[bank]: add balance tracking events (#8656)

* change(bank): add utxo events and simplify logic

* add(bank): balance and supply tracking test

* chore(bank): fix balance tracking test comment

* fix(grpc): service test

* fix(bank): sub unlocked coins to use less gas

* fix(auth): cli test gas

* fix(rest): grpc gas test

* fix(staking/cli): increase delegation required gas

* add: burn events, fix tests

* fix(auth/tx): grpc test

* add(bank): coin events in delegate

* fix(bank): add amt check in delegate coins back

* change(bank): add coin spent and coin recv events in burn and mint

* change(bank): revert sub coin function

* change(auth): revert cli test

* change(auth): revert service test

* chore(auth): fix events comment in service_test.go

* chore: update CHANGELOG.md

* remove(bank): balanceError func

* chore(bank): address lint warnings

* chore(bank): update events spec

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -58,6 +58,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (x/ibc) [\#8405](https://github.com/cosmos/cosmos-sdk/pull/8405) Refactor IBC client update governance proposals to use a substitute client to update a frozen or expired client.
 * (x/evidence) [\#8502](https://github.com/cosmos/cosmos-sdk/pull/8502) `HandleEquivocationEvidence` persists the evidence to state.
 * (x/gov) [\#7733](https://github.com/cosmos/cosmos-sdk/pull/7733) ADR 037 Implementation: Governance Split Votes
+* (x/bank) [\#8656](https://github.com/cosmos/cosmos-sdk/pull/8656) balance and supply are now correctly tracked via `coin_spent`, `coin_received`, `coinbase` and `burn` events.
 
 ### Improvements
 

x/auth/client/cli/cli_test.go

@@ -1102,7 +1102,7 @@ func (s *IntegrationTestSuite) TestSignWithMultiSigners_AminoJSON() {
 		banktypes.NewMsgSend(val1.Address, addr1, sdk.NewCoins(val1Coin)),
 	)
 	txBuilder.SetFeeAmount(sdk.NewCoins(sdk.NewCoin(s.cfg.BondDenom, sdk.NewInt(10))))
-	txBuilder.SetGasLimit(testdata.NewTestGasLimit())
+	txBuilder.SetGasLimit(testdata.NewTestGasLimit()) // min required is 101892
 	require.Equal([]sdk.AccAddress{val0.Address, val1.Address}, txBuilder.GetTx().GetSigners())
 
 	// Write the unsigned tx into a file.
@@ -1126,7 +1126,12 @@ func (s *IntegrationTestSuite) TestSignWithMultiSigners_AminoJSON() {
 	signedTxFile := testutil.WriteToNewTempFile(s.T(), signedTx.String())
 
 	// Now let's try to send this tx.
-	res, err := authtest.TxBroadcastExec(val0.ClientCtx, signedTxFile.Name(), fmt.Sprintf("--%s=%s", flags.FlagBroadcastMode, flags.BroadcastBlock))
+	res, err := authtest.TxBroadcastExec(
+		val0.ClientCtx,
+		signedTxFile.Name(),
+		fmt.Sprintf("--%s=%s", flags.FlagBroadcastMode, flags.BroadcastBlock),
+	)
+
 	require.NoError(err)
 	var txRes sdk.TxResponse
 	require.NoError(val0.ClientCtx.JSONMarshaler.UnmarshalJSON(res.Bytes(), &txRes))

x/auth/tx/service_test.go

@@ -5,13 +5,14 @@ import (
 	"fmt"
 	"testing"
 
+	"github.com/cosmos/cosmos-sdk/testutil/testdata"
+
 	"github.com/stretchr/testify/suite"
 
