Added support for indivisible tokens in capped STO

CHANGELOG.md

@@ -7,6 +7,7 @@ All notable changes to this project will be documented in this file.
 
 ## CappedSTO 2.0.1
 * `rate` is now accepted as multiplied by 10^18 to allow settting higher price than 1ETH/POLY per token.
+* Indivisble tokens are now supported. When trying to buy partial tokens, allowed full units of tokens will be purchased and remaining funds will be returned.
 
 ## USDTieredSTO 2.1.0
 * Added `buyTokensView` and `getTokensMintedByTier` to USDTSTO.

contracts/modules/STO/CappedSTO.sol

@@ -66,6 +66,7 @@ contract CappedSTO is ISTO, ReentrancyGuard {
     public
     onlyFactory
     {
+        require(endTime == 0, "Already configured");
         require(_rate > 0, "Rate of token should be greater than 0");
         require(_fundsReceiver != address(0), "Zero address is not permitted");
         /*solium-disable-next-line security/no-block-members*/
@@ -110,9 +111,10 @@ contract CappedSTO is ISTO, ReentrancyGuard {
         require(fundRaiseTypes[uint8(FundRaiseType.ETH)], "Mode of investment is not ETH");
 
         uint256 weiAmount = msg.value;
-        _processTx(_beneficiary, weiAmount);
+        uint256 refund = _processTx(_beneficiary, weiAmount);
+        weiAmount = weiAmount.sub(refund);
 
-        _forwardFunds();
+        _forwardFunds(refund);
         _postValidatePurchase(_beneficiary, weiAmount);
     }
 
@@ -123,9 +125,9 @@ contract CappedSTO is ISTO, ReentrancyGuard {
     function buyTokensWithPoly(uint256 _investedPOLY) public nonReentrant{
         require(!paused, "Should not be paused");
         require(fundRaiseTypes[uint8(FundRaiseType.POLY)], "Mode of investment is not POLY");
-        _processTx(msg.sender, _investedPOLY);
-        _forwardPoly(msg.sender, wallet, _investedPOLY);
-        _postValidatePurchase(msg.sender, _investedPOLY);
+        uint256 refund = _processTx(msg.sender, _investedPOLY);
+        _forwardPoly(msg.sender, wallet, _investedPOLY.sub(refund));
+        _postValidatePurchase(msg.sender, _investedPOLY.sub(refund));
     }
 
     /**
@@ -183,11 +185,13 @@ contract CappedSTO is ISTO, ReentrancyGuard {
       * @param _beneficiary Address performing the token purchase
       * @param _investedAmount Value in wei involved in the purchase
     */
-    function _processTx(address _beneficiary, uint256 _investedAmount) internal {
+    function _processTx(address _beneficiary, uint256 _investedAmount) internal returns(uint256 refund) {
 
         _preValidatePurchase(_beneficiary, _investedAmount);
         // calculate token amount to be created
-        uint256 tokens = _getTokenAmount(_investedAmount);
+        uint256 tokens;
+        (tokens, refund) = _getTokenAmount(_investedAmount);
+        _investedAmount = _investedAmount.sub(refund);
 
