mongoose-version-handler

A Mongoose plugin to manage document versioning and history with JSON Patch diffs, now featuring rollback functionality and full support for NestJS.

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Installation

Install the plugin via npm:

1npm install mongoose-version-handler

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Purpose

The mongoose-version-handler plugin allows you to:

1. Track changes made to documents over time.
2. Maintain a version history using JSON Patch format.
3. Retrieve any version of a document easily.
4. Rollback documents to previous versions.
5. Seamlessly integrate with NestJS.

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Basic Usage

Add the plugin to your schema:

1import { Schema } from 'mongoose';
2import mongooseVersionHandler from 'mongoose-version-handler';
3
4const UserSchema = new Schema({
5    name: {
6        firstname: String,
7        lastname: String,
8    },
9});
10
11// Add versioning plugin
12UserSchema.plugin(mongooseVersionHandler);

The plugin will:

• Add a version field (documentVersion by default) to your schema.
• Maintain a separate history collection storing JSON Patch diffs for each change.
• Automatically increment the version number on each save/update.

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Options

versionKey

Specifies the version field name added to the schema. Default: documentVersion.

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collection

Sets the name of the history collection. Default: <original_collection>_h.

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connection

Passes a specific database connection for version tracking. This is required when using mongoose.createConnection.

Example:

1import mongoose, { Schema } from 'mongoose';
2import mongooseVersionHandler from 'mongoose-version-handler';
3
4const db = mongoose.createConnection('mongodb://localhost/my-database');
5
6const UserSchema = new Schema({
7    name: {
8        first: String,
9        last: String,
10    },
11});
12
13UserSchema.plugin(mongooseVersionHandler, { connection: db });

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trackDate

Tracks the creation date for each version. Adds a date field to the history collection when enabled.

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addDateToDocument

Stores the version creation date redundantly in the main document. Requires trackDate: true.

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versionDateKey

Specifies the name of the date field added to the document when addDateToDocument is enabled. Default: documentVersionDate.

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Retrieving a Specific Document Version

You can retrieve any version of a document using the getVersion() method:

1const user = await User.findOne({ ... });
2const version2 = await user.getVersion(2);

getVersion() returns a Promise resolving to the document version.

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Rolling Back a Document

Rollback to a previous version using the rollback() method:

1const user = await User.findOne({ ... });
2await user.rollback();

• If a previous version exists, the document rolls back to that version.
• If no previous version exists, the document will be deleted.

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Accessing the History Collection

To query the history collection directly, use the getHistoryModel() method:

1const UserHistory = User.getHistoryModel();
2const history = await UserHistory.find({ parent: user._id });

The history collection schema looks like this:

1const ChangeSet = new mongoose.Schema({
2    parent: mongoose.SchemaTypes.ObjectId, // Source document ID
3    version: Number,                      // Version number
4    patches: [{                           // JSON Patch changes
5        op: String,
6        path: String,
7        value: mongoose.SchemaTypes.Mixed,
8    }],
9    date: Date, // Available if 'trackDate' is enabled
10});

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NestJS Integration

The plugin includes support for NestJS applications.

Example: Using the Plugin in a NestJS Module

1import { Module } from '@nestjs/common';
2import { MongooseModule, getConnectionToken } from '@nestjs/mongoose';
3import { Connection } from 'mongoose';
4import mongooseVersionHandler from 'mongoose-version-handler';
5
6import { CatSchema, Cat } from './cat.schema';
7import { CatController } from './cat.controller';
8import { CatService } from './cat.service';
9
10@Module({
11    imports: [
12        MongooseModule.forFeatureAsync([
13            {
14                name: Cat.name,
15                inject: [getConnectionToken()],
16                useFactory: (connection: Connection) => {
17                    const schema = CatSchema;
18                    schema.plugin(mongooseVersionHandler, { connection });
19                    return schema;
20                },
21            },
22        ]),
23    ],
24    controllers: [CatController],
25    providers: [CatService],
26})
27export class CatModule {}

Using Versioning Methods in Your Service

In your NestJS service, you can use the getVersion() and rollback() methods as demonstrated:

1const cat = await this.catModel.findOne({ ... });
2const previousVersion = await cat.getVersion(2);
3await cat.rollback();

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Key Features Recap

• Automatic Version Tracking: Tracks document changes with JSON Patch diffs.
• Rollback Support: Revert documents to previous versions with ease.
• Customizable Options: Configure version keys, history collections, and connection settings.
• NestJS Ready: Works seamlessly with NestJS and dependency injection.

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Why Use mongoose-version-handler?

• Provides a reliable, structured way to manage document versions.
• Enables clear tracking of changes and rollbacks.
• Fits naturally into both Mongoose and NestJS workflows.

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Feel free to explore the plugin, contribute, or report any issues.