Equivalence of Rails console for Node.js

Question

I am trying out Node.js Express framework, and looking for plugin that allows me to interact with my models via console, similar to Rails console. Is there such a thing in NodeJS world?

If not, how can I interact with my Node.js models and data, such as manually add/remove objects, test methods on data etc.?

Answer 1

Create your own REPL by making a js file (ie: console.js) with the following lines/components:

1. Require node's built-in repl: var repl = require("repl");
2. Load in all your key variables like db, any libraries you swear by, etc.
3. Load the repl by using var replServer = repl.start({});
4. Attach the repl to your key variables with replServer.context.<your_variable_names_here> = <your_variable_names_here>. This makes the variable available/usable in the REPL (node console).

For example: If you have the following line in your node app: var db = require('./models/db') Add the following lines to your console.js

 var db = require('./models/db');
 replServer.context.db = db;

5. Run your console with the command node console.js

---

Your console.js file should look something like this:

var repl = require("repl");

var epa = require("epa");
var db = require("db");

// connect to database
db.connect(epa.mongo, function(err){
  if (err){ throw err; }

  // open the repl session
  var replServer = repl.start({});

  // attach modules to the repl context
  replServer.context.epa = epa;
  replServer.context.db = db;  
});

---

You can even customize your prompt like this:

var replServer = repl.start({
  prompt: "Node Console > ",
});

---

For the full setup and more details, check out: http://derickbailey.com/2014/07/02/build-your-own-app-specific-repl-for-your-nodejs-app/

For the full list of options you can pass the repl like prompt, color, etc: https://nodejs.org/api/repl.html#repl_repl_start_options

Thank you to Derick Bailey for this info.

---

UPDATE:

GavinBelson has a great recommendation for running with sequelize ORM (or anything that requires promise handling in the repl).

I am now running sequelize as well, and for my node console I'm adding the --experimental-repl-await flag.

It's a lot to type in every time, so I highly suggest adding:

"console": "node --experimental-repl-await ./console.js"

to the scripts section in your package.json so you can just run:

npm run console

and not have to type the whole thing out.

Then you can handle promises without getting errors, like this:

const product = await Product.findOne({ where: { id: 1 });