fix: use safe erc (#37)

* fix: use safe erc

* test: adjust for usdt

src/swappers/SolidlySwapper.sol

@@ -2,6 +2,7 @@
 pragma solidity 0.8.18;
 
 import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 
 import {ISolidly} from "../interfaces/Solidly/ISolidly.sol";
 
@@ -20,6 +21,8 @@ import {ISolidly} from "../interfaces/Solidly/ISolidly.sol";
  *   will need to be set for any token pairs that should use a stable pool.
  */
 contract SolidlySwapper {
+    using SafeERC20 for ERC20;
+
     // Optional Variable to be set to not sell dust.
     uint256 public minAmountToSell;
     // Defaults to WETH on mainnet.
@@ -145,8 +148,8 @@ contract SolidlySwapper {
         uint256 _amount
     ) internal virtual {
         if (ERC20(_token).allowance(address(this), _contract) < _amount) {
-            ERC20(_token).approve(_contract, 0);
-            ERC20(_token).approve(_contract, _amount);
+            ERC20(_token).safeApprove(_contract, 0);
+            ERC20(_token).safeApprove(_contract, _amount);
         }
     }
 }

src/swappers/UniswapV2Swapper.sol

@@ -2,6 +2,7 @@
 pragma solidity 0.8.18;
 
 import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 
 import {IUniswapV2Router02} from "../interfaces/Uniswap/V2/IUniswapV2Router02.sol";
 
@@ -17,6 +18,8 @@ import {IUniswapV2Router02} from "../interfaces/Uniswap/V2/IUniswapV2Router02.so
  *   based on needs or chain its used on.
  */
 contract UniswapV2Swapper {
+    using SafeERC20 for ERC20;
+
     // Optional Variable to be set to not sell dust.
     uint256 public minAmountToSell;
     // Defaults to WETH on mainnet.
@@ -119,8 +122,8 @@ contract UniswapV2Swapper {
         uint256 _amount
     ) internal virtual {
         if (ERC20(_token).allowance(address(this), _contract) < _amount) {
-            ERC20(_token).approve(_contract, 0);
-            ERC20(_token).approve(_contract, _amount);
+            ERC20(_token).safeApprove(_contract, 0);
+            ERC20(_token).safeApprove(_contract, _amount);
         }
     }
 }

src/swappers/UniswapV3Swapper.sol

@@ -2,6 +2,7 @@
 pragma solidity 0.8.18;
 
 import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 
 import {ISwapRouter} from "../interfaces/Uniswap/V3/ISwapRouter.sol";
 
@@ -21,6 +22,8 @@ import {ISwapRouter} from "../interfaces/Uniswap/V3/ISwapRouter.sol";
  *   function to easily set this for any token pairs needed.
  */
 contract UniswapV3Swapper {
+    using SafeERC20 for ERC20;
+
     // Optional Variable to be set to not sell dust.
     uint256 public minAmountToSell;
     // Defaults to WETH on mainnet.
@@ -187,8 +190,8 @@ contract UniswapV3Swapper {
         uint256 _amount
     ) internal virtual {
         if (ERC20(_token).allowance(address(this), _contract) < _amount) {
-            ERC20(_token).approve(_contract, 0);
-            ERC20(_token).approve(_contract, _amount);
+            ERC20(_token).safeApprove(_contract, 0);
+            ERC20(_token).safeApprove(_contract, _amount);
         }
     }
 }

src/test/HealthCheck.t.sol

@@ -1,11 +1,13 @@
 // SPDX-License-Identifier: AGPL-3.0
 pragma solidity 0.8.18;
 
-import {Setup, IStrategy} from "./utils/Setup.sol";
+import {Setup, IStrategy, SafeERC20, ERC20} from "./utils/Setup.sol";
 
 import {MockHealthCheck, IMockHealthCheck} from "./mocks/MockHealthCheck.sol";
 
 contract HealthCheckTest is Setup {
+    using SafeERC20 for ERC20;
+
     IMockHealthCheck public healthCheck;
 
     function setUp() public override {
@@ -294,11 +296,11 @@ contract HealthCheckTest is Setup {
         );
 
         // Loose .01%
-        uint256 loss = _amount / 10000;
+        uint256 loss = _amount / MAX_BPS;
 
         // simulate loss
         vm.prank(address(healthCheck));
-        asset.transfer(management, loss);
+        asset.safeTransfer(management, loss);
 
         assertEq(
             healthCheck.doHealthCheck(),
@@ -391,11 +393,11 @@ contract HealthCheckTest is Setup {
         );
 
         // Loose .01%
-        uint256 loss = _amount / 10_000;
+        uint256 loss = _amount / MAX_BPS;
 
         // simulate loss
         vm.prank(address(healthCheck));
-        asset.transfer(management, loss);
+        asset.safeTransfer(management, loss);
 
         assertEq(
             healthCheck.doHealthCheck(),

src/test/UniV2Swapper.t.sol

@@ -11,7 +11,7 @@ contract UniswapV2SwapperTest is Setup {
 
     ERC20 public base;
 
-    uint256 public minBaseAmount = 1e8;
+    uint256 public minBaseAmount = 1e10;
     uint256 public maxBaseAmount = 1e20;
 
     function setUp() public override {
@@ -74,7 +74,7 @@ contract UniswapV2SwapperTest is Setup {
 
     function test_swapFrom_multiHop(uint256 amount) public {
         // Need to make sure we are getting enough DAI to be non 0 USDC.
-        vm.assume(amount >= 1e15 && amount <= maxFuzzAmount);
+        vm.assume(amount >= minFuzzAmount && amount <= maxFuzzAmount);
         ERC20 swapTo = ERC20(tokenAddrs["USDC"]);
 
