change-log-plugin.ts

import { appLogger } from 'loaders/logger';
import userContext from 'loaders/userContext';
import mongoose from 'mongoose';

const CHANGE_LOG_COLLECTION_NAME = 'changelog';

interface ChangeLogDocument extends mongoose.Document {
	operation: string;
}

const createChangeLogModel = () => {
	if (mongoose.models[CHANGE_LOG_COLLECTION_NAME]) {
		return mongoose.models[CHANGE_LOG_COLLECTION_NAME];
	}

	const changelogSchema = new mongoose.Schema(
		{
			operation: {
				type: String,
				enum: ['create', 'update', 'delete'],
				required: true,
			},
			timestamp: {
				type: Date,
				required: true,
			},
			data: {
				type: Object,
			},
			query: {
				type: Object,
			},
			entity: {
				type: String,
			},
			user: {
				type: mongoose.Schema.Types.ObjectId,
				ref: 'User',
			},
		},
		{ timestamps: true },
	);

	changelogSchema.index({
		timestamp: -1,
		entity: 1,
		operation: 1,
		user: 1,
		'data._id': 1,
		'query._id': 1,
	});

	return mongoose.model(CHANGE_LOG_COLLECTION_NAME, changelogSchema, CHANGE_LOG_COLLECTION_NAME);
};

const saveChangeLog = async (changeLog: ChangeLogDocument) => {
	try {
		await changeLog.save();
	} catch (error) {
		appLogger.error({
			message: `Error in changelog ${changeLog.operation}`,
			error: error.stack,
		});
	}
};

const changeLogPlugin = (
	schema: mongoose.Schema<any>,
	options: {
		collectionName: string;
	},
) => {
	const ChangeLog = createChangeLogModel();

	schema.post('save', async function () {
		appLogger.info({ message: 'executing post changelog save' });
		const doc = this as any;
		const changelog = new ChangeLog({
			operation: 'create',
			timestamp: new Date(),
			data: doc,
			user: userContext.getUserId(),
			entity: options.collectionName,
		});
		await saveChangeLog(changelog);
	});

	schema.post('updateOne', async function (this) {
		appLogger.info({ message: 'executing post changelog updateOne' });
		const doc = this as any;
		const query = this.getQuery();
		const data = doc._update.$set || doc._update;
		const changelog = new ChangeLog({
			operation: 'update',
			timestamp: new Date(),
			query,
			data,
			user: userContext.getUserId(),
			entity: options.collectionName,
		});
		await saveChangeLog(changelog);
	});

	schema.post('findOneAndUpdate', async function (this): Promise<void> {
		appLogger.info({ message: 'executing post changelog findOneAndUpdate' });
		const doc = this as any;
		const query = this.getQuery();
		const data = doc._update.$set || doc._update;
		const changelog = new ChangeLog({
			operation: 'update',
			timestamp: new Date(),
			query,
			data,
			user: userContext.getUserId(),
			entity: options.collectionName,
		});
		await saveChangeLog(changelog);
	});

	schema.post('deleteOne', async function (this) {
		appLogger.info({ message: 'executing post changelog deleteOne' });
		const doc = this as any;
		const query = this.getQuery();
		const changelog = new ChangeLog({
			operation: 'delete',
			timestamp: new Date(),
			query,
			data: doc,
			user: userContext.getUserId(),
			entity: options.collectionName,
		});
		await saveChangeLog(changelog);
	});
};

export default changeLogPlugin;

Example usage:

User.plugin(changeLogPlugin, {
	collectionName: 'user',
});