Merge branch 'polygon' into master-v2

.commitlintrc.js

@@ -0,0 +1,7 @@
+module.exports = {
+  extends: ['@commitlint/config-conventional'],
+  rules: {
+    "scope-case": [2, 'always', 'lower-case'],
+    "subject-case": [2, 'always', 'sentence-case'],
+  }
+}

.husky/.gitignore

@@ -0,0 +1 @@
+_

.husky/commit-msg

@@ -0,0 +1,4 @@
+#!/bin/sh
+. "$(dirname "$0")/_/husky.sh"
+
+yarn commitlint --edit "$1"

.husky/pre-commit

@@ -0,0 +1,4 @@
+#!/bin/sh
+. "$(dirname "$0")/_/husky.sh"
+
+yarn lint:fix

contracts/feeders/InterestValidator.sol

@@ -5,6 +5,7 @@ import { IFeederPool } from "../interfaces/IFeederPool.sol";
 import { PausableModule } from "../shared/PausableModule.sol";
 import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+import { YieldValidator } from "../shared/YieldValidator.sol";
 
 /**
  * @title   InterestValidator
@@ -25,11 +26,6 @@ contract InterestValidator is PausableModule {
     );
     event GovFeeCollected(address indexed feederPool, address mAsset, uint256 amount);
 
-    // Utils to help keep interest under check
-    uint256 private constant SECONDS_IN_YEAR = 365 days;
-    // Theoretical cap on APY to avoid excess inflation
-    uint256 private constant MAX_APY = 15e18;
-
     mapping(address => uint256) public lastBatchCollected;
 
     constructor(address _nexus) PausableModule(_nexus) {}
@@ -60,7 +56,11 @@ contract InterestValidator is PausableModule {
             if (interestCollected > 0) {
                 // Validate APY
                 uint256 apy =
-                    _validateCollection(totalSupply, interestCollected, timeSincePreviousBatch);
+                    YieldValidator.validateCollection(
+                        totalSupply,
+                        interestCollected,
+                        timeSincePreviousBatch
+                    );
 
                 emit InterestCollected(feeder, interestCollected, totalSupply, apy);
             } else {
@@ -87,42 +87,14 @@ contract InterestValidator is PausableModule {
             if (fpTokenBal > 0) {
                 address mAsset = IFeederPool(fPool).mAsset();
                 uint256 outputAmt =
-                    IFeederPool(fPool).redeem(mAsset, fpTokenBal, (fpTokenBal * 7) / 10, savingsManager);
+                    IFeederPool(fPool).redeem(
+                        mAsset,
+                        fpTokenBal,
+                        (fpTokenBal * 7) / 10,
+                        savingsManager
+                    );
                 emit GovFeeCollected(fPool, mAsset, outputAmt);
             }
         }
     }
-
-    /**
-     * @dev Validates that an interest collection does not exceed a maximum APY. If last collection
-     * was under 30 mins ago, simply check it does not exceed 10bps
-     * @param _newSupply               New total supply of the mAsset
-     * @param _interest                Increase in total supply since last collection
-     * @param _timeSinceLastCollection Seconds since last collection
-     */
-    function _validateCollection(
-        uint256 _newSupply,
-        uint256 _interest,
-        uint256 _timeSinceLastCollection
-    ) internal pure returns (uint256 extrapolatedAPY) {
-        // Percentage increase in total supply
-        // e.g. (1e20 * 1e18) / 1e24 = 1e14 (or a 0.01% increase)
-        // e.g. (5e18 * 1e18) / 1.2e24 = 4.1667e12
-        // e.g. (1e19 * 1e18) / 1e21 = 1e16
-        uint256 oldSupply = _newSupply - _interest;
-        uint256 percentageIncrease = (_interest * 1e18) / oldSupply;
-
-        //      If over 30 mins, extrapolate APY
-        // e.g. day: (86400 * 1e18) / 3.154e7 = 2.74..e15
-        // e.g. 30 mins: (1800 * 1e18) / 3.154e7 = 5.7..e13
-        // e.g. epoch: (1593596907 * 1e18) / 3.154e7 = 50.4..e18
-        uint256 yearsSinceLastCollection = (_timeSinceLastCollection * 1e18) / SECONDS_IN_YEAR;
-
-        // e.g. 0.01% (1e14 * 1e18) / 2.74..e15 = 3.65e16 or 3.65% apr
-        // e.g. (4.1667e12 * 1e18) / 5.7..e13 = 7.1e16 or 7.1% apr
-        // e.g. (1e16 * 1e18) / 50e18 = 2e14
-        extrapolatedAPY = (percentageIncrease * 1e18) / yearsSinceLastCollection;
-
-        require(extrapolatedAPY < MAX_APY, "Interest protected from inflating past maxAPY");
-    }
 }

