Avoid +InfYs and similar, just display +Inf.

rules/ast/quantile.go

@@ -25,8 +25,8 @@ import (
 // excludedLabels are the labels to exclude from signature calculation for
 // quantiles.
 var excludedLabels = map[clientmodel.LabelName]struct{}{
-	clientmodel.MetricNameLabel: struct{}{},
-	clientmodel.BucketLabel:     struct{}{},
+	clientmodel.MetricNameLabel: {},
+	clientmodel.BucketLabel:     {},
 }
 
 type bucket struct {

templates/templates.go

@@ -140,7 +140,7 @@ func NewTemplateExpander(text string, name string, data interface{}, timestamp c
 				return v
 			},
 			"humanize": func(v float64) string {
-				if v == 0 {
+				if v == 0 || math.IsNaN(v) || math.IsInf(v, 0) {
 					return fmt.Sprintf("%.4g", v)
 				}
 				if math.Abs(v) >= 1 {
@@ -165,7 +165,7 @@ func NewTemplateExpander(text string, name string, data interface{}, timestamp c
 				return fmt.Sprintf("%.4g%s", v, prefix)
 			},
 			"humanize1024": func(v float64) string {
-				if math.Abs(v) <= 1 {
+				if math.Abs(v) <= 1 || math.IsNaN(v) || math.IsInf(v, 0) {
 					return fmt.Sprintf("%.4g", v)
 				}
 				prefix := ""
@@ -179,6 +179,9 @@ func NewTemplateExpander(text string, name string, data interface{}, timestamp c
 				return fmt.Sprintf("%.4g%s", v, prefix)
 			},
 			"humanizeDuration": func(v float64) string {
+				if math.IsNaN(v) || math.IsInf(v, 0) {
+					return fmt.Sprintf("%.4g", v)
+				}
 				if v == 0 {
 					return fmt.Sprintf("%.4gs", v)
 				}

templates/templates_test.go

@@ -14,6 +14,7 @@
 package templates
 
 import (
+	"math"
 	"testing"
 
 	clientmodel "github.com/prometheus/client_golang/model"
@@ -122,6 +123,12 @@ func TestTemplateExpansion(t *testing.T) {
 			input:  []float64{.1, .0001, .12345, 60.1, 60.5, 1.2345, 12.345},
 			output: "100ms:100us:123.5ms:1m 0s:1m 0s:1.234s:12.35s:",
 		},
+		{
+			// Humanize* Inf and NaN.
+			text:   "{{ range . }}{{ humanize . }}:{{ humanize1024 . }}:{{ humanizeDuration . }}:{{ end }}",
+			input:  []float64{math.Inf(1), math.Inf(-1), math.NaN()},
+			output: "+Inf:+Inf:+Inf:-Inf:-Inf:-Inf:NaN:NaN:NaN:",
+		},
 		{
 			// Title.
 			text:   "{{ \"aa bb CC\" | title }}",