Merge c8cf416 into 6d08743

Author: LeoPatOZ

src/protocol/CheckpointTracker.sol

@@ -35,8 +35,9 @@ contract CheckpointTracker is ICheckpointTracker {
     }
 
     /// @inheritdoc ICheckpointTracker
+    /// @dev This function does not use the `start` checkpoint since we don't support parallel transitions.
     function proveTransition(
-        Checkpoint calldata start,
+        Checkpoint calldata,
         Checkpoint calldata end,
         uint256 numPublications,
         bytes calldata proof
@@ -47,19 +48,17 @@ contract CheckpointTracker is ICheckpointTracker {
 
         require(end.commitment != 0, "Checkpoint commitment cannot be 0");
 
-        require(
-            start.publicationId == _provenCheckpoint.publicationId && start.commitment == _provenCheckpoint.commitment,
-            "Start checkpoint must be the latest proven checkpoint"
-        );
-
-        require(start.publicationId < end.publicationId, "End publication must be after the last proven publication");
-
-        bytes32 startPublicationHash = publicationFeed.getPublicationHash(start.publicationId);
+        bytes32 startPublicationHash = publicationFeed.getPublicationHash(_provenCheckpoint.publicationId);
         bytes32 endPublicationHash = publicationFeed.getPublicationHash(end.publicationId);
         require(endPublicationHash != 0, "End publication does not exist");
 
         verifier.verifyProof(
-            startPublicationHash, endPublicationHash, start.commitment, end.commitment, numPublications, proof
+            startPublicationHash,
+            endPublicationHash,
+            _provenCheckpoint.commitment,
+            end.commitment,
+            numPublications,
+            proof
         );
 
         _provenCheckpoint = end;

test/CheckpointTracker.t.sol

@@ -59,54 +59,33 @@ contract CheckpointTrackerTest is Test {
     }
 
     function test_proveTransition_SuccessfulTransition() public {
-        ICheckpointTracker.Checkpoint memory start =
-            ICheckpointTracker.Checkpoint({publicationId: 0, commitment: keccak256(abi.encode("genesis"))});
         ICheckpointTracker.Checkpoint memory end =
             ICheckpointTracker.Checkpoint({publicationId: 3, commitment: keccak256(abi.encode("end"))});
         uint256 numRelevantPublications = 2;
 
         vm.expectEmit();
         emit ICheckpointTracker.CheckpointUpdated(end);
-        tracker.proveTransition(start, end, numRelevantPublications, proof);
+
+        // Empty checkpoint needed to comply with the interface, but not used in `CheckpointTracker`
+        ICheckpointTracker.Checkpoint memory emptyCheckpoint =
+            ICheckpointTracker.Checkpoint({publicationId: 0, commitment: bytes32(0)});
+        tracker.proveTransition(emptyCheckpoint, end, numRelevantPublications, proof);
 
         ICheckpointTracker.Checkpoint memory provenCheckpoint = tracker.getProvenCheckpoint();
         assertEq(provenCheckpoint.publicationId, end.publicationId);
         assertEq(provenCheckpoint.commitment, end.commitment);
     }
 
     function test_proveTransition_RevertWhenEndCommitmentIsZero() public {
-        ICheckpointTracker.Checkpoint memory start =
-            ICheckpointTracker.Checkpoint({publicationId: 0, commitment: keccak256(abi.encode("genesis"))});
         ICheckpointTracker.Checkpoint memory end =
             ICheckpointTracker.Checkpoint({publicationId: 3, commitment: bytes32(0)});
         uint256 numRelevantPublications = 2;
 
         vm.expectRevert("Checkpoint commitment cannot be 0");
-        tracker.proveTransition(start, end, numRelevantPublications, proof);
-    }
-
-    function test_proveTransition_RevertWhenStartCheckpointNotLatestProven() public {
-        ICheckpointTracker.Checkpoint memory start =
-            ICheckpointTracker.Checkpoint({publicationId: 1, commitment: keccak256(abi.encode("wrong"))});
-        ICheckpointTracker.Checkpoint memory end =
-            ICheckpointTracker.Checkpoint({publicationId: 3, commitment: keccak256(abi.encode("end"))});
-        uint256 numRelevantPublications = 2;
-
-        vm.expectRevert("Start checkpoint must be the latest proven checkpoint");
-        tracker.proveTransition(start, end, numRelevantPublications, proof);
-    }
-
-    function test_proveTransition_RevertWhenEndPublicationNotAfterStart() public {
-        ICheckpointTracker.Checkpoint memory start =
-            ICheckpointTracker.Checkpoint({publicationId: 0, commitment: keccak256(abi.encode("genesis"))});
-        ICheckpointTracker.Checkpoint memory end =
-            ICheckpointTracker.Checkpoint({publicationId: 0, commitment: keccak256(abi.encode("end"))});
-        // this is nonsensical, but we're testing the publicationId check so I think it makes sense for the other
-        // parameters to match previous tests.
-        uint256 numRelevantPublications = 2;
-
-        vm.expectRevert("End publication must be after the last proven publication");
-        tracker.proveTransition(start, end, numRelevantPublications, proof);
+        // Empty checkpoint needed to comply with the interface, but not used in `CheckpointTracker`
+        ICheckpointTracker.Checkpoint memory emptyCheckpoint =
+            ICheckpointTracker.Checkpoint({publicationId: 0, commitment: bytes32(0)});
+        tracker.proveTransition(emptyCheckpoint, end, numRelevantPublications, proof);
     }
 
     function createSampleFeed() private {

test/mocks/MockCheckpointTracker.sol

@@ -14,7 +14,7 @@ contract MockCheckpointTracker is ICheckpointTracker {
 
     /// @notice Do nothing. All checkpoints and proofs are accepted.
     function proveTransition(
-        Checkpoint calldata start,
+        Checkpoint calldata,
         Checkpoint calldata end,
         uint256 numPublications,
         bytes calldata proof