removes start publication from checkpoint

Author: LeoPatOZ

src/protocol/CheckpointTracker.sol

@@ -35,31 +35,24 @@ contract CheckpointTracker is ICheckpointTracker {
     }
 
     /// @inheritdoc ICheckpointTracker
-    function proveTransition(
-        Checkpoint calldata start,
-        Checkpoint calldata end,
-        uint256 numPublications,
-        bytes calldata proof
-    ) external {
+    function proveTransition(Checkpoint calldata end, uint256 numPublications, bytes calldata proof) external {
         require(
             proverManager == address(0) || msg.sender == proverManager, "Only the prover manager can call this function"
         );
 
         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;

src/protocol/ICheckpointTracker.sol

@@ -15,16 +15,10 @@ interface ICheckpointTracker {
     function getProvenCheckpoint() external view returns (Checkpoint memory);
 
     /// @notice Verifies a transition between two checkpoints. Update the latest `provenCheckpoint` if possible
-    /// @param start The initial checkpoint before the transition
     /// @param end The final checkpoint after the transition
     /// @param numPublications The number of publications that need to be processed between the two checkpoints.
     /// Note that this is not necessarily (end.publicationId - start.publicationId) because there could be irrelevant
     /// publications.
     /// @param proof Arbitrary data passed to the `verifier` contract to confirm the transition validity
-    function proveTransition(
-        Checkpoint calldata start,
-        Checkpoint calldata end,
-        uint256 numPublications,
-        bytes calldata proof
-    ) external;
+    function proveTransition(Checkpoint calldata end, uint256 numPublications, bytes calldata proof) external;
 }

src/protocol/taiko_alethia/ProverManager.sol

@@ -238,7 +238,7 @@ contract ProverManager is IProposerFees, IProverManager {
         require(start.publicationId + 1 == firstPub.id, "First publication not immediately after start checkpoint");
         require(firstPub.timestamp > previousPeriodEnd, "First publication is before the period");
 
-        checkpointTracker.proveTransition(start, end, numPublications, proof);
+        checkpointTracker.proveTransition(end, numPublications, proof);
 
         bool isPastDeadline = block.timestamp > period.deadline && period.deadline != 0;
         if (isPastDeadline) {

test/CheckpointTracker.t.sol

@@ -59,54 +59,37 @@ 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);
+        tracker.proveTransition(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);
+        tracker.proveTransition(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);
+        tracker.proveTransition(end, numRelevantPublications, proof);
     }
 
     function createSampleFeed() private {

test/mocks/MockCheckpointTracker.sol

@@ -13,12 +13,7 @@ contract MockCheckpointTracker is ICheckpointTracker {
     }
 
     /// @notice Do nothing. All checkpoints and proofs are accepted.
-    function proveTransition(
-        Checkpoint calldata start,
-        Checkpoint calldata end,
-        uint256 numPublications,
-        bytes calldata proof
-    ) external {}
+    function proveTransition(Checkpoint calldata end, uint256 numPublications, bytes calldata proof) external {}
 
     /// @notice Helper to set the proven hash for easier testing
     /// @param checkpoint the checkpoint to set as proven, that will be hashed and stored as the proven hash