The proposal is currently on Stage 2.

This is being set as a P3 like other Stage 2 proposals

This proposal has been promoted to Stage 3

Changing "Blocks" to Stage 3 per https://github.com/tc39/proposals/commit/25f8d6a4db03bcdd2cfd49bf32e312ce80e1c80e

It's implemented in both V8 and JSC now

The proposal is now on Stage 4.

Depends on D58973

Depends on D58974

Depends on D58975

Depends on D58976

Depends on D58977

Depends on D58974

Depends on D59869

https://hg.mozilla.org/mozilla-central/rev/37071f53b00b
https://hg.mozilla.org/mozilla-central/rev/35b55a5b0e4d
https://hg.mozilla.org/mozilla-central/rev/254be9b0aaee
https://hg.mozilla.org/mozilla-central/rev/5d3392ccb733

Yulia, as I started working on Bug 1594009 for console support, I wanted to check with you if it's normal for

document?.location?["origin"];

to throw a SyntaxError ? Chrome does the same, but in https://tc39.es/proposal-optional-chaining/ there are a few places where it looks like it should be possible? (I'm really not used to read specs, so I definitely can be wrong).

Hi Nicolas,

Unfortunately, we can't use location?["origin"] because we cannot distinguish it from a ternary without a look ahead larger than one or two characters. the engine, when it sees a bare ?, it expects a ternary operator -> location ? ["origin"] : ..., which is what the syntax error refers to.

As a result, the committee settled on this syntax -> location?.["origin"] -- it isn't ideal, but it resolves the lookahead problem. if we didn't do it right away, we would have potential errors with automatic semicolon insertion, thus making it impossible for us to include it later due to web compat.

The same is true for function calls.

So, tl;dr-> yes, it should be a syntax error specifically for an incomplete ternary expression.

(In reply to Yulia Startsev [:yulia] from comment #18)

So, tl;dr-> yes, it should be a syntax error specifically for an incomplete ternary expression.

Thanks a lot for the explanation :)

Release notes: https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/74#JavaScript
Reference docs: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining