link up bid txs and memdb storage + key fixes

lfg it works

x/cosmostest/keeper/msg_server_new_bid.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"math/big"
+	"reflect"
 
 	"cosmos-test/x/cosmostest/memdb"
 	"cosmos-test/x/cosmostest/types"
@@ -30,9 +31,12 @@ func (k msgServer) NewBid(goCtx context.Context, msg *types.MsgNewBid) (*types.M
 	}
 
 	highestBid, err := memdb.BidDB.GetHighestBid(msg.AuctionIndex)
+	// we manually handle KeyNotFound in GetHighestBid, so should return (nil, nil) if not found
 	if err != nil {
-		return nil, fmt.Errorf("failed to get highest bid: %s", err)
+		return nil, fmt.Errorf("failed to get highest bid: %s", reflect.TypeOf(err))
 	}
+
+	if highestBid != nil {
 		amtPrev := new(big.Int)
 		amtPrev, ok = amtPrev.SetString(highestBid.Amount, 10)
 		if !ok { // this should have been checked before, but whatever
@@ -42,6 +46,7 @@ func (k msgServer) NewBid(goCtx context.Context, msg *types.MsgNewBid) (*types.M
 		if amt.Cmp(amtPrev) < 1 {
 			return nil, fmt.Errorf("bid amount must be greater than largest bid")
 		}
+	}
 
 	bid := &types.Bid{
 		Amount: msg.Amount,

x/cosmostest/memdb/biddb.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"cosmos-test/x/cosmostest/types"
 	"encoding/gob"
+	"errors"
 	"log"
 	"math/big"
 
@@ -36,7 +37,7 @@ func (b *bidDB) AddBid(auctionId string, bid *types.Bid) error {
 	err := b.db.Update(func(txn *badger.Txn) error {
 		var bids []*types.Bid
 		bidsOld, err := txn.Get(k)
-		if err == badger.ErrKeyNotFound {
+		if errors.Is(err, badger.ErrKeyNotFound) {
 			// key not found -> just create a new Bid array
 			bids = []*types.Bid{}
 		} else {
@@ -81,7 +82,11 @@ func (b *bidDB) GetHighestBid(auctionId string) (*types.Bid, error) {
 	err := b.db.View(func(txn *badger.Txn) error {
 		bidData, err := txn.Get(k)
 		if err != nil {
+			if !errors.Is(err, badger.ErrKeyNotFound) {
 				return err
+			} else {
+				return nil
+			}
 		}
 
 		err = bidData.Value(func(val []byte) error {
@@ -91,6 +96,10 @@ func (b *bidDB) GetHighestBid(auctionId string) (*types.Bid, error) {
 				return err
 			}
 
+			if bids == nil {
+				return nil
+			}
+
 			amt := big.NewInt(0)
 			rAmt := big.NewInt(0)
 			for _, rBid := range bids {

x/cosmostest/module.go

@@ -13,7 +13,9 @@ import (
 
 	"cosmos-test/x/cosmostest/client/cli"
 	"cosmos-test/x/cosmostest/keeper"
+	"cosmos-test/x/cosmostest/memdb"
 	"cosmos-test/x/cosmostest/types"
+
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/codec"
 	cdctypes "github.com/cosmos/cosmos-sdk/codec/types"
@@ -109,6 +111,10 @@ func NewAppModule(
 	accountKeeper types.AccountKeeper,
 	bankKeeper types.BankKeeper,
 ) AppModule {
+
+	// initialize in-memory database
+	memdb.BidDB.Mount()
+
 	return AppModule{
 		AppModuleBasic: NewAppModuleBasic(cdc),
 		keeper:         keeper,