Fix

report/custom.go

@@ -26,6 +26,8 @@ type CustomMetric struct {
 type DiffCustomMetricSet struct {
 	Key     string              `json:"key"`
 	Name    string              `json:"name,omitempty"`
+	A       *CustomMetricSet    `json:"a"`
+	B       *CustomMetricSet    `json:"b"`
 	Metrics []*DiffCustomMetric `json:"metrics"`
 	reportA *Report
 	reportB *Report
@@ -88,19 +90,20 @@ func (s *CustomMetricSet) Out(w io.Writer) error {
 }
 
 func (s *CustomMetricSet) Compare(s2 *CustomMetricSet) *DiffCustomMetricSet {
-	if s2 == nil {
-		s2 = &CustomMetricSet{}
-	}
 	d := &DiffCustomMetricSet{
 		Key:     s.Key,
 		Name:    s.Name,
+		A:       s,
+		B:       s2,
 		Metrics: []*DiffCustomMetric{},
 		reportA: s.report,
-		reportB: s2.report,
 	}
-	for _, metric := range s.Metrics {
-		metric2 := s2.findMetricByKey(metric.Key)
-		d.Metrics = append(d.Metrics, metric.Compare(metric2))
+	if s2 != nil {
+		d.reportB = s2.report
+		for _, metric := range s.Metrics {
+			metric2 := s2.findMetricByKey(metric.Key)
+			d.Metrics = append(d.Metrics, metric.Compare(metric2))
+		}
 	}
 
 	return d
@@ -138,6 +141,9 @@ func (d *DiffCustomMetricSet) Table() string {
 	if len(d.Metrics) == 0 {
 		return ""
 	}
+	if d.B == nil {
+		return d.A.Table()
+	}
 	buf := new(bytes.Buffer)
 	_, _ = buf.WriteString(fmt.Sprintf("## %s\n\n", d.Name))
 	table := tablewriter.NewWriter(buf)