed[from][msg.sender].sub(amountWithFee);
     }
 
     function _transfer(address from, address to, uint transferAmount, string narrative) private {
         uint fee = feeAccount.calculateTransferFee(from, to, transferAmount);
-
         _transfer(from, to, transferAmount, narrative, fee);
     }
 
@@ -229,5 +230,4 @@ contract AugmintToken is AugmintTokenInterface {
 
         emit AugmintTransfer(from, to, transferAmount, narrative, fee);
     }
-
 }

test/helpers/tokenTestHelpers.js

@@ -135,6 +135,9 @@ async function transferFromTest(testInstance, expTransfer) {
     if (!expTransfer.to) {
         expTransfer.to = expTransfer.spender;
     }
+    if (!expTransfer.spender) {
+        expTransfer.spender = expTransfer.to;
+    }
     if (typeof expTransfer.narrative === "undefined") expTransfer.narrative = "";
     expTransfer.fee = typeof expTransfer.fee === "undefined" ? await getTransferFee(expTransfer) : expTransfer.fee;
 
@@ -170,9 +173,9 @@ async function transferFromTest(testInstance, expTransfer) {
 
     const allowanceAfter = await augmintToken.allowance(expTransfer.from, expTransfer.spender);
     assert.equal(
-        allowanceBefore.sub(expTransfer.amount).toString(),
+        allowanceBefore.sub(expTransfer.amount).sub(expTransfer.fee).toString(),
         allowanceAfter.toString(),
-        "allowance should be reduced with transferred amount"
+        "allowance should be reduced with transferred amount and fee"
     );
 
     await assertBalances(balBefore, {

test/tokenTransferFrom.js

@@ -17,26 +17,33 @@ contract("TransferFrom AugmintToken tests", accounts => {
     });
 
     it("transferFrom", async function() {
-        let expApprove = {
-            owner: accounts[1],
-            spender: accounts[2],
-            value: 100000
+        const from = accounts[1];
+        const to = accounts[2];
+
+        const transfer1 = {
+            from: from,
+            to: to,
+            amount: 75000
         };
+        const fee1 = await tokenTestHelpers.getTransferFee(transfer1);
 
-        await tokenTestHelpers.approveTest(this, expApprove);
+        const transfer2 = {
+            from: from,
+            to: to,
+            amount: 25000,
+            narrative: "Test with narrative"
+        };
+        const fee2 = await tokenTestHelpers.getTransferFee(transfer2);
 
-        await tokenTestHelpers.transferFromTest(this, {
-            from: expApprove.owner,
-            spender: expApprove.spender,
-            amount: Math.round(expApprove.value / 2)
-        });
+        const expApprove = {
+            owner: from,
+            spender: to,
+            value: transfer1.amount + fee1 + transfer2.amount + fee2
+        };
 
-        await tokenTestHelpers.transferFromTest(this, {
-            from: expApprove.owner,
-            spender: expApprove.spender,
-            amount: Math.round(expApprove.value / 2),
-            narrative: "Test with narrative"
-        });
+        await tokenTestHelpers.approveTest(this, expApprove);
+        await tokenTestHelpers.transferFromTest(this, transfer1);
+        await tokenTestHelpers.transferFromTest(this, transfer2);
     });
 
     it("transferFrom spender to send to different to than itself", async function() {