Migrate via previous approval from urn owner

makerdao · Nov 28, 2023 · c83060c · c83060c
1 parent b69c955
commit c83060c
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Showing 2 changed files with 45 additions and 0 deletions.
diff --git a/src/LockstakeEngine.sol b/src/LockstakeEngine.sol
@@ -55,6 +55,10 @@ interface JugLike {
     function drip(bytes32) external returns (uint256);
 }
 
+interface MovLike {
+    function registerMigration(address, address) external;
+}
+
 contract LockstakeEngine {
     // --- storage variables ---
 
@@ -65,6 +69,7 @@ contract LockstakeEngine {
     mapping(address => address) public urnDelegates; // urn => current associated delegate
     mapping(address => address) public selectedFarm; // urn => current selected farm
     JugLike                     public jug;
+    address                     public mov;
 
     // --- constants ---
 
@@ -90,6 +95,7 @@ contract LockstakeEngine {
     event AddFarm(address farm);
     event DelFarm(address farm);
     event Open(address indexed owner, address urn);
+    event Migrate(address indexed urn, address mov_);
     event Delegate(address indexed urn, address indexed delegate);
     event Lock(address indexed urn, uint256 wad);
     event Free(address indexed urn, uint256 wad, uint256 burn);
@@ -156,6 +162,8 @@ contract LockstakeEngine {
     function file(bytes32 what, address data) external auth {
         if (what == "jug") {
             jug = JugLike(data);
+        } else if (what == "mov") {
+            mov = data;
         } else revert("LockstakeEngine/file-unrecognized-param");
         emit File(what, data);
     }
@@ -198,6 +206,13 @@ contract LockstakeEngine {
         emit Open(msg.sender, urn);
     }
 
+    function migrate(address urn, address mov_) external urnOwner(urn) {
+        require(mov == mov_ && mov_ != address(0), "LockstakeEngine/mover-not-available");
+        urnOwners[urn] = mov_;
+        MovLike(mov_).registerMigration(urn, msg.sender);
+        emit Migrate(urn, mov_);
+    }
+
     function lock(address urn, uint256 wad) external urnOwner(urn) {
         require(wad <= uint256(type(int256).max), "LockstakeEngine/wad-overflow");
         gov.transferFrom(msg.sender, address(this), wad);

diff --git a/test/LockstakeEngine.t.sol b/test/LockstakeEngine.t.sol
@@ -54,6 +54,13 @@ interface CalcLike {
     function file(bytes32, uint256) external;
 }
 
+contract MigratorMock {
+    mapping (address => address) public registeredUrns;
+    function registerMigration(address urn, address owner) external {
+        registeredUrns[urn] = owner;
+    }
+}
+
 contract AllocatorVaultTest is DssTest {
     using stdStorage for StdStorage;
 
@@ -214,6 +221,29 @@ contract AllocatorVaultTest is DssTest {
         assertEq(engine.usrAmts(address(this)), 3);
     }
 
+    function testMigrator() external {
+        address urnOwner = address(123);
+        MigratorMock migrator = new MigratorMock();
+        deal(address(gov), urnOwner, 100_000 * 10**18, true);
+        vm.prank(urnOwner); address urn = engine.open();
+        assertEq(engine.urnOwners(urn), urnOwner);
+        vm.prank(urnOwner); gov.approve(address(engine), 100_000 * 10**18);
+        vm.prank(urnOwner); engine.lock(urn, 100_000 * 10**18);
+        assertEq(engine.mov(), address(0));
+        vm.expectRevert("LockstakeEngine/mover-not-available");
+        vm.prank(urnOwner); engine.migrate(urn, address(0));
+        vm.prank(pauseProxy); engine.file("mov", address(migrator));
+        assertEq(engine.mov(), address(migrator));
+        vm.expectRevert("LockstakeEngine/mover-not-available");
+        vm.prank(urnOwner); engine.migrate(urn, address(789));
+        vm.prank(urnOwner); engine.migrate(urn, address(migrator));
+        assertEq(engine.urnOwners(urn), address(migrator));
+        assertEq(migrator.registeredUrns(urn), urnOwner);
+        assertEq(gov.balanceOf(address(migrator)), 0);
+        vm.prank(address(migrator)); engine.free(urn, 100_000 * 10**18);
+        assertEq(gov.balanceOf(address(migrator)), 85_000 * 10**18);
+    }
+
     function _testLockFree(bool withDelegate) internal {
         uint256 initialSupply = gov.totalSupply();
         assertEq(gov.balanceOf(address(this)), 100_000 * 10**18);