From 8b7ef7380673f4208c69a5041ed88b41a1437603 Mon Sep 17 00:00:00 2001
From: go-to-k <24818752+go-to-k@users.noreply.github.com>
Date: Sat, 20 Jan 2024 23:44:13 +0900
Subject: [PATCH] fix(autoscaling): step scaling without adjustmentType fails

---
 .../lib/step-scaling-policy.ts                |  4 ++--
 .../aws-autoscaling/test/scaling.test.ts      | 22 +++++++++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/packages/aws-cdk-lib/aws-autoscaling/lib/step-scaling-policy.ts b/packages/aws-cdk-lib/aws-autoscaling/lib/step-scaling-policy.ts
index 1e467ada652c5..23daf1e0909f5 100644
--- a/packages/aws-cdk-lib/aws-autoscaling/lib/step-scaling-policy.ts
+++ b/packages/aws-cdk-lib/aws-autoscaling/lib/step-scaling-policy.ts
@@ -112,7 +112,7 @@ export class StepScalingPolicy extends Construct {
       const threshold = intervals[alarms.lowerAlarmIntervalIndex].upper;
 
       this.lowerAction = new StepScalingAction(this, 'LowerPolicy', {
-        adjustmentType: props.adjustmentType,
+        adjustmentType,
         cooldown: props.cooldown,
         estimatedInstanceWarmup: props.estimatedInstanceWarmup,
         metricAggregationType: props.metricAggregationType ?? aggregationTypeFromMetric(props.metric),
@@ -143,7 +143,7 @@ export class StepScalingPolicy extends Construct {
       const threshold = intervals[alarms.upperAlarmIntervalIndex].lower;
 
       this.upperAction = new StepScalingAction(this, 'UpperPolicy', {
-        adjustmentType: props.adjustmentType,
+        adjustmentType,
         cooldown: props.cooldown,
         estimatedInstanceWarmup: props.estimatedInstanceWarmup,
         metricAggregationType: props.metricAggregationType ?? aggregationTypeFromMetric(props.metric),
diff --git a/packages/aws-cdk-lib/aws-autoscaling/test/scaling.test.ts b/packages/aws-cdk-lib/aws-autoscaling/test/scaling.test.ts
index f99b132087382..ddfde79ed967c 100644
--- a/packages/aws-cdk-lib/aws-autoscaling/test/scaling.test.ts
+++ b/packages/aws-cdk-lib/aws-autoscaling/test/scaling.test.ts
@@ -294,6 +294,28 @@ test('step scaling from percentile metric', () => {
   });
 });
 
+test('step scaling with adjustmentType by default', () => {
+  // GIVEN
+  const stack = new cdk.Stack();
+  const fixture = new ASGFixture(stack, 'Fixture');
+
+  // WHEN
+  fixture.asg.scaleOnMetric('Tracking', {
+    metric: new cloudwatch.Metric({ namespace: 'Test', metricName: 'Metric', statistic: 'p99' }),
+    scalingSteps: [
+      { upper: 0, change: -1 },
+      { lower: 100, change: +1 },
+      { lower: 500, change: +5 },
+    ],
+  });
+
+  // THEN
+  Template.fromStack(stack).hasResourceProperties('AWS::AutoScaling::ScalingPolicy', {
+    PolicyType: 'StepScaling',
+    AdjustmentType: 'ChangeInCapacity',
+  });
+});
+
 test('step scaling with evaluation period configured', () => {
   // GIVEN
   const stack = new cdk.Stack();