How does mongoose's find() function hold on to its execution and wait for a later function in its chain to complete first?
The
find()function in mongoose calls theexec()function in the Query object to complete the query and return the result, like in the line of this file.
Actually no, it doesn't, at least not in your case. See the comment from three lines above:
// if we don't have a callback, then just return the query objectThe .exec() method is only called by find(…, callback) if you pass a callback. When using promises, you don't.
Instead, the exec method is called by the then() method of the query which makes the query thenable, and which gets used when you await the query object.