Input:

({...(obj)} = foo)

Expecting similar output as Babel (which will accept it). This is a destructuring assignment rest property which has looser syntax than with other patterns. The parenthesis are fine here because it's supposed to match a LeftHandSideExpression.

https://tc39.es/ecma262/#prod-AssignmentRestProperty
https://tc39.es/ecma262/#prod-DestructuringAssignmentTarget

https://astexplorer.net/#/gist/15eb31fbb1024faa6f42a4940d8beb4a/4aee1037f36aee9aaa0ffaac61e7ce4a3c1ba95e

(Unfortunately, Babel also accepts ({...(obj)}) => x, which is definitely illegal but regardless I'm confident it is legit in assignments)