Merge 32b130d into bff8877

.gitignore

@@ -13,8 +13,10 @@
 abis
 artifacts
 cache
+deployments/localhost/
 node_modules
 types
+deployments/localhost/
 
 # Solidity Coverage
 coverage

.prettierignore

@@ -0,0 +1 @@
+types

.prettierrc

@@ -0,0 +1,6 @@
+{
+  "printWidth": 100,
+  "singleQuote": true,
+  "trailingComma": "all",
+  "tabWidth": 2
+}

Constant.ts

@@ -1,10 +1,5 @@
-export const ADAI_ADDRESS_KOVAN = '0xdCf0aF9e59C002FA3AA091a46196b37530FD48a8';
-export const LENDING_POOL_ADDRESSES_PROVIDER_REGISTRY_ADDRESS_KOVAN =
-  '0x1E40B561EC587036f9789aF83236f057D1ed2A90';
-
 export const USDC_VAULT_ADDRESS_MAINNET = '0x5f18C75AbDAe578b483E5F43f12a39cF75b973a9';
-export const USDC_ADDRESS_MAINNET =
-  '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48';
+export const USDC_ADDRESS_MAINNET = '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48';
 
 export const DAI_VAULT_ADDRESS_MAINNET = '0x19D3364A399d251E894aC732651be8B0E4e85001';
 export const DAI_ADDRESS_MAINNET = '0x6B175474E89094C44Da98b954EedeAC495271d0F';
@@ -14,4 +9,4 @@ export const BINANCE7_ADDRESS = '0xBE0eB53F46cd790Cd13851d5EFf43D12404d33E8';
 export const DAI_RICH_ADDRESS = '0xF977814e90dA44bFA03b6295A0616a897441aceC';
 export const USDC_RICH_ADDRESS = '0x55FE002aefF02F77364de339a1292923A15844B8';
 
-export const YEARN_GOV_ADDRESS = '0x0';
+export const YEARN_GOV_ADDRESS = '0x0';

README.md

@@ -6,10 +6,11 @@
 
 <br />
 
-# PoolTogether YearnV2 Yield Source 👻
-
-[![Coverage Status](https://coveralls.io/repos/github/jmonteer/pooltogether-yearnv2-yield-source/badge.svg?branch=master)](https://coveralls.io/github/jmonteer/pooltogether-yearnv2-yield-source?branch=master) [![built-with openzeppelin](https://img.shields.io/badge/built%20with-OpenZeppelin-3677FF)](https://docs.openzeppelin.com/) [![Coveralls](https://github.com/jmonteer/pooltogether-yearnv2-yield-source/actions/workflows/main.yml/badge.svg)](https://github.com/jmonteer/pooltogether-yearnv2-yield-source/actions/workflows/main.yml)
+# PoolTogether YearnV2 Yield Source
 
+[![Coverage Status](https://coveralls.io/repos/github/pooltogether/pooltogether-yearnv2-yield-source/badge.svg?branch=master)](https://coveralls.io/github/pooltogether/pooltogether-yearnv2-yield-source?branch=master)
+[![Coveralls](https://github.com/pooltogether/pooltogether-yearnv2-yield-source/actions/workflows/main.yml/badge.svg)](https://github.com/pooltogether/pooltogether-yearnv2-yield-source/actions/workflows/main.yml)
+[![built-with openzeppelin](https://img.shields.io/badge/built%20with-OpenZeppelin-3677FF)](https://docs.openzeppelin.com/)
 
 PoolTogether Yield Source that uses [Yearn](https://yearn.finance/) V2 to generate yield by depositing the deposit token in any Yearn Vault that accepts that token.
 
@@ -89,7 +90,7 @@ Start Mainnet fork in a terminal window with the command:
 yarn start-fork
 ```
 
-In another window, start the scripts to deploy and create a YearnV2 Yield Source Prize Pool, deposit USDC into it, send some profit to the Vault, award the prize and withdraw. 
+In another window, start the scripts to deploy and create a YearnV2 Yield Source Prize Pool, deposit USDC into it, send some profit to the Vault, award the prize and withdraw.
 
