java (dotnet?): arrays in CFN layer are always List<Object>

[eladb]

The type of subscription should be List<CfnTopic.SubscriptionProperty> but instead it is List<Object>.

Reproduction Steps

CfnTopic.Builder.create(this, "YourTopic").subscription(...)

Environment

• Framework Version: 1.16.3.DEVPREVIEW
• Language : Java (& .NET?)

[RomainMuller]

The property is typed (in TypeScript) as:

Array<SubscriptionProperty | IResolvable> | IResolvable

The List<Object> java signature is actually the best that can be emitted for this... :(

[eladb]

Why we can't generate the following overloads?

subscription(List<Object> subscription)
subscription(IResolvable subscription)
subscription(List<SubscriptionProperty> subscription)
subscription(List<IResolvable> subscription)

[RomainMuller]

No we cannot - List<Object>, List<SubscriptionProperty>, and List<IResolvable> are all reified to List once compiled, so the java dispatcher wouldn't be able to effectively differentiate them (to schematize heavily - one could understand Java generics information is "lost" during compilation).

[eladb]

I am wondering if we should sacrifice List<IResolvable> and List<Object> in favor of List<Type> which is the common case and will have a dramatic improvement over the current t state. The other cases could be addressed through escape hatches easily.

[RomainMuller]

The only way you can get List<IResolvable> sacrificed is by removing the option from the TS code, which would result in a breaking change.

[RomainMuller]

Since this is now in the v2.0 issue, resolving this one.