Implement Annex B.3.9 ("Runtime Errors for Function Call Assignment Targets")

[adams85]

Implements func() = 1 Annex B.3.9 browser quirk formalized by ES2026.

Resolves #1398

[marijnh]

While it is true that browser error on this in the evaluation stage rather than the parse stage, none of them actually do anything meaningful with it. What would be the practical value of implementing this quirk?

[adams85]

There's zero practical value in this, it's just for standards-compliance and consistency:

1. acorn implements the other Annex B.3 quirks like for (var x = 0 in {}) {}, try {} catch(e) { var e = null } and so on. Why should this one be an exception?
2. Browser engines, including V8 has had this quirk for ages. As V8 is used in a lot of non-browser runtime engines like Node, those also have this quirk.
3. The corresponding test262 cases don't need to be whitelisted.

That being said, I'm perfectly okay with scrapping this change if you say so. I just got a request for my acorn-port to implement this and backported it while I was at it.

[marijnh]

@RReverser Do you have an opinion on whether this is a good idea?

[rubienterprise5667-pixel]

Hi