From 1d3afd469f15e202eccc2191dfccc3ed65428288 Mon Sep 17 00:00:00 2001
From: kannar <kannarfr@gmail.com>
Date: Mon, 24 Apr 2023 20:47:07 +0200
Subject: [PATCH] fix(outputs.warp10): Support Infinity/-Infinity/NaN values
 (#13126)

---
 plugins/outputs/warp10/warp10.go      | 31 ++++++++++++++++++++++++
 plugins/outputs/warp10/warp10_test.go | 34 +++++++++++++++++++++++++++
 testutil/testutil.go                  |  7 ++++++
 3 files changed, 72 insertions(+)

diff --git a/plugins/outputs/warp10/warp10.go b/plugins/outputs/warp10/warp10.go
index 97a3ea019..5796a3be4 100644
--- a/plugins/outputs/warp10/warp10.go
+++ b/plugins/outputs/warp10/warp10.go
@@ -198,7 +198,38 @@ func boolToString(inputBool bool) string {
 	return strconv.FormatBool(inputBool)
 }
 
+/*
+Warp10 supports Infinity/-Infinity/NaN
+<'
+// class{label=value} 42.0
+0// class-1{label=value}{attribute=value} 42
+=1// Infinity
+'>
+PARSE
+
+<'
+// class{label=value} 42.0
+0// class-1{label=value}{attribute=value} 42
+=1// -Infinity
+'>
+PARSE
+
+<'
+// class{label=value} 42.0
+0// class-1{label=value}{attribute=value} 42
+=1// NaN
+'>
+PARSE
+*/
 func floatToString(inputNum float64) string {
+	switch {
+	case math.IsNaN(inputNum):
+		return "NaN"
+	case math.IsInf(inputNum, -1):
+		return "-Infinity"
+	case math.IsInf(inputNum, 1):
+		return "Infinity"
+	}
 	return strconv.FormatFloat(inputNum, 'f', 6, 64)
 }
 
diff --git a/plugins/outputs/warp10/warp10_test.go b/plugins/outputs/warp10/warp10_test.go
index 798a9610d..8ffdbe06b 100644
--- a/plugins/outputs/warp10/warp10_test.go
+++ b/plugins/outputs/warp10/warp10_test.go
@@ -1,6 +1,7 @@
 package warp10
 
 import (
+	"math"
 	"testing"
 
 	"github.com/influxdata/telegraf/config"
@@ -24,6 +25,39 @@ func TestWriteWarp10(t *testing.T) {
 	require.Exactly(t, "1257894000000000// unit.testtest1.value{source=telegraf,tag1=value1} 1.000000\n", payload)
 }
 
+func TestWriteWarp10ValueNaN(t *testing.T) {
+	w := Warp10{
+		Prefix:  "unit.test",
+		WarpURL: "http://localhost:8090",
+		Token:   config.NewSecret([]byte("WRITE")),
+	}
+
+	payload := w.GenWarp10Payload(testutil.MockMetricsWithValue(math.NaN()))
+	require.Exactly(t, "1257894000000000// unit.testtest1.value{source=telegraf,tag1=value1} NaN\n", payload)
+}
+
+func TestWriteWarp10ValueInfinity(t *testing.T) {
+	w := Warp10{
+		Prefix:  "unit.test",
+		WarpURL: "http://localhost:8090",
+		Token:   config.NewSecret([]byte("WRITE")),
+	}
+
+	payload := w.GenWarp10Payload(testutil.MockMetricsWithValue(math.Inf(1)))
+	require.Exactly(t, "1257894000000000// unit.testtest1.value{source=telegraf,tag1=value1} Infinity\n", payload)
+}
+
+func TestWriteWarp10ValueMinusInfinity(t *testing.T) {
+	w := Warp10{
+		Prefix:  "unit.test",
+		WarpURL: "http://localhost:8090",
+		Token:   config.NewSecret([]byte("WRITE")),
+	}
+
+	payload := w.GenWarp10Payload(testutil.MockMetricsWithValue(math.Inf(-1)))
+	require.Exactly(t, "1257894000000000// unit.testtest1.value{source=telegraf,tag1=value1} -Infinity\n", payload)
+}
+
 func TestWriteWarp10EncodedTags(t *testing.T) {
 	w := Warp10{
 		Prefix:  "unit.test",
diff --git a/testutil/testutil.go b/testutil/testutil.go
index 80bee356e..916271d05 100644
--- a/testutil/testutil.go
+++ b/testutil/testutil.go
@@ -42,6 +42,13 @@ func MockMetrics() []telegraf.Metric {
 	return metrics
 }
 
+func MockMetricsWithValue(value float64) []telegraf.Metric {
+	metrics := make([]telegraf.Metric, 0)
+	// Create a new point batch
+	metrics = append(metrics, TestMetric(value))
+	return metrics
+}
+
 // TestMetric Returns a simple test point:
 //
 //	measurement -> "test1" or name