fix bugs

contracts/UniswapERC20Factory.sol

@@ -1,5 +1,5 @@
 pragma solidity ^0.5.11;
-import "./UniswapERC20.sol";ss
+import "./UniswapERC20.sol";
 
 contract UniswapERC20Factory {
 

contracts/UniswapETH.sol

@@ -29,7 +29,7 @@ contract UniswapETH is ERC20 {
 
 
   constructor(address tokenAddr) public {
-    require(address(tokenAddr != address(0), 'INVALID_ADDRESS');
+    require(address(tokenAddr) != address(0), 'INVALID_ADDRESS');
     factory = IUniswapFactory(msg.sender);
     token = IERC20(tokenAddr);
     name = 'Uniswap V2';

contracts/UniswapETHFactory.sol

@@ -13,7 +13,7 @@ contract UniswapETHFactory {
   function createExchange(address token) public returns (address) {
     require(token != address(0));
     require(getExchange[token] == address(0), 'EXCHANGE_EXISTS');
-    UniswapExchange exchange = new UniswapExchange(token);
+    UniswapETH exchange = new UniswapETH(token);
     getExchange[token] = address(exchange);
     getToken[address(exchange)] = token;
     uint256 tokenId = tokenCount + 1;

contracts/interfaces/IUniswapERC20.sol

@@ -0,0 +1,41 @@
+pragma solidity ^0.5.11;
+
+interface IUniswapERC20 {
+
+  event SwapAForB(address indexed buyer, uint256 amountSold, uint256 amountBought);
+  event SwapBForA(address indexed buyer, uint256 amountSold, uint256 amountBought);
+  event AddLiquidity(address indexed provider, uint256 amountTokenA, uint256 amountTokenB);
+  event RemoveLiquidity(address indexed provider, uint256 amountTokenA, uint256 amountTokenB);
+
+
+  function getInputPrice(uint256 inputAmount, uint256 inputReserve, uint256 outputReserve) external pure returns (uint256);
+
+
+  function getOutputPrice(uint256 outputAmount, uint256 inputReserve, uint256 outputReserve) external pure returns (uint256);
+
+
+  //TO: DO msg.sender is wrapper
+  function swapInput(address inputToken, uint256 amountSold, address recipient) external returns (uint256);
+
+
+  //TO: DO msg.sender is wrapper
+  function swapOutput(address outputToken, uint256 amountBought, address recipient) external returns (uint256);
+
+
+  function getInputPrice(address inputToken, uint256 amountSold) external view returns (uint256);
+
+
+  function getOutputPrice(address outputToken, uint256 amountBought) external view returns (uint256);
+
+
+  function tokenAAddress() external view returns (address);
+
+
+  function tokenBAddress() external view returns (address);
+
+
+  function addLiquidity(uint256 amountA, uint256 maxTokenB, uint256 minLiquidity) external returns (uint256);
+
+
+  function removeLiquidity(uint256 amount, uint256 minTokenA, uint256 minTokenB) external returns (uint256, uint256);
+}

contracts/interfaces/IUniswapERC20Factory.sol

@@ -0,0 +1,8 @@
+pragma solidity ^0.5.11;
+
+interface IUniswapERC20Factory {
+
+  event NewERC20Exchange(address indexed tokenA, address indexed tokenB, address indexed exchange);
+
+  function createExchange(address token1, address token2) external returns (address);
+}