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/client/flags"
 	clienttx "github.com/cosmos/cosmos-sdk/client/tx"
 	"github.com/cosmos/cosmos-sdk/testutil/network"
-	"github.com/cosmos/cosmos-sdk/testutil/testdata"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	query "github.com/cosmos/cosmos-sdk/types/query"
@@ -106,7 +107,7 @@ func (s IntegrationTestSuite) TestSimulateTx_GRPC() {
 			} else {
 				s.Require().NoError(err)
 				// Check the result and gas used are correct.
-				s.Require().Equal(len(res.GetResult().GetEvents()), 4) // 1 transfer, 3 messages.
+				s.Require().Equal(len(res.GetResult().GetEvents()), 6) // 1 coin recv 1 coin spent, 1 transfer, 3 messages.
 				s.Require().True(res.GetGasInfo().GetGasUsed() > 0)    // Gas used sometimes change, just check it's not empty.
 			}
 		})
@@ -143,7 +144,7 @@ func (s IntegrationTestSuite) TestSimulateTx_GRPCGateway() {
 				err = val.ClientCtx.JSONMarshaler.UnmarshalJSON(res, &result)
 				s.Require().NoError(err)
 				// Check the result and gas used are correct.
-				s.Require().Equal(len(result.GetResult().GetEvents()), 4) // 1 transfer, 3 messages.
+				s.Require().Equal(len(result.GetResult().GetEvents()), 6) // 1 coin recv, 1 coin spent,1 transfer, 3 messages.
 				s.Require().True(result.GetGasInfo().GetGasUsed() > 0)    // Gas used sometimes change, just check it's not empty.
 			}
 		})
@@ -412,7 +413,7 @@ func (s IntegrationTestSuite) TestBroadcastTx_GRPCGateway() {
 				var result tx.BroadcastTxResponse
 				err = val.ClientCtx.JSONMarshaler.UnmarshalJSON(res, &result)
 				s.Require().NoError(err)
-				s.Require().Equal(uint32(0), result.TxResponse.Code)
+				s.Require().Equal(uint32(0), result.TxResponse.Code, "rawlog", result.TxResponse.RawLog)
 			}
 		})
 	}

x/bank/keeper/genesis_test.go

@@ -25,8 +25,6 @@ func (suite *IntegrationTestSuite) TestExportGenesis() {
 			Require().
 			NoError(app.BankKeeper.SendCoinsFromModuleToAccount(ctx, minttypes.ModuleName, accAddr, expectedBalances[i].Coins))
 	}
-	// add mint module balance as nil
-	expectedBalances = append(expectedBalances, types.Balance{Address: "cosmos1m3h30wlvsf8llruxtpukdvsy0km2kum8g38c8q", Coins: nil})
 	app.BankKeeper.SetParams(ctx, types.DefaultParams())
 
 	exportGenesis := app.BankKeeper.ExportGenesis(ctx)
@@ -34,6 +32,8 @@ func (suite *IntegrationTestSuite) TestExportGenesis() {
 	suite.Require().Len(exportGenesis.Params.SendEnabled, 0)
 	suite.Require().Equal(types.DefaultParams().DefaultSendEnabled, exportGenesis.Params.DefaultSendEnabled)
 	suite.Require().Equal(totalSupply.Total, exportGenesis.Supply)
+	// add mint module balance as nil
+	expectedBalances = append(expectedBalances, types.Balance{Address: "cosmos1m3h30wlvsf8llruxtpukdvsy0km2kum8g38c8q", Coins: nil})
 	suite.Require().Equal(expectedBalances, exportGenesis.Balances)
 	suite.Require().Equal(expectedMetadata, exportGenesis.DenomMetadata)
 }

x/bank/keeper/keeper.go

@@ -1,8 +1,6 @@
 package keeper
 
 import (
-	"time"
-
 	"github.com/cosmos/cosmos-sdk/codec"
 	"github.com/cosmos/cosmos-sdk/store/prefix"
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -107,9 +105,13 @@ func (k BaseKeeper) DelegateCoins(ctx sdk.Context, delegatorAddr, moduleAccAddr
 		}
 	}
 
-	if err := k.trackDelegation(ctx, delegatorAddr, ctx.BlockHeader().Time, balances, amt); err != nil {
+	if err := k.trackDelegation(ctx, delegatorAddr, balances, amt); err != nil {
 		return sdkerrors.Wrap(err, "failed to track delegation")
 	}
+	// emit coin spent event
+	ctx.EventManager().EmitEvent(
+		types.NewCoinSpentEvent(delegatorAddr, amt),
+	)
 
 	err := k.addCoins(ctx, moduleAccAddr, amt)
 	if err != nil {
@@ -134,7 +136,7 @@ func (k BaseKeeper) UndelegateCoins(ctx sdk.Context, moduleAccAddr, delegatorAdd
 		return sdkerrors.Wrap(sdkerrors.ErrInvalidCoins, amt.String())
 	}
 
-	err := k.subtractCoins(ctx, moduleAccAddr, amt)
+	err := k.subUnlockedCoins(ctx, moduleAccAddr, amt)
 	if err != nil {
 		return err
 	}
@@ -345,6 +347,11 @@ func (k BaseKeeper) MintCoins(ctx sdk.Context, moduleName string, amt sdk.Coins)
 	logger := k.Logger(ctx)
 	logger.Info("minted coins from module account", "amount", amt.String(), "from", moduleName)
 
+	// emit mint event
+	ctx.EventManager().EmitEvent(
+		types.NewCoinMintEvent(acc.GetAddress(), amt),
+	)
+
 	return nil
 }
 
