Migrate contracts & add husky precommits (mstable#167)

* chore: Migrate SavingsManager and add Husky precommits

* chore: Add husky precommits

* chore: Import SavingsManager

* fix: Remove duplicate Uniswap interface

* chore: Migrate SM test cases

.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

@@ -13,7 +13,6 @@ import { Governable } from "./Governable.sol";
  *          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);
@@ -67,4 +66,4 @@ contract ClaimableGovernor is Governable {
         emit GovernorChangeClaimed(proposedGovernor);
         proposedGovernor = address(0);
     }
-}
+}

contracts/governance/DelayedClaimableGovernor.sol

@@ -13,7 +13,6 @@ import { ClaimableGovernor } from "./ClaimableGovernor.sol";
  *          DATE:    2021-04-15
  */
 contract DelayedClaimableGovernor is ClaimableGovernor {
-
     uint256 public delay = 0;
     uint256 public requestTime = 0;
 
@@ -22,9 +21,7 @@ contract DelayedClaimableGovernor is ClaimableGovernor {
      * @param _governorAddr Initial governor
      * @param _delay    Delay in seconds for 2 way handshake
      */
-    constructor(address _governorAddr, uint256 _delay)
-        ClaimableGovernor(_governorAddr)
-    {
+    constructor(address _governorAddr, uint256 _delay) ClaimableGovernor(_governorAddr) {
         require(_delay > 0, "Delay must be greater than zero");
         delay = _delay;
     }
@@ -54,4 +51,4 @@ contract DelayedClaimableGovernor is ClaimableGovernor {
         super.claimGovernorChange();
         requestTime = 0;
     }
-}
+}

contracts/governance/Governable.sol

@@ -13,12 +13,10 @@ pragma solidity 0.8.2;
  *          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.
      */
@@ -67,4 +65,4 @@ contract Governable {
         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/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);
 }

contracts/masset/liquidator/ICurveMetaPool.sol

@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+pragma solidity 0.8.2;
+
+interface ICurveMetaPool {
+    function exchange_underlying(int128 i, int128 j, uint256 dx, uint256 min_dy) external returns (uint256);
+    function get_dy(int128 i, int128 j, uint256 dx) external view returns (uint256);
+}

contracts/masset/liquidator/ILiquidator.sol

@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+pragma solidity 0.8.2;
+
+interface ILiquidator {
+
+    function createLiquidation(
+        address _integration,
+        address _sellToken,
+        address _bAsset,
+        int128 _curvePosition,
+        address[] calldata _uniswapPath,
+        uint256 _trancheAmount,
+        uint256 _minReturn
+    )
+        external;
+
+    function updateBasset(
+        address _integration,
+        address _bAsset,
+        int128 _curvePosition,
+        address[] calldata _uniswapPath,
+        uint256 _trancheAmount,
+        uint256 _minReturn
+    )
+        external;
+
+    function deleteLiquidation(address _integration) external;
+
+    function triggerLiquidation(address _integration) external;
+}