mongoose-doc-merge

This is a Mongoose plugin that adds a merge method to all your documents.

Setup

Add the module:

npm install mongoose-doc-merge

Require it:

import mergePlugin from 'mongoose-doc-merge'

Initialize it:

    mongoose.plugin(mergePlugin)

Use it:

let doc = new Model({...})
let otherDoc = new Model(req.body)

doc.merge(otherDoc)

The merge() method overwrites any path values in doc that exist in otherDoc. Path values that that have a value of undefined are ignored, but path values that are nullare merged.

The algorithm doesn't do anything fancy with arrays. The new array overwrites the old one entirely.

Why?

If you are updating documents from a partial update, for example as part of a PUT method in a REST API, you will want to merge new data in with existing data. It's got to be Mongoose document aware because a straight Javascript object merge doesn't work. You also don't need anything fancy. You just want the new path values to overwrite the old ones, leaving the rest of the document intact. That's what this method does.