@@ -360,7 +367,7 @@ func (k BaseKeeper) BurnCoins(ctx sdk.Context, moduleName string, amt sdk.Coins)
 		panic(sdkerrors.Wrapf(sdkerrors.ErrUnauthorized, "module account %s does not have permissions to burn tokens", moduleName))
 	}
 
-	err := k.subtractCoins(ctx, acc.GetAddress(), amt)
+	err := k.subUnlockedCoins(ctx, acc.GetAddress(), amt)
 	if err != nil {
 		return err
 	}
@@ -373,10 +380,15 @@ func (k BaseKeeper) BurnCoins(ctx sdk.Context, moduleName string, amt sdk.Coins)
 	logger := k.Logger(ctx)
 	logger.Info("burned tokens from module account", "amount", amt.String(), "from", moduleName)
 
+	// emit burn event
+	ctx.EventManager().EmitEvent(
+		types.NewCoinBurnEvent(acc.GetAddress(), amt),
+	)
+
 	return nil
 }
 
-func (k BaseKeeper) trackDelegation(ctx sdk.Context, addr sdk.AccAddress, blockTime time.Time, balance, amt sdk.Coins) error {
+func (k BaseKeeper) trackDelegation(ctx sdk.Context, addr sdk.AccAddress, balance, amt sdk.Coins) error {
 	acc := k.ak.GetAccount(ctx, addr)
 	if acc == nil {
 		return sdkerrors.Wrapf(sdkerrors.ErrUnknownAddress, "account %s does not exist", addr)
@@ -385,7 +397,7 @@ func (k BaseKeeper) trackDelegation(ctx sdk.Context, addr sdk.AccAddress, blockT
 	vacc, ok := acc.(vestexported.VestingAccount)
 	if ok {
 		// TODO: return error on account.TrackDelegation
-		vacc.TrackDelegation(blockTime, balance, amt)
+		vacc.TrackDelegation(ctx.BlockHeader().Time, balance, amt)
 	}
 
 	return nil

x/bank/keeper/keeper_test.go

@@ -153,17 +153,17 @@ func (suite *IntegrationTestSuite) TestSupply_SendCoins() {
 	suite.Require().NoError(
 		keeper.SendCoinsFromModuleToModule(ctx, holderAcc.GetName(), authtypes.Burner, initCoins),
 	)
-	suite.Require().Equal(sdk.Coins(nil), getCoinsByName(ctx, keeper, authKeeper, holderAcc.GetName()))
+	suite.Require().Equal(sdk.NewCoins().String(), getCoinsByName(ctx, keeper, authKeeper, holderAcc.GetName()).String())
 	suite.Require().Equal(initCoins, getCoinsByName(ctx, keeper, authKeeper, authtypes.Burner))
 
 	suite.Require().NoError(
 		keeper.SendCoinsFromModuleToAccount(ctx, authtypes.Burner, baseAcc.GetAddress(), initCoins),
 	)
-	suite.Require().Equal(sdk.Coins(nil), getCoinsByName(ctx, keeper, authKeeper, authtypes.Burner))
+	suite.Require().Equal(sdk.NewCoins().String(), getCoinsByName(ctx, keeper, authKeeper, authtypes.Burner).String())
 	suite.Require().Equal(initCoins, keeper.GetAllBalances(ctx, baseAcc.GetAddress()))
 
 	suite.Require().NoError(keeper.SendCoinsFromAccountToModule(ctx, baseAcc.GetAddress(), authtypes.Burner, initCoins))
-	suite.Require().Equal(sdk.Coins(nil), keeper.GetAllBalances(ctx, baseAcc.GetAddress()))
+	suite.Require().Equal(sdk.NewCoins().String(), keeper.GetAllBalances(ctx, baseAcc.GetAddress()).String())
 	suite.Require().Equal(initCoins, getCoinsByName(ctx, keeper, authKeeper, authtypes.Burner))
 }
 
@@ -266,7 +266,7 @@ func (suite *IntegrationTestSuite) TestSupply_BurnCoins() {
 
 	err = keeper.BurnCoins(ctx, authtypes.Burner, initCoins)
 	suite.Require().NoError(err)
-	suite.Require().Equal(sdk.Coins(nil), getCoinsByName(ctx, keeper, authKeeper, authtypes.Burner))
+	suite.Require().Equal(sdk.NewCoins().String(), getCoinsByName(ctx, keeper, authKeeper, authtypes.Burner).String())
 	suite.Require().Equal(supplyAfterInflation.GetTotal().Sub(initCoins), keeper.GetSupply(ctx).GetTotal())
 
