Feat/pricer fixes

contracts/mocks/MockDumbERC20.sol

@@ -62,7 +62,7 @@ contract MockDumbERC20 {
         return true;
     }
 
-    function allowance(address owner, address spender) public view virtual returns (uint256) {
+    function allowance(address owner, address spender) public virtual view returns (uint256) {
         return _allowances[owner][spender];
     }
 

contracts/packages/oz/Context.sol

@@ -14,11 +14,11 @@ pragma solidity 0.6.10;
  * This contract is only required for intermediate, library-like contracts.
  */
 abstract contract Context {
-    function _msgSender() internal view virtual returns (address payable) {
+    function _msgSender() internal virtual view returns (address payable) {
         return msg.sender;
     }
 
-    function _msgData() internal view virtual returns (bytes memory) {
+    function _msgData() internal virtual view returns (bytes memory) {
         this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
         return msg.data;
     }

contracts/packages/oz/upgradeability/ERC20Upgradeable.sol

@@ -100,14 +100,14 @@ contract ERC20Upgradeable is Initializable, ContextUpgradeable, IERC20Upgradeabl
     /**
      * @dev See {IERC20-totalSupply}.
      */
-    function totalSupply() public view override returns (uint256) {
+    function totalSupply() public override view returns (uint256) {
         return _totalSupply;
     }
 
     /**
      * @dev See {IERC20-balanceOf}.
      */
-    function balanceOf(address account) public view override returns (uint256) {
+    function balanceOf(address account) public override view returns (uint256) {
         return _balances[account];
     }
 
@@ -127,7 +127,7 @@ contract ERC20Upgradeable is Initializable, ContextUpgradeable, IERC20Upgradeabl
     /**
      * @dev See {IERC20-allowance}.
      */
-    function allowance(address owner, address spender) public view virtual override returns (uint256) {
+    function allowance(address owner, address spender) public virtual override view returns (uint256) {
         return _allowances[owner][spender];
     }
 

contracts/packages/oz/upgradeability/GSN/ContextUpgradeable.sol

@@ -22,11 +22,11 @@ abstract contract ContextUpgradeable is Initializable {
 
     function __Context_init_unchained() internal initializer {}
 
-    function _msgSender() internal view virtual returns (address payable) {
+    function _msgSender() internal virtual view returns (address payable) {
         return msg.sender;
     }
 
-    function _msgData() internal view virtual returns (bytes memory) {
+    function _msgData() internal virtual view returns (bytes memory) {
         this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
         return msg.data;
     }

contracts/packages/oz/upgradeability/Proxy.sol

@@ -12,7 +12,7 @@ abstract contract Proxy {
      * @dev Tells the address of the implementation where every call will be delegated.
      * @return address of the implementation to which it will be delegated
      */
-    function implementation() public view virtual returns (address);
+    function implementation() public virtual view returns (address);
 
     /**
      * @dev Fallback function allowing to perform a delegatecall to the given implementation.
@@ -30,12 +30,12 @@ abstract contract Proxy {
             returndatacopy(ptr, 0, size)
 
             switch result
-            case 0 {
-                revert(ptr, size)
-            }
-            default {
-                return(ptr, size)
-            }
+                case 0 {
+                    revert(ptr, size)
+                }
+                default {
+                    return(ptr, size)
+                }
         }
     }
 }

contracts/packages/oz/upgradeability/UpgradeabilityProxy.sol

@@ -23,7 +23,7 @@ contract UpgradeabilityProxy is Proxy {
      * @dev Tells the address of the current implementation
      * @return impl address of the current implementation
      */
-    function implementation() public view override returns (address impl) {
+    function implementation() public override view returns (address impl) {
         bytes32 position = implementationPosition;
         assembly {
             impl := sload(position)

contracts/packages/oz/upgradeability/erc20-permit/EIP712Upgradeable.sol

@@ -25,8 +25,9 @@ abstract contract EIP712Upgradeable is Initializable {
     /* solhint-disable var-name-mixedcase */
     bytes32 private _HASHED_NAME;
     bytes32 private _HASHED_VERSION;
-    bytes32 private constant _TYPE_HASH =
-        keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");
+    bytes32 private constant _TYPE_HASH = keccak256(
+        "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
+    );
 
