[ENG-585]: Setting min bid increment in ante (#28)

mempool/mempool.go

@@ -158,6 +158,16 @@ func (am *AuctionMempool) RemoveWithoutRefTx(tx sdk.Tx) error {
 	return nil
 }
 
+// GetTopAuctionTx returns the highest bidding transaction in the auction mempool.
+func (am *AuctionMempool) GetTopAuctionTx(ctx context.Context) sdk.Tx {
+	iterator := am.auctionIndex.Select(ctx, nil)
+	if iterator == nil {
+		return nil
+	}
+
+	return iterator.Tx()
+}
+
 // AuctionBidSelect returns an iterator over auction bids transactions only.
 func (am *AuctionMempool) AuctionBidSelect(ctx context.Context) sdkmempool.Iterator {
 	return am.auctionIndex.Select(ctx, nil)

x/auction/ante/ante.go

@@ -12,12 +12,14 @@ var _ sdk.AnteDecorator = AuctionDecorator{}
 type AuctionDecorator struct {
 	auctionKeeper keeper.Keeper
 	txDecoder     sdk.TxDecoder
+	mempool       *mempool.AuctionMempool
 }
 
-func NewAuctionDecorator(ak keeper.Keeper, txDecoder sdk.TxDecoder) AuctionDecorator {
+func NewAuctionDecorator(ak keeper.Keeper, txDecoder sdk.TxDecoder, mempool *mempool.AuctionMempool) AuctionDecorator {
 	return AuctionDecorator{
 		auctionKeeper: ak,
 		txDecoder:     txDecoder,
+		mempool:       mempool,
 	}
 }
 
@@ -46,10 +48,25 @@ func (ad AuctionDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool,
 			transactions[i] = decodedTx
 		}
 
-		if err := ad.auctionKeeper.ValidateAuctionMsg(ctx, bidder, auctionMsg.Bid, transactions); err != nil {
+		highestBid, err := ad.GetHighestAuctionBid(ctx)
+		if err != nil {
+			return ctx, errors.Wrap(err, "failed to get highest auction bid")
+		}
+
+		if err := ad.auctionKeeper.ValidateAuctionMsg(ctx, bidder, auctionMsg.Bid, highestBid, transactions); err != nil {
 			return ctx, errors.Wrap(err, "failed to validate auction bid")
 		}
 	}
 
 	return next(ctx, tx, simulate)
 }
+
+// GetHighestAuctionBid returns the highest auction bid if one exists.
+func (ad AuctionDecorator) GetHighestAuctionBid(ctx sdk.Context) (sdk.Coins, error) {
+	auctionTx := ad.mempool.GetTopAuctionTx(ctx)
+	if auctionTx == nil {
+		return sdk.NewCoins(), nil
+	}
+
+	return auctionTx.(*mempool.WrappedBidTx).GetBid(), nil
+}

x/auction/keeper/auction.go

@@ -6,10 +6,8 @@ import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 )
 
-// ValidateAuctionMsg validates that the MsgAuctionBid is valid. It checks that the bidder has sufficient funds to bid the
-// amount specified in the message, that the bundle size is not greater than the max bundle size, and that the bundle
-// transactions are valid.
-func (k Keeper) ValidateAuctionMsg(ctx sdk.Context, bidder sdk.AccAddress, bid sdk.Coins, transactions []sdk.Tx) error {
+// ValidateAuctionMsg validates that the MsgAuctionBid can be included in the auction.
+func (k Keeper) ValidateAuctionMsg(ctx sdk.Context, bidder sdk.AccAddress, bid, highestBid sdk.Coins, transactions []sdk.Tx) error {
 	// Validate the bundle size.
 	maxBundleSize, err := k.GetMaxBundleSize(ctx)
 	if err != nil {
@@ -21,7 +19,7 @@ func (k Keeper) ValidateAuctionMsg(ctx sdk.Context, bidder sdk.AccAddress, bid s
 	}
 
 	// Validate the bid amount.
-	if err := k.ValidateAuctionBid(ctx, bidder, bid); err != nil {
+	if err := k.ValidateAuctionBid(ctx, bidder, bid, highestBid); err != nil {
 		return err
 	}
 
@@ -40,8 +38,20 @@ func (k Keeper) ValidateAuctionMsg(ctx sdk.Context, bidder sdk.AccAddress, bid s
 	return nil
 }
 