         // update state
         if (fundRaiseTypes[uint8(FundRaiseType.POLY)]) {
@@ -212,7 +216,9 @@ contract CappedSTO is ISTO, ReentrancyGuard {
     function _preValidatePurchase(address _beneficiary, uint256 _investedAmount) internal view {
         require(_beneficiary != address(0), "Beneficiary address should not be 0x");
         require(_investedAmount != 0, "Amount invested should not be equal to 0");
-        require(totalTokensSold.add(_getTokenAmount(_investedAmount)) <= cap, "Investment more than cap is not allowed");
+        uint256 tokens;
+        (tokens, ) = _getTokenAmount(_investedAmount);
+        require(totalTokensSold.add(tokens) <= cap, "Investment more than cap is not allowed");
         /*solium-disable-next-line security/no-block-members*/
         require(now >= startTime && now <= endTime, "Offering is closed/Not yet started");
     }
@@ -261,18 +267,23 @@ contract CappedSTO is ISTO, ReentrancyGuard {
     * @notice Overrides to extend the way in which ether is converted to tokens.
     * @param _investedAmount Value in wei to be converted into tokens
     * @return Number of tokens that can be purchased with the specified _investedAmount
+    * @return Remaining amount that should be refunded to the investor
     */
-    function _getTokenAmount(uint256 _investedAmount) internal view returns (uint256 tokenAmount) {
-        tokenAmount = _investedAmount.mul(rate);
-        tokenAmount = tokenAmount.div(uint256(10) ** 18);
-        return tokenAmount;
+    function _getTokenAmount(uint256 _investedAmount) internal view returns (uint256 _tokens, uint256 _refund) {
+        _tokens = _investedAmount.mul(rate);
+        _tokens = _tokens.div(uint256(10) ** 18);
+        uint256 granularity = ISecurityToken(securityToken).granularity();
+        _tokens = _tokens.div(granularity);
+        _tokens = _tokens.mul(granularity);
+        _refund = _investedAmount.sub((_tokens.mul(uint256(10) ** 18)).div(rate));
     }
 
     /**
     * @notice Determines how ETH is stored/forwarded on purchases.
     */
-    function _forwardFunds() internal {
-        wallet.transfer(msg.value);
+    function _forwardFunds(uint256 _refund) internal {
+        wallet.transfer(msg.value.sub(_refund));
+        msg.sender.transfer(_refund);
     }
 
     /**

test/b_capped_sto.js

@@ -338,16 +338,6 @@ contract("CappedSTO", accounts => {
             );
         });
 
-        it("Should buy the tokens -- Failed due to wrong granularity", async () => {
-            await catchRevert(
-                web3.eth.sendTransaction({
-                    from: account_investor1,
-                    to: I_CappedSTO_Array_ETH[0].address,
-                    value: web3.utils.toWei("0.1111", "ether")
-                })
-            );
-        });
-
         it("Should Buy the tokens", async () => {
             blockNo = latestBlock();
             fromTime = latestTime();
@@ -427,17 +417,8 @@ contract("CappedSTO", accounts => {
             assert.isFalse(await I_CappedSTO_Array_ETH[0].paused.call());
         });
 
-        it("Should buy the tokens -- Failed due to wrong granularity", async () => {
-            await catchRevert(
-                web3.eth.sendTransaction({
-                    from: account_investor1,
-                    to: I_CappedSTO_Array_ETH[0].address,
-                    value: web3.utils.toWei("0.1111", "ether")
-                })
-            );
-        });
-
-        it("Should restrict to buy tokens after hiting the cap in second tx first tx pass", async () => {
+        it("Should buy the granular unit tokens and refund pending amount", async () => {
+            await I_SecurityToken_ETH.changeGranularity(10 ** 21, {from: token_owner});
             let tx = await I_GeneralTransferManager.modifyWhitelist(
                 account_investor2,
                 fromTime,
@@ -448,15 +429,26 @@ contract("CappedSTO", accounts => {
                     from: account_issuer
                 }
             );
-
             assert.equal(tx.logs[0].args._investor, account_investor2, "Failed in adding the investor in whitelist");
+            const initBalance = BigNumber(await web3.eth.getBalance(account_investor2));
+            tx = await I_CappedSTO_Array_ETH[0].buyTokens(account_investor2, {from: account_investor2, value: web3.utils.toWei("1.5", "ether"), gasPrice: 1});
+            const finalBalance = BigNumber(await web3.eth.getBalance(account_investor2));
+            assert.equal(finalBalance.add(BigNumber(tx.receipt.gasUsed)).add(web3.utils.toWei("1", "ether")).toNumber(), initBalance.toNumber());
+            await I_SecurityToken_ETH.changeGranularity(1, {from: token_owner});
+            assert.equal((await I_CappedSTO_Array_ETH[0].getRaised.call(ETH)).dividedBy(new BigNumber(10).pow(18)).toNumber(), 2);
+
+            assert.equal((await I_SecurityToken_ETH.balanceOf(account_investor2)).dividedBy(new BigNumber(10).pow(18)).toNumber(), 1000);
+        });
+
+        it("Should restrict to buy tokens after hiting the cap in second tx first tx pass", async () => {
+
 
