How to check rabbit connection in node js for unit test using mocha and chi

Question

I'm using amqplib-package for connecting to RabbitMQ in nodeJS and want to know how I can check/verify my RabbitMQ-connection using Mocha and Chai in nodeJS?

Answer 1

If you are using ampqlib package and you want to test whether the connection is established or not then it is not considered as a unit test, we can call it an integration test.

Other answers have good content about integration testing, but for unit testing you can use amqplib-mocks (https://www.npmjs.com/package/amqplib-mocks) which is a simple mocking framework for amqplib.

For a basic unit test you can check if amqp.connect(url) is called and expect the URL you want.

I can also show a basic example how you can get a stubbed connection object: (ps: This is not a running code, this is just for reference)

subscriber.js

const amqp = require('amqplib');
class Subscriber {
   async getConnection(url) {
        const connection = await amqp.connect(url);
        return connection;
   }
}

Subscriber class has a method getConnection which establishes and return a connection object with rabbitmq.

subscriber.test.js

const amqpMock = require('amqplib-mocks');
const sinon = require('sinon');

const mockConnection = await amqpMock.connect('mockurl.com');
const getConnectionStub = sinon.stub(Subscriber.prototype, 'getConnection').returns(mockConnection);

In above code you can either stub ampq.connect directly or stub getConnection method and return a connection object as returned by amqp-mock's connect method.

To know more about sinon used above, click.

Answer 2

You can try one of the following:

• you can create a valid rabbit-mq connection using a docker iamage docker-rabbitmq and make real requests to your application but this is not unit testing, but more like integration testing.

• You can mock it using sinon a very good article I can suggest on this topic is Best practices for spies, stubs, and mocks in sinonjs

• You can follow this topic on google groups NodeJS + RabbitMQ (amqplib): How to write good Unit Test against them.