Rails 8: Introducing the New Default Asset Pipeline – Propshaft

The Rails asset pipeline helps manage static assets like CSS, JavaScript, and images. It improves delivery speed by compressing and combining these files. Sprockets used to be the main tool for this, providing useful features like precompilation and versioning. However, it was often too complicated.

With Propshaft, Rails aims for simplicity. It focuses on key tasks like direct file linking and caching. This makes it easier for developers to manage their assets without extra confusion.

What’s New in Rails 8?

Rails 8 changes the default asset pipeline to Propshaft. Propshaft is designed to be more lightweight and straightforward than Sprockets, making it a good fit for modern web applications. Unlike Sprockets, Propshaft focuses solely on serving traditional static assets (images, CSS, and non-JavaScript assets), letting developers choose their own JavaScript bundling tool (like esbuild or Vite).

With Propshaft, Rails aims to provide:

• Simpler configuration: No complex setup, only a few paths are required.
• File-based asset resolution: Propshaft links to files directly, eliminating the need for runtime compilation.
• Seamless support for asset fingerprinting: Adds unique identifiers to filenames for cache busting.

Propshaft is optimized for serving and organizing assets without the extra overhead that some Sprockets features introduced.

Key Differences Between Sprockets and Propshaft

The primary differences revolve around simplicity and performance. With Propshaft:

• No runtime compilation: Propshaft serves assets as they are, which avoids the need for heavy configuration or precompilation in development.
• Streamlined setup: Propshaft uses a more direct approach to