 	// test same functionality on module account with multiple permissions
@@ -280,7 +280,7 @@ func (suite *IntegrationTestSuite) TestSupply_BurnCoins() {
 
 	err = keeper.BurnCoins(ctx, multiPermAcc.GetName(), initCoins)
 	suite.Require().NoError(err)
-	suite.Require().Equal(sdk.Coins(nil), getCoinsByName(ctx, keeper, authKeeper, multiPermAcc.GetName()))
+	suite.Require().Equal(sdk.NewCoins().String(), getCoinsByName(ctx, keeper, authKeeper, multiPermAcc.GetName()).String())
 	suite.Require().Equal(supplyAfterInflation.GetTotal().Sub(initCoins), keeper.GetSupply(ctx).GetTotal())
 }
 
@@ -537,6 +537,7 @@ func (suite *IntegrationTestSuite) TestMsgSendEvents() {
 		event1.Attributes,
 		abci.EventAttribute{Key: []byte(sdk.AttributeKeyAmount), Value: []byte(newCoins.String())},
 	)
+
 	event2 := sdk.Event{
 		Type:       sdk.EventTypeMessage,
 		Attributes: []abci.EventAttribute{},
@@ -556,9 +557,9 @@ func (suite *IntegrationTestSuite) TestMsgSendEvents() {
 
 	// events are shifted due to the funding account events
 	events = ctx.EventManager().ABCIEvents()
-	suite.Require().Equal(6, len(events))
+	suite.Require().Equal(12, len(events))
-	suite.Require().Equal(abci.Event(event1), events[4])
+	suite.Require().Equal(abci.Event(event1), events[8])
-	suite.Require().Equal(abci.Event(event2), events[5])
+	suite.Require().Equal(abci.Event(event2), events[9])
 }
 
 func (suite *IntegrationTestSuite) TestMsgMultiSendEvents() {
@@ -597,7 +598,7 @@ func (suite *IntegrationTestSuite) TestMsgMultiSendEvents() {
 	suite.Require().Error(app.BankKeeper.InputOutputCoins(ctx, inputs, outputs))
 
 	events = ctx.EventManager().ABCIEvents()
-	suite.Require().Equal(3, len(events)) // 3 events because minting event is there
+	suite.Require().Equal(8, len(events)) // 7 events because account funding causes extra minting + coin_spent + coin_recv events
 
 	event1 := sdk.Event{
 		Type:       sdk.EventTypeMessage,
@@ -607,7 +608,7 @@ func (suite *IntegrationTestSuite) TestMsgMultiSendEvents() {
 		event1.Attributes,
 		abci.EventAttribute{Key: []byte(types.AttributeKeySender), Value: []byte(addr.String())},
 	)
-	suite.Require().Equal(abci.Event(event1), events[2]) // it's the third event since we have the minting event before
+	suite.Require().Equal(abci.Event(event1), events[7])
 
 	// Set addr's coins and addr2's coins
 	suite.Require().NoError(simapp.FundAccount(app, ctx, addr, sdk.NewCoins(sdk.NewInt64Coin(fooDenom, 50))))
@@ -619,7 +620,7 @@ func (suite *IntegrationTestSuite) TestMsgMultiSendEvents() {
 	suite.Require().NoError(app.BankKeeper.InputOutputCoins(ctx, inputs, outputs))
 
 	events = ctx.EventManager().ABCIEvents()
-	suite.Require().Equal(11, len(events))
+	suite.Require().Equal(28, len(events)) // 25 due to account funding + coin_spent + coin_recv events
 
 	event2 := sdk.Event{
 		Type:       sdk.EventTypeMessage,
@@ -652,12 +653,11 @@ func (suite *IntegrationTestSuite) TestMsgMultiSendEvents() {
 		event4.Attributes,
 		abci.EventAttribute{Key: []byte(sdk.AttributeKeyAmount), Value: []byte(newCoins2.String())},
 	)
-
 	// events are shifted due to the funding account events
-	suite.Require().Equal(abci.Event(event1), events[7])
+	suite.Require().Equal(abci.Event(event1), events[21])
-	suite.Require().Equal(abci.Event(event2), events[8])
+	suite.Require().Equal(abci.Event(event2), events[23])
-	suite.Require().Equal(abci.Event(event3), events[9])
+	suite.Require().Equal(abci.Event(event3), events[25])
-	suite.Require().Equal(abci.Event(event4), events[10])
+	suite.Require().Equal(abci.Event(event4), events[27])
 }
 
 func (suite *IntegrationTestSuite) TestSpendableCoins() {
@@ -1002,6 +1002,103 @@ func (suite *IntegrationTestSuite) TestIterateAllDenomMetaData() {
 	}
 }
 