-// ValidateAuctionBid validates that the bidder has sufficient funds to participate in the auction.
-func (k Keeper) ValidateAuctionBid(ctx sdk.Context, bidder sdk.AccAddress, bid sdk.Coins) error {
+// ValidateAuctionBid validates that the bidder has sufficient funds to participate in the auction and that the bid amount
+// is sufficiently high enough.
+func (k Keeper) ValidateAuctionBid(ctx sdk.Context, bidder sdk.AccAddress, bid, highestBid sdk.Coins) error {
+	// Ensure the bid is greater than the highest bid + min bid increment.
+	minBidIncrement, err := k.GetMinBidIncrement(ctx)
+	if err != nil {
+		return err
+	}
+
+	minBid := highestBid.Add(minBidIncrement...)
+	if !bid.IsAllGTE(minBid) {
+		return fmt.Errorf("bid amount (%s) is less than the highest bid (%s) + min bid increment (%s)", bid, highestBid, minBidIncrement)
+	}
+
 	// Get the bid floor.
 	reserveFee, err := k.GetReserveFee(ctx)
 	if err != nil {

x/auction/keeper/auction_test.go

@@ -24,8 +24,12 @@ func (suite *IntegrationTestSuite) TestValidateAuctionMsg() {
 		maxBundleSize          uint32 = 10
 		reserveFee                    = sdk.NewCoins(sdk.NewCoin("foo", sdk.NewInt(1000)))
 		minBuyInFee                   = sdk.NewCoins(sdk.NewCoin("foo", sdk.NewInt(1000)))
+		minBidIncrement               = sdk.NewCoins(sdk.NewCoin("foo", sdk.NewInt(1000)))
 		escrowAddress                 = sdk.AccAddress([]byte("escrow"))
 		frontRunningProtection        = true
+
+		// mempool variables
+		highestBid = sdk.NewCoins()
 	)
 
 	rnd := rand.New(rand.NewSource(time.Now().Unix()))
@@ -123,6 +127,23 @@ func (suite *IntegrationTestSuite) TestValidateAuctionMsg() {
 			},
 			true,
 		},
+		{
+			"invalid bundle that does not outbid the highest bid",
+			func() {
+				accounts = []Account{bidder, bidder, bidder}
+				highestBid = sdk.NewCoins(sdk.NewCoin("foo", sdk.NewInt(500)))
+				bid = sdk.NewCoins(sdk.NewCoin("foo", sdk.NewInt(500)))
+			},
+			false,
+		},
+		{
+			"valid bundle that outbids the highest bid",
+			func() {
+				highestBid = sdk.NewCoins(sdk.NewCoin("foo", sdk.NewInt(500)))
+				bid = sdk.NewCoins(sdk.NewCoin("foo", sdk.NewInt(1500)))
+			},
+			true,
+		},
 	}
 
 	for _, tc := range cases {
@@ -148,6 +169,7 @@ func (suite *IntegrationTestSuite) TestValidateAuctionMsg() {
 				MinBuyInFee:            minBuyInFee,
 				EscrowAccountAddress:   escrowAddress.String(),
 				FrontRunningProtection: frontRunningProtection,
+				MinBidIncrement:        minBidIncrement,
 			}
 			suite.auctionKeeper.SetParams(suite.ctx, params)
 
@@ -159,7 +181,7 @@ func (suite *IntegrationTestSuite) TestValidateAuctionMsg() {
 				bundle = append(bundle, tx)
 			}
 
-			err := suite.auctionKeeper.ValidateAuctionMsg(suite.ctx, bidder.Address, bid, bundle)
+			err := suite.auctionKeeper.ValidateAuctionMsg(suite.ctx, bidder.Address, bid, highestBid, bundle)
 			if tc.pass {
 				suite.Require().NoError(err)
 			} else {

x/auction/keeper/keeper_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/auth/tx"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 	"github.com/golang/mock/gomock"
+	"github.com/skip-mev/pob/mempool"
 	"github.com/skip-mev/pob/x/auction/ante"
 	"github.com/skip-mev/pob/x/auction/keeper"
 	"github.com/skip-mev/pob/x/auction/types"
@@ -37,6 +38,8 @@ type IntegrationTestSuite struct {
 	msgServer        types.MsgServer
 	key              *storetypes.KVStoreKey
 	authorityAccount sdk.AccAddress
+
+	mempool *mempool.AuctionMempool
 }
 
 func TestKeeperTestSuite(t *testing.T) {
@@ -60,7 +63,8 @@ func (suite *IntegrationTestSuite) SetupTest() {
 	err := suite.auctionKeeper.SetParams(suite.ctx, types.DefaultParams())
 	suite.Require().NoError(err)
 
-	suite.AuctionDecorator = ante.NewAuctionDecorator(suite.auctionKeeper, suite.encCfg.TxConfig.TxDecoder())
+	suite.mempool = mempool.NewAuctionMempool(suite.encCfg.TxConfig.TxDecoder(), 0)
+	suite.AuctionDecorator = ante.NewAuctionDecorator(suite.auctionKeeper, suite.encCfg.TxConfig.TxDecoder(), suite.mempool)
 	suite.msgServer = keeper.NewMsgServerImpl(suite.auctionKeeper)
 }