Scrap is the way

4. 9. 2023

Empowering the Transition: The Story of Scrap

My coding journey began with Scratch, an intuitive platform that introduced me to the world of programming. Yet, as I ventured into JavaScript, I faced a formidable challenge. While Scratch had provided a solid foundation, the transition to JavaScript felt like a daunting leap. This challenge ignited the idea for Scrap, a tool designed to simplify the transition from block-based programming to JavaScript.

Run Scrap


  1. Block-based coding – While Scrap encourages transition to text-based programming, it supports both block an text editors.
  2. Type-safe – In text editor, Scrap supports JSDoc type annotations, which are used to provide type safety. In block editor, Scrap won't allow you to connect blocks with incompatible types.
  3. Blocks ⇆ Code – Scrap allows you to convert blocks to code and vice versa. This feature is especially useful for learning JavaScript syntax.
  4. No VM, no interpreter – Scrap compiles your code to JavaScript, which means that you can run it anywhere, without Scrap.
  5. HTML output – Scrap allows you to export your code as HTML, which means that you can share your projects with anyone, anywhere.
  6. Open-source – Scrap is open-source, which means that you can contribute to it and make it better.

The Future

Scrap is still in its infancy, but I have big plans for it. I want to make Scrap a tool that will help anyone learn JavaScript, regardless of their age or experience. You can track my progress on GitHub.

The inspiration

The name Scrap is a combination of the words Scratch and Snap, two block-based programming languages that inspired me to create Scrap. Snap gave me an idea to make the IDE advanced and powerful, while Scratch inspired me to make it intuitive and easy to use.

The technology

Scrap is built with vanilla TypeScript and is hosted on GitHub Pages.

It uses Blockly as a block editor. I still look for a good text editor, which is simple, yet powerful. Meanwhile, I have created a simple text editor with highlight.js and <textarea> element.

Scrap uses technology based on BlockLike.js as an engine (not VM).

Scrap output uses JSDoc for type annotations and is compiled by Babel.

Why Babel?

Babel is used to walk through the AST and:

  1. Make JavaScript code asynchronous.
  2. Convert code into blocks.

BlockLike.js includes a rewriter that adds async/await keywords to the code, but it relies on RegEx, which isn't ideal. Additionally, it lacks support for nested blocks.

To address these issues, I forked BlockLike.js and developed Scrap Engine. Scrap Engine eliminates the rewriter, making it necessary to manually add async/await keywords. This is where Babel comes into play, as it compiles the code and inserts the required keywords.

Why just not let users add async/await keywords manually? Because it's not intuitive. Some methods are asynchronous, while others are synchronous. Scrap is designed to be intuitive and easy to use, so it should handle this for the user.