+func (suite *IntegrationTestSuite) TestBalanceTrackingEvents() {
+	// replace account keeper and bank keeper otherwise the account keeper won't be aware of the
+	// existence of the new module account because GetModuleAccount checks for the existence via
+	// permissions map and not via state... weird
+	maccPerms := simapp.GetMaccPerms()
+	maccPerms[multiPerm] = []string{authtypes.Burner, authtypes.Minter, authtypes.Staking}
+
+	suite.app.AccountKeeper = authkeeper.NewAccountKeeper(
+		suite.app.AppCodec(), suite.app.GetKey(authtypes.StoreKey), suite.app.GetSubspace(authtypes.ModuleName),
+		authtypes.ProtoBaseAccount, maccPerms,
+	)
+
+	suite.app.BankKeeper = keeper.NewBaseKeeper(suite.app.AppCodec(), suite.app.GetKey(types.StoreKey),
+		suite.app.AccountKeeper, suite.app.GetSubspace(types.ModuleName), nil)
+
+	// set account with multiple permissions
+	suite.app.AccountKeeper.SetModuleAccount(suite.ctx, multiPermAcc)
+	// mint coins
+	suite.Require().NoError(
+		suite.app.BankKeeper.MintCoins(
+			suite.ctx,
+			multiPermAcc.Name,
+			sdk.NewCoins(sdk.NewCoin("utxo", sdk.NewInt(100000)))),
+	)
+	// send coins to address
+	addr1 := sdk.AccAddress("addr1_______________")
+	suite.Require().NoError(
+		suite.app.BankKeeper.SendCoinsFromModuleToAccount(
+			suite.ctx,
+			multiPermAcc.Name,
+			addr1,
+			sdk.NewCoins(sdk.NewCoin("utxo", sdk.NewInt(50000))),
+		),
+	)
+
+	// burn coins from module account
+	suite.Require().NoError(
+		suite.app.BankKeeper.BurnCoins(
+			suite.ctx,
+			multiPermAcc.Name,
+			sdk.NewCoins(sdk.NewInt64Coin("utxo", 1000)),
+		),
+	)
+
+	// process balances and supply from events
+	supply := sdk.NewCoins()
+
+	balances := make(map[string]sdk.Coins)
+
+	for _, e := range suite.ctx.EventManager().ABCIEvents() {
+		switch e.Type {
+		case types.EventTypeCoinBurn:
+			burnedCoins, err := sdk.ParseCoinsNormalized((string)(e.Attributes[1].Value))
+			suite.Require().NoError(err)
+			supply = supply.Sub(burnedCoins)
+
+		case types.EventTypeCoinMint:
+			mintedCoins, err := sdk.ParseCoinsNormalized((string)(e.Attributes[1].Value))
+			suite.Require().NoError(err)
+			supply = supply.Add(mintedCoins...)
+
+		case types.EventTypeCoinSpent:
+			coinsSpent, err := sdk.ParseCoinsNormalized((string)(e.Attributes[1].Value))
+			suite.Require().NoError(err)
+			spender, err := sdk.AccAddressFromBech32((string)(e.Attributes[0].Value))
+			suite.Require().NoError(err)
+			balances[spender.String()] = balances[spender.String()].Sub(coinsSpent)
+
+		case types.EventTypeCoinReceived:
+			coinsRecv, err := sdk.ParseCoinsNormalized((string)(e.Attributes[1].Value))
+			suite.Require().NoError(err)
+			receiver, err := sdk.AccAddressFromBech32((string)(e.Attributes[0].Value))
+			suite.Require().NoError(err)
+			balances[receiver.String()] = balances[receiver.String()].Add(coinsRecv...)
+		}
+	}
+
+	// check balance and supply tracking
+	savedSupply := suite.app.BankKeeper.GetSupply(suite.ctx)
+	utxoSupply := savedSupply.GetTotal().AmountOf("utxo")
+	suite.Require().Equal(utxoSupply, supply.AmountOf("utxo"))
+	// iterate accounts and check balances
+	suite.app.BankKeeper.IterateAllBalances(suite.ctx, func(address sdk.AccAddress, coin sdk.Coin) (stop bool) {
+		// if it's not utxo coin then skip
+		if coin.Denom != "utxo" {
+			return false
+		}
+
+		balance, exists := balances[address.String()]
+		suite.Require().True(exists)
+
+		expectedUtxo := sdk.NewCoin("utxo", balance.AmountOf(coin.Denom))
+		suite.Require().Equal(expectedUtxo.String(), coin.String())
+		return false
+	})
+}
+
 func (suite *IntegrationTestSuite) getTestMetadata() []types.Metadata {
 	return []types.Metadata{{
 		Name:        "Cosmos Hub Atom",

x/bank/keeper/send.go

@@ -83,7 +83,7 @@ func (k BaseSendKeeper) InputOutputCoins(ctx sdk.Context, inputs []types.Input,
 			return err
 		}
 
