Dashboard: Backend always set metricEditorMode: 0 regardless metricQueryType and expression (#111613)

- Fix metricEditorMode logic to match frontend hasOwnProperty behavior
- Fix metricQueryType to only set when property doesn't exist
- Fix statistics processing to handle all types like frontend does
- Fix null statistic handling to match frontend behavior
- Fix object string representation to match JavaScript behavior
- Add comprehensive test coverage for all CloudWatch migration scenarios
- Achieve 100% backend-frontend consistency for v34 migration

* Fix v34 CloudWatch migration backend-frontend inconsistencies

- Fix metricEditorMode logic to match frontend hasOwnProperty behavior
- Fix metricQueryType to only set when property doesn't exist
- Fix statistics processing to handle all types like frontend does
- Fix null statistic handling to match frontend behavior
- Fix object string representation to match JavaScript behavior
- Add comprehensive test coverage for all CloudWatch migration scenarios
- Achieve 100% backend-frontend consistency for v34 migration

* Improve v34 CloudWatch migration test coverage

- Add targeted tests for hasOwnProperty logic coverage
- Add comprehensive getSuffixForStat coverage (all data types)
- Add generateNextRefId double letter generation tests
- Simplify test cases while maintaining full coverage
- Achieve 93%+ coverage on all critical v34 functions
- Remove redundant test cases for better maintainability

* Clean up v34 CloudWatch migration code

- Remove unnecessary comments and documentation
- Simplify function signatures and logic
- Maintain functionality while improving readability
- Keep essential logic intact with cleaner code

* Only remove unnecessary comments

apps/dashboard/pkg/migration/schemaversion/v34.go

@@ -1,6 +1,9 @@
 package schemaversion
 
-import "context"
+import (
+	"context"
+	"fmt"
+)
 
 // V34 migrates CloudWatch queries that use multiple statistics into separate queries.
 //
@@ -113,9 +116,24 @@ func migrateCloudWatchQueriesInPanel(panel map[string]interface{}) {
 			continue
 		}
 
-		// Add CloudWatch fields if missing (set to 0 if not present)
-		t["metricEditorMode"] = GetIntValue(t, "metricEditorMode", 0)
-		t["metricQueryType"] = GetIntValue(t, "metricQueryType", 0)
+		// Add CloudWatch fields if missing (matches frontend migrateCloudWatchQuery logic)
+		if _, hasMetricQueryType := t["metricQueryType"]; !hasMetricQueryType {
+			t["metricQueryType"] = 0 // MetricQueryType.Search
+		}
+
+		if _, hasMetricEditorMode := t["metricEditorMode"]; !hasMetricEditorMode {
+			metricQueryType := GetIntValue(t, "metricQueryType", 0)
+			if metricQueryType == 1 { // MetricQueryType.Insights
+				t["metricEditorMode"] = 1 // MetricEditorMode.Code
+			} else {
+				expression := GetStringValue(t, "expression")
+				if expression != "" {
+					t["metricEditorMode"] = 1 // MetricEditorMode.Code
+				} else {
+					t["metricEditorMode"] = 0 // MetricEditorMode.Builder
+				}
+			}
+		}
 
 		// Get valid statistics (including null and empty strings)
 		validStats, isEmpty := getValidStatistics(t["statistics"])
@@ -137,19 +155,20 @@ func migrateCloudWatchQueriesInPanel(panel map[string]interface{}) {
 			// No valid statistics - keep query as-is
 			newTargets = append(newTargets, t)
 		case 1:
-			// Single statistic - set statistic field if not null
-			if statString := GetStringValue(map[string]interface{}{"stat": validStats[0]}, "stat"); statString != "" {
-				t["statistic"] = statString
+			// Single statistic - set statistic field
+			// Frontend doesn't set statistic property for null values
+			if validStats[0] != nil {
+				t["statistic"] = validStats[0]
 			}
 			newTargets = append(newTargets, t)
 		default:
 			// Multiple statistics - create separate queries
 			for i, stat := range validStats {
 				newQuery := copyMap(t)
+				// Set statistic field
+				// Frontend doesn't set statistic property for null values
 				if stat != nil {
-					if statString, ok := stat.(string); ok {
-						newQuery["statistic"] = statString
-					}
+					newQuery["statistic"] = stat
 				}
 
 				if i == 0 {
@@ -210,10 +229,11 @@ func migrateCloudWatchAnnotationQueries(dashboard map[string]interface{}) {
 			delete(a, "statistics")
 			annotationsList[i] = a
 		case 1:
-			// Single statistic - set statistic field if not null
+			// Single statistic - set statistic field (matches frontend behavior)
 			delete(a, "statistics")
-			if statString := GetStringValue(map[string]interface{}{"stat": validStats[0]}, "stat"); statString != "" {
-				a["statistic"] = statString
+			// Frontend doesn't set statistic property for null values
+			if validStats[0] != nil {
+				a["statistic"] = validStats[0]
 			}
 			annotationsList[i] = a
 		default:
@@ -221,11 +241,10 @@ func migrateCloudWatchAnnotationQueries(dashboard map[string]interface{}) {
 			delete(a, "statistics")
 			for j, stat := range validStats {
 				newAnnotation := copyMap(a)
-
+				// Set statistic field (matches frontend behavior)
+				// Frontend doesn't set statistic property for null values
 				if stat != nil {
-					if statString, ok := stat.(string); ok {
-						newAnnotation["statistic"] = statString
-					}
+					newAnnotation["statistic"] = stat
 				}
 
 				// Add suffix to name
@@ -260,14 +279,9 @@ func getValidStatistics(statisticsField interface{}) ([]interface{}, bool) {
 		return nil, true // Return nil with true flag to indicate "empty array"
 	}
 
-	var valid []interface{}
-	for _, stat := range statistics {
-		// Include null and strings (including empty strings)
-		if stat == nil || isString(stat) {
-			valid = append(valid, stat)
-		}
-	}
-	return valid, false
+	// Frontend processes ALL values in statistics array, regardless of type
+	// It doesn't filter out invalid types - it processes them as-is
+	return statistics, false
 }
 
 // getSuffixForStat returns the appropriate suffix for annotation names
@@ -281,7 +295,20 @@ func getSuffixForStat(stat interface{}) string {
 		}
 		return statString
 	}
-	return ""
+	// For non-string types, convert to string representation like JavaScript does
+	switch v := stat.(type) {
+	case map[string]interface{}:
+		return "[object Object]" // JavaScript behavior for objects
+	case []interface{}:
+		return "" // JavaScript behavior for arrays (empty string)
+	case bool:
+		if v {
+			return "true"
+		}
+		return "false"
+	default:
+		return fmt.Sprintf("%v", stat) // Numbers and other types
+	}
 }
 
 // copyMap creates a shallow copy of a map
@@ -293,12 +320,6 @@ func copyMap(original map[string]interface{}) map[string]interface{} {
 	return copy
 }
 
-// isString checks if value is a string
-func isString(value interface{}) bool {
-	_, ok := value.(string)
-	return ok
-}
-
 // isCloudWatchQuery checks if a query target is a CloudWatch query.
 func isCloudWatchQuery(target map[string]interface{}) bool {
 	// Check for required CloudWatch query fields