feat(cloudwatch): parse all metrics statistics and support long format

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

@@ -292,6 +292,8 @@ export class Metric implements IMetric {
     if (periodSec !== 1 && periodSec !== 5 && periodSec !== 10 && periodSec !== 30 && periodSec % 60 !== 0) {
       throw new Error(`'period' must be 1, 5, 10, 30, or a multiple of 60 seconds, received ${periodSec}`);
     }
+
+    this.warnings = undefined;
     this.dimensions = this.validateDimensions(props.dimensionsMap ?? props.dimensions);
     this.namespace = props.namespace;
     this.metricName = props.metricName;
@@ -300,12 +302,12 @@ export class Metric implements IMetric {
     if (parsedStat.type === 'generic') {
       // Unrecognized statistic, do not throw, just warn
       // There may be a new statistic that this lib does not support yet
-      // eslint-disable-next-line no-console
-      console.warn(
-        `WARNING: Unrecognized statistic "${props.statistic}" for metric with namespace "${props.namespace}", label "${props.label}" and metric name "${props.metricName}".` +
-          ' Use the `aws_cloudwatch.Stats` helper class to specify a statistic.' +
+      const label = props.label ? ` label "${props.label}"`: '';
+      this.warnings = [
+        `Unrecognized statistic "${props.statistic}" for metric with namespace "${props.namespace}",${label} and metric name "${props.metricName}".` +
+          ' Preferably use the `aws_cloudwatch.Stats` helper class to specify a statistic.' +
           ' You can ignore this warning if your statistic is valid but not yet supported by the `aws_cloudwatch.Stats` helper class.',
-      );
+      ];
     }
     this.statistic = normalizeStatistic(parsedStat);
 
@@ -314,7 +316,6 @@ export class Metric implements IMetric {
     this.unit = props.unit;
     this.account = props.account;
     this.region = props.region;
-    this.warnings = undefined;
   }
 
   /**

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

@@ -324,7 +324,27 @@ describe('Alarm', () => {
     });
   });
 
-  test('metric warnings are added to Alarm', () => {
+  test('metric warnings are added to Alarm for unrecognized statistic', () => {
+    const stack = new Stack(undefined, 'MyStack');
+    const m = new Metric({
+      namespace: 'CDK/Test',
+      metricName: 'Metric',
+      statistic: 'invalid',
+    });
+
+    // WHEN
+    new Alarm(stack, 'MyAlarm', {
+      metric: m,
+      evaluationPeriods: 1,
+      threshold: 1,
+    });
+
+    // THEN
+    const template = Annotations.fromStack(stack);
+    template.hasWarning('/MyStack/MyAlarm', Match.stringLikeRegexp('Unrecognized statistic.*Preferably use the `aws_cloudwatch.Stats` helper class to specify a statistic'));
+  });
+
+  test('metric warnings are added to Alarm for math expressions', () => {
     const stack = new Stack(undefined, 'MyStack');
     const m = new MathExpression({ expression: 'oops' });