-		err = k.subtractCoins(ctx, inAddress, in.Coins)
+		err = k.subUnlockedCoins(ctx, inAddress, in.Coins)
 		if err != nil {
 			return err
 		}
@@ -144,7 +144,7 @@ func (k BaseSendKeeper) SendCoins(ctx sdk.Context, fromAddr sdk.AccAddress, toAd
 		),
 	})
 
-	err := k.subtractCoins(ctx, fromAddr, amt)
+	err := k.subUnlockedCoins(ctx, fromAddr, amt)
 	if err != nil {
 		return err
 	}
@@ -167,9 +167,10 @@ func (k BaseSendKeeper) SendCoins(ctx sdk.Context, fromAddr sdk.AccAddress, toAd
 	return nil
 }
 
-// subtractCoins removes amt coins the account by the given address. An error is
+// subUnlockedCoins removes the unlocked amt coins of the given account. An error is
 // returned if the resulting balance is negative or the initial amount is invalid.
-func (k BaseSendKeeper) subtractCoins(ctx sdk.Context, addr sdk.AccAddress, amt sdk.Coins) error {
+// A coin_spent event is emitted after.
+func (k BaseSendKeeper) subUnlockedCoins(ctx sdk.Context, addr sdk.AccAddress, amt sdk.Coins) error {
 	if !amt.IsValid() {
 		return sdkerrors.Wrap(sdkerrors.ErrInvalidCoins, amt.String())
 	}
@@ -194,12 +195,15 @@ func (k BaseSendKeeper) subtractCoins(ctx sdk.Context, addr sdk.AccAddress, amt
 		}
 	}
 
+	// emit coin spent event
+	ctx.EventManager().EmitEvent(
+		types.NewCoinSpentEvent(addr, amt),
+	)
 	return nil
 }
 
-// addCoins adds amt to the account balance given by the provided address. An
+// addCoins increase the addr balance by the given amt. Fails if the provided amt is invalid.
-// error is returned if the initial amount is invalid or if any resulting new
+// It emits a coin received event.
-// balance is negative.
 func (k BaseSendKeeper) addCoins(ctx sdk.Context, addr sdk.AccAddress, amt sdk.Coins) error {
 	if !amt.IsValid() {
 		return sdkerrors.Wrap(sdkerrors.ErrInvalidCoins, amt.String())
@@ -215,11 +219,16 @@ func (k BaseSendKeeper) addCoins(ctx sdk.Context, addr sdk.AccAddress, amt sdk.C
 		}
 	}
 
+	// emit coin received event
+	ctx.EventManager().EmitEvent(
+		types.NewCoinReceivedEvent(addr, amt),
+	)
+
 	return nil
 }
 
-// ClearBalances removes all balances for a given account by address.
+// clearBalances removes all balances for a given account by address.
-func (k BaseSendKeeper) ClearBalances(ctx sdk.Context, addr sdk.AccAddress) {
+func (k BaseSendKeeper) clearBalances(ctx sdk.Context, addr sdk.AccAddress) {
 	keys := [][]byte{}
 	k.IterateAccountBalances(ctx, addr, func(balance sdk.Coin) bool {
 		keys = append(keys, []byte(balance.Denom))
@@ -237,7 +246,7 @@ func (k BaseSendKeeper) ClearBalances(ctx sdk.Context, addr sdk.AccAddress) {
 // clear out all balances prior to setting the new coins as to set existing balances
 // to zero if they don't exist in amt. An error is returned upon failure.
 func (k BaseSendKeeper) setBalances(ctx sdk.Context, addr sdk.AccAddress, balances sdk.Coins) error {
-	k.ClearBalances(ctx, addr)
+	k.clearBalances(ctx, addr)
 
 	for _, balance := range balances {
 		err := k.setBalance(ctx, addr, balance)

x/bank/keeper/view.go

@@ -171,15 +171,23 @@ func (k BaseViewKeeper) LockedCoins(ctx sdk.Context, addr sdk.AccAddress) sdk.Co
 // by address. If the account has no spendable coins, an empty Coins slice is
 // returned.
 func (k BaseViewKeeper) SpendableCoins(ctx sdk.Context, addr sdk.AccAddress) sdk.Coins {
-	balances := k.GetAllBalances(ctx, addr)
+	spendable, _ := k.spendableCoins(ctx, addr)
+	return spendable
+}
+
+// spendableCoins returns the coins the given address can spend alongside the total amount of coins it holds.
+// It exists for gas efficiency, in order to avoid to have to get balance multiple times.
+func (k BaseViewKeeper) spendableCoins(ctx sdk.Context, addr sdk.AccAddress) (spendable, total sdk.Coins) {
+	total = k.GetAllBalances(ctx, addr)
 	locked := k.LockedCoins(ctx, addr)
 
