From 0afb8d1323d23d3f1f97ced15a6396464e5372c6 Mon Sep 17 00:00:00 2001
From: Noah Zinsmeister <noahwz@gmail.com>
Date: Thu, 31 Oct 2019 11:16:17 -0400
Subject: [PATCH] tweaks

---
 contracts/UniswapV2.sol   | 5 +++--
 contracts/test/Oracle.sol | 2 +-
 contracts/token/ERC20.sol | 5 +++--
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/contracts/UniswapV2.sol b/contracts/UniswapV2.sol
index 4a457e3..4657695 100644
--- a/contracts/UniswapV2.sol
+++ b/contracts/UniswapV2.sol
@@ -11,6 +11,7 @@ import "./libraries/SafeMath256.sol";
 import "./token/ERC20.sol";
 
 contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0) {
+    using Math for uint256;
     using SafeMath128 for uint128;
     using SafeMath256 for uint256;
 
@@ -35,7 +36,7 @@ contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0) {
     }
 
     bool private locked; // reentrancy lock
-    
+
     address public factory;
     address public token0;
     address public token1;
@@ -66,7 +67,7 @@ contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0) {
     function safeTransfer(address token, address to, uint128 value) private returns (bool result) {
         IIncompatibleERC20(token).transfer(to, uint256(value));
         assembly {
-            switch returndatasize()   
+            switch returndatasize()
                 case 0 {
                     result := not(0) // for no-bool responses, treat as successful
                 }
diff --git a/contracts/test/Oracle.sol b/contracts/test/Oracle.sol
index 295fc6f..d0326bd 100644
--- a/contracts/test/Oracle.sol
+++ b/contracts/test/Oracle.sol
@@ -56,7 +56,7 @@ contract Oracle {
                     token0: deltas.token0 / blocksElapsed,
                     token1: deltas.token1 / blocksElapsed
                 });
-    
+
                 uint128 timeElapsed = blockTimestamp - lastUpdate.blockTimestamp;
                 _updateCurrentPrice(averages, timeElapsed);
             }
diff --git a/contracts/token/ERC20.sol b/contracts/token/ERC20.sol
index 66cf90f..6087c0a 100644
--- a/contracts/token/ERC20.sol
+++ b/contracts/token/ERC20.sol
@@ -35,7 +35,7 @@ contract ERC20 is IERC20 {
         require(chainId == 0, "ERC20: ALREADY_INITIALIZED");
         chainId = _chainId;
     }
-    
+
     function mint(address to, uint256 value) internal {
         totalSupply = totalSupply.add(value);
         balanceOf[to] = balanceOf[to].add(value);
@@ -110,7 +110,8 @@ contract ERC20 is IERC20 {
                 owner, spender, value, nonce, expiration, chainId
             ))
         ));
-        require(owner == ecrecover(digest, v, r, s), "ERC20: INVALID_SIGNATURE"); // TODO add ECDSA checks? https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/cryptography/ECDSA.sol
+        // TODO add ECDSA checks? https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/cryptography/ECDSA.sol
+        require(owner == ecrecover(digest, v, r, s), "ERC20: INVALID_SIGNATURE");
 
         _approve(owner, spender, value);
     }