         // Send some asset to the contract
@@ -110,7 +110,7 @@ contract UniswapV2SwapperTest is Setup {
         assertEq(base.balanceOf(address(uniV2Swapper)), 0);
 
         // Define the minimum amount of Base to receive
-        uint256 minOut = amount;
+        uint256 minOut = amount * 1e12;
 
         // Perform swap from asset to Base with minimum output requirement
         vm.expectRevert();

src/test/UniV3Swapper.t.sol

@@ -10,7 +10,7 @@ contract UniswapV3SwapperTest is Setup {
 
     ERC20 public weth;
 
-    uint256 public minWethAmount = 1e8;
+    uint256 public minWethAmount = 1e10;
     uint256 public maxWethAmount = 1e20;
 
     function setUp() public override {
@@ -105,7 +105,7 @@ contract UniswapV3SwapperTest is Setup {
         // Assert WETH balance in the contract is 0
         assertEq(weth.balanceOf(address(uniV3Swapper)), 0);
 
-        uint256 toGet = amount / 4_000;
+        uint256 toGet = (amount * 1e12) / 4_000;
 
         // Perform swap from asset to WETH
         uint256 amountIn = uniV3Swapper.swapTo(
@@ -136,7 +136,7 @@ contract UniswapV3SwapperTest is Setup {
         // Assert asset balance in the contract is 0
         assertEq(asset.balanceOf(address(uniV3Swapper)), 0);
 
-        uint256 toGet = amount * 1_000;
+        uint256 toGet = (amount * 1_000) / 1e12;
 
         // Perform swap from WETH to asset
         uint256 amountIn = uniV3Swapper.swapTo(
@@ -156,7 +156,7 @@ contract UniswapV3SwapperTest is Setup {
 
     function test_swapFrom_multiHop(uint256 amount) public {
         // Need to make sure we are getting enough DAI to be non 0 USDC.
-        vm.assume(amount >= 1e15 && amount <= maxFuzzAmount);
+        vm.assume(amount >= minFuzzAmount && amount <= maxFuzzAmount);
         ERC20 swapTo = ERC20(tokenAddrs["USDC"]);
         // Set fees for weth and asset
         uniV3Swapper.setUniFees(address(weth), address(asset), 500);
@@ -192,7 +192,8 @@ contract UniswapV3SwapperTest is Setup {
 
     function test_swapTo_multiHop(uint256 amount) public {
         // Need to make sure we are getting enough DAI to be non 0 USDC.
-        vm.assume(amount >= 1e15 && amount <= maxFuzzAmount);
+        vm.assume(amount >= minFuzzAmount && amount <= maxFuzzAmount);
+
         ERC20 swapTo = ERC20(tokenAddrs["USDC"]);
         // Set fees for weth and asset
         uniV3Swapper.setUniFees(address(weth), address(asset), 500);
@@ -209,7 +210,7 @@ contract UniswapV3SwapperTest is Setup {
         assertEq(swapTo.balanceOf(address(uniV3Swapper)), 0);
 
         // Define the desired amount to receive
-        uint256 toGet = amount / 2e12;
+        uint256 toGet = amount / 10;
 
         // Perform swap from asset to swap_to
         uint256 amountIn = uniV3Swapper.swapTo(
@@ -243,7 +244,7 @@ contract UniswapV3SwapperTest is Setup {
         assertEq(weth.balanceOf(address(uniV3Swapper)), 0);
 
         // Define the minimum amount of WETH to receive
-        uint256 minOut = amount;
+        uint256 minOut = amount * 1e12;
 
         // Perform swap from asset to WETH with minimum output requirement
         vm.expectRevert();

src/test/utils/Setup.sol

@@ -5,6 +5,7 @@ import "forge-std/console.sol";
 import {ExtendedTest} from "./ExtendedTest.sol";
 
 import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 
 import {VyperDeployer} from "./VyperDeployer.sol";
 import {IStrategy} from "@tokenized-strategy/interfaces/IStrategy.sol";
@@ -15,6 +16,8 @@ import {IVaultFactory} from "@yearn-vaults/interfaces/IVaultFactory.sol";
 import {MockStrategy} from "../mocks/MockStrategy.sol";
 
 contract Setup is ExtendedTest {
+    using SafeERC20 for ERC20;
+
     VyperDeployer public vyperDeployer = new VyperDeployer();
 
     // Contract instances that we will use repeatedly.
@@ -41,17 +44,17 @@ contract Setup is ExtendedTest {
     uint256 public MAX_BPS = 10_000;
 
     // Fuzz amount
-    uint256 public maxFuzzAmount = 1e24;
-    uint256 public minFuzzAmount = 100_000;
+    uint256 public maxFuzzAmount = 1e12;
+    uint256 public minFuzzAmount = MAX_BPS;
 
     // Default profit max unlock time is set for 10 days
     uint256 public profitMaxUnlockTime = 10 days;
 
     function setUp() public virtual {
         _setTokenAddrs();
 
-        // Set asset
-        asset = ERC20(tokenAddrs["DAI"]);
+        // Make sure everything works with USDT
+        asset = ERC20(tokenAddrs["USDT"]);
 
         // Set decimals
         decimals = asset.decimals();
@@ -122,11 +125,11 @@ contract Setup is ExtendedTest {
         address _user,
         uint256 _amount
     ) public {
-        vm.prank(_user);
-        asset.approve(address(_strategy), _amount);
+        vm.startPrank(_user);
+        asset.safeApprove(address(_strategy), _amount);
 
-        vm.prank(_user);
         _strategy.deposit(_amount, _user);
+        vm.stopPrank();
     }
 
     function mintAndDepositIntoStrategy(