Test repeat auction bidding (#1159)

* improve error messages

* add tests for re-bidding with small balance

x/auction/keeper/bidding_test.go

@@ -1,7 +1,6 @@
 package keeper_test
 
 import (
-	"errors"
 	"strings"
 	"testing"
 	"time"
@@ -39,6 +38,8 @@ func TestAuctionBidding(t *testing.T) {
 	collateralAddrs := addrs[2:]
 	collateralWeights := is(30, 20, 10)
 
+	initialBalance := cs(c("token1", 1000), c("token2", 1000))
+
 	type auctionArgs struct {
 		auctionType AuctionType
 		seller      string
@@ -330,6 +331,18 @@ func TestAuctionBidding(t *testing.T) {
 			false,
 			false,
 		},
+		{
+			"collateral [forward]: bidder replaces previous bid with only funds for difference",
+			auctionArgs{Collateral, modName, c("token1", 1000), c("token2", 2000), c("debt", 50), collateralAddrs, collateralWeights}, // lot, max bid
+			[]bidArgs{{buyer, c("token2", 900)}},
+			bidArgs{buyer, c("token2", 1000)}, // buyer only has enough to cover the increase from previous bid
+			nil,
+			someTime.Add(types.DefaultBidDuration),
+			buyer,
+			c("token2", 1000),
+			true,
+			false,
+		},
 		{
 			"collateral [reverse]: normal",
 			auctionArgs{Collateral, modName, c("token1", 20), c("token2", 50), c("debt", 50), collateralAddrs, collateralWeights}, // lot, max bid
@@ -402,6 +415,18 @@ func TestAuctionBidding(t *testing.T) {
 			false,
 			false,
 		},
+		{
+			"collateral [reverse]: bidder replaces previous bid without funds",
+			auctionArgs{Collateral, modName, c("token1", 1000), c("token2", 1000), c("debt", 50), collateralAddrs, collateralWeights}, // lot, max bid
+			[]bidArgs{{buyer, c("token2", 1000)}},
+			bidArgs{buyer, c("token1", 100)}, // buyer has already bid all of their token2
+			nil,
+			someTime.Add(types.DefaultBidDuration),
+			buyer,
+			c("token2", 1000),
+			true,
+			false,
+		},
 	}
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
@@ -414,11 +439,10 @@ func TestAuctionBidding(t *testing.T) {
 			modAcc := authtypes.NewModuleAccount(modBaseAcc, modName, []string{authtypes.Minter, authtypes.Burner}...)
 
 			// Set up normal accounts
-			coins := cs(c("token1", 1000), c("token2", 1000))
 			addrs := []sdk.AccAddress{buyer, secondBuyer, collateralAddrs[0], collateralAddrs[1], collateralAddrs[2]}
 
 			// Initialize app
-			authGS := app.NewFundedGenStateWithSameCoinsWithModuleAccount(tApp.AppCodec(), coins, addrs, modAcc)
+			authGS := app.NewFundedGenStateWithSameCoinsWithModuleAccount(tApp.AppCodec(), initialBalance, addrs, modAcc)
 			params := types.NewParams(
 				types.DefaultMaxAuctionDuration,
 				types.DefaultBidDuration,
@@ -487,7 +511,7 @@ func TestAuctionBidding(t *testing.T) {
 
 			// Check success/failure
 			if tc.expectPass {
-				require.Nil(t, err)
+				require.NoError(t, err)
 				// Check auction was found
 				newAuction, found := keeper.GetAuction(ctx, id)
 				require.True(t, found)
@@ -526,8 +550,8 @@ func TestAuctionBidding(t *testing.T) {
 
 			} else {
 				// Check expected error code type
-				require.NotNil(t, err, "PlaceBid did not return an error") // catch nil values before they cause a panic below
+				require.Error(t, err, "PlaceBid did not return an error")
-				require.True(t, errors.Is(err, tc.expectedError))
+				require.ErrorIs(t, err, tc.expectedError)
 
 				// Check auction values
 				newAuction, found := keeper.GetAuction(ctx, id)