add unguarded initializer

contracts/SushiYieldSource.sol

@@ -13,17 +13,22 @@ import "./ISushiBar.sol";
 contract SushiYieldSource is IYieldSource {
     using SafeERC20 for IERC20;
     using SafeMath for uint256;
-    
+
     ISushiBar public immutable sushiBar;
     IERC20 public immutable sushiAddr;
-    
+
     mapping(address => uint256) public balances;
 
     constructor(ISushiBar _sushiBar, IERC20 _sushiAddr) public {
         sushiBar = _sushiBar;
         sushiAddr = _sushiAddr;
     }
 
+    /// @notice Approve SUSHI to spend infinite sushiBar (xSUSHI)
+    function intialize() external {
+        sushiAddr.safeApprove(address(sushiBar), type(uint256).max);
+    }
+
     /// @notice Returns the ERC20 asset token used for deposits.
     /// @return The ERC20 asset token
     function depositToken() public view override returns (address) {
@@ -38,56 +43,55 @@ contract SushiYieldSource is IYieldSource {
         uint256 totalShares = sushiBar.totalSupply();
         uint256 barSushiBalance = sushiAddr.balanceOf(address(sushiBar));
 
-        return balances[addr].mul(barSushiBalance).div(totalShares);       
+        return balances[addr].mul(barSushiBalance).div(totalShares);
     }
 
     /// @notice Allows assets to be supplied on other user's behalf using the `to` param.
     /// @param amount The amount of `token()` to be supplied
     /// @param to The user whose balance will receive the tokens
     function supplyTokenTo(uint256 amount, address to) public override {
         sushiAddr.safeTransferFrom(msg.sender, address(this), amount);
-        sushiAddr.approve(address(sushiBar), amount);
 
         ISushiBar bar = sushiBar;
         uint256 beforeBalance = bar.balanceOf(address(this));
-        
+
         bar.enter(amount);
-        
+
         uint256 afterBalance = bar.balanceOf(address(this));
         uint256 balanceDiff = afterBalance.sub(beforeBalance);
-        
+
         balances[to] = balances[to].add(balanceDiff);
     }
 
     /// @notice Redeems tokens from the yield source to the msg.sender, it burns yield bearing tokens and returns token to the sender.
     /// @param amount The amount of `token()` to withdraw.  Denominated in `token()` as above.
     /// @dev The maxiumum that can be called for token() is calculated by balanceOfToken() above.
-    /// @return The actual amount of tokens that were redeemed. This may be different from the amount passed due to the fractional math involved. 
+    /// @return The actual amount of tokens that were redeemed. This may be different from the amount passed due to the fractional math involved.
     function redeemToken(uint256 amount) public override returns (uint256) {
         ISushiBar bar = sushiBar;
         IERC20 sushi = sushiAddr;
-        
+
         uint256 totalShares = bar.totalSupply();
-        if(totalShares == 0) return 0; 
+        if (totalShares == 0) return 0;
 
         uint256 barSushiBalance = sushi.balanceOf(address(bar));
-        if(barSushiBalance == 0) return 0;
+        if (barSushiBalance == 0) return 0;
 
         uint256 sushiBeforeBalance = sushi.balanceOf(address(this));
 
         uint256 requiredShares = ((amount.mul(totalShares) + totalShares)).div(barSushiBalance);
-        if(requiredShares == 0) return 0;
-        
+        if (requiredShares == 0) return 0;
+
         uint256 requiredSharesBalance = requiredShares.sub(1);
         bar.leave(requiredSharesBalance);
 
         uint256 sushiAfterBalance = sushi.balanceOf(address(this));
-        
+
         uint256 sushiBalanceDiff = sushiAfterBalance.sub(sushiBeforeBalance);
 
         balances[msg.sender] = balances[msg.sender].sub(requiredSharesBalance);
         sushi.safeTransfer(msg.sender, sushiBalanceDiff);
-        
+
         return (sushiBalanceDiff);
     }
 

test/integration_test.js

@@ -144,6 +144,8 @@ describe("SushiYieldSource integration", function () {
       "0x6B3595068778DD592e39A122f4f5a5cF09C90fE2",
       { gasLimit: 9500000 }
     );
+    await yieldSource.intialize()
+
     const yieldSourcePrizePoolConfig = {
       yieldSource: yieldSource.address,
       maxExitFeeMantissa: toWei("0.5"),

test/unit_test.js

@@ -42,6 +42,7 @@ describe("SushiYieldSource", function () {
       overrides
     );
     amount = toWei("100");
+    await yieldSource.intialize()
     await sushi.mint(wallet.address, amount);
     await sushi.mint(wallet2.address, amount.mul(99));
     await sushi.connect(wallet2).approve(sushiBar.address, amount.mul(99));