🇺🇦 Transactions for mongoose

Transactions allow you to perform multiple group operations in isolation and undo all operations if one of them fails.

This module allows you to combine different transactions and operations into a group and execute them together. Pre-checks the schema for errors, duplication of unique indexes/fields

Very simple and extremely easy ☕️ :

• A couple of methods for everything
• Mix executors as you like
• Use the session for your usual, standard saving

And yes, let's start!

☕️ buy me a coffee

Installation

First install Node.js and MongoDB. Then:

npm i transactions-mongoose

Mongoose latest also included

Usage

const {Transaction} = require("transactions-mongoose");
const transaction = new Transaction();

// or with debug log
const transaction = new Transaction().setSendbox(true);

An exemplary use case

Create / Insert new document

const {Transaction} = require("transactions-mongoose");
const transaction = new Transaction().setSendbox(true);

const transactionData1 = transaction.add({
    Person,
    firstname: 'Sancho',
    lastname: 'Panse',
    age: 22,
    sex: 'male',
    status: 'free'
});
const transactionData2 = transaction.add({
    Model: 'Person',
    firstname: 'Janna',
    lastname: 'Dark',
    age: 21,
    sex: 'female',
    status: 'free'
});
transaction.add(Person, {
    firstname: 'Hulio',
    lastname: 'Iglessias',
    age: 35,
    sex: 'male',
    status: 'free'
});
await transaction.commit();

console.log('transaction 1 result', transactionData1.result) // the result of the save() operation
console.log('transaction 2 document', transactionData2.document)

Update an existing one

const {Transaction} = require("transactions-mongoose");
const transaction = new Transaction().setSendbox(true);

// variant #1 - use standard setters
let personSancho = await Person.findById('...Sancho id');
personSancho.age += 1;
personSancho.status = 'married';
personSancho.friend_id = '...Hulio Iglessias id';
transaction.add(personSancho);

// variant #2 - by document and update object
let personJanna = await Person.findById('...Janna id');
transaction.add(personJanna).update({
    age: ++personJanna.age,
    status: 'married',
    friend_id: personSancho._id,
    bodyFriend_id: '...Hulio Iglessias id',
});

// variant #3 - by ObjectId
transaction.add(Person, {_id: personSancho._id}).update({
    friend_id: personJanna._id
});
transaction.add({Person, _id: personSancho._id}).update({
    friend_id: personJanna._id
});

await transaction.commit();

Executing an isolated block that may fail is not related to Mongo but affects whether the data is saved or not.

const fetch = require("node-fetch");
const {Transaction} = require("transactions-mongoose");
const transaction = new Transaction().setSendbox(true);

const getAvatar = async (id) => {
    const response = await fetch('https://i.pravatar.cc/300?u=' + id);
    const blob = await response.blob()
    return "data:" + blob.type + ';base64,' + Buffer.from(await blob.arrayBuffer()).toString('base64');
};

const transactionData = transaction.execute(async () => {
    let personSancho = await Person.findById('...Sancho id');
    transaction.add(personSancho).update({
        updatedAt: Date.now(),
        __v: ++personSancho.__v
    });
    // there may be a timeout error or a reader processing error
    personSancho.avatar = await getAvatar(personSancho._id)

    transaction.execute(async () => {
        let personHulio = await Person.findById('...Hulio id');
        personHulio.avatar = await getAvatar(personHulio._id);
        transaction.add(personHulio)
    });

    let personJanna = await Person.findById('...Janna id');
    personJanna.avatar = await getAvatar(personJanna._id);
    const td = transaction.add(personJanna)
    
    // The result can be whatever you want
    // we will return the Janna document update result
    // https://mongoosejs.com/docs/api/query.html#Query.prototype.updateOne()
    return td
});

// and also execute it :)
personJanna.updatedAt = Date.now()
transaction.add(personJanna)

await transaction.commit();
console.log('transaction result', transactionData.result.result);

With session executor

To use with Mongo Replica set

const {Transaction} = require("transactions-mongoose");
const transaction = new Transaction().setSendbox(true);

transaction.session(async (session) => {

    let personSancho = await Person.findById('...Sancho id').session(session);
    let personJanna = await Person.findById('...Janna id').session(session);
    let personHulio = await Person.findById('...Hulio id').session(session);

    personSancho.age = 100; // <-- let's try to make it more mature
    await personSancho.save({session})

    personJanna.age = 100; // <-- let's try to make it more mature too
    await personJanna.save({session})

    personHulio.age = 100; // <-- let's try to make it more mature too
    await personHulio.save({session})

    throw new Error('Test an error - or remark me') // No changes will be saved

    // return result - The result can be whatever you want
    return personJanna
});

await transaction.commit();

If the scheme uses {timestamps: true} in the options, or the fields createdAt (if the document is new), updatedAt (for new and updates) - they will be automatically created or updated updatedAt.