Move string trim outside loop and add test for totaltotaltotal

exporter/collector/googlemanagedprometheus/naming.go

@@ -70,24 +70,25 @@ func getUnknownMetricName(points pmetric.NumberDataPointSlice, suffix, secondary
 		func(r rune) bool { return !unicode.IsLetter(r) && !unicode.IsDigit(r) },
 	)
 
+	untyped := false
 	newSuffix := suffix
 	for i := 0; i < points.Len(); i++ {
 		point := points.At(i)
 		if val, ok := point.Attributes().Get(GCPOpsAgentUntypedMetricKey); ok && val.AsString() == "true" {
+			untyped = true
 			// delete the special Ops Agent untyped attribute
 			point.Attributes().Remove(GCPOpsAgentUntypedMetricKey)
-
-			// de-normalize "_total" suffix for counters where not present on original metric name
-			if nameTokens[len(nameTokens)-1] != "total" && strings.HasSuffix(compliantName, "_total") {
-				compliantName = strings.TrimSuffix(compliantName, "_total")
-			}
-
 			newSuffix = "/unknown"
 			if len(secondarySuffix) > 0 {
 				newSuffix = newSuffix + ":" + secondarySuffix
 			}
 			// even though we have the suffix, keep looping to remove the attribute from other points, if any
 		}
 	}
+
+	// de-normalize "_total" suffix for counters where not present on original metric name
+	if untyped && nameTokens[len(nameTokens)-1] != "total" && strings.HasSuffix(compliantName, "_total") {
+		compliantName = strings.TrimSuffix(compliantName, "_total")
+	}
 	return compliantName + newSuffix
 }

exporter/collector/googlemanagedprometheus/naming_test.go

@@ -205,6 +205,23 @@ func TestGetMetricName(t *testing.T) {
 			},
 			expected: "bar/unknown:counter",
 		},
+		{
+			desc:     "untyped sum with multiple data points and preexisting 'total' suffix and feature gate enabled and name normalization returns unknown:counter with _total",
+			baseName: "bar.total.total.total.total",
+			metric: func(m pmetric.Metric) {
+				//nolint:errcheck
+				featuregate.GlobalRegistry().Set(gcpUntypedDoubleExportGateKey, true)
+				//nolint:errcheck
+				featuregate.GlobalRegistry().Set("pkg.translator.prometheus.NormalizeName", true)
+				m.SetName("bar.total.total.total.total")
+				m.SetEmptySum()
+				m.Sum().SetIsMonotonic(true)
+				m.Sum().DataPoints().AppendEmpty().Attributes().PutStr(GCPOpsAgentUntypedMetricKey, "true")
+				m.Sum().DataPoints().AppendEmpty().Attributes().PutStr(GCPOpsAgentUntypedMetricKey, "true")
+			},
+			// prometheus name normalization removes all preexisting "total"s before appending its own
+			expected: "bar_total/unknown:counter",
+		},
 		{
 			desc:     "normal sum without total and feature gate enabled + name normalization adds _total",
 			baseName: "foo",