From 4ee168bb47fd26958fa0b8dd9a7d87983e725601 Mon Sep 17 00:00:00 2001
From: Lucas Manuel <lucas@maple.finance>
Date: Thu, 3 Nov 2022 00:50:47 -0400
Subject: [PATCH] feat: Update to add `acceptLender` function (SC-9368) (#67)

* feat: update to add acceptLender function

* fix: rm unused vars and use expectRevert
---
 contracts/DebtLocker.sol             | 23 +++++++++++++++++------
 contracts/interfaces/IDebtLocker.sol |  5 +++++
 contracts/interfaces/Interfaces.sol  |  2 ++
 tests/DebtLocker.t.sol               | 19 ++++++++++++++++++-
 tests/accounts/LoanMigrator.sol      |  8 ++++++++
 tests/mocks/Mocks.sol                |  8 ++++++++
 6 files changed, 58 insertions(+), 7 deletions(-)

diff --git a/contracts/DebtLocker.sol b/contracts/DebtLocker.sol
index 4d6ebf3..e383a3f 100644
--- a/contracts/DebtLocker.sol
+++ b/contracts/DebtLocker.sol
@@ -45,6 +45,23 @@ contract DebtLocker is IDebtLocker, DebtLockerStorage, MapleProxiedInternals {
         IMapleProxyFactory(_factory()).upgradeInstance(toVersion_, arguments_);
     }
 
+    /*************************************/
+    /*** Liquidity Migration Functions ***/
+    /*************************************/
+
+    function acceptLender() override external whenProtocolNotPaused {
+        require(msg.sender == _loanMigrator, "DL:AL:NOT_MIGRATOR");
+
+        IMapleLoanLike(_loan).acceptLender();
+    }
+
+    function setPendingLender(address newLender_) override external whenProtocolNotPaused {
+        require(msg.sender == _loanMigrator, "DL:SPL:NOT_MIGRATOR");
+
+        IMapleLoanLike(_loan).setPendingLender(newLender_);
+    }
+
+
     /*******************************/
     /*** Pool Delegate Functions ***/
     /*******************************/
@@ -110,12 +127,6 @@ contract DebtLocker is IDebtLocker, DebtLockerStorage, MapleProxiedInternals {
         emit FundsToCaptureSet(_fundsToCapture = amount_);
     }
 
-    function setPendingLender(address newLender_) override external whenProtocolNotPaused {
-        require(msg.sender == _loanMigrator, "DL:SPL:NOT_MIGRATOR");
-
-        IMapleLoanLike(_loan).setPendingLender(newLender_);
-    }
-
     function setMinRatio(uint256 minRatio_) external override whenProtocolNotPaused {
         require(msg.sender == _getPoolDelegate(), "DL:SMR:NOT_PD");
 
diff --git a/contracts/interfaces/IDebtLocker.sol b/contracts/interfaces/IDebtLocker.sol
index 3bf0ac0..575eb0f 100644
--- a/contracts/interfaces/IDebtLocker.sol
+++ b/contracts/interfaces/IDebtLocker.sol
@@ -43,6 +43,11 @@ interface IDebtLocker is IMapleProxied {
     /*** Functions ***/
     /*****************/
 
+    /**
+     * @dev Accepts the lender on a Maple Loan.
+     */
+    function acceptLender() external;
+
     /**
      * @dev   Accept the new loan terms and trigger a refinance.
      * @param refinancer_ The address of the refinancer contract.
diff --git a/contracts/interfaces/Interfaces.sol b/contracts/interfaces/Interfaces.sol
index a0518fe..9558d95 100644
--- a/contracts/interfaces/Interfaces.sol
+++ b/contracts/interfaces/Interfaces.sol
@@ -36,6 +36,8 @@ interface IMapleGlobalsLike {
 
 interface IMapleLoanLike {
 
+    function acceptLender() external;
+
     function acceptNewTerms(address refinancer_, uint256 deadline_, bytes[] calldata calls_, uint256 amount_) external;
 
     function claimableFunds() external view returns (uint256 claimableFunds_);
diff --git a/tests/DebtLocker.t.sol b/tests/DebtLocker.t.sol
index 8fdb753..bfd10e7 100644
--- a/tests/DebtLocker.t.sol
+++ b/tests/DebtLocker.t.sol
@@ -35,6 +35,8 @@ interface Hevm {
     // Sets block timestamp to `x`.
     function warp(uint256 x) external view;
 
