fix: do not flatten events attributes by event types (backport #14691)

CHANGELOG.md

@@ -39,6 +39,8 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## Improvements
 
+* [#14691](https://github.com/cosmos/cosmos-sdk/pull/14691) Change behavior of `sdk.StringifyEvents` to not flatten events attributes by events type.
+    * This change only affects ABCI message logs, and not the actual events.
 * [#14017](https://github.com/cosmos/cosmos-sdk/pull/14017) Simplify ADR-028 and `address.Module`.
     * This updates the [ADR-028](https://docs.cosmos.network/main/architecture/adr-028-public-key-addresses) and enhance the `address.Module` API to support module addresses and sub-module addresses in a backward compatible way.
 * (snapshots) [#14608](https://github.com/cosmos/cosmos-sdk/pull/14608/) Deprecate unused structs `SnapshotKVItem` and `SnapshotSchema`.

types/events.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"reflect"
-	"sort"
 	"strings"
 
 	"golang.org/x/exp/maps"
@@ -278,29 +277,6 @@ func (se StringEvents) String() string {
 	return strings.TrimRight(sb.String(), "\n")
 }
 
-// Flatten returns a flattened version of StringEvents by grouping all attributes
-// per unique event type.
-func (se StringEvents) Flatten() StringEvents {
-	flatEvents := make(map[string][]Attribute)
-
-	for _, e := range se {
-		flatEvents[e.Type] = append(flatEvents[e.Type], e.Attributes...)
-	}
-	keys := make([]string, 0, len(flatEvents))
-	res := make(StringEvents, 0, len(flatEvents)) // appeneded to keys, same length of what is allocated to keys
-
-	for ty := range flatEvents {
-		keys = append(keys, ty)
-	}
-
-	sort.Strings(keys)
-	for _, ty := range keys {
-		res = append(res, StringEvent{Type: ty, Attributes: flatEvents[ty]})
-	}
-
-	return res
-}
-
 // StringifyEvent converts an Event object to a StringEvent object.
 func StringifyEvent(e abci.Event) StringEvent {
 	res := StringEvent{Type: e.Type}
@@ -324,7 +300,7 @@ func StringifyEvents(events []abci.Event) StringEvents {
 		res = append(res, StringifyEvent(e))
 	}
 
-	return res.Flatten()
+	return res
 }
 
 // MarkEventsToIndex returns the set of ABCI events, where each event's attribute

types/events_test.go

@@ -145,8 +145,8 @@ func (s *eventsTestSuite) TestStringifyEvents() {
 				sdk.NewEvent("message", sdk.NewAttribute(sdk.AttributeKeySender, "foo")),
 				sdk.NewEvent("message", sdk.NewAttribute(sdk.AttributeKeyModule, "bank")),
 			},
-			expTxtStr:  "\t\t- message\n\t\t\t- sender: foo\n\t\t\t- module: bank",
-			expJSONStr: "[{\"type\":\"message\",\"attributes\":[{\"key\":\"sender\",\"value\":\"foo\"},{\"key\":\"module\",\"value\":\"bank\"}]}]",
+			expTxtStr:  "\t\t- message\n\t\t\t- sender: foo\n\t\t- message\n\t\t\t- module: bank",
+			expJSONStr: "[{\"type\":\"message\",\"attributes\":[{\"key\":\"sender\",\"value\":\"foo\"}]},{\"type\":\"message\",\"attributes\":[{\"key\":\"module\",\"value\":\"bank\"}]}]",
 		},
 		{
 			name: "multiple events with same attributes",
@@ -158,8 +158,8 @@ func (s *eventsTestSuite) TestStringifyEvents() {
 				),
 				sdk.NewEvent("message", sdk.NewAttribute(sdk.AttributeKeySender, "foo")),
 			},
-			expTxtStr:  "\t\t- message\n\t\t\t- module: staking\n\t\t\t- sender: cosmos1foo\n\t\t\t- sender: foo",
-			expJSONStr: `[{"type":"message","attributes":[{"key":"module","value":"staking"},{"key":"sender","value":"cosmos1foo"},{"key":"sender","value":"foo"}]}]`,
+			expTxtStr:  "\t\t- message\n\t\t\t- module: staking\n\t\t\t- sender: cosmos1foo\n\t\t- message\n\t\t\t- sender: foo",
+			expJSONStr: `[{"type":"message","attributes":[{"key":"module","value":"staking"},{"key":"sender","value":"cosmos1foo"}]},{"type":"message","attributes":[{"key":"sender","value":"foo"}]}]`,
 		},
 	}
 

types/result_test.go

@@ -42,13 +42,17 @@ func (s *resultTestSuite) TestParseABCILog() {
 
 func (s *resultTestSuite) TestABCIMessageLog() {
 	cdc := codec.NewLegacyAmino()
-	events := sdk.Events{sdk.NewEvent("transfer", sdk.NewAttribute("sender", "foo"))}
+	events := sdk.Events{
+		sdk.NewEvent("transfer", sdk.NewAttribute("sender", "foo")),
+		sdk.NewEvent("transfer", sdk.NewAttribute("sender", "bar")),
+	}
 	msgLog := sdk.NewABCIMessageLog(0, "", events)
 	msgLogs := sdk.ABCIMessageLogs{msgLog}
 	bz, err := cdc.MarshalJSON(msgLogs)
 
 	s.Require().NoError(err)
 	s.Require().Equal(string(bz), msgLogs.String())
+	s.Require().Equal(`[{"msg_index":0,"events":[{"type":"transfer","attributes":[{"key":"sender","value":"foo"}]},{"type":"transfer","attributes":[{"key":"sender","value":"bar"}]}]}]`, msgLogs.String())
 }
 
 func (s *resultTestSuite) TestNewSearchTxsResult() {