-	spendable, hasNeg := balances.SafeSub(locked)
+	spendable, hasNeg := total.SafeSub(locked)
 	if hasNeg {
-		return sdk.NewCoins()
+		spendable = sdk.NewCoins()
+		return
 	}
 
-	return spendable
+	return
 }
 
 // ValidateBalance validates all balances for a given account address returning

x/bank/spec/04_events.md

@@ -27,3 +27,123 @@ The bank module emits the following events:
 | message  | module        | bank               |
 | message  | action        | multisend          |
 | message  | sender        | {senderAddress}    |
+
+## Keeper events
+
+In addition to handlers events, the bank keeper will produce events when the following methods are called (or any method which ends up calling them)
+
+### MintCoins
+
+```json
+{
+  "type": "coinbase",
+  "attributes": [
+    {
+      "key": "minter",
+      "value": "{{sdk.AccAddress of the module minting coins}}",
+      "index": true
+    },
+    {
+      "key": "amount",
+      "value": "{{sdk.Coins being minted}}",
+      "index": true
+    }
+  ]
+}
+```
+
+```json
+{
+  "type": "coin_received",
+  "attributes": [
+    {
+      "key": "receiver",
+      "value": "{{sdk.AccAddress of the module minting coins}}",
+      "index": true
+    },
+    {
+      "key": "amount",
+      "value": "{{sdk.Coins being received}}",
+      "index": true
+    }
+  ]
+}
+```
+
+### BurnCoins
+
+```json
+{
+  "type": "burn",
+  "attributes": [
+    {
+      "key": "burner",
+      "value": "{{sdk.AccAddress of the module burning coins}}",
+      "index": true
+    },
+    {
+      "key": "amount",
+      "value": "{{sdk.Coins being burned}}",
+      "index": true
+    }
+  ]
+}
+```
+
+```json
+{
+  "type": "coin_spent",
+  "attributes": [
+    {
+      "key": "spender",
+      "value": "{{sdk.AccAddress of the module burning coins}}",
+      "index": true
+    },
+    {
+      "key": "amount",
+      "value": "{{sdk.Coins being burned}}",
+      "index": true
+    }
+  ]
+}
+```
+
+### addCoins
+
+```json
+{
+  "type": "coin_received",
+  "attributes": [
+    {
+      "key": "receiver",
+      "value": "{{sdk.AccAddress of the address beneficiary of the coins}}",
+      "index": true
+    },
+    {
+      "key": "amount",
+      "value": "{{sdk.Coins being received}}",
+      "index": true
+    }
+  ]
+}
+```
+
+### subUnlockedCoins/DelegateCoins
+
+```json
+{
+  "type": "coin_spent",
+  "attributes": [
+    {
+      "key": "spender",
+      "value": "{{sdk.AccAddress of the address which is spending coins}}",
+      "index": true
+    },
+    {
+      "key": "amount",
+      "value": "{{sdk.Coins being spent}}",
+      "index": true
+    }
+  ]
+}
+```

x/bank/types/events.go

@@ -1,5 +1,9 @@
 package types
 
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
 // bank module event types
 const (
 	EventTypeTransfer = "transfer"
@@ -8,4 +12,55 @@ const (
 	AttributeKeySender    = "sender"
 
