Azure: Handle real type nan/inf values in Log/Insights Analytics (#26342)

Before this, if the user were to divide by 0.0, "Infinity" would be returned in the result and the user would get an error: "unexpected type, expected json.Number but got string". Now these values are properly set as Inf values (and also made sure to handle NaN as well).

pkg/tsdb/azuremonitor/azure-log-analytics-table-frame.go

@@ -3,6 +3,7 @@ package azuremonitor
 import (
 	"encoding/json"
 	"fmt"
+	"math"
 	"strconv"
 	"time"
 
@@ -115,7 +116,21 @@ var realConverter = data.FieldConverter{
 		}
 		jN, ok := v.(json.Number)
 		if !ok {
-			return nil, fmt.Errorf("unexpected type, expected json.Number but got %T", v)
+			s, sOk := v.(string)
+			if sOk {
+				switch s {
+				case "Infinity":
+					f := math.Inf(0)
+					return &f, nil
+				case "-Infinity":
+					f := math.Inf(-1)
+					return &f, nil
+				case "NaN":
+					f := math.NaN()
+					return &f, nil
+				}
+			}
+			return nil, fmt.Errorf("unexpected type, expected json.Number but got type %T for value %v", v, v)
 		}
 		f, err := jN.Float64()
 		if err != nil {

pkg/tsdb/azuremonitor/azure-log-analytics-table-frame_test.go

@@ -2,6 +2,7 @@ package azuremonitor
 
 import (
 	"encoding/json"
+	"math"
 	"os"
 	"path/filepath"
 	"testing"
@@ -119,6 +120,21 @@ func TestLogTableToFrame(t *testing.T) {
 				return frame
 			},
 		},
+		{
+			name:     "nan and infinity in real response",
+			testFile: "loganalytics/8-log-analytics-response-nan-inf.json",
+			expectedFrame: func() *data.Frame {
+				frame := data.NewFrame("",
+					data.NewField("XInf", nil, []*float64{pointer.Float64(math.Inf(0))}),
+					data.NewField("XInfNeg", nil, []*float64{pointer.Float64(math.Inf(-2))}),
+					data.NewField("XNan", nil, []*float64{pointer.Float64(math.NaN())}),
+				)
+				frame.Meta = &data.FrameMeta{
+					Custom: &LogAnalyticsMeta{ColumnTypes: []string{"real", "real", "real"}},
+				}
+				return frame
+			},
+		},
 	}
 
 	for _, tt := range tests {

pkg/tsdb/azuremonitor/testdata/loganalytics/8-log-analytics-response-nan-inf.json

+{
+    "tables": [
+      {
+        "name": "PrimaryResult",
+        "columns": [
+          {
+            "name": "XInf",
+            "type": "real"
+          },
+          {
+            "name": "XInfNeg",
+            "type": "real"
+          },
+          {
+            "name": "XNan",
+            "type": "real"
+          }
+        ],
+        "rows": [
+          [
+            "Infinity",
+            "-Infinity",
+            "NaN"
+          ]
+        ]
+      }
+    ]
+  }
+  
\ No newline at end of file