Groovy had the same feature well over a decade ago[1] (at least in 2005) and other languages possibly even before that. Swift was first announced in 2014.

Swift's is also tied to their `Optional<T>` wrapper type, any potential JS implementation would be more like Groovy's.

[1] https://web.archive.org/web/20050815012153/http://groovy.cod... , bottom of the page

I'm no lawyer, but I think the Apache2 license on Swift would mean that the JS community has access to the patent.

https://github.com/apple/swift/blob/master/LICENSE.txt

TC39 (who defines Javascript) is a collaboration of several companies, so I'm not sure who Apple could/would even sue if this was proposed and adopted for JS. I doubt we would see legal activity over it.

That sounds like a truly ridiculous patent! Optional chaining is just another syntax for the Maybe-monad, surely?

Which has been around since 1998 at least (When Haskell 1.3 added monads)

I would have thought that Coffeescript's optional chaining, present at least as early as v1.0 in 2010[0], would have counted as prior art.

[0]: https://github.com/jashkenas/coffeescript/blob/1.0.0/lib/par...

Is it even a useful feature?

Will it lead to many JS bugs simply disappearing and applications getting more stable or will it just obfuscate bugs in the long run?

Presumably people will only use it in situations where null (or undefined, or however it works) is a valid and expected value for a particular property.

In TypeScript, these properties would explicitly have a `MyType|null` or `MyType|undefined` type.

Roughly speaking, one less place where we need to use lodash.

"or will it just obfuscate bugs in the long run?"

Probably. :shrug emojii:

But more stable in the sense of turning hard crashes into UI quirks.