Infinity values to not produce invalid JSONs

api/models/series.go

@@ -291,7 +291,7 @@ func (series SeriesByTarget) MarshalJSONFast(b []byte) ([]byte, error) {
 		b = append(b, `,"datapoints":[`...)
 		for _, p := range s.Datapoints {
 			b = append(b, '[')
-			if math.IsNaN(p.Val) {
+			if math.IsNaN(p.Val) || math.IsInf(p.Val, 1) || math.IsInf(p.Val, -1) {
 				b = append(b, `null,`...)
 			} else {
 				b = strconv.AppendFloat(b, p.Val, 'f', -1, 64)
@@ -330,7 +330,7 @@ func (series SeriesByTarget) MarshalJSONFastWithMeta(b []byte) ([]byte, error) {
 		b = append(b, `,"datapoints":[`...)
 		for _, p := range s.Datapoints {
 			b = append(b, '[')
-			if math.IsNaN(p.Val) {
+			if math.IsNaN(p.Val) || math.IsInf(p.Val, 1) || math.IsInf(p.Val, -1) {
 				b = append(b, `null,`...)
 			} else {
 				b = strconv.AppendFloat(b, p.Val, 'f', -1, 64)

api/models/series_test.go

@@ -38,6 +38,18 @@ func TestJsonMarshal(t *testing.T) {
 			},
 			out: `[{"target":"a\\b","datapoints":[]}]`,
 		},
+		{
+			in: []Series{
+				{
+					Target: `a`,
+					Datapoints: []schema.Point{
+						{Val: math.Inf(1), Ts: 60},
+					},
+					Interval: 60,
+				},
+			},
+			out: `[{"target":"a","datapoints":[[null,60]]}]`,
+		},
 		{
 			in: []Series{
 				{