@cisl/express

An opinionated wrapper around the popular express and websockets/ws libraries. It assumes that you are running an application with a cog.json file.

The library assumes that you want to use cookie-parser, JSON (with 2 spaces), and the ejs as the view engine. Finally, the port is read in from the cog.json file.

Installation

npm install @cisl/express

Usage

In straight JS:

const express = require('@cisl/express');
const app = express();
app.listen();

or in TypeScript:

// or typescript
import express from '@cisl/express';
const app = express();

app.listen();

The listen method above does not accept any parameters, and will automatically use the port specified in the cog.json file that should exist in current working directory when running the above.

After creating the object, it can be used as a regular express app:

app.get('/', (req, res) => {
    res.json({'msg': 'Hello World'});
});

as well as accessing the attached WebSocket server:

app.wsServer.on('connection', (socket) => {
    console.log('a user connected');
    socket.on('message', data => {
        console.log(`Received: ${data}`);
        socket.send('pong');
    });
});

The available objects off the original (in addition to the normal express stuff) is:

• expressListen - original express listen method, should largely not be necessary/used over listen()
• httpServer - the underlying HttpServer instance
• wsServer - the underlying WebSocket.Server instance

Finally, the package will automatically add a /test GET route that returns a JSON object with the following definition:

{
    "response": "AOK",
    "error": null
}

which can be used as a small healthcheck for apps running @cisl/express.

Configuration

Using this package assumes you have a cog.json file with at least the following in it:

{
    "port": number
}

Output

@cisl/express will only output a single line when you run the listen() command with the following message @cisl/express listening on port <PORT>. This will be output as a standard console.log, or if you have @cisl/logger installed, using logger.info. You can silence the output, by sending {quiet: True} to the express() method above.