Thread safety when JSON.stringifyAsync

[mohsen1]

Mostly from nodejs/node#2031 (comment)

Consider following code:

let obj = {foo: 1};
JSON.stringifyAsync(obj, result => console.log(result));
delete obj.foo

There could be a thread collision issue here. What can be done?

[ljharb]

JS is single-threaded. While an implementation may choose to implement it in that way, they'd have to ensure that observable semantics didn't conflict with that. Thus, any mention of threading in the spec is unlikely to pass muster.