             // Fallback transaction
             await web3.eth.sendTransaction({
                 from: account_investor2,
                 to: I_CappedSTO_Array_ETH[0].address,
                 gas: 2100000,
-                value: web3.utils.toWei("9", "ether")
+                value: web3.utils.toWei("8", "ether")
             });
 
             assert.equal((await I_CappedSTO_Array_ETH[0].getRaised.call(ETH)).dividedBy(new BigNumber(10).pow(18)).toNumber(), 10);
@@ -793,8 +785,8 @@ contract("CappedSTO", accounts => {
                 await I_CappedSTO_Array_POLY[0].unpause({ from: account_issuer });
             });
 
-
-            it("Should restrict to buy tokens after hiting the cap in second tx first tx pass", async () => {
+            it("Should buy the granular unit tokens and charge only required POLY", async () => {
+                await I_SecurityToken_POLY.changeGranularity(10 ** 22, {from: token_owner});
                 let tx = await I_GeneralTransferManager.modifyWhitelist(
                     account_investor2,
                     P_fromTime,
@@ -806,15 +798,25 @@ contract("CappedSTO", accounts => {
                         gas: 500000
                     }
                 );
-
+                console.log((await I_SecurityToken_POLY.balanceOf(account_investor2)).dividedBy(new BigNumber(10).pow(18)).toNumber());
                 assert.equal(tx.logs[0].args._investor, account_investor2, "Failed in adding the investor in whitelist");
-
                 await I_PolyToken.getTokens(10000 * Math.pow(10, 18), account_investor2);
-
                 await I_PolyToken.approve(I_CappedSTO_Array_POLY[0].address, 9000 * Math.pow(10, 18), { from: account_investor2 });
+                const initRaised = (await I_CappedSTO_Array_POLY[0].getRaised.call(POLY)).dividedBy(new BigNumber(10).pow(18)).toNumber();
+                tx = await I_CappedSTO_Array_POLY[0].buyTokensWithPoly(3000 * Math.pow(10, 18), { from: account_investor2 });
+                await I_SecurityToken_POLY.changeGranularity(1, {from: token_owner});
+                assert.equal((await I_CappedSTO_Array_POLY[0].getRaised.call(POLY)).dividedBy(new BigNumber(10).pow(18)).toNumber(), initRaised + 2000); //2000 this call, 1000 earlier
+                assert.equal((await I_PolyToken.balanceOf(account_investor2)).dividedBy(new BigNumber(10).pow(18)).toNumber(), 8000);
+                assert.equal(
+                    (await I_SecurityToken_POLY.balanceOf(account_investor2)).dividedBy(new BigNumber(10).pow(18)).toNumber(),
+                    10000
+                );
+            });
 
+
+            it("Should restrict to buy tokens after hiting the cap in second tx first tx pass", async () => {
                 // buyTokensWithPoly transaction
-                await I_CappedSTO_Array_POLY[0].buyTokensWithPoly(9000 * Math.pow(10, 18), { from: account_investor2 });
+                await I_CappedSTO_Array_POLY[0].buyTokensWithPoly(7000 * Math.pow(10, 18), { from: account_investor2 });
 
                 assert.equal((await I_CappedSTO_Array_POLY[0].getRaised.call(POLY)).dividedBy(new BigNumber(10).pow(18)).toNumber(), 10000);