Try: https://treeherder.mozilla.org/#/jobs?repo=try&revision=2d1a7e159cc637ce0dccca3b74a6aad6b2510ec6

Restricted to Nightly because there's still an open issue about inferred
function names and because the proposal was only recently moved to stage 3.

Depends on D70821

Depends on D70823

Hi Christian,
just wanted to give you a heads-up that this bug will add three new compound assignment operators (&&=, ||=, and ??=) to JS. The changes are currently restricted to Nightly builds, because the proposal only just recently reached stage 3.

Thanks,
André

Thanks for the heads-up! I will run the parser target on this for extensive testing once it has landed.

https://hg.mozilla.org/mozilla-central/rev/17566bf1e9cd
https://hg.mozilla.org/mozilla-central/rev/373440004686

This should be documented here (and also in https://github.com/mdn/browser-compat-data to update the table in the end):
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Assignment_Operators

Updated:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence#Table
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Expressions_and_Operators
https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators

New pages:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_nullish_assignment
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_OR_assignment
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_AND_assignment

Compat data:
https://github.com/mdn/browser-compat-data/pull/6363

Fx79 release notes announcement:
https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/79#JavaScript