chore: apply code rabbit comments

abci/example/kvstore/kvstore.go

@@ -586,11 +586,13 @@ func (app *Application) FinalizeSnapshot(_ctx context.Context, req *abci.Request
 
 	// we verify snapshot height and app hash, as there is no additional logic to be called here
 	if app.LastCommittedState.GetHeight() != req.LightBlock.SignedHeader.Header.Height {
-		return &abci.ResponseFinalizeSnapshot{}, fmt.Errorf("snapshot height mismatch")
+		return &abci.ResponseFinalizeSnapshot{}, fmt.Errorf("snapshot height mismatch: expected %d, got %d",
+			app.LastCommittedState.GetHeight(), req.LightBlock.SignedHeader.Header.Height)
 	}
 
 	if !app.LastCommittedState.GetAppHash().Equal(req.LightBlock.SignedHeader.Header.AppHash) {
-		return &abci.ResponseFinalizeSnapshot{}, fmt.Errorf("snapshot apphash mismatch")
+		return &abci.ResponseFinalizeSnapshot{}, fmt.Errorf("snapshot apphash mismatch: expected %x, got %x",
+			app.LastCommittedState.GetAppHash(), req.LightBlock.SignedHeader.Header.AppHash)
 	}
 
 	app.logger.Debug("FinalizeSnapshot finished successfully", "req", req)

abci/types/application.go

@@ -99,6 +99,7 @@ func (BaseApplication) ApplySnapshotChunk(_ context.Context, _req *RequestApplyS
 	return &ResponseApplySnapshotChunk{}, nil
 }
 
+// FinalizeSnapshot provides a no-op implementation for the StateSyncer interface
 func (BaseApplication) FinalizeSnapshot(_ context.Context, _req *RequestFinalizeSnapshot) (*ResponseFinalizeSnapshot, error) {
 	return &ResponseFinalizeSnapshot{}, nil
 }

proto/tendermint/abci/types.proto

@@ -183,10 +183,13 @@ message RequestApplySnapshotChunk {
   bytes  chunk    = 2;  // The binary chunk contents, as returned by LoadSnapshotChunk.
   string sender   = 3;  // The P2P ID of the node who sent this chunk.
 }
-
-// After snapshot sync, Tenderdash calls this to finalize the snapshot sync.
-// It includes the light block committed at the synced height, which Tenderdash uses
-// to reconstruct its own state.
+// RequestFinalizeSnapshot is called by Tenderdash after successfully applying all snapshot chunks, eg.
+// when the ABCI application returned `ResponseApplySnapshotChunk` with `Result = ACCEPT`.
+// It includes the light block committed at the synced height, which Tenderdash uses to reconstruct its own state.
+// The application should validate the light block against its restored state.
+//
+// If the application fails to validate the light block, it should return error in the response.
+// This is considered fatal, non-recoverable consensus failure and will cause Tenderdash to restart.
 message RequestFinalizeSnapshot {
   // light block committed at the synced height
   tendermint.types.LightBlock light_block = 1;

spec/abci++/api.md

@@ -429,9 +429,13 @@ Finalize newly decided block.
 <a name="tendermint-abci-RequestFinalizeSnapshot"></a>
 
 ### RequestFinalizeSnapshot
-After snapshot sync, Tenderdash calls this to finalize the snapshot sync.
-It includes the light block committed at the synced height, which Tenderdash uses
-to reconstruct its own state.
+RequestFinalizeSnapshot is called by Tenderdash after successfully applying all snapshot chunks, eg.
+when the ABCI application returned `ResponseApplySnapshotChunk` with `Result = ACCEPT`.
+It includes the light block committed at the synced height, which Tenderdash uses to reconstruct its own state.
+The application should validate the light block against its restored state.
+
+If the application fails to validate the light block, it should return error in the response.
+This is considered fatal, non-recoverable consensus failure and will cause Tenderdash to restart.
 
 
 | Field | Type | Label | Description |