What is the problem?

The issue has to do with these lines (possibly more, but these are the only two that I saw):

The .toLowerCase messes up the tokens.

Reproduction Steps

new rds.DatabaseCluster(scope, 'DB', {
  clusterIdentifier: `my-${cdk.Lazy.string({ produce(): string { return 'prod' }})}-db-cluster`,
  engine: rds.DatabaseClusterEngine.auroraPostgres({ version: rds.AuroraPostgresEngineVersion.VER_13_4 }),
  instanceProps: { vpc }
})

What did you expect to happen?

Cluster identifier = my-prod-db-cluster

What actually happened?

Cluster identifier = my-${token[token.1234]}-db-cluster

CDK CLI Version

2.8.0

Framework Version

2.8.0

Node.js Version

16.13.1

OS

Microsoft Windows 10 Enterprise

Language

Typescript

Language Version

4.5.5

Other information

I am not sure how this should be handled, but some options are:

• Simply ignore this feature when there is a token in the cluster identifier by adding && !cdk.Token.isUnresolved(clusterIdentifier) to the condition that checks if the feature flag is enabled
• Print a warning when a token is in the cluster identifier, but still skip the toLowerCase method in that case
• Convert everything besides the token(s) to lower case (I am not sure if there is a simple way to identify which parts of a string are tokens and which aren't)