I have a const object In it I have a const list

I try to initialize the list in the constructor ... but any call to "add" (in the ctor) results in a runtime error : "list is readonly"

Can I do it a different way ... maybe create a new list in the ctor that I add to, and then assign it to my const list

Would that be the proper way to do it ?

The key thing to remember is that when you assign a list to a const field, that is when it is made immutable:

// this code
this.constField = list

// always gets translated into this
this.constField = list?.toImmutable

So the best way to do it is built up your list via a local variable, then assign to the field once you are ready to lock it down.

Cool, that's what I did.

One thing I don't like is that it's a runtime error(don't like those), maybe the compiler could warn about this ?