[7.x] [Metrics UI] Display No Data context.values as [NO DATA] (#78038) (#79161)

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

Author: Zacqary

x-pack/plugins/infra/server/lib/alerting/inventory_metric_threshold/inventory_metric_threshold_executor.ts

@@ -148,8 +148,10 @@ export const FIRED_ACTIONS = {
 
 const formatMetric = (metric: SnapshotMetricType, value: number) => {
   const metricFormatter = get(METRIC_FORMATTERS, metric, METRIC_FORMATTERS.count);
-  if (value == null) {
-    return '';
+  if (isNaN(value)) {
+    return i18n.translate('xpack.infra.metrics.alerting.inventory.noDataFormattedValue', {
+      defaultMessage: '[NO DATA]',
+    });
   }
   const formatter = createFormatter(metricFormatter.formatter, metricFormatter.template);
   return formatter(value);

x-pack/plugins/infra/server/lib/alerting/metric_threshold/metric_threshold_executor.ts

@@ -131,11 +131,24 @@ const formatAlertResult = <AlertResult>(
   } & AlertResult
 ) => {
   const { metric, currentValue, threshold } = alertResult;
-  if (!metric.endsWith('.pct')) return alertResult;
+  const noDataValue = i18n.translate(
+    'xpack.infra.metrics.alerting.threshold.noDataFormattedValue',
+    {
+      defaultMessage: '[NO DATA]',
+    }
+  );
+  if (!metric.endsWith('.pct'))
+    return {
+      ...alertResult,
+      currentValue: currentValue ?? noDataValue,
+    };
   const formatter = createFormatter('percent');
   return {
     ...alertResult,
-    currentValue: formatter(currentValue),
+    currentValue:
+      currentValue !== null && typeof currentValue !== 'undefined'
+        ? formatter(currentValue)
+        : noDataValue,
     threshold: Array.isArray(threshold) ? threshold.map((v: number) => formatter(v)) : threshold,
   };
 };