Mongo Client Typescript

The purpose of this module is to provide a wrapper for using mongodb functions easier and provide a straightforward way of supporting schema validation.

Changelog

Changelod.md

Dependencies

• Ajv
• flat
• fast-deep-equal
• kareem
• mongodb

Installation

First install Node.js. Then:

npm i @gkampitakis/mongo-client --save

Importing

// Using Node.js `require()`
const { MongoClient } = require('@gkampitakis/mongo-client');

//Using ES6 import
import { MongoClient } from '@gkampitakis/mongo-client';

Overview

Connecting to MongoDB

await MongoClient.connect('mongodb://localhost:27017', 'databaseName', {
	useNewUrlParser: true,
	useUnifiedTopology: true
});

Note: You only have to create the connection once and then have access from anywhere in your application.

Model

Models are referring to mongo collections

Defining a Model

const user = Model('user');

// or

const user = Model('user', new Schema());

A model gives access to collection manipulation. You can provide a Schema on Model initialisation that provides extra functionality as schema validation and hooks.

• instance javascript await model.instance(data); Returns a Document.
• create javascript await model.create(data,options); Creates an entry to database and returns a Document or a plain object depending on options:{lean} boolean flag.
• deleteOne javascript await model.deleteOne(filter,options); Deletes the first entry from database that matches the given filter.
• findOne javascript await model.findOne(filter,options); Returns the first entry from database that matches the filter. The return value is either a Document or a plain object depending on options:{lean} boolean flag.
• updateOne javascript await model.updateOne(filter,data,options); Updates an entry to database and returns a Document or a plain object depending on options:{lean} boolean flag.
• findByIdAndDelete javascript await model.findByIdAndDelete(id,options); Deletes an entry from database that has the id given as parameter.
• findById javascript await model.findById(id,options); Returns an entry from database that matches the id given. The return value is either a Document or a plain object depending on options:{lean} boolean flag.
• findByIdAndUpdate javascript await model.findByIdAndUpdate(id,updateObject,options); Finds an entry based on the id provided, updates it and return a Document or a plain object depending on options:{lean} boolean flag.
• deleteMany javascript await model.deleteMany(filter); Deletes multiples entries from database based on the filter provided.

Document

The document is the wrapper object for the data. It has the structure:

{
	"collectionName": "users",
	"data": {...},
	"schema": {...},
	"lean": () => object,
	"save": () => Document,
	"remove": () => Document
}

• data the actual data saved in the database.
• collectionName the name of the collection where the data are saved.
• schema contains the definition for the schema.
• lean returns the plain object of data.
• save saves the data or updates it.
• remove deletes the entry from the database.

Schema

The schema has a description about how the data object should look like. It can contain more restrictions about the type of data.

const userSchema = new Schema({
	type: 'object',
	properties: {
		username: {
			type: 'string'
		},
		password: {
			type: 'string'
		},
		age: {
			type: 'number'
		}
	},
	required: ['username', 'password']
});

Validation

For the validation of the object Ajv library is used. The same syntax is used.

When you try to create a new entry with a model that has been initialised with schema, the data are being validated against this schema.

Hooks

For the hooks the kareem library is being used. There are two hooks pre and post and currently 6 supported types ( save, delete, update, remove, create, delete ) and registered in the schema like:

const schema = new Schema();

// it is important to be a function and not an arrow function
// cause inside the callback you have access on the context of `hooked` object

schema.pre('save', function () {
	console.log(this.data);
	// or
	console.log(this);

	//depending on **lean** boolean flag
	//if it returns a document or plain object
});

schema.post('save', function () {});

Commands

• npm run playground An example of simple test cases on how to use this module.

• npm run playground:mongo Run the examples on your local mongo instance.

• npm run test Run Jest testing suite.

• npm run benchmarks Run benchmark suite for Mongo Client, Mongoose and Native MongoDb for Nodejs.

Author and Maintainer

Georgios Kampitakis

For any issues.