add mock module acc balance and refactor test case (cosmos#1942)

* add mock module acc balance and refactor test case

* add changelog entry

CHANGELOG.md

@@ -81,6 +81,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+* (testing) [\#1942](https://github.com/cosmos/ibc-go/pull/1942) Add a balance for the mock module account upon testing package initialization. 
 * (linting) [\#1418](https://github.com/cosmos/ibc-go/pull/1418) Fix linting errors, resulting compatiblity with go1.18 linting style, golangci-lint 1.46.2 and the revivie linter.  This caused breaking changes in core/04-channel, core/ante, and the testing library.
 * (app/20-transfer) [\#1680](https://github.com/cosmos/ibc-go/pull/1680) Adds migration to correct any malformed trace path information of tokens with denoms that contains slashes. The transfer module consensus version has been bumped to 2.
 * (app/20-transfer) [\#1730](https://github.com/cosmos/ibc-go/pull/1730) parse the ics20 denomination provided via a packet using the channel identifier format specified by ibc-go.

modules/apps/29-fee/keeper/escrow_test.go

@@ -76,7 +76,7 @@ func (suite *KeeperTestSuite) TestDistributeFee() {
 			},
 			func() {
 				// check if the refund acc has been refunded the timeoutFee
-				expectedRefundAccBal := defaultTimeoutFee[0].Add(defaultTimeoutFee[0])
+				expectedRefundAccBal := refundAccBal.Add(defaultTimeoutFee[0]).Add(defaultTimeoutFee[0])
 				balance := suite.chainA.GetSimApp().BankKeeper.GetBalance(suite.chainA.GetContext(), refundAcc, sdk.DefaultBondDenom)
 				suite.Require().Equal(expectedRefundAccBal, balance)
 			},

modules/apps/29-fee/keeper/msg_server_test.go

@@ -2,12 +2,12 @@ package keeper_test
 
 import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
-	disttypes "github.com/cosmos/cosmos-sdk/x/distribution/types"
 
 	"github.com/cosmos/ibc-go/v5/modules/apps/29-fee/types"
 	clienttypes "github.com/cosmos/ibc-go/v5/modules/core/02-client/types"
 	channeltypes "github.com/cosmos/ibc-go/v5/modules/core/04-channel/types"
 	ibctesting "github.com/cosmos/ibc-go/v5/testing"
+	ibcmock "github.com/cosmos/ibc-go/v5/testing/mock"
 )
 
 func (suite *KeeperTestSuite) TestRegisterPayee() {
@@ -185,7 +185,7 @@ func (suite *KeeperTestSuite) TestPayPacketFee() {
 		{
 			"refund account is module account",
 			func() {
-				msg.Signer = suite.chainA.GetSimApp().AccountKeeper.GetModuleAddress(disttypes.ModuleName).String()
+				msg.Signer = suite.chainA.GetSimApp().AccountKeeper.GetModuleAddress(ibcmock.ModuleName).String()
 				expPacketFee := types.NewPacketFee(fee, msg.Signer, nil)
 				expFeesInEscrow = []types.PacketFee{expPacketFee}
 			},

testing/chain.go

@@ -103,6 +103,7 @@ func NewTestChainWithValSet(t *testing.T, coord *Coordinator, chainID string, va
 		amount, ok := sdk.NewIntFromString("10000000000000000000")
 		require.True(t, ok)
 
+		// add sender account
 		balance := banktypes.Balance{
 			Address: acc.GetAddress().String(),
 			Coins:   sdk.NewCoins(sdk.NewCoin(sdk.DefaultBondDenom, amount)),
@@ -119,6 +120,12 @@ func NewTestChainWithValSet(t *testing.T, coord *Coordinator, chainID string, va
 		senderAccs = append(senderAccs, senderAcc)
 	}
 
+	// add mock module account balance
+	genBals = append(genBals, banktypes.Balance{
+		Address: authtypes.NewModuleAddress(mock.ModuleName).String(),
+		Coins:   sdk.Coins{sdk.NewCoin(sdk.DefaultBondDenom, sdk.NewInt(1000000000))},
+	})
+
 	app := SetupWithGenesisValSet(t, valSet, genAccs, chainID, sdk.DefaultPowerReduction, genBals...)
 
 	// create current header and call begin block
@@ -148,6 +155,10 @@ func NewTestChainWithValSet(t *testing.T, coord *Coordinator, chainID string, va
 		SenderAccounts: senderAccs,
 	}
 
+	// creates mock module account
+	mockModuleAcc := chain.GetSimApp().AccountKeeper.GetModuleAccount(chain.GetContext(), mock.ModuleName)
+	require.NotNil(t, mockModuleAcc)
+
 	coord.CommitBlock(chain)
 
 	return chain