Deflake gappy state integration test

tests-integration/poller_test.go

@@ -2,6 +2,7 @@ package syncv3
 
 import (
 	"encoding/json"
+	"fmt"
 	"net/http"
 	"testing"
 	"time"
@@ -186,7 +187,16 @@ func TestPollerHandlesUnknownStateEventsOnIncrementalSync(t *testing.T) {
 		res,
 		m.MatchRoomSubscription(
 			roomID,
-			m.MatchRoomTimeline([]json.RawMessage{nameEvent, powerLevelsEvent, messageEvent}),
+			func(r sync3.Room) error {
+				// syncv2 doesn't assign any meaning to the order of events in a state
+				// block, so check for both possibilities
+				nameFirst := m.MatchRoomTimeline([]json.RawMessage{nameEvent, powerLevelsEvent, messageEvent})
+				powerLevelsFirst := m.MatchRoomTimeline([]json.RawMessage{powerLevelsEvent, nameEvent, messageEvent})
+				if nameFirst(r) != nil && powerLevelsFirst(r) != nil {
+					return fmt.Errorf("did not see state before message")
+				}
+				return nil
+			},
 			m.MatchRoomName("banana"),
 		),
 	)

testutils/m/match.go

@@ -17,6 +17,16 @@ type ListMatcher func(list sync3.ResponseList) error
 type OpMatcher func(op sync3.ResponseOp) error
 type RoomMatcher func(r sync3.Room) error
 
+// LogRoom builds a matcher that always succeeds. As a side-effect, it pretty-prints
+// the given room to the test log. This is useful when debugging a test.
+func LogRoom(t *testing.T) RoomMatcher {
+	return func(room sync3.Room) error {
+		dump, _ := json.MarshalIndent(room, "", "    ")
+		t.Logf("Response was: %s", dump)
+		return nil
+	}
+}
+
 func MatchRoomName(name string) RoomMatcher {
 	return func(r sync3.Room) error {
 		if name == "" {