In mongosh, we desugar objects and arrays destructuring, which might create issues for example when a function is used as the body of a $function expression in an aggregation.

For example, (function(foo) {const [a, b] = foo.split();}).toString()

becomes:

function (foo) { const _foo$split = foo.split(), _foo$split2 = _slicedToArray(_foo$split, 2), a = _foo$split2[0], b = _foo$split2[1]; }

and _sliceToArray does not exist on the server and breaks the pipeline.