sacred slate
I should note that I know how to get a similar result by simply using a separate chain of classes for this data. However this is a DX thing, so I would prefer to achieve this as described.
what i would like is to have some property on a class, say $foo, which when overridden will not simply wipe and overwrite the parent class' value of $foo, but instead merge with it in a similar way to top-level properties in class inheritance. I would like this to work all the way down the chain, such that if there's a great-great-great-grandchild of Parent it can still access the same $foo.a that Parent defines (overrides permitting).
class Parent {
$foo = {
a: 1,
b: 2,
}
// insert magic here...
}
class Child {
$foo = {
c: 3,
d: 4,
}
// ! important: there can't be additional magic here, as it will defeat the DX purpose of this
}
new Child().a; // 1
new Child().b; // 2
new Child().c; // 3
new Child().d; // 4
I'm happy to do anything in the private space of the Parent class to make this work - type safety is the last of my concerns so long as it works (I would like proper type inference somewhere, perhaps a getFoo method to avoid missing property warnings on $foo).
I'd even be content with writing a separate JS file and a DTS file, with the DTS claiming Parent is a class class, and the underlying JS messing around with prototypes and such. If it's stupid and it works, it's not stupid, right?
As mentioned above, I could totally just do this with a neighboring class chain. Child$foo extends Parent$foo and $foo = new Child$foo() or something. But I want to avoid requiring the authors of Child and any further derived classes from having to do additional work.
If there's a name for this I'd also like to know. I've been calling it "inner level inheritance" and variations of, but googling those terms gets me nowhere.
paper kraken