     /* solhint-enable var-name-mixedcase */
 
@@ -101,7 +102,7 @@ abstract contract EIP712Upgradeable is Initializable {
      * NOTE: This function reads from storage by default, but can be redefined to return a constant value if gas costs
      * are a concern.
      */
-    function _EIP712NameHash() internal view virtual returns (bytes32) {
+    function _EIP712NameHash() internal virtual view returns (bytes32) {
         return _HASHED_NAME;
     }
 
@@ -111,7 +112,7 @@ abstract contract EIP712Upgradeable is Initializable {
      * NOTE: This function reads from storage by default, but can be redefined to return a constant value if gas costs
      * are a concern.
      */
-    function _EIP712VersionHash() internal view virtual returns (bytes32) {
+    function _EIP712VersionHash() internal virtual view returns (bytes32) {
         return _HASHED_VERSION;
     }
 

contracts/packages/oz/upgradeability/erc20-permit/ERC20PermitUpgradeable.sol

@@ -79,15 +79,15 @@ abstract contract ERC20PermitUpgradeable is
     /**
      * @dev See {IERC20Permit-nonces}.
      */
-    function nonces(address owner) public view override returns (uint256) {
+    function nonces(address owner) public override view returns (uint256) {
         return _nonces[owner].current();
     }
 
     /**
      * @dev See {IERC20Permit-DOMAIN_SEPARATOR}.
      */
     // solhint-disable-next-line func-name-mixedcase
-    function DOMAIN_SEPARATOR() external view override returns (bytes32) {
+    function DOMAIN_SEPARATOR() external override view returns (bytes32) {
         return _domainSeparatorV4();
     }
 

contracts/pricers/ChainlinkPricer.sol

@@ -52,25 +52,35 @@ contract ChainLinkPricer is OpynPricerInterface {
         aggregatorDecimals = uint256(aggregator.decimals());
     }
 
-    /**
-     * @notice modifier to check if sender address is equal to bot address
-     */
-    modifier onlyBot() {
-        require(msg.sender == bot, "ChainLinkPricer: unauthorized sender");
-
-        _;
-    }
-
     /**
      * @notice set the expiry price in the oracle, can only be called by Bot address
      * @dev a roundId must be provided to confirm price validity, which is the first Chainlink price provided after the expiryTimestamp
      * @param _expiryTimestamp expiry to set a price for
      * @param _roundId the first roundId after expiryTimestamp
      */
-    function setExpiryPriceInOracle(uint256 _expiryTimestamp, uint80 _roundId) external onlyBot {
+    function setExpiryPriceInOracle(uint256 _expiryTimestamp, uint80 _roundId) external {
         (, int256 price, , uint256 roundTimestamp, ) = aggregator.getRoundData(_roundId);
 
-        require(_expiryTimestamp <= roundTimestamp, "ChainLinkPricer: invalid roundId");
+        require(_expiryTimestamp <= roundTimestamp, "ChainLinkPricer: roundId not first after expiry");
+        require(price >= 0, "ChainLinkPricer: invalid price");
+
+        if (msg.sender != bot) {
+            bool isCorrectRoundId;
+            uint80 previousRoundId = uint80(uint256(_roundId).sub(1));
+
+            while (!isCorrectRoundId) {
+                (, , , uint256 previousRoundTimestamp, ) = aggregator.getRoundData(previousRoundId);
+
+                if (previousRoundTimestamp == 0) {
+                    require(previousRoundId > 0, "ChainLinkPricer: Invalid previousRoundId");
+                    previousRoundId = previousRoundId - 1;
+                } else if (previousRoundTimestamp > _expiryTimestamp) {
+                    revert("ChainLinkPricer: previousRoundId not last before expiry");
+                } else {
+                    isCorrectRoundId = true;
+                }
+            }
+        }
 
         oracle.setExpiryPrice(asset, _expiryTimestamp, uint256(price));
     }