feat(AlarmFactory): allow accessing action strategy as part of alarm naming strategy (#625)

This can be useful if you want to name the alarm based on properties of the action being applied.

---

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

Author: Eugene Cheung

API.md

@@ -23,7 +23,7 @@ import {
   IAlarmAnnotationStrategy,
 } from "./IAlarmAnnotationStrategy";
 import { IAlarmDedupeStringProcessor } from "./IAlarmDedupeStringProcessor";
-import { IAlarmNamingStrategy } from "./IAlarmNamingStrategy";
+import { AlarmNamingInput, IAlarmNamingStrategy } from "./IAlarmNamingStrategy";
 import {
   CompositeMetricAdjuster,
   DefaultMetricAdjuster,
@@ -580,16 +580,22 @@ export class AlarmFactory {
       props.disambiguator,
       props.actionOverride,
     );
-    const alarmName = this.alarmNamingStrategy.getName(props);
+    const alarmNamingInput: AlarmNamingInput = {
+      ...props,
+      action,
+    };
+    const alarmName = this.alarmNamingStrategy.getName(alarmNamingInput);
     const alarmNameSuffix = props.alarmNameSuffix;
-    const alarmLabel = this.alarmNamingStrategy.getWidgetLabel(props);
+    const alarmLabel =
+      this.alarmNamingStrategy.getWidgetLabel(alarmNamingInput);
     const alarmDescription = this.generateDescription(
       props.alarmDescription,
       props.alarmDescriptionOverride,
       props.runbookLink,
       props.documentationLink,
     );
-    const dedupeString = this.alarmNamingStrategy.getDedupeString(props);
+    const dedupeString =
+      this.alarmNamingStrategy.getDedupeString(alarmNamingInput);
     const evaluateLowSampleCountPercentile =
       props.evaluateLowSampleCountPercentile ?? true;
 

lib/common/alarm/AlarmFactory.ts

@@ -1,4 +1,8 @@
+import { IAlarmActionStrategy } from "./action";
+
 export interface AlarmNamingInput {
+  // TODO: make this required
+  readonly action?: IAlarmActionStrategy;
   readonly alarmNameSuffix: string;
   readonly alarmNameOverride?: string;
   readonly alarmDedupeStringSuffix?: string;

lib/common/alarm/IAlarmNamingStrategy.ts

@@ -14,10 +14,12 @@ import { Construct } from "constructs";
 
 import {
   AddAlarmProps,
+  AlarmActionStrategyProps,
   AlarmFactory,
   AlarmFactoryDefaults,
   AlarmNamingInput,
   CompositeAlarmOperator,
+  IAlarmActionStrategy,
   IAlarmNamingStrategy,
   MetricFactoryDefaults,
   MetricStatistic,
@@ -32,6 +34,16 @@ const construct = new Construct(stack, "SampleConstruct");
 const snsAction = new SnsAlarmActionStrategy({
   onAlarmTopic: new Topic(stack, "Dummy2"),
 });
+
+class SampleAlarmActionStrategy implements IAlarmActionStrategy {
+  readonly prop = "Sample";
+
+  addAlarmActions(_props: AlarmActionStrategyProps): void {
+    // No-op
+  }
+}
+const sampleAction = new SampleAlarmActionStrategy();
+
 const globalMetricDefaults: MetricFactoryDefaults = {
   namespace: "DummyNamespace",
 };
@@ -722,11 +734,18 @@ test("addAlarm: custom alarm naming strategy", () => {
   const disambiguator = "Critical";
   const stack = new Stack();
   const customNamingStrategy: IAlarmNamingStrategy = {
-    getName: (props: AlarmNamingInput) => `${alarmName}-${props.disambiguator}`,
+    getName: (props: AlarmNamingInput) =>
+      `${alarmName}-${props.disambiguator}-${
+        (props.action as SampleAlarmActionStrategy).prop
+      }`,
     getWidgetLabel: (props: AlarmNamingInput) =>
-      `${alarmLabel}-${props.disambiguator}`,
+      `${alarmLabel}-${props.disambiguator}-${
+        (props.action as SampleAlarmActionStrategy).prop
+      }`,
     getDedupeString: (props: AlarmNamingInput) =>
-      `${alarmDedupe}-${props.disambiguator}`,
+      `${alarmDedupe}-${props.disambiguator}-${
+        (props.action as SampleAlarmActionStrategy).prop
+      }`,
   };
   const factory = new AlarmFactory(stack, {
     globalMetricDefaults,
@@ -736,13 +755,15 @@ test("addAlarm: custom alarm naming strategy", () => {
     },
     localAlarmNamePrefix: "prefix",
   });
+  const action = sampleAction;
   const alarm = factory.addAlarm(metric, {
     ...props,
     disambiguator,
+    actionOverride: action,
   });
-  expect(alarm.alarmName).toBe(`${alarmName}-${disambiguator}`);
-  expect(alarm.alarmLabel).toBe(`${alarmLabel}-${disambiguator}`);
-  expect(alarm.dedupeString).toBe(`${alarmDedupe}-${disambiguator}`);
+  expect(alarm.alarmName).toBe(`${alarmName}-${disambiguator}-Sample`);
+  expect(alarm.alarmLabel).toBe(`${alarmLabel}-${disambiguator}-Sample`);
+  expect(alarm.dedupeString).toBe(`${alarmDedupe}-${disambiguator}-Sample`);
 });
 
 test("addAlarm: custom metric adjuster, applies it and DefaultMetricAdjuster after it", () => {