baseapp: track events emitted from AnteHandler (#6187)

* baseapp: append AnteHandler events to tx result

* changelog

* baseapp tests

* fix test

* update changelog

* update log

* move event out from conditional

* minor update

* fix panic

* add switch case

* remove result on error

* change conditional

* check for event len

* update tests

CHANGELOG.md

@@ -206,6 +206,7 @@ Buffers for state serialization instead of Amino.
 
 ### Improvements
 
+* (baseapp) [\#6186](https://github.com/cosmos/cosmos-sdk/issues/6186) Support emitting events during `AnteHandler` execution.
 * (x/auth) [\#5702](https://github.com/cosmos/cosmos-sdk/pull/5702) Add parameter querying support for `x/auth`.
 * (types) [\#5581](https://github.com/cosmos/cosmos-sdk/pull/5581) Add convenience functions {,Must}Bech32ifyAddressBytes.
 * (staking) [\#5584](https://github.com/cosmos/cosmos-sdk/pull/5584) Add util function `ToTmValidator` that converts a `staking.Validator` type to `*tmtypes.Validator`.
@@ -231,7 +232,7 @@ functionality that requires an online connection.
 * (simulation) [\#6002](https://github.com/cosmos/cosmos-sdk/pull/6002) Add randomized consensus params into simulation.
 * (x/staking) [\#6059](https://github.com/cosmos/cosmos-sdk/pull/6059) Updated `HistoricalEntries` parameter default to 100.
 * (x/ibc) [\#5948](https://github.com/cosmos/cosmos-sdk/issues/5948) Add `InitGenesis` and `ExportGenesis` functions for `ibc` module.
-* (types) [\#6128](https://github.com/cosmos/cosmos-sdk/pull/6137) Add String() method to GasMeter
+* (types) [\#6128](https://github.com/cosmos/cosmos-sdk/pull/6137) Add `String()` method to `GasMeter`.
 
 ## [v0.38.3] - 2020-04-09
 

baseapp/baseapp.go

@@ -536,6 +536,7 @@ func (app *BaseApp) runTx(mode runTxMode, txBytes []byte, tx sdk.Tx) (gInfo sdk.
 		return sdk.GasInfo{}, nil, err
 	}
 
+	var events sdk.Events
 	if app.anteHandler != nil {
 		var (
 			anteCtx sdk.Context
@@ -563,6 +564,8 @@ func (app *BaseApp) runTx(mode runTxMode, txBytes []byte, tx sdk.Tx) (gInfo sdk.
 			ctx = newCtx.WithMultiStore(ms)
 		}
 
+		events = ctx.EventManager().Events()
+
 		// GasMeter expected to be set in AnteHandler
 		gasWanted = ctx.GasMeter().Limit()
 
@@ -584,6 +587,11 @@ func (app *BaseApp) runTx(mode runTxMode, txBytes []byte, tx sdk.Tx) (gInfo sdk.
 	result, err = app.runMsgs(runMsgCtx, msgs, mode)
 	if err == nil && mode == runTxModeDeliver {
 		msCache.Write()
+
+		if len(events) > 0 {
+			// append the events in the order of occurrence
+			result.Events = append(events.ToABCIEvents(), result.Events...)
+		}
 	}
 
 	return gInfo, result, err

baseapp/baseapp_test.go

@@ -665,7 +665,8 @@ func testTxDecoder(cdc *codec.Codec) sdk.TxDecoder {
 
 func anteHandlerTxTest(t *testing.T, capKey sdk.StoreKey, storeKey []byte) sdk.AnteHandler {
 	return func(ctx sdk.Context, tx sdk.Tx, simulate bool) (newCtx sdk.Context, err error) {
-		store := ctx.KVStore(capKey)
+		newCtx = ctx.WithEventManager(sdk.NewEventManager())
+		store := newCtx.KVStore(capKey)
 		txTest := tx.(txTest)
 
 		if txTest.FailOnAnte {
@@ -677,12 +678,26 @@ func anteHandlerTxTest(t *testing.T, capKey sdk.StoreKey, storeKey []byte) sdk.A
 			return newCtx, err
 		}
 
+		newCtx.EventManager().EmitEvents(
+			counterEvent("ante_handler", txTest.Counter),
+		)
+
 		return newCtx, nil
 	}
 }
 
+func counterEvent(evType string, msgCount int64) sdk.Events {
+	return sdk.Events{
+		sdk.NewEvent(
+			evType,
+			sdk.NewAttribute("update_counter", fmt.Sprintf("%d", msgCount)),
+		),
+	}
+}
+
 func handlerMsgCounter(t *testing.T, capKey sdk.StoreKey, deliverKey []byte) sdk.Handler {
 	return func(ctx sdk.Context, msg sdk.Msg) (*sdk.Result, error) {
+		ctx = ctx.WithEventManager(sdk.NewEventManager())
 		store := ctx.KVStore(capKey)
 		var msgCount int64
 
@@ -693,12 +708,21 @@ func handlerMsgCounter(t *testing.T, capKey sdk.StoreKey, deliverKey []byte) sdk
 			}
 
 			msgCount = m.Counter
-
 		case *msgCounter2:
 			msgCount = m.Counter
 		}
 
-		return incrementingCounter(t, store, deliverKey, msgCount)
+		ctx.EventManager().EmitEvents(
+			counterEvent(sdk.EventTypeMessage, msgCount),
+		)
+
+		res, err := incrementingCounter(t, store, deliverKey, msgCount)
+		if err != nil {
+			return nil, err
+		}
+
+		res.Events = ctx.EventManager().Events().ToABCIEvents()
+		return res, nil
 	}
 }
 
@@ -761,11 +785,12 @@ func TestCheckTx(t *testing.T) {
 	registerTestCodec(codec)
 
 	for i := int64(0); i < nTxs; i++ {
-		tx := newTxCounter(i, 0)
+		tx := newTxCounter(i, 0) // no messages
 		txBytes, err := codec.MarshalBinaryBare(tx)
 		require.NoError(t, err)
 		r := app.CheckTx(abci.RequestCheckTx{Tx: txBytes})
-		assert.True(t, r.IsOK(), fmt.Sprintf("%v", r))
+		require.Empty(t, r.GetEvents())
+		require.True(t, r.IsOK(), fmt.Sprintf("%v", r))
 	}
 
 	checkStateStore := app.checkState.ctx.KVStore(capKey1)
@@ -821,6 +846,10 @@ func TestDeliverTx(t *testing.T) {
 
 			res := app.DeliverTx(abci.RequestDeliverTx{Tx: txBytes})
 			require.True(t, res.IsOK(), fmt.Sprintf("%v", res))
+			events := res.GetEvents()
+			require.Len(t, events, 3, "should contain ante handler, message type and counter events respectively")
+			require.Equal(t, counterEvent("ante_handler", counter).ToABCIEvents()[0], events[0], "ante handler event")
+			require.Equal(t, counterEvent(sdk.EventTypeMessage, counter).ToABCIEvents()[0], events[2], "msg handler update counter event")
 		}
 
 		app.EndBlock(abci.RequestEndBlock{})