fix: improve baseapp event emission (backport #14356) (#14362)

Co-authored-by: Julien Robert <julien@rbrt.fr>

CHANGELOG.md

@@ -44,6 +44,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+* [#14356](https://github.com/cosmos/cosmos-sdk/pull/14356) Add `events.GetAttributes` and `event.GetAttribute` methods to simplify the retrieval of an attribute from event(s).
 * (types) [#14332](https://github.com/cosmos/cosmos-sdk/issues/14332) Reduce state export time by 50%.
 * (types) [#14163](https://github.com/cosmos/cosmos-sdk/pull/14163) Refactor `(coins Coins) Validate()` to avoid unnecessary map.
 * [#13881](https://github.com/cosmos/cosmos-sdk/pull/13881) Optimize iteration on nested cached KV stores and other operations in general.

UPGRADING.md

@@ -100,6 +100,10 @@ ctx.EventManager().EmitEvent(
 )
 ```
 
+The module name is assumed by `baseapp` to be the second element of the message route: `"cosmos.bank.v1beta1.MsgSend" -> "bank"`.
+In case a module does not follow the standard message path, (e.g. IBC), it is advised to keep emitting the module name event.
+`Baseapp` only emits that event if the module have not already done so.
+
 #### `x/gov`
 
 ##### Minimum Proposal Deposit At Time of Submission

baseapp/baseapp.go

@@ -797,7 +797,7 @@ func (app *BaseApp) runMsgs(ctx sdk.Context, msgs []sdk.Msg, mode runTxMode) (*s
 		}
 
 		// create message events
-		msgEvents := createEvents(msg).AppendEvents(msgResult.GetEvents())
+		msgEvents := createEvents(msgResult.GetEvents(), msg)
 
 		// append message events, data and logs
 		//
@@ -839,7 +839,7 @@ func makeABCIData(msgResponses []*codectypes.Any) ([]byte, error) {
 	return proto.Marshal(&sdk.TxMsgData{MsgResponses: msgResponses})
 }
 
-func createEvents(msg sdk.Msg) sdk.Events {
+func createEvents(events sdk.Events, msg sdk.Msg) sdk.Events {
 	eventMsgName := sdk.MsgTypeURL(msg)
 	msgEvent := sdk.NewEvent(sdk.EventTypeMessage, sdk.NewAttribute(sdk.AttributeKeyAction, eventMsgName))
 
@@ -848,14 +848,17 @@ func createEvents(msg sdk.Msg) sdk.Events {
 		msgEvent = msgEvent.AppendAttributes(sdk.NewAttribute(sdk.AttributeKeySender, msg.GetSigners()[0].String()))
 	}
 
-	// here we assume that routes module name is the second element of the route
-	// e.g. "cosmos.bank.v1beta1.MsgSend" => "bank"
-	moduleName := strings.Split(eventMsgName, ".")
-	if len(moduleName) > 1 {
-		msgEvent = msgEvent.AppendAttributes(sdk.NewAttribute(sdk.AttributeKeyModule, moduleName[1]))
+	// verify that events have no module attribute set
+	if _, found := events.GetAttributes(sdk.AttributeKeyModule); !found {
+		// here we assume that routes module name is the second element of the route
+		// e.g. "cosmos.bank.v1beta1.MsgSend" => "bank"
+		moduleName := strings.Split(eventMsgName, ".")
+		if len(moduleName) > 1 {
+			msgEvent = msgEvent.AppendAttributes(sdk.NewAttribute(sdk.AttributeKeyModule, moduleName[1]))
+		}
 	}
 
-	return sdk.Events{msgEvent}
+	return sdk.Events{msgEvent}.AppendEvents(events)
 }
 
 // DefaultPrepareProposal returns the default implementation for processing an

types/events.go

@@ -197,6 +197,17 @@ func (e Event) AppendAttributes(attrs ...Attribute) Event {
 	return e
 }
 
+// GetAttribute returns an attribute for a given key present in an event.
+// If the key is not found, the boolean value will be false.
+func (e Event) GetAttribute(key string) (Attribute, bool) {
+	for _, attr := range e.Attributes {
+		if attr.Key == key {
+			return Attribute{Key: attr.Key, Value: attr.Value}, true
+		}
+	}
+	return Attribute{}, false
+}
+
 // AppendEvent adds an Event to a slice of events.
 func (e Events) AppendEvent(event Event) Events {
 	return append(e, event)
@@ -218,6 +229,19 @@ func (e Events) ToABCIEvents() []abci.Event {
 	return res
 }
 
+// GetAttributes returns all attributes matching a given key present in events.
+// If the key is not found, the boolean value will be false.
+func (e Events) GetAttributes(key string) ([]Attribute, bool) {
+	attrs := make([]Attribute, 0)
+	for _, event := range e {
+		if attr, found := event.GetAttribute(key); found {
+			attrs = append(attrs, attr)
+		}
+	}
+
+	return attrs, len(attrs) > 0
+}
+
 // Common event types and attribute keys
 const (
 	EventTypeTx = "tx"

types/events_test.go

@@ -39,6 +39,25 @@ func (s *eventsTestSuite) TestAppendAttributes() {
 	s.Require().Equal(e, sdk.NewEvent("transfer", sdk.NewAttribute("sender", "foo"), sdk.NewAttribute("recipient", "bar")))
 }
 
+func (s *eventsTestSuite) TestGetAttributes() {
+	e := sdk.NewEvent("transfer", sdk.NewAttribute("sender", "foo"))
+	e = e.AppendAttributes(sdk.NewAttribute("recipient", "bar"))
+	attr, found := e.GetAttribute("recipient")
+	s.Require().True(found)
+	s.Require().Equal(attr, sdk.NewAttribute("recipient", "bar"))
+	_, found = e.GetAttribute("foo")
+	s.Require().False(found)
+
+	events := sdk.Events{e}.AppendEvent(sdk.NewEvent("message", sdk.NewAttribute("sender", "bar")))
+	attrs, found := events.GetAttributes("sender")
+	s.Require().True(found)
+	s.Require().Len(attrs, 2)
+	s.Require().Equal(attrs[0], sdk.NewAttribute("sender", "foo"))
+	s.Require().Equal(attrs[1], sdk.NewAttribute("sender", "bar"))
+	_, found = events.GetAttributes("foo")
+	s.Require().False(found)
+}
+
 func (s *eventsTestSuite) TestEmptyEvents() {
 	s.Require().Equal(sdk.EmptyEvents(), sdk.Events{})
 }