https://github.com/privatenumber/dbgr

Lightweight debugger for Node.js
https://github.com/privatenumber/dbgr

alternative debugger lightweight nodejs

Last synced: 7 days ago
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Lightweight debugger for Node.js

• Host: GitHub
• URL: https://github.com/privatenumber/dbgr
• Owner: privatenumber
• License: mit
• Created: 2021-04-18T02:58:50.000Z (about 3 years ago)
• Default Branch: develop
• Last Pushed: 2021-04-21T01:24:09.000Z (about 3 years ago)
• Last Synced: 2024-06-12T23:32:17.016Z (24 days ago)
• Topics: alternative, debugger, lightweight, nodejs
• Language: TypeScript
• Homepage:
• Size: 43.9 KB
• Stars: 44
• Watchers: 4
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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• awesome-stars - dbgr - Lightweight debugger for Node.js (TypeScript)

README

        
# dbgr   

**dbgr** is a lightweight debugger function that pauses your script, watches the current file for any changes and only re-runs the specific code that's passed in to it. It's just like `debugger` but requires no IDE or browser dev-tools integrations.

If you like this project, please star it & [follow me](https://github.com/privatenumber) to see what other cool projects I'm working on! ❤️

## 🙋‍♂️ Why?

You can set breakpoints in Node.js with breakpoints or `debugger` statements, but it could be a hassle to set up and can slow down your script.

When you're debugging something heavy with slow startup (eg. server, headless Chrome, etc), you want to use something simple & light to debug.

## 🚀 Install

```sh

npm i -D dbgr

```

## 🚦 Quick Setup

```js

import dbgr from 'dbgr'

// Some async process

(async () => {

    // ...

    await dbgr((resume) => {

        console.log('The debugger has started');

        // Write code here and hit save to

        // automatically re-run this function

        // Call resume() and save to resume the debugger

        // ↓ The eval below is necessary for this to work

    }, _ => eval(_))

})();

```

## 🙋‍♀️ FAQ

### How does it work?

Upon invoking dbgr, it detects the file path of the caller by using [V8 stack trace API](https://v8.dev/docs/stack-trace-api) via [callsites](https://github.com/sindresorhus/callsites). It then watches the file for changes using [`fs.watch`](https://nodejs.org/docs/latest/api/fs.html#fs_fs_watch_filename_options_listener). When a change is detected, it parses the source code using [acorn](https://github.com/acornjs/acorn) to extract the specific function passed into dbgr. It then passes it into the `_ => eval(_)` to run in the original context.

### Does it work in TypeScript files?

Yes. While the AST parser acorn is designed for ES parsing, TS files can be loosely parsed via [acorn-loose](https://github.com/acornjs/acorn/tree/master/acorn-loose), and the content inside the dbgr hook has the types stripped via [esbuild](https://esbuild.github.io/) for it to be "safely" `eval()`'d by the JavaScript runtime.