 ```
 yarn deploy-fork && yarn run-fork

contracts/external/yearn/IYVaultV2.sol

@@ -35,7 +35,7 @@ interface IYVaultV2 is IERC20 {
 
     function withdraw(uint256 maxShares) external returns (uint256);
 
-    // function withdraw(uint256 maxShares, address recipient) external returns (uint256);
+    function withdraw(uint256 maxShares, address recipient) external returns (uint256);
 
     function withdraw(uint256 maxShares, address recipient, uint256 maxLoss) external returns (uint256);
 
@@ -118,4 +118,4 @@ interface IYVaultV2 is IERC20 {
      * is subject to guardian defined by the Vault.
      */
     function guardian() external view returns (address);
-}
+}

contracts/yield-source/YearnV2YieldSource.sol

@@ -9,6 +9,7 @@ import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
 import "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";
 import "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
 import "@openzeppelin/contracts-upgradeable/token/ERC20/SafeERC20Upgradeable.sol";
+import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
 import "@openzeppelin/contracts-upgradeable/utils/ReentrancyGuardUpgradeable.sol";
 
 
@@ -18,13 +19,16 @@ import "@openzeppelin/contracts-upgradeable/utils/ReentrancyGuardUpgradeable.sol
 /// @dev are not compatible, as they had dips in shareValue due to a small miscalculation
 /// @notice Yield Source Prize Pools subclasses need to implement this interface so that yield can be generated.
 contract YearnV2YieldSource is IYieldSource, ERC20Upgradeable, OwnableUpgradeable, ReentrancyGuardUpgradeable {
+    using AddressUpgradeable for address;
     using SafeERC20Upgradeable for IERC20Upgradeable;
     using SafeMathUpgradeable for uint;
-    
+
     /// @notice Yearn Vault which manages `token` to generate yield
     IYVaultV2 public vault;
+
     /// @dev Deposit Token contract address
-    IERC20Upgradeable internal token; 
+    IERC20Upgradeable internal token;
+
     /// @dev Max % of losses that the Yield Source will accept from the Vault in BPS
     uint256 public maxLosses = 0; // 100% would be 10_000
 
@@ -33,11 +37,13 @@ contract YearnV2YieldSource is IYieldSource, ERC20Upgradeable, OwnableUpgradeabl
         address indexed user,
         uint256 amount
     );
-    
+
     /// @notice Emitted when the yield source is initialized
-    event YieldSourceYearnV2Initialized(
+    event YearnV2YieldSourceInitialized(
         IYVaultV2 vault,
-        IERC20Upgradeable token
+        uint8 decimals,
+        string symbol,
+        string name
     );
 
     /// @notice Emitted when the Max Losses accepted when withdrawing from yVault are changed
@@ -60,44 +66,81 @@ contract YearnV2YieldSource is IYieldSource, ERC20Upgradeable, OwnableUpgradeabl
         uint256 amount
     );
 
-    /// @notice Initializes the yield source with 
-    /// @param _vault YearnV2 Vault in which the Yield Source will deposit `token` to generate Yield
-    /// @param _token Underlying Token / Deposit Token
+    /// @notice Mock Initializer to initialize implementations used by minimal proxies.
+    function freeze() public initializer {
+        //no-op
+    }
+
+    /// @notice Initializes the yield source with
+    /// @param _vault Yearn V2 Vault in which the Yield Source will deposit `token` to generate Yield
+    /// @param _decimals Number of decimals the shares (inherited ERC20) will have.  Same as underlying asset to ensure same ExchangeRates.
+    /// @param _symbol Token symbol for the underlying ERC20 shares (eg: yvysDAI).
+    /// @param _name Token name for the underlying ERC20 shares (eg: PoolTogether Yearn V2 Vault DAI Yield Source).
     function initialize(
         IYVaultV2 _vault,
-        IERC20Upgradeable _token
-    ) 
-        public 
+        uint8 _decimals,
+        string calldata _symbol,
+        string calldata _name
+    )
+        public
         initializer
+        returns (bool)
     {
-        require(address(vault) == address(0), "YearnV2YieldSource:: already initialized");
-        require(_vault.token() == address(_token), "YearnV2YieldSource:: incorrect vault");
-        require(_vault.activation() != uint256(0), "YearnV2YieldSource:: vault not initialized");
+        require(address(_vault) != address(0), "YearnV2YieldSource/vault-not-zero-address");
+        require(_vault.activation() != uint256(0), "YearnV2YieldSource/vault-not-initialized");
+
         // NOTE: Vaults from 0.3.2 to 0.3.4 have dips in shareValue
-        require(!areEqualStrings(_vault.apiVersion(), "0.3.2"), "YearnV2YieldSource:: vault not compatible");
-        require(!areEqualStrings(_vault.apiVersion(), "0.3.3"), "YearnV2YieldSource:: vault not compatible");
-        require(!areEqualStrings(_vault.apiVersion(), "0.3.4"), "YearnV2YieldSource:: vault not compatible");
+        string memory _vaultAPIVersion = _vault.apiVersion();
+
+        require(!_areEqualStrings(_vaultAPIVersion, "0.3.2"), "YearnV2YieldSource/vault-not-compatible");
+        require(!_areEqualStrings(_vaultAPIVersion, "0.3.3"), "YearnV2YieldSource/vault-not-compatible");
+        require(!_areEqualStrings(_vaultAPIVersion, "0.3.4"), "YearnV2YieldSource/vault-not-compatible");
 
