delete output proposal only if it is not finalized

x/ophost/keeper/output.go

@@ -22,6 +22,16 @@ func (k Keeper) GetOutputProposal(ctx context.Context, bridgeId, outputIndex uin
 }
 
 func (k Keeper) DeleteOutputProposal(ctx context.Context, bridgeId, outputIndex uint64) error {
+	output, err := k.GetOutputProposal(ctx, bridgeId, outputIndex)
+	if err != nil {
+		return err
+	}
+	if isFinal, err := k.isFinalized(ctx, bridgeId, output); err != nil {
+		return err
+	} else if isFinal {
+		return types.ErrAlreadyFinalized
+	}
+
 	return k.OutputProposals.Remove(ctx, collections.Join(bridgeId, outputIndex))
 }
 
@@ -35,6 +45,10 @@ func (k Keeper) IsFinalized(ctx context.Context, bridgeId, outputIndex uint64) (
 		return false, err
 	}
 
+	return k.isFinalized(ctx, bridgeId, output)
+}
+
+func (k Keeper) isFinalized(ctx context.Context, bridgeId uint64, output types.Output) (bool, error) {
 	bridgeConfig, err := k.GetBridgeConfig(ctx, bridgeId)
 	if err != nil {
 		return false, err

x/ophost/types/error.go

@@ -13,6 +13,7 @@ var (
 	ErrInvalidSequence            = errorsmod.Register(ModuleName, 6, "invalid sequence")
 	ErrInvalidL2BlockNumber       = errorsmod.Register(ModuleName, 7, "invalid l2 block number")
 	ErrNotFinalized               = errorsmod.Register(ModuleName, 8, "output has not finalized")
-	ErrFailedToVerifyWithdrawal   = errorsmod.Register(ModuleName, 9, "failed to verify withdrawal tx")
-	ErrWithdrawalAlreadyFinalized = errorsmod.Register(ModuleName, 10, "withdrawal already finalized")
+	ErrAlreadyFinalized           = errorsmod.Register(ModuleName, 9, "output has already finalized")
+	ErrFailedToVerifyWithdrawal   = errorsmod.Register(ModuleName, 10, "failed to verify withdrawal tx")
+	ErrWithdrawalAlreadyFinalized = errorsmod.Register(ModuleName, 11, "withdrawal already finalized")
 )