feat(cloudwatch): GraphWidget supports period and statistic (aws#14679)

Dashboard metric widgets support overridding/setting both period and stat on the
widget as a whole. This is often useful in combination with `MathExpression`
metrics.

Reference: https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/CloudWatch-Dashboard-Body-Structure.html#CloudWatch-Dashboard-Properties-Metric-Widget-Object


----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk/aws-cloudwatch/lib/graph.ts

@@ -206,7 +206,6 @@ export interface GraphWidgetProps extends MetricWidgetProps {
    */
   readonly liveData?: boolean;
 
-
   /**
    * Display this metric
    *
@@ -223,6 +222,23 @@ export interface GraphWidgetProps extends MetricWidgetProps {
    * @default false
    */
   readonly setPeriodToTimeRange?: boolean;
+
+  /**
+   * The default period for all metrics in this widget.
+   * The period is the length of time represented by one data point on the graph.
+   * This default can be overridden within each metric definition.
+   *
+   * @default cdk.Duration.seconds(300)
+   */
+  readonly period?: cdk.Duration;
+
+  /**
+   * The default statistic to be displayed for each metric.
+   * This default can be overridden within the definition of each individual metric
+   *
+   * @default - The statistic for each metric is used
+   */
+  readonly statistic?: string;
 }
 
 /**
@@ -287,6 +303,8 @@ export class GraphWidget extends ConcreteWidget {
         legend: this.props.legendPosition !== undefined ? { position: this.props.legendPosition } : undefined,
         liveData: this.props.liveData,
         setPeriodToTimeRange: this.props.setPeriodToTimeRange,
+        period: this.props.period?.toSeconds(),
+        stat: this.props.statistic,
       },
     }];
   }

packages/@aws-cdk/aws-cloudwatch/test/test.graphs.ts

@@ -1,4 +1,4 @@
-import { Stack } from '@aws-cdk/core';
+import { Duration, Stack } from '@aws-cdk/core';
 import { Test } from 'nodeunit';
 import { Alarm, AlarmWidget, Color, GraphWidget, GraphWidgetView, LegendPosition, LogQueryWidget, Metric, Shading, SingleValueWidget, LogQueryVisualizationType } from '../lib';
 
@@ -688,4 +688,33 @@ export = {
 
     test.done();
   },
+
+  'GraphWidget supports stat and period'(test: Test) {
+    // GIVEN
+    const stack = new Stack();
+    const widget = new GraphWidget({
+      left: [new Metric({ namespace: 'CDK', metricName: 'Test' })],
+      statistic: 'Average',
+      period: Duration.days(2),
+    });
+
+    // THEN
+    test.deepEqual(stack.resolve(widget.toJson()), [{
+      type: 'metric',
+      width: 6,
+      height: 6,
+      properties: {
+        view: 'timeSeries',
+        region: { Ref: 'AWS::Region' },
+        metrics: [
+          ['CDK', 'Test'],
+        ],
+        yAxis: {},
+        stat: 'Average',
+        period: 172800,
+      },
+    }]);
+
+    test.done();
+  },
 };