         vault = _vault;
-        token = _token;
+        token = IERC20Upgradeable(_vault.token());
 
         __Ownable_init();
         __ReentrancyGuard_init();
 
-        _token.safeApprove(address(vault), type(uint256).max);
+        __ERC20_init(_name, _symbol);
+        require(_decimals > 0, "YearnV2YieldSource/decimals-not-greater-than-zero");
+        _setupDecimals(_decimals);
 
-        emit YieldSourceYearnV2Initialized(
+        token.safeApprove(address(_vault), type(uint256).max);
+
+        emit YearnV2YieldSourceInitialized(
             _vault,
-            _token
+            _decimals,
+            _symbol,
+            _name
         );
+
+        return true;
     }
 
-    function setMaxLosses(uint256 _maxLosses) external onlyOwner {
-        require(_maxLosses <= 10_000, "YearnV2YieldSource:: losses set too high");
+    /// @notice Approve vault contract to spend max uint256 amount
+    /// @dev Emergency function to re-approve max amount if approval amount dropped too low
+    /// @return true if operation is successful
+    function approveMaxAmount() external onlyOwner returns (bool) {
+        address _vault = address(vault);
+        IERC20Upgradeable _token = token;
+        uint256 allowance = _token.allowance(address(this), _vault);
+
+        _token.safeIncreaseAllowance(_vault, type(uint256).max.sub(allowance));
+        return true;
+    }
+
+    /// @notice Sets the maximum acceptable loss to sustain on withdrawal.
+    /// @dev This function is only callable by the owner of the yield source.
+    /// @param _maxLosses Max Losses in double decimal precision.
+    /// @return True if maxLosses was set successfully.
+    function setMaxLosses(uint256 _maxLosses) external onlyOwner returns(bool) {
+        require(_maxLosses <= 10_000, "YearnV2YieldSource/losses-set-too-high");
 
         maxLosses = _maxLosses;
 
         emit MaxLossesChanged(_maxLosses);
+        return true;
     }
 
     /// @notice Returns the ERC20 asset token used for deposits
@@ -168,9 +211,12 @@ contract YearnV2YieldSource is IYieldSource, ERC20Upgradeable, OwnableUpgradeabl
     /// @return The actual amount of shares that were received for the deposited tokens
     function _depositInVault() internal returns (uint256) {
         IYVaultV2 v = vault; // NOTE: for gas usage
-        if(token.allowance(address(this), address(v)) < token.balanceOf(address(this))) {
-            token.safeApprove(address(v), type(uint256).max);
+        IERC20Upgradeable _token = token;
+
+        if (_token.allowance(address(this), address(v)) < _token.balanceOf(address(this))) {
+            _token.safeApprove(address(v), type(uint256).max);
         }
+
         // this will deposit full balance (for cases like not enough room in Vault)
         return v.deposit();
     }
@@ -181,17 +227,23 @@ contract YearnV2YieldSource is IYieldSource, ERC20Upgradeable, OwnableUpgradeabl
     /// @param amount amount of asset tokens to be redeemed
     /// @return Tokens received from the Vault
     function _withdrawFromVault(uint amount) internal returns (uint256) {
+        IERC20Upgradeable _token = token;
+        IYVaultV2 _vault = vault;
         uint256 yShares = _tokenToYShares(amount);
-        uint256 previousBalance = token.balanceOf(address(this));
+        uint256 previousBalance = _token.balanceOf(address(this));
+
         // we accept losses to avoid being locked in the Vault (if losses happened for some reason)
-        if(maxLosses != 0) {
-            vault.withdraw(yShares, address(this), maxLosses);
+        uint256 _maxLosses = maxLosses;
+
+        if (_maxLosses != 0) {
+            _vault.withdraw(yShares, address(this), _maxLosses);
         } else {
-            vault.withdraw(yShares);
+            _vault.withdraw(yShares, address(this));
         }
-        uint256 currentBalance = token.balanceOf(address(this));
 
