node.js - One-liner $in nullification MongoDB -

the idea make request (in js) fetch documents field being contained in given array if array defined, or documents if array not defined.

i wondered if there elegant mean give $in argument parameter nullifies behavior, can used one-liner. take idea have make kind of conditional request more elegant.

here snippet using mongoose:

let query = somemodel.find(); if (somearray) {     query = query.where(somefield).in(somearray); } query.exec(); 

sure works, requires store query in variable, not cool.

aggregation might help.

let itemvalues = somearray || []; somemodel.aggregate([ {     $match: {         "somefield": {             [itemvalues.length > 0 ? "$in" : "$nin"]: itemvalues}         } } ]).exec()