refactor: remove min-buy-in param (#135)

Co-authored-by: David Terpay <35130517+davidterpay@users.noreply.github.com>

x/builder/keeper/auction.go

@@ -75,17 +75,10 @@ func (k Keeper) ValidateAuctionBid(ctx sdk.Context, bidder sdk.AccAddress, bid,
 		}
 	}
 
-	// Get the pay-to-play fee.
-	minBuyInFee, err := k.GetMinBuyInFee(ctx)
-	if err != nil {
-		return err
-	}
-
-	// Ensure the bidder has enough funds to cover all the inclusion fees.
-	minBalance := bid.Add(minBuyInFee)
+	// ensure the bidder has enough funds to cover all the inclusion fees
 	balances := k.bankKeeper.GetAllBalances(ctx, bidder)
-	if !balances.IsAllGTE(sdk.NewCoins(minBalance)) {
-		return fmt.Errorf("insufficient funds to bid %s (reserve fee + bid) with balance %s", minBalance, balances)
+	if !balances.IsAllGTE(sdk.NewCoins(bid)) {
+		return fmt.Errorf("insufficient funds to bid %s with balance %s", bid, balances)
 	}
 
 	return nil

x/builder/keeper/auction_test.go

@@ -21,7 +21,6 @@ func (suite *KeeperTestSuite) TestValidateBidInfo() {
 		// Auction params
 		maxBundleSize          uint32 = 10
 		reserveFee                    = sdk.NewCoin("foo", sdk.NewInt(1000))
-		minBuyInFee                   = sdk.NewCoin("foo", sdk.NewInt(1000))
 		minBidIncrement               = sdk.NewCoin("foo", sdk.NewInt(1000))
 		escrowAddress                 = sdk.AccAddress([]byte("escrow"))
 		frontRunningProtection        = true
@@ -53,14 +52,6 @@ func (suite *KeeperTestSuite) TestValidateBidInfo() {
 			},
 			false,
 		},
-		{
-			"bid amount equals the balance (not accounting for the reserve fee)",
-			func() {
-				balance = sdk.NewCoins(sdk.NewCoin("foo", sdk.NewInt(2000)))
-				bid = sdk.NewCoin("foo", sdk.NewInt(2000))
-			},
-			false,
-		},
 		{
 			"too many transactions in the bundle",
 			func() {
@@ -174,7 +165,6 @@ func (suite *KeeperTestSuite) TestValidateBidInfo() {
 			params := buildertypes.Params{
 				MaxBundleSize:          maxBundleSize,
 				ReserveFee:             reserveFee,
-				MinBuyInFee:            minBuyInFee,
 				EscrowAccountAddress:   escrowAddress.String(),
 				FrontRunningProtection: frontRunningProtection,
 				MinBidIncrement:        minBidIncrement,

x/builder/keeper/keeper.go

@@ -131,16 +131,6 @@ func (k Keeper) GetReserveFee(ctx sdk.Context) (sdk.Coin, error) {
 	return params.ReserveFee, nil
 }
 
-// GetMinBuyInFee returns the fee that the bidder must pay to enter the builder.
-func (k Keeper) GetMinBuyInFee(ctx sdk.Context) (sdk.Coin, error) {
-	params, err := k.GetParams(ctx)
-	if err != nil {
-		return sdk.Coin{}, err
-	}
-
-	return params.MinBuyInFee, nil
-}
-
 // GetMinBidIncrement returns the minimum bid increment for the builder.
 func (k Keeper) GetMinBidIncrement(ctx sdk.Context) (sdk.Coin, error) {
 	params, err := k.GetParams(ctx)

x/builder/keeper/msg_server_test.go

@@ -164,7 +164,6 @@ func (suite *KeeperTestSuite) TestMsgUpdateParams() {
 					ProposerFee:          sdk.MustNewDecFromStr("0.1"),
 					MaxBundleSize:        2,
 					EscrowAccountAddress: suite.authorityAccount.String(),
-					MinBuyInFee:          sdk.NewInt64Coin("foo", 100),
 					MinBidIncrement:      sdk.NewInt64Coin("foo", 100),
 					ReserveFee:           sdk.NewInt64Coin("foo", 100),
 				},