create generic helper function for parsing event attributes (#6792)

* create generic helper function for parsing event attributes

* review:

Align sig with other attr helpers (attrs, key)
Slap docusting
Amend contains to re-use it.
Use in ParseAckFromEvents

---------

Co-authored-by: DimitrisJim <[email protected]>

testing/events.go

@@ -157,15 +157,13 @@ func ParsePacketsFromEvents(eventType string, events []abci.Event) ([]channeltyp
 func ParseAckFromEvents(events []abci.Event) ([]byte, error) {
 	for _, ev := range events {
 		if ev.Type == channeltypes.EventTypeWriteAck {
-			for _, attr := range ev.Attributes {
-				if attr.Key == channeltypes.AttributeKeyAckHex {
-					value, err := hex.DecodeString(attr.Value)
-					if err != nil {
-						return nil, err
-					}
-
-					return value, nil
+			if attribute, found := attributeByKey(ev.Attributes, channeltypes.AttributeKeyAckHex); found {
+				value, err := hex.DecodeString(attribute.Value)
+				if err != nil {
+					return nil, err
 				}
+
+				return value, nil
 			}
 		}
 	}
@@ -175,26 +173,20 @@ func ParseAckFromEvents(events []abci.Event) ([]byte, error) {
 // ParseProposalIDFromEvents parses events emitted from MsgSubmitProposal and returns proposalID
 func ParseProposalIDFromEvents(events []abci.Event) (uint64, error) {
 	for _, event := range events {
-		for _, attribute := range event.Attributes {
-			if attribute.Key == "proposal_id" {
-				return strconv.ParseUint(attribute.Value, 10, 64)
-			}
+		if attribute, found := attributeByKey(event.Attributes, "proposal_id"); found {
+			return strconv.ParseUint(attribute.Value, 10, 64)
 		}
 	}
-
 	return 0, fmt.Errorf("proposalID event attribute not found")
 }
 
 // ParsePacketSequenceFromEvents parses events emitted from MsgRecvPacket and returns the packet sequence
 func ParsePacketSequenceFromEvents(events []abci.Event) (uint64, error) {
 	for _, event := range events {
-		for _, attribute := range event.Attributes {
-			if attribute.Key == "packet_sequence" {
-				return strconv.ParseUint(attribute.Value, 10, 64)
-			}
+		if attribute, found := attributeByKey(event.Attributes, "packet_sequence"); found {
+			return strconv.ParseUint(attribute.Value, 10, 64)
 		}
 	}
-
 	return 0, fmt.Errorf("packet sequence event attribute not found")
 }
 
@@ -253,7 +245,15 @@ func containsAttribute(attrs []abci.EventAttribute, key, value string) bool {
 
 // containsAttributeKey returns true if the given key is contained in the given attributes.
 func containsAttributeKey(attrs []abci.EventAttribute, key string) bool {
-	return slices.ContainsFunc(attrs, func(attr abci.EventAttribute) bool {
-		return attr.Key == key
-	})
+	_, found := attributeByKey(attrs, key)
+	return found
+}
+
+// attributeByKey returns the event attribute's value keyed by the given key and a boolean indicating its presence in the given attributes.
+func attributeByKey(attributes []abci.EventAttribute, key string) (abci.EventAttribute, bool) {
+	idx := slices.IndexFunc(attributes, func(a abci.EventAttribute) bool { return a.Key == key })
+	if idx == -1 {
+		return abci.EventAttribute{}, false
+	}
+	return attributes[idx], true
 }