fix by the review

change test name

fix trailing-spaces

Author: go-to-k

packages/aws-cdk-lib/aws-cloudwatch-actions/lib/lambda.ts

@@ -21,12 +21,12 @@ export class LambdaAction implements cloudwatch.IAlarmAction {
    *
    * @see https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_PutMetricAlarm.html
    */
-  bind(_scope: Construct, _alarm: cloudwatch.IAlarm): cloudwatch.AlarmActionConfig {
-    const idPrefix = FeatureFlags.of(_scope).isEnabled(LAMBDA_PERMISSION_LOGICAL_ID_FOR_LAMBDA_ACTION) ? _alarm.node.id : '';
+  bind(scope: Construct, alarm: cloudwatch.IAlarm): cloudwatch.AlarmActionConfig {
+    const idPrefix = FeatureFlags.of(scope).isEnabled(LAMBDA_PERMISSION_LOGICAL_ID_FOR_LAMBDA_ACTION) ? alarm.node.id : '';
     this.lambdaFunction.addPermission(`${idPrefix}AlarmPermission`, {
-      sourceAccount: Stack.of(_scope).account,
+      sourceAccount: Stack.of(scope).account,
       action: 'lambda:InvokeFunction',
-      sourceArn: _alarm.alarmArn,
+      sourceArn: alarm.alarmArn,
       principal: new iam.ServicePrincipal('lambda.alarms.cloudwatch.amazonaws.com'),
     });
 

packages/aws-cdk-lib/aws-cloudwatch-actions/test/lambda.test.ts

@@ -144,4 +144,38 @@ def handler(event, context):
   // THEN
   Template.fromStack(stack).resourceCountIs('AWS::CloudWatch::Alarm', 2);
   Template.fromStack(stack).resourceCountIs('AWS::Lambda::Permission', 2);
+});
+
+test('throws when multiple alarms are created for the same lambda if feature flag is set to false', () => {
+  // GIVEN
+  const stack = new Stack();
+  stack.node.setContext(LAMBDA_PERMISSION_LOGICAL_ID_FOR_LAMBDA_ACTION, false); // Default, but explicit just in case.
+  const alarm1 = new cloudwatch.Alarm(stack, 'Alarm1', {
+    metric: new cloudwatch.Metric({ namespace: 'AWS', metricName: 'Test' }),
+    evaluationPeriods: 3,
+    threshold: 100,
+  });
+  const alarm2 = new cloudwatch.Alarm(stack, 'Alarm2', {
+    metric: new cloudwatch.Metric({ namespace: 'AWS', metricName: 'Test2' }),
+    evaluationPeriods: 3,
+    threshold: 100,
+  });
+
+  // WHEN
+  const alarmLambda = new lambda.Function(stack, 'alarmLambda', {
+    runtime: lambda.Runtime.PYTHON_3_12,
+    functionName: 'alarmLambda',
+    code: lambda.Code.fromInline(`
+def handler(event, context):
+  print('event:', event)
+  print('.............................................')
+  print('context:', context)`),
+    handler: 'index.handler',
+  });
+  alarm1.addAlarmAction(new actions.LambdaAction(alarmLambda));
+
+  // THEN
+  expect(() => {
+    alarm2.addAlarmAction(new actions.LambdaAction(alarmLambda));
+  }).toThrow(/There is already a Construct with name 'AlarmPermission' in Function \[alarmLambda\]/);
 });