A library for applying and manipulating MongoDB style queries and deltas purely in JavaScript.

The idea behind this library is to allow the use of MongoDB style queries and deltas in your JavaScript code, working directly with arrays and objects in your program -- no MongoDB required.

Applies a delta to a document (object). Please see https://docs.mongodb.com/manual/reference/operator/update/ for documentation on operators you can use. Note that not all operators are implemented, but most are. Please note that if you are using typescript, operators will properly effect to shape of the resulting document.

• $currentDate
• $inc
• $min
• $max
• $mul
• $rename
• $set
• $setOnInsert (with asInsert set to true)
• $unset
• $addToSet
• $pop
• $pull
• $push
• $pullAll

applyDelta({ number: 10 }, { $inc: 2 }) // returns { number: 12 }

applyDelta(document, delta, options?) -> document

document : the document you wish the apply the delta to. Note that this document can be any object.

delta : the delta you wish to the document. The delta must be an object containing mongoDB delta operators.

options : an options object. Can contain the property asInsert to enable $setOnInsert.

Applies a query to a collection of documents, filtering out ones that do not meet the query. The matching documents will be returned by the method in a results array. Please see https://docs.mongodb.com/manual/reference/operator/query/ for query operators you can use. Note that not all operators are implemented, but most are.

• direct matches
• $eq
• $gt
• $gte
• $in
• $lt
• $lte
• $ne
• $nin
• $exists
• $type
• $mod
• $regex

applyQuery([{ number: 10 }, { text: 'hello world' }], { number: { $gt: 5 } }) // returns [{ number: 10 }]

applyQuery(collection, query) -> filteredCollection

collection : the array of documents you wish to filter using the query.

query : the query you wish to use to filter the collection. The query must be an object containing mongoDB query operators.

Takes a delta and renames the fields effected using a projection, and returns a new delta with the updated field names.

projectDelta({ $set: { number: 5 } }, { number: 'int' } as const) // returns { $set: { int: 5 } }

projectDelta(delta, projection) -> projectedQuery

delta : the delta to modify using the projection.

projection : the projection used to modify the delta.

Takes a query and renames the fields effected using a projection, and returns a new query with the updated field names.

projectQuery({ number: { $gt: 5 } }, { number: 'int' } as const) // returns { int: { $gt: 5 } }

projectQuery(query, projection) -> projectedQuery

query : the query to modify using the projection.

projection : the projection used to modify the query.