Fix SushiMaker and add tests

contracts/SushiMaker.sol

@@ -34,7 +34,16 @@ contract SushiMaker {
     }
 
     function _toWETH(address token) internal returns (uint256) {
-        if (token == sushi || token == weth) return 0; // No action needed
+        if (token == sushi) {
+            uint amount = IERC20(token).balanceOf(address(this));
+            IERC20(token).transfer(bar, amount);
+            return 0;
+        }
+        if (token == weth) {
+            uint amount = IERC20(token).balanceOf(address(this));
+            IERC20(token).transfer(factory.getPair(weth, sushi), amount);
+            return amount;
+        }
         IUniswapV2Pair pair = IUniswapV2Pair(factory.getPair(token, weth));
         (uint reserve0, uint reserve1,) = pair.getReserves();
         address token0 = pair.token0();
@@ -45,6 +54,7 @@ contract SushiMaker {
         uint denominator = reserveIn.mul(1000).add(amountInWithFee);
         uint amountOut = numerator / denominator;
         (uint amount0Out, uint amount1Out) = token0 == token ? (uint(0), amountOut) : (amountOut, uint(0));
+        IERC20(token).transfer(address(pair), amountIn);
         pair.swap(amount0Out, amount1Out, factory.getPair(weth, sushi), new bytes(0));
         return amountOut;
     }
@@ -59,6 +69,6 @@ contract SushiMaker {
         uint denominator = reserveIn.mul(1000).add(amountInWithFee);
         uint amountOut = numerator / denominator;
         (uint amount0Out, uint amount1Out) = token0 == weth ? (uint(0), amountOut) : (amountOut, uint(0));
-        pair.swap(amount0Out, amount1Out, factory.getPair(weth, sushi), new bytes(0));
+        pair.swap(amount0Out, amount1Out, bar, new bytes(0));
     }
 }

test/SushiMaker.test.js

@@ -0,0 +1,61 @@
+const SushiToken = artifacts.require('SushiToken');
+const SushiMaker = artifacts.require('SushiMaker');
+const MockERC20 = artifacts.require('MockERC20');
+const UniswapV2Pair = artifacts.require('UniswapV2Pair');
+const UniswapV2Factory = artifacts.require('UniswapV2Factory');
+
+contract('SushiMaker', ([alice, bar, minter]) => {
+    beforeEach(async () => {
+        this.factory = await UniswapV2Factory.new(alice, { from: alice });
+        this.sushi = await SushiToken.new({ from: alice });
+        await this.sushi.mint(minter, '100000000', { from: alice });
+        this.weth = await MockERC20.new('WETH', 'WETH', '100000000', { from: minter });
+        this.token1 = await MockERC20.new('TOKEN1', 'TOKEN', '100000000', { from: minter });
+        this.token2 = await MockERC20.new('TOKEN2', 'TOKEN2', '100000000', { from: minter });
+        this.maker = await SushiMaker.new(this.factory.address, bar, this.sushi.address, this.weth.address);
+        this.sushiWETH = await UniswapV2Pair.at((await this.factory.createPair(this.weth.address, this.sushi.address)).logs[0].args.pair);
+        this.wethToken1 = await UniswapV2Pair.at((await this.factory.createPair(this.weth.address, this.token1.address)).logs[0].args.pair);
+        this.wethToken2 = await UniswapV2Pair.at((await this.factory.createPair(this.weth.address, this.token2.address)).logs[0].args.pair);
+        this.token1Token2 = await UniswapV2Pair.at((await this.factory.createPair(this.token1.address, this.token2.address)).logs[0].args.pair);
+    });
+
+    it('should make SUSHIs successfully', async () => {
+        await this.factory.setFeeTo(this.maker.address, { from: alice });
+        await this.weth.transfer(this.sushiWETH.address, '10000000', { from: minter });
+        await this.sushi.transfer(this.sushiWETH.address, '10000000', { from: minter });
+        await this.sushiWETH.mint(minter);
+        await this.weth.transfer(this.wethToken1.address, '10000000', { from: minter });
+        await this.token1.transfer(this.wethToken1.address, '10000000', { from: minter });
+        await this.wethToken1.mint(minter);
+        await this.weth.transfer(this.wethToken2.address, '10000000', { from: minter });
+        await this.token2.transfer(this.wethToken2.address, '10000000', { from: minter });
+        await this.wethToken2.mint(minter);
+        await this.token1.transfer(this.token1Token2.address, '10000000', { from: minter });
+        await this.token2.transfer(this.token1Token2.address, '10000000', { from: minter });
+        await this.token1Token2.mint(minter);
+        // Fake some revenue
+        await this.token1.transfer(this.token1Token2.address, '100000', { from: minter });
+        await this.token2.transfer(this.token1Token2.address, '100000', { from: minter });
+        await this.token1Token2.sync();
+        await this.token1.transfer(this.token1Token2.address, '10000000', { from: minter });
+        await this.token2.transfer(this.token1Token2.address, '10000000', { from: minter });
+        await this.token1Token2.mint(minter);
+        // Maker should have the LP now
+        assert.equal((await this.token1Token2.balanceOf(this.maker.address)).valueOf(), '16528');
+        // After calling convert, bar should have SUSHI value at ~1/6 of revenue
+        await this.maker.convert(this.token1.address, this.token2.address);
+        assert.equal((await this.sushi.balanceOf(bar)).valueOf(), '32965');
+        assert.equal((await this.token1Token2.balanceOf(this.maker.address)).valueOf(), '0');
+        // Should also work for SUSHI-ETH pair
+        await this.sushi.transfer(this.sushiWETH.address, '100000', { from: minter });
+        await this.weth.transfer(this.sushiWETH.address, '100000', { from: minter });
+        await this.sushiWETH.sync();
+        await this.sushi.transfer(this.sushiWETH.address, '10000000', { from: minter });
+        await this.weth.transfer(this.sushiWETH.address, '10000000', { from: minter });
+        await this.sushiWETH.mint(minter);
+        assert.equal((await this.sushiWETH.balanceOf(this.maker.address)).valueOf(), '16537');
+        await this.maker.convert(this.sushi.address, this.weth.address);
+        assert.equal((await this.sushi.balanceOf(bar)).valueOf(), '66249');
+        assert.equal((await this.sushiWETH.balanceOf(this.maker.address)).valueOf(), '0');
+    });
+});