### Install mongo-message-queue

Source: https://github.com/wonderlic/mongo-message-queue/blob/master/README.md

Installs the mongo-message-queue package using npm. This is the first step to integrate the message queue into your Node.js project.

```bash
npm install mongo-message-queue --save
```

--------------------------------

### Instantiate MessageQueue

Source: https://github.com/wonderlic/mongo-message-queue/blob/master/README.md

Demonstrates how to require and create an instance of the MessageQueue class in a Node.js application. This sets up the basic message queue object.

```javascript
const MessageQueue = require('mongo-message-queue');

const mQueue = new MessageQueue();
```

--------------------------------

### Configure Database Connection

Source: https://github.com/wonderlic/mongo-message-queue/blob/master/README.md

Configures the message queue to use a specific MongoDB database connection. The `databasePromise` property should be set to a function returning a promise that resolves with a MongoDB database connection.

```javascript
const MongoClient = require('mongodb').MongoClient;

const mongoUri = ...;
const mongoOptions = ...;

mQueue.databasePromise = function() {
  // Return a promise to return a mongo database connection here...
  return MongoClient.connect(mongoUri, mongoOptions);
};
```

--------------------------------

### Enqueue and Process Message Immediately

Source: https://github.com/wonderlic/mongo-message-queue/blob/master/README.md

Enqueues a message and attempts to process it immediately using a locally registered worker. If no local worker is available, the message will be processed later when a worker becomes available.

```javascript
mQueue.enqueueAndProcess('doSomething', {id: 123, status: 'done'});
```

--------------------------------

### Enqueue Message for Processing

Source: https://github.com/wonderlic/mongo-message-queue/blob/master/README.md

Enqueues a message to be processed by a registered worker. Messages are typically processed immediately by available workers. An optional third parameter can specify a future `nextReceivableTime`.

```javascript
mQueue.enqueue('doSomething', {id: 123, status: 'done'});

mQueue.enqueue('doSomething', {id: 123, status: 'done'}, {nextReceivableTime: new Date(Date.now() + 30 * 1000)});
```

--------------------------------

### Register Worker for Message Processing

Source: https://github.com/wonderlic/mongo-message-queue/blob/master/README.md

Registers a worker function to process messages of a specific type. The worker function receives a `queueItem` object containing the message and retry information. It should return a promise resolving to 'Completed', 'Rejected', or 'Retry'.

```javascript
mQueue.registerWorker('doSomething', function (queueItem) {
  // Return a promise to do something here...
  return database.collection('somecollection')
    .updateOne({_id: queueItem.message.id}, {status: queueItem.message.status})
    .then(function (result) {
      return 'Completed';
    })
    .catch(function (err) {
      queueItem.releasedReason = err.message;
      if ((queueItem.retryCount || 0) < 5) {
        queueItem.nextReceivableTime = new Date(Date.now() + 30 * 1000); // Retry after 30 seconds...
        return 'Retry';
      } else {
        queueItem.rejectionReason = 'Gave up after 5 retries.';
        return 'Rejected';
      }
    });
});
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.