youch

What is youch?

Youch is a package for pretty-printing error objects in Node.js. It provides a user-friendly way to display error stack traces, making it easier to debug issues in your application.

What are youch's main functionalities?

Pretty-Print Error Stack Traces

This feature allows you to catch errors in your Node.js application and render a pretty HTML page with the error stack trace. This makes it easier to identify and fix issues.

const Youch = require('youch');
const http = require('http');

http.createServer((req, res) => {
  try {
    throw new Error('Something went wrong!');
  } catch (error) {
    new Youch(error, req).toHTML().then(html => {
      res.writeHead(200, { 'content-type': 'text/html' });
      res.end(html);
    });
  }
}).listen(3000);

JSON Output

This feature allows you to catch errors and output the error stack trace as a JSON object. This can be useful for logging or for APIs that need to return error details in JSON format.

const Youch = require('youch');
const http = require('http');

http.createServer((req, res) => {
  try {
    throw new Error('Something went wrong!');
  } catch (error) {
    new Youch(error, req).toJSON().then(json => {
      res.writeHead(200, { 'content-type': 'application/json' });
      res.end(JSON.stringify(json));
    });
  }
}).listen(3000);

Other packages similar to youch

express-error-handler

Express Error Handler is a middleware for handling errors in Express applications. It provides a way to catch and handle errors, and can be configured to display error details in development mode. Unlike Youch, it is specifically designed for use with Express.

errorhandler

Errorhandler is a middleware for handling errors in Connect and Express applications. It provides a simple way to catch and display error stack traces. It is similar to Youch in that it provides a user-friendly way to display errors, but it is more lightweight and less feature-rich.

pretty-error

Pretty-Error is a package for rendering error stack traces in a more readable format. It can be used with any Node.js application and provides a way to customize the appearance of error stack traces. It is similar to Youch in that it focuses on making error stack traces more readable, but it does not provide HTML or JSON output.

README

Youch!

Pretty error reporting for Node.js :rocket:

---

Youch is inspired by Whoops but with a modern design. Reading stack trace of the console slows you down from active development. Instead Youch print those errors in structured HTML to the browser.

Features

1. HTML reporter
2. JSON reporter, if request accepts a json instead of text/html.
3. Sorted frames of error stack.
4. Support for ESM.

Checkout youch terminal to beautify errors on terminal.

Installation

npm i --save youch

Basic Usage

Youch is used by AdonisJs, but it can be used by express or raw HTTP server as well.

const Youch = require('youch')
const http = require('http')

http.createServer(async function (req, res) {

  // PERFORM SOME ACTION
  if (error) {
    const youch = new Youch(error, req)
    const html = await youch.toHTML()

    res.writeHead(200, {'content-type': 'text/html'})
    res.write(html)
    res.end()
  }

}).listen(8000)

Adding helpful links

Everytime an error occurs, we can help users we letting search for the error on Google, over even on the Github repo of our project.

Youch let you define clickable links to redirect the user to a website with the error message.

const youch = new Youch(error)

await youch
  .addLink(({ message }) => {
    const url = `https://stackoverflow.com/search?q=${encodeURIComponent(`[adonis.js] ${message}`)}`
    
    return `<a href="${url}" target="_blank" title="Search on stackoverflow">Search stackoverflow</a>`
  })
  .toHTML()

Also you can make use of Font awesome brands icons to display icons.

If you will use fontawesome icons, then Youch will automatically load the CSS files from the font awesome CDN for you.

const youch = new Youch(error)

await youch
  .addLink(({ message }) => {
    const url = `https://stackoverflow.com/search?q=${encodeURIComponent(`[adonis.js] ${message}`)}`
    return `<a href="${url}" target="_blank" title="Search on stackoverflow"><i class="fab fa-stack-overflow"></i></a>`
  })
  .toHTML()

Toggle show all frames checkbox

When rendering HTML you can call the toggleShowAllFrames method to check/uncheck the show all frames checkbox.

By default, the checkbox is not checked and calling this method once will toggle the state.

const youch = new Youch(error)

await youch
  .toggleShowAllFrames()
  .toHTML()

Adding CSP nonce

Youch HTML output outputs inline style and script tags and therefore you will have add nonce attribute to them when you have enabled CSP on your website.

You can pass the cspNonce property to the toHTML method at the time of rendering the error to an HTML output.

const youch = new Youch(error, req)
const html = await youch.toHTML({
  cspNonce: 'nonce-value'
})

Get stack as JSON

You can also the error stack frames as JSON by calling the .toJSON method.

const youch = new Youch(error, {})
const jsonResponse = await youch.toJSON()

Following is the shape of the toJSON return data type.

type JsonResponse = {
  error: {
    message: string;
    name: string;
    status: number;
    frames: {
      file: string,
      filePath: string,
      line: number,
      column: number,
      callee: string,
      calleeShort: string,
      context: {
        start: number,
        pre: string,
        line: string,
        post: string,
      },
      isModule: boolean,
      isNative: boolean,
      isApp: boolean
    }[];
  };
}

Release History

Checkout CHANGELOG.md file for release history.

Meta

Checkout LICENSE.md for license information Harminder Virk (Aman) - https://github.com/thetutlage