improve error handling for approval

Author: keithsue

x/lending/keeper/approval.go

@@ -14,22 +14,24 @@ func (k Keeper) HandleApproval(ctx sdk.Context, loan *types.Loan) error {
 		return types.ErrInsufficientLiquidity
 	}
 
+	// initiate signing request for repayment cet adaptor signatures from DCM
+	if err := k.InitiateRepaymentCetSigningRequest(ctx, loan.VaultAddress); err != nil {
+		return err
+	}
+
 	amount := sdk.NewCoin(loan.BorrowAmount.Denom, loan.BorrowAmount.Amount.Sub(loan.OriginationFee))
 	if err := k.bankKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleName, sdk.MustAccAddressFromBech32(loan.Borrower), sdk.NewCoins(amount)); err != nil {
-		return err
+		// unexpected error
+		return types.ErrUnexpected
 	}
 
 	if loan.OriginationFee.IsPositive() {
 		if err := k.handleOriginationFee(ctx, loan); err != nil {
-			return err
+			// unexpected error
+			return types.ErrUnexpected
 		}
 	}
 
-	// initiate signing request for repayment cet adaptor signatures from DCM
-	if err := k.InitiateRepaymentCetSigningRequest(ctx, loan.VaultAddress); err != nil {
-		return err
-	}
-
 	// update pool
 	k.AfterPoolBorrowed(ctx, loan.PoolId, loan.Maturity, loan.BorrowAmount)
 

x/lending/module/abci.go

@@ -2,6 +2,7 @@ package lending
 
 import (
 	"encoding/hex"
+	"errors"
 	"fmt"
 
 	sdkmath "cosmossdk.io/math"
@@ -24,7 +25,9 @@ func BeginBlocker(ctx sdk.Context, k keeper.Keeper) error {
 // EndBlocker called at the end of each block
 func EndBlocker(ctx sdk.Context, k keeper.Keeper) error {
 	// handle pending loans
-	handlePendingLoans(ctx, k)
+	if err := handlePendingLoans(ctx, k); err != nil {
+		return err
+	}
 
 	// handle active loans
 	handleActiveLoans(ctx, k)
@@ -37,7 +40,7 @@ func EndBlocker(ctx sdk.Context, k keeper.Keeper) error {
 }
 
 // handleActiveLoans handles pending loans
-func handlePendingLoans(ctx sdk.Context, k keeper.Keeper) {
+func handlePendingLoans(ctx sdk.Context, k keeper.Keeper) error {
 	// handler on loan rejected
 	rejectHandler := func(loan *types.Loan, authorizationId uint64, reason error) {
 		if authorizationId > 0 {
@@ -99,6 +102,10 @@ func handlePendingLoans(ctx sdk.Context, k keeper.Keeper) {
 
 				// approve loan
 				if err := k.HandleApproval(ctx, loan); err != nil {
+					if errors.Is(err, types.ErrUnexpected) {
+						return err
+					}
+
 					rejectHandler(loan, authorizationId, err)
 					continue
 				}
@@ -110,6 +117,8 @@ func handlePendingLoans(ctx sdk.Context, k keeper.Keeper) {
 			}
 		}
 	}
+
+	return nil
 }
 
 // handleActiveLoans handles active loans

x/lending/types/errors.go

@@ -9,6 +9,7 @@ import (
 var (
 	ErrInvalidAmount = errorsmod.Register(ModuleName, 1000, "invalid amount")
 	ErrInvalidParams = errorsmod.Register(ModuleName, 1001, "invalid params")
+	ErrUnexpected    = errorsmod.Register(ModuleName, 1002, "unexpected error")
 
 	ErrInvalidPoolId         = errorsmod.Register(ModuleName, 2000, "invalid pool id")
 	ErrInvalidPoolConfig     = errorsmod.Register(ModuleName, 2001, "invalid pool config")