feat(custom): use addToSummaryDashboard from CustomMonitoringProps if not specified in metric groups (#278)

It's confusing that the top-level `addToSummaryDashboard` didn't do anything. This is now the lowest-precedence way to add things to the summary dashboard. This still defaults to `false` to maintain existing behaviour.

---

_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

@@ -171,13 +171,12 @@ export interface CustomMetricGroup {
   readonly graphWidgetLegend?: LegendPosition;
   /**
    * @deprecated use addToSummaryDashboard. addToSummaryDashboard will take precedence over important.
-   * Flag indicating, whether this is an important metric group that should be included in the summary as well.
-   * @default false
+   * @see addToSummaryDashboard
    */
   readonly important?: boolean;
   /**
    * Flag indicating this metric group should be included in the summary as well.
-   * @default false
+   * @default - addToSummaryDashboard from CustomMonitoringProps, defaulting to false
    */
   readonly addToSummaryDashboard?: boolean;
   /**
@@ -238,6 +237,7 @@ export class CustomMonitoring extends Monitoring {
   readonly description?: string;
   readonly descriptionWidgetHeight?: number;
   readonly height?: number;
+  readonly addToSummaryDashboard: boolean;
   readonly customAlarmFactory: CustomAlarmFactory;
   readonly anomalyDetectingAlarmFactory: AnomalyDetectingAlarmFactory;
   readonly metricGroups: CustomMetricGroupWithAnnotations[];
@@ -251,6 +251,7 @@ export class CustomMonitoring extends Monitoring {
     this.description = props.description;
     this.descriptionWidgetHeight = props.descriptionWidgetHeight;
     this.height = props.height;
+    this.addToSummaryDashboard = props.addToSummaryDashboard ?? false;
 
     const alarmFactory = this.createAlarmFactory(
       namingStrategy.resolveAlarmFriendlyName()
@@ -313,7 +314,7 @@ export class CustomMonitoring extends Monitoring {
           (group) =>
             group.metricGroup.addToSummaryDashboard ??
             group.metricGroup.important ??
-            false
+            this.addToSummaryDashboard
         )
       : this.metricGroups;
 

lib/monitoring/custom/CustomMonitoring.ts

@@ -189,8 +189,34 @@ test("addToSummaryDashboard attribute takes precedence over important in metric
     metricGroups: [
       {
         title: "DummyGroup1",
-        important: false,
         addToSummaryDashboard: true,
+        important: false,
+        metrics: [
+          // regular metric
+          new Metric({ metricName: "DummyMetric1", namespace, dimensionsMap }),
+        ],
+      },
+    ],
+  });
+
+  addMonitoringDashboardsToStack(stack, monitoring);
+  expect(Template.fromStack(stack)).toMatchSnapshot();
+});
+
+test("addToSummaryDashboard attribute takes value from CustomMonitoringProps if not specified in metric group", () => {
+  const stack = new Stack();
+  const scope = new TestMonitoringScope(stack, "Scope");
+
+  const monitoring = new CustomMonitoring(scope, {
+    alarmFriendlyName: "DummyAlarmName",
+    humanReadableName: "DummyName",
+    description: "Monitoring widget that shows up in the summary dashboard",
+    descriptionWidgetHeight: 2,
+    height: 100,
+    addToSummaryDashboard: true,
+    metricGroups: [
+      {
+        title: "DummyGroup1",
         metrics: [
           // regular metric
           new Metric({ metricName: "DummyMetric1", namespace, dimensionsMap }),