+    function expectRevert(bytes calldata) external;
+
 }
 
 contract DebtLockerTests is TestUtils {
@@ -1114,7 +1116,6 @@ contract DebtLockerV4Migration is TestUtils {
         assertEq(debtLocker_.loanMigrator(), loanMigrator);
     }
 
-
     function test_acl_setPendingLender() external {
         ( MapleLoan loan, DebtLocker debtLocker ) = _createFundAndDrawdownLoan(1_000_000, 30_000);
 
@@ -1133,6 +1134,22 @@ contract DebtLockerV4Migration is TestUtils {
         assertEq(loan.pendingLender(), newLender);
     }
 
+    function test_acl_acceptLender() external {
+        ( , DebtLocker debtLocker ) = _createFundAndDrawdownLoan(1_000_000, 30_000);
+
+        LoanMigrator loanMigrator    = new LoanMigrator();
+        LoanMigrator notLoanMigrator = new LoanMigrator();
+
+        poolDelegate.debtLocker_upgrade(address(debtLocker), 2, abi.encode(address(loanMigrator)));
+
+        loanMigrator.debtLocker_setPendingLender(address(debtLocker), address(debtLocker));  // Set pending lender in Loan to get ACL to work
+
+        vm.expectRevert("DL:AL:NOT_MIGRATOR");
+        notLoanMigrator.debtLocker_acceptLender(address(debtLocker));
+
+        loanMigrator.try_debtLocker_acceptLender(address(debtLocker));
+    }
+
     function _createLoan(uint256 principalRequested_, uint256 collateralRequired_) internal returns (MapleLoan loan_) {
         address[2] memory assets      = [address(collateralAsset), address(fundsAsset)];
         uint256[3] memory termDetails = [uint256(10 days), uint256(30 days), 6];
diff --git a/tests/accounts/LoanMigrator.sol b/tests/accounts/LoanMigrator.sol
index 2a6f267..9769d4a 100644
--- a/tests/accounts/LoanMigrator.sol
+++ b/tests/accounts/LoanMigrator.sol
@@ -5,10 +5,18 @@ import { IDebtLocker } from "../../contracts/interfaces/IDebtLocker.sol";
 
 contract LoanMigrator {
 
+    function debtLocker_acceptLender(address debtLocker_) external {
+        IDebtLocker(debtLocker_).acceptLender();
+    }
+
     function debtLocker_setPendingLender(address debtLocker_, address newLender_) external {
         IDebtLocker(debtLocker_).setPendingLender(newLender_);
     }
 
+    function try_debtLocker_acceptLender(address debtLocker_) external returns (bool ok_) {
+        ( ok_, ) = debtLocker_.call(abi.encodeWithSelector(IDebtLocker.acceptLender.selector));
+    }
+
     function try_debtLocker_setPendingLender(address debtLocker_, address newLender_) external returns (bool ok_) {
         ( ok_, ) = debtLocker_.call(abi.encodeWithSelector(IDebtLocker.setPendingLender.selector, newLender_));
     }
diff --git a/tests/mocks/Mocks.sol b/tests/mocks/Mocks.sol
index 39187b5..b729991 100644
--- a/tests/mocks/Mocks.sol
+++ b/tests/mocks/Mocks.sol
@@ -74,10 +74,18 @@ contract MockLoan {
         return 0;
     }
 
+    function acceptLender() external {
+        // Empty, just testing ACL
+    }
+
     function acceptNewTerms(address refinancer_, bytes[] calldata calls_, uint256 amount_) external {
         // Empty, just testing ACL
     }
 
+    function setPendingLender(address lender_) external {
+        // Empty, just testing ACL
+    }
+
 }
 
 contract MockGlobals {