contracts/governance/ClaimableGovernor.sol

@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+pragma solidity 0.8.2;
+
+import { Governable } from "./Governable.sol";
+
+/**
+ * @title   ClaimableGovernor
+ * @author  mStable
+ * @notice  2 way handshake for Governance transfer
+ * @dev     Overrides the public functions in Governable to provide
+ * a second step of validation.
+ *          VERSION: 1.1
+ *          DATE:    2021-04-15
+ */
+contract ClaimableGovernor is Governable {
+    event GovernorChangeClaimed(address indexed proposedGovernor);
+    event GovernorChangeCancelled(address indexed governor, address indexed proposed);
+    event GovernorChangeRequested(address indexed governor, address indexed proposed);
+
+    address public proposedGovernor = address(0);
+
+    /**
+     * @dev Throws if called by any account other than the Proposed Governor.
+     */
+    modifier onlyProposedGovernor() {
+        require(msg.sender == proposedGovernor, "Sender is not proposed governor");
+        _;
+    }
+
+    constructor(address _governorAddr) {
+        _changeGovernor(_governorAddr);
+    }
+
+    // @override
+    function changeGovernor(address) external view override onlyGovernor {
+        revert("Direct change not allowed");
+    }
+
+    /**
+     * @dev Current Governor request to proposes a new Governor
+     * @param _proposedGovernor Address of the proposed Governor
+     */
+    function requestGovernorChange(address _proposedGovernor) public virtual onlyGovernor {
+        require(_proposedGovernor != address(0), "Proposed governor is address(0)");
+        require(proposedGovernor == address(0), "Proposed governor already set");
+
+        proposedGovernor = _proposedGovernor;
+        emit GovernorChangeRequested(governor(), _proposedGovernor);
+    }
+
+    /**
+     * @dev Current Governor cancel Governor change request
+     */
+    function cancelGovernorChange() public virtual onlyGovernor {
+        require(proposedGovernor != address(0), "Proposed Governor not set");
+
+        emit GovernorChangeCancelled(governor(), proposedGovernor);
+        proposedGovernor = address(0);
+    }
+
+    /**
+     * @dev Proposed Governor can claim governance ownership
+     */
+    function claimGovernorChange() public virtual onlyProposedGovernor {
+        _changeGovernor(proposedGovernor);
+        emit GovernorChangeClaimed(proposedGovernor);
+        proposedGovernor = address(0);
+    }
+}

