fix(autoscaling): error not thrown when associatePublicIpAddress is set to false when specifying launchTemplate (#21714)

Setting `associatePublicIpAddress` prop when also setting `launchTemplate` prop on a new ASG is supposed to throw an error, but doesn't due to `associatePublicIpAddress` being a boolean, and the error message not triggering if a falsy value is used for the prop. This PR will ensure an error is thrown when `associatePublicIpAddress` is set, even when the value passed is falsy. It also updates the documentation on all props which conflict with `launchTemplate` or `mixedInstancesPolicy`

fixes: #21576

----

### All Submissions:

* [ ] Have you followed the guidelines in our [Contributing guide?](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md)

### Adding new Unconventional Dependencies:

* [ ] This PR adds new unconventional dependencies following the process described [here](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md/#adding-new-unconventional-dependencies)

### New Features

* [ ] Have you added the new feature to an [integration test](https://github.com/aws/aws-cdk/blob/main/INTEGRATION_TESTS.md)?
	* [ ] Did you use `yarn integ` to deploy the infrastructure and generate the snapshot (i.e. `yarn integ` without `--dry-run`)?

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

Author: peterwoodworth

packages/@aws-cdk/aws-autoscaling/lib/auto-scaling-group.ts

@@ -80,6 +80,8 @@ export interface CommonAutoScalingGroupProps {
   /**
    * Name of SSH keypair to grant access to instances
    *
+   * `launchTemplate` and `mixedInstancesPolicy` must not be specified when this property is specified
+   *
    * @default - No SSH access will be possible.
    */
   readonly keyName?: string;
@@ -190,6 +192,8 @@ export interface CommonAutoScalingGroupProps {
    * Whether instances in the Auto Scaling Group should have public
    * IP addresses associated with them.
    *
+   * `launchTemplate` and `mixedInstancesPolicy` must not be specified when this property is specified
+   *
    * @default - Use subnet setting.
    */
   readonly associatePublicIpAddress?: boolean;
@@ -198,6 +202,8 @@ export interface CommonAutoScalingGroupProps {
    * The maximum hourly price (in USD) to be paid for any Spot Instance launched to fulfill the request. Spot Instances are
    * launched when the price you specify exceeds the current Spot market price.
    *
+   * `launchTemplate` and `mixedInstancesPolicy` must not be specified when this property is specified
+   *
    * @default none
    */
   readonly spotPrice?: string;
@@ -217,6 +223,8 @@ export interface CommonAutoScalingGroupProps {
    * You can use block device mappings to specify additional EBS volumes or
    * instance store volumes to attach to an instance when it is launched.
    *
+   * `launchTemplate` and `mixedInstancesPolicy` must not be specified when this property is specified
+   *
    * @see https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html
    *
    * @default - Uses the block device mapping of the AMI
@@ -243,6 +251,8 @@ export interface CommonAutoScalingGroupProps {
    * When detailed monitoring is enabled, Amazon CloudWatch generates metrics every minute and your account
    * is charged a fee. When you disable detailed monitoring, CloudWatch generates metrics every 5 minutes.
    *
+   * `launchTemplate` and `mixedInstancesPolicy` must not be specified when this property is specified
+   *
    * @see https://docs.aws.amazon.com/autoscaling/latest/userguide/as-instance-monitoring.html#enable-as-instance-metrics
    *
    * @default - Monitoring.DETAILED
@@ -543,7 +553,7 @@ export interface AutoScalingGroupProps extends CommonAutoScalingGroupProps {
   /**
    * Type of instance to launch
    *
-   * `launchTemplate` must not be specified when this property is specified.
+   * `launchTemplate` and `mixedInstancesPolicy` must not be specified when this property is specified
    *
    * @default - Do not provide any instance type
    */
@@ -552,7 +562,7 @@ export interface AutoScalingGroupProps extends CommonAutoScalingGroupProps {
   /**
    * AMI to launch
    *
-   * `launchTemplate` must not be specified when this property is specified.
+   * `launchTemplate` and `mixedInstancesPolicy` must not be specified when this property is specified
    *
    * @default - Do not provide any machine image
    */
@@ -561,7 +571,7 @@ export interface AutoScalingGroupProps extends CommonAutoScalingGroupProps {
   /**
    * Security group to launch the instances in.
    *
-   * `launchTemplate` must not be specified when this property is specified.
+   * `launchTemplate` and `mixedInstancesPolicy` must not be specified when this property is specified
    *
    * @default - A SecurityGroup will be created if none is specified.
    */
@@ -572,7 +582,7 @@ export interface AutoScalingGroupProps extends CommonAutoScalingGroupProps {
    *
    * The UserData may still be mutated after creation.
    *
-   * `launchTemplate` must not be specified when this property is specified.
+   * `launchTemplate` and `mixedInstancesPolicy` must not be specified when this property is specified
    *
    * @default - A UserData object appropriate for the MachineImage's
    * Operating System is created.
@@ -584,7 +594,7 @@ export interface AutoScalingGroupProps extends CommonAutoScalingGroupProps {
    *
    * The role must be assumable by the service principal `ec2.amazonaws.com`:
    *
-   * `launchTemplate` must not be specified when this property is specified.
+   * `launchTemplate` and `mixedInstancesPolicy` must not be specified when this property is specified
    *
    * @example
    *
@@ -1523,7 +1533,7 @@ export class AutoScalingGroup extends AutoScalingGroupBase implements
     if (props.instanceMonitoring) {
       throw new Error('Setting \'instanceMonitoring\' must not be set when \'launchTemplate\' or \'mixedInstancesPolicy\' is set');
     }
-    if (props.associatePublicIpAddress) {
+    if (props.associatePublicIpAddress !== undefined) {
       throw new Error('Setting \'associatePublicIpAddress\' must not be set when \'launchTemplate\' or \'mixedInstancesPolicy\' is set');
     }
     if (props.spotPrice) {

packages/@aws-cdk/aws-autoscaling/test/auto-scaling-group.test.ts

@@ -1525,6 +1525,7 @@ describe('auto scaling group', () => {
       launchTemplateId: 'test-lt-id',
       versionNumber: '0',
     });
+    const vpc = mockVpc(stack);
 
     // THEN
     expect(() => {
@@ -1535,9 +1536,16 @@ describe('auto scaling group', () => {
           generation: AmazonLinuxGeneration.AMAZON_LINUX_2,
           cpuType: AmazonLinuxCpuType.X86_64,
         }),
-        vpc: mockVpc(stack),
+        vpc,
       });
     }).toThrow('Setting \'machineImage\' must not be set when \'launchTemplate\' or \'mixedInstancesPolicy\' is set');
+    expect(() => {
+      new autoscaling.AutoScalingGroup(stack, 'imported-lt-asg-2', {
+        launchTemplate: lt,
+        associatePublicIpAddress: true,
+        vpc,
+      });
+    }).toThrow('Setting \'associatePublicIpAddress\' must not be set when \'launchTemplate\' or \'mixedInstancesPolicy\' is set');
   });
 
   test('Cannot specify Launch Template without instance type', () => {