(cloudfront): Lamda@Edge synth fails with newStyleStackSynthesis

[jumi-dev]

If newStyleStackSynthesis is enabled in a CDK stack and the stack uses a Lamda@Edge function, the synth-action leads to an error: Cannot add assets to a Stack that uses the BootstraplessSynthesizer

Reproduction Steps

Create a new CDK project and enable newStyleStackSynthesis in cdk.json by adding "@aws-cdk/core:newStyleStackSynthesis": true.

Add a Lambda@Edge function to the new stack as described in the documentation:

export class CloudfrontEdgeStack extends cdk.Stack {
  constructor(scope: cdk.Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    const myFunc = new cloudfront.experimental.EdgeFunction(this, 'MyFunction', {
      runtime: lambda.Runtime.NODEJS_10_X,
      handler: 'index.handler',
      code: lambda.Code.fromAsset(path.join(__dirname, 'lambda-handler')),
    });
    
  }
}

Set the region to a value which is different to us-east-1.

Execute cdk synth.

What did you expect to happen?

CDK stack should be synthesized successfully.

What actually happened?

Error message appears:
Cannot add assets to a Stack that uses the BootstraplessSynthesizer

Environment

• **CDK CLI Version : 1.79.0
• **Framework Version: 1.79.0
• **Node.js Version: v12.18.3
• **OS : macOS 10.15.7
• **Language (Version): TypeScript (4.0.2)

Other

In class edge-function.ts, the method crossRegionSupportSynthesizer returns the BootstraplessSynthesizer.
For testing, I replaced

new BootstraplessSynthesizer({
  deployRoleArn: scopeStackSynthesizer.deployRoleArn,
  cloudFormationExecutionRoleArn: scopeStackSynthesizer.cloudFormationExecutionRoleArn,
})

with

new DefaultStackSynthesizer()

After doing this change, I could deploy my stack and the edge-lambda-stack successfully. Is this the correct fix for the issue?

---

This is 🐛 Bug Report

[github-actions]

⚠️COMMENT VISIBILITY WARNING⚠️

Comments on closed issues are hard for our team to see.
If you need more assistance, please either tag a team member or open a new issue that references this one.
If you wish to keep having a conversation with other community members under this issue feel free to do so.