contracts/governance/DelayedClaimableGovernor.sol

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+pragma solidity 0.8.2;
+
+import { ClaimableGovernor } from "./ClaimableGovernor.sol";
+
+/**
+ * @title   DelayedClaimableGovernor
+ * @author  mStable
+ * @notice  Current Governor can initiate governance change request.
+ *          After a defined delay, proposed Governor can claim governance
+ *          ownership.
+ *          VERSION: 1.1
+ *          DATE:    2021-04-15
+ */
+contract DelayedClaimableGovernor is ClaimableGovernor {
+    uint256 public delay = 0;
+    uint256 public requestTime = 0;
+
+    /**
+     * @dev Initializes the contract with given delay
+     * @param _governorAddr Initial governor
+     * @param _delay    Delay in seconds for 2 way handshake
+     */
+    constructor(address _governorAddr, uint256 _delay) ClaimableGovernor(_governorAddr) {
+        require(_delay > 0, "Delay must be greater than zero");
+        delay = _delay;
+    }
+
+    /**
+     * @dev Requests change of governor and logs request time
+     * @param _proposedGovernor Address of the new governor
+     */
+    function requestGovernorChange(address _proposedGovernor) public override onlyGovernor {
+        requestTime = block.timestamp;
+        super.requestGovernorChange(_proposedGovernor);
+    }
+
+    /**
+     * @dev Cancels an outstanding governor change request by resetting request time
+     */
+    function cancelGovernorChange() public override onlyGovernor {
+        requestTime = 0;
+        super.cancelGovernorChange();
+    }
+
+    /**
+     * @dev Proposed governor claims new position, callable after time elapsed
+     */
+    function claimGovernorChange() public override onlyProposedGovernor {
+        require(block.timestamp >= (requestTime + delay), "Delay not over");
+        super.claimGovernorChange();
+        requestTime = 0;
+    }
+}

contracts/governance/Governable.sol

@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+pragma solidity 0.8.2;
+
+/**
+ * @title   Governable
+ * @author  mStable
+ * @notice  Simple contract implementing an Ownable pattern.
+ * @dev     Derives from V2.3.0 @openzeppelin/contracts/ownership/Ownable.sol
+ *          Modified to have custom name and features
+ *              - Removed `renounceOwnership`
+ *              - Changes `_owner` to `_governor`
+ *          VERSION: 1.1
+ *          DATE:    2021-04-15
+ */
+contract Governable {
+    event GovernorChanged(address indexed previousGovernor, address indexed newGovernor);
+
+    address private _governor;
+
+    /**
+     * @dev Initializes the contract setting the deployer as the initial Governor.
+     */
+    constructor() {
+        _governor = msg.sender;
+        emit GovernorChanged(address(0), _governor);
+    }
+
+    /**
+     * @dev Returns the address of the current Governor.
+     */
+    function governor() public view virtual returns (address) {
+        return _governor;
+    }
+
+    /**
+     * @dev Throws if called by any account other than the Governor.
+     */
+    modifier onlyGovernor() {
+        require(isGovernor(), "GOV: caller is not the Governor");
+        _;
+    }
+
+    /**
+     * @dev Returns true if the caller is the current Governor.
+     */
+    function isGovernor() public view returns (bool) {
+        return msg.sender == _governor;
+    }
+
+    /**
+     * @dev Transfers Governance of the contract to a new account (`newGovernor`).
+     * Can only be called by the current Governor.
+     * @param _newGovernor Address of the new Governor
+     */
+    function changeGovernor(address _newGovernor) external virtual onlyGovernor {
+        _changeGovernor(_newGovernor);
+    }
+
+    /**
+     * @dev Change Governance of the contract to a new account (`newGovernor`).
+     * @param _newGovernor Address of the new Governor
+     */
+    function _changeGovernor(address _newGovernor) internal {
+        require(_newGovernor != address(0), "GOV: new Governor is address(0)");
+        emit GovernorChanged(_governor, _newGovernor);
+        _governor = _newGovernor;
+    }
+}

contracts/interfaces/IEjector.sol

@@ -8,5 +8,5 @@ pragma solidity 0.8.2;
 interface IEjector {
     function ejectMany(address[] calldata _users) external;
 
-    function votingLockup() view external returns (address);
+    function votingLockup() external view returns (address);
 }

contracts/interfaces/IInvariantValidator.sol

@@ -46,7 +46,7 @@ abstract contract IInvariantValidator {
 
     function computePrice(BassetData[] memory _bAssets, InvariantConfig memory _config)
         public
-        virtual
         pure
+        virtual
         returns (uint256 price, uint256 k);
 }

contracts/interfaces/ISavingsManager.sol

@@ -18,5 +18,5 @@ interface ISavingsManager {
     function collectAndDistributeInterest(address _mAsset) external;
 
     /** @dev getter for public lastBatchCollected mapping */
-    function lastBatchCollected(address _mAsset) view external returns (uint256);
+    function lastBatchCollected(address _mAsset) external view returns (uint256);
 }