Non-existent attributes still match in a rule head specializer in Node.JS library

[leina05]

A rule like:

allow(actor, action, resource: {attr: attr});

still matches even if the object passed in as resource does not have the attr attribute. This has to do with how the library handles undefined (it passed it back into Polar instead of treating it as a failed match).

[samscott89]

Is there a distinction in Node between a non-existent attribute and one which is undefined?

e.g.

d = { a: 1 }
d.b
// returns undefined

vs

d = { a: 1, b: undefined }
d.b
// also returns undefined

[dhatch]

> x = {b: undefined}
{ b: undefined }
> x.hasOwnProperty("b")
true
> x.hasOwnProperty("b")
true
> x.b
undefined
> x.hasOwnProperty("foo")
false
> x.foo
undefined

[dhatch]

Should be doing a similar check like this: https://github.com/osohq/oso/blob/main/languages/python/oso/polar/query.py#L98