 	AttributeValueCategory = ModuleName
+
+	// supply and balance tracking events name and attributes
+	EventTypeCoinSpent    = "coin_spent"
+	EventTypeCoinReceived = "coin_received"
+	EventTypeCoinMint     = "coinbase" // NOTE(fdymylja): using mint clashes with mint module event
+	EventTypeCoinBurn     = "burn"
+
+	AttributeKeySpender  = "spender"
+	AttributeKeyReceiver = "receiver"
+	AttributeKeyMinter   = "minter"
+	AttributeKeyBurner   = "burner"
 )
+
+// NewCoinSpentEvent constructs a new coin spent sdk.Event
+// nolint: interfacer
+func NewCoinSpentEvent(spender sdk.AccAddress, amount sdk.Coins) sdk.Event {
+	return sdk.NewEvent(
+		EventTypeCoinSpent,
+		sdk.NewAttribute(AttributeKeySpender, spender.String()),
+		sdk.NewAttribute(sdk.AttributeKeyAmount, amount.String()),
+	)
+}
+
+// NewCoinReceivedEvent constructs a new coin received sdk.Event
+// nolint: interfacer
+func NewCoinReceivedEvent(receiver sdk.AccAddress, amount sdk.Coins) sdk.Event {
+	return sdk.NewEvent(
+		EventTypeCoinReceived,
+		sdk.NewAttribute(AttributeKeyReceiver, receiver.String()),
+		sdk.NewAttribute(sdk.AttributeKeyAmount, amount.String()),
+	)
+}
+
+// NewCoinMintEvent construct a new coin minted sdk.Event
+// nolint: interfacer
+func NewCoinMintEvent(minter sdk.AccAddress, amount sdk.Coins) sdk.Event {
+	return sdk.NewEvent(
+		EventTypeCoinMint,
+		sdk.NewAttribute(AttributeKeyMinter, minter.String()),
+		sdk.NewAttribute(sdk.AttributeKeyAmount, amount.String()),
+	)
+}
+
+// NewCoinBurnEvent constructs a new coin burned sdk.Event
+// nolint: interfacer
+func NewCoinBurnEvent(burner sdk.AccAddress, amount sdk.Coins) sdk.Event {
+	return sdk.NewEvent(
+		EventTypeCoinBurn,
+		sdk.NewAttribute(AttributeKeyBurner, burner.String()),
+		sdk.NewAttribute(sdk.AttributeKeyAmount, amount.String()),
+	)
+}

x/staking/client/cli/cli_test.go

@@ -58,11 +58,17 @@ func (s *IntegrationTestSuite) SetupSuite() {
 	val2 := s.network.Validators[1]
 
 	// redelegate
-	_, err = stakingtestutil.MsgRedelegateExec(val.ClientCtx, val.Address, val.ValAddress, val2.ValAddress, unbond)
+	_, err = stakingtestutil.MsgRedelegateExec(
+		val.ClientCtx,
+		val.Address,
+		val.ValAddress,
+		val2.ValAddress,
+		unbond,
+		fmt.Sprintf("--%s=%d", flags.FlagGas, 202954), //  202954 is the required
+	)
 	s.Require().NoError(err)
 	_, err = s.network.WaitForHeight(1)
 	s.Require().NoError(err)
-
 	// unbonding
 	_, err = stakingtestutil.MsgUnbondExec(val.ClientCtx, val.Address, val.ValAddress, unbond)
 	s.Require().NoError(err)

x/staking/client/rest/grpc_query_test.go

@@ -6,6 +6,8 @@ import (
 	"fmt"
 	"testing"
 
+	"github.com/cosmos/cosmos-sdk/client/flags"
+
 	"github.com/gogo/protobuf/proto"
 	"github.com/stretchr/testify/suite"
 
@@ -46,7 +48,15 @@ func (s *IntegrationTestSuite) SetupSuite() {
 	val2 := s.network.Validators[1]
 
 	// redelegate
-	_, err = stakingtestutil.MsgRedelegateExec(val.ClientCtx, val.Address, val.ValAddress, val2.ValAddress, unbond)
+	_, err = stakingtestutil.MsgRedelegateExec(
+		val.ClientCtx,
+		val.Address,
+		val.ValAddress,
+		val2.ValAddress,
+		unbond,
+		fmt.Sprintf("--%s=%d", flags.FlagGas, 254000),
+	) // expected gas is 202987
+
 	s.Require().NoError(err)
 	_, err = s.network.WaitForHeight(1)
 	s.Require().NoError(err)
@@ -330,7 +340,7 @@ func (s *IntegrationTestSuite) TestQueryDelegationGRPC() {
 		s.Run(tc.name, func() {
 			resp, err := rest.GetRequest(tc.url)
 			s.Require().NoError(err)
-
+			s.T().Logf("%s", resp)
 			err = val.ClientCtx.JSONMarshaler.UnmarshalJSON(resp, tc.respType)
 
 			if tc.error {

x/staking/client/testutil/test_helpers.go

@@ -27,6 +27,7 @@ func MsgRedelegateExec(clientCtx client.Context, from, src, dst, amount fmt.Stri
 		amount.String(),
 		fmt.Sprintf("--%s=%s", flags.FlagFrom, from.String()),
 	}
+	args = append(args, extraArgs...)
 
 	args = append(args, commonArgs...)
 	return clitestutil.ExecTestCLICmd(clientCtx, stakingcli.NewRedelegateCmd(), args)
@@ -43,5 +44,6 @@ func MsgUnbondExec(clientCtx client.Context, from fmt.Stringer, valAddress,
 	}
 
 	args = append(args, commonArgs...)
+	args = append(args, extraArgs...)
 	return clitestutil.ExecTestCLICmd(clientCtx, stakingcli.NewUnbondCmd(), args)
 }