From 24e012b6aa2163f7b037f94d171b078f1d9f9403 Mon Sep 17 00:00:00 2001
From: BLasan <benuraab@gmail.com>
Date: Fri, 12 Mar 2021 11:12:52 +0530
Subject: [PATCH] fix(aws-cloudwatch): metric id should be started with a
 lowercase letter fixes #13434

---
 packages/@aws-cdk/aws-cloudwatch/lib/alarm.ts                 | 4 ++--
 .../aws-cloudwatch/test/integ.alarm-with-label.expected.json  | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/@aws-cdk/aws-cloudwatch/lib/alarm.ts b/packages/@aws-cdk/aws-cloudwatch/lib/alarm.ts
index d8c93f66aa910..05fa7d67c0649 100644
--- a/packages/@aws-cdk/aws-cloudwatch/lib/alarm.ts
+++ b/packages/@aws-cdk/aws-cloudwatch/lib/alarm.ts
@@ -257,7 +257,7 @@ export class Alarm extends AlarmBase {
     return dispatchMetric(metric, {
       withStat(stat, conf) {
         self.validateMetricStat(stat, metric);
-
+        const id = 'm_' + stat.metricName
         if (conf.renderingProperties?.label == undefined) {
           return dropUndefined({
             dimensions: stat.dimensions,
@@ -283,7 +283,7 @@ export class Alarm extends AlarmBase {
                 stat: stat.statistic,
                 unit: stat.unitFilter,
               },
-              id: stat.metricName,
+              id: id,
               label: conf.renderingProperties?.label,
               returnData: true,
             } as CfnAlarm.MetricDataQueryProperty,
diff --git a/packages/@aws-cdk/aws-cloudwatch/test/integ.alarm-with-label.expected.json b/packages/@aws-cdk/aws-cloudwatch/test/integ.alarm-with-label.expected.json
index 9ab6e14f29a6e..6f9f5a43351f1 100644
--- a/packages/@aws-cdk/aws-cloudwatch/test/integ.alarm-with-label.expected.json
+++ b/packages/@aws-cdk/aws-cloudwatch/test/integ.alarm-with-label.expected.json
@@ -5,7 +5,7 @@
             "Properties": {
                 "Metrics": [
                     {
-                        "Id": "Metric",
+                        "Id": "m_Metric",
                         "Label": "Metric [AVG: ${AVG}]",
                         "MetricStat": {
                             "Metric": {
@@ -28,7 +28,7 @@
             "Properties": {
                 "Metrics": [
                     {
-                        "Id": "Metric",
+                        "Id": "m_Metric",
                         "Label": "Metric [AVG: ${AVG}]",
                         "MetricStat": {
                             "Metric": {