shall this validation be done earlier (at line 427) with other validations instead?

if (!logs && !logs.level != LogLevel.OFF && !logs.destination) { ...

reasons for ask:

• with current change, validations will be split across various places and as this file is big (and keep getting bigger), hence, it will become difficult to have complete picture of validation
• ideally, caller shall not even call buildLoggingConfiguration if prerequisites are not met

added a separate validation method validateLogOptions()

if we do this like as follows - will it reduce need to check logOptions.destination twice and simplify a bit?

let destinations = undefined;
if (logOptions.destination) {
  // Policy addition
  destinations = [{
    cloudWatchLogsLogGroup: { logGroupArn: logOptions.destination.logGroupArn },
  }];
}

return {
  destinations,
  ...,
  level: logOptions.level || LogLevel.ERROR
}

updated.

will this not be a breaking change for existing usage? example:

const logOptions: LogOptions = {
  destination: <LogGroup>
}

const stateMachine: StateMachine = new StateMachine(parent, 'ID', {
  logs: logOptions,
  ...
}
... 

stateMachine.logs.destination.logGroupName // Error
stateMachine.logs.destination!.logGroupName // Change needed

Some user(s) might be utilising ILogGroup's public properties from logOptions which will now cause issues because now such users will need to make non-null assertions before using such properties (e.g. with !)

According to the jsii-diff documentation:

You are allowed to make inputs optional

So i think this change is not a breaking change.

can we not directly pass new sfn.Pass(stack, 'Pass') to DefintionBody.fromChainable as Pass implements IChainable?

it's just a copy & paste.
README also uses sfn.Chain.start() instead of bare sfn.Pass.