javascriptAsync race conditionHard

Doubled value returned before it's ready

Time: 0:00

What it should do

delayedDouble(n) should asynchronously resolve to n doubled, e.g. delayedDouble(5) eventually resolves to 10.

What goes wrong

Awaiting delayedDouble(5) gives undefined instead of 10.

Hints

This is an async and race conditions bug

A missing await, results in the wrong order, and updates that overwrite each other under load.