How to create your custom Node.js REPL (#tilPost)

Today I came across a quick video which explains Node.js’ REPL functionality (Read-Eval-Print loop).
While I use the built-in REPL from time to time (type node into your terminal to start it) to prototype code, I haven’t used the RE…

Today I came across a quick video which explains Node.js’ REPL functionality (Read-Eval-Print loop).

While I use the built-in REPL from time to time (type node into your terminal to start it) to prototype code, I haven’t used the REPL module before. It turns out that you can create custom REPLs with just a few lines of JavaScript:

// index.js
const repl = require('repl');

// define available methods and state
const state = {
  printSomething() {
    console.log("That's awesome!");
  }
};

const myRepl = repl.start("stefan's repl > ");

Object.assign(myRepl.context, state);

If you’re like me and like to prototype in a console, the repl package is handy. You could create an application entry script that provides all the initialized objects and functionality. Or you could even build a little shell for everyday tasks.



Screenshot of a terminal: start a new REPL by running "node index.js" and see the available command 'printSomething'

Let me know what REPL’s you’re building. I’d love to see more examples and real-world use cases. And now, let’s "just REPL away"! ?



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» How to create your custom Node.js REPL (#tilPost) | Stefan Judis | Sciencx | https://www.scien.cx/2019/08/25/how-to-create-your-custom-node-js-repl-tilpost/ | 2024-03-29T10:56:57+00:00
https://github.com/addpipe/simple-recorderjs-demo