Aggregate.prototype.replaceRoot()

Parameters

• the «String|Object» field or document which will become the new root document

Returns:

• «Aggregate»

Appends a new $replaceRoot operator to this aggregate pipeline.

Note that the $replaceRoot operator requires field strings to start with ‘$’. If you are passing in a string Mongoose will prepend ‘$’ if the specified field doesn’t start ‘$’. If you are passing in an object the strings in your expression will not be altered.

Examples:

aggregate.replaceRoot("user");
aggregate.replaceRoot({ x: { $concat: ['$this', '$that'] } });