chore: count created alarms in custom anomaly tests [skip ci] (#272)

Minor gap in tests.

---

_By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license_

Author: Eugene Cheung

test/monitoring/custom/CustomMonitoring.test.ts

@@ -185,6 +185,8 @@ test("anomaly detection", () => {
 
   const scope = new TestMonitoringScope(stack, "Scope");
 
+  let numAlarmsCreated = 0;
+
   new CustomMonitoring(scope, {
     alarmFriendlyName: "AnomalyAlarmName",
     metricGroups: [
@@ -215,15 +217,24 @@ test("anomaly detection", () => {
         ],
       },
     ],
+    useCreatedAlarms: {
+      consume(alarms) {
+        numAlarmsCreated = alarms.length;
+      },
+    },
   });
 
+  expect(numAlarmsCreated).toStrictEqual(1);
+
   expect(Template.fromStack(stack)).toMatchSnapshot();
 });
 
 test("enhanced anomaly detection", () => {
   const stack = new Stack();
   const scope = new TestMonitoringScope(stack, "Scope");
 
+  let numAlarmsCreated = 0;
+
   new CustomMonitoring(scope, {
     alarmFriendlyName: "AnomalyAlarmName",
     metricGroups: [
@@ -271,15 +282,24 @@ test("enhanced anomaly detection", () => {
         ],
       },
     ],
+    useCreatedAlarms: {
+      consume(alarms) {
+        numAlarmsCreated = alarms.length;
+      },
+    },
   });
 
+  expect(numAlarmsCreated).toStrictEqual(3);
+
   expect(Template.fromStack(stack)).toMatchSnapshot();
 });
 
 test("enhanced anomaly detection with more complex metric", () => {
   const stack = new Stack();
   const scope = new TestMonitoringScope(stack, "Scope");
 
+  let numAlarmsCreated = 0;
+
   new CustomMonitoring(scope, {
     alarmFriendlyName: "AnomalyAlarmName",
     metricGroups: [
@@ -307,15 +327,24 @@ test("enhanced anomaly detection with more complex metric", () => {
         ],
       },
     ],
+    useCreatedAlarms: {
+      consume(alarms) {
+        numAlarmsCreated = alarms.length;
+      },
+    },
   });
 
+  expect(numAlarmsCreated).toStrictEqual(1);
+
   expect(Template.fromStack(stack)).toMatchSnapshot();
 });
 
 test("enhanced anomaly detection with metric math", () => {
   const stack = new Stack();
   const scope = new TestMonitoringScope(stack, "Scope");
 
+  let numAlarmsCreated = 0;
+
   const m1 = new Metric({
     metricName: "Metric1",
     namespace: "AnomalyNamespace",
@@ -349,8 +378,15 @@ test("enhanced anomaly detection with metric math", () => {
         ],
       },
     ],
+    useCreatedAlarms: {
+      consume(alarms) {
+        numAlarmsCreated = alarms.length;
+      },
+    },
   });
 
+  expect(numAlarmsCreated).toStrictEqual(1);
+
   expect(Template.fromStack(stack)).toMatchSnapshot();
 });