-        return previousBalance.sub(currentBalance);
+        uint256 currentBalance = _token.balanceOf(address(this));
+
+        return currentBalance.sub(previousBalance);
     }
 
     /// @notice Returns the amount of shares of yearn's vault that the Yield Source holds
@@ -222,7 +274,7 @@ contract YearnV2YieldSource is IYieldSource, ERC20Upgradeable, OwnableUpgradeabl
     }
 
     /// @notice Support function to retrieve used by Vault
-    /// @dev used to correctly scale prices 
+    /// @dev used to correctly scale prices
     /// @return decimals of vault's shares (and underlying token)
     function _vaultDecimals() internal view returns (uint256) {
         return vault.decimals();
@@ -237,7 +289,7 @@ contract YearnV2YieldSource is IYieldSource, ERC20Upgradeable, OwnableUpgradeabl
         return tokens.mul(10 ** _vaultDecimals()).div(_pricePerYShare());
     }
 
-    /// @notice Converter from deposit yShares (yearn vault's shares) to token 
+    /// @notice Converter from deposit yShares (yearn vault's shares) to token
     /// @param yShares Vault's shares to be converted
     /// @return tokens that will be received if yShares shares are redeemed
     function _ySharesToToken(uint256 yShares) internal view returns (uint256) {
@@ -248,11 +300,13 @@ contract YearnV2YieldSource is IYieldSource, ERC20Upgradeable, OwnableUpgradeabl
     /// @param tokens amount of tokens to be converted
     /// @return shares number of shares equivalent to the amount of tokens
     function _tokenToShares(uint256 tokens) internal view returns (uint256 shares) {
-        if(totalSupply() == 0) {
+        uint256 _totalSupply = totalSupply();
+
+        if (_totalSupply == 0) {
             shares = tokens;
         } else {
             uint256 _totalTokens = _totalAssetsInToken();
-            shares = tokens.mul(totalSupply()).div(_totalTokens);
+            shares = tokens.mul(_totalSupply).div(_totalTokens);
         }
     }
 
@@ -261,19 +315,21 @@ contract YearnV2YieldSource is IYieldSource, ERC20Upgradeable, OwnableUpgradeabl
     /// @dev used to calculate how many shares to mint / burn when depositing / withdrawing
     /// @return tokens number of tokens equivalent (in value) to the amount of Yield Source shares
     function _sharesToToken(uint256 shares) internal view returns (uint256 tokens) {
-        if(totalSupply() == 0) {
+        uint256 _totalSupply = totalSupply();
+
+        if (_totalSupply == 0) {
             tokens = shares;
         } else {
             uint256 _totalTokens = _totalAssetsInToken();
-            tokens = shares.mul(_totalTokens).div(totalSupply());
+            tokens = shares.mul(_totalTokens).div(_totalSupply);
         }
     }
 
     /// @notice Pure support function to compare strings
     /// @param a One string
     /// @param b Another string
     /// @return Whether or not the strings are the same or not
-    function areEqualStrings(string memory a, string memory b) internal pure returns (bool) {
+    function _areEqualStrings(string memory a, string memory b) internal pure returns (bool) {
         return keccak256(abi.encodePacked(a)) == keccak256(abi.encodePacked(b));
     }
-}
+}