Do not add roleMetrics when row is not valid

Signed-off-by: Jocelyn Thode <jocelyn@thode.email>

Author: jocelynthode

collector/pg_roles.go

@@ -71,15 +71,15 @@ func (c PGRolesCollector) Update(ctx context.Context, instance *instance, ch cha
 			return err
 		}
 
-		rolnameLabel := "unknown"
-		if rolname.Valid {
-			rolnameLabel = rolname.String
+		if !rolname.Valid {
+			continue
 		}
+		rolnameLabel := rolname.String
 
-		connLimitMetric := 0.0
-		if connLimit.Valid {
-			connLimitMetric = float64(connLimit.Int64)
+		if !connLimit.Valid {
+			continue
 		}
+		connLimitMetric := float64(connLimit.Int64)
 
 		ch <- prometheus.MustNewConstMetric(
 			pgRolesConnectionLimitsDesc,

collector/pg_roles_test.go

@@ -79,9 +79,7 @@ func TestPGRolesCollectorNullMetric(t *testing.T) {
 		}
 	}()
 
-	expected := []MetricResult{
-		{labels: labelMap{"rolname": "unknown"}, value: 0, metricType: dto.MetricType_GAUGE},
-	}
+	expected := []MetricResult{}
 	convey.Convey("Metrics comparison", t, func() {
 		for _, expect := range expected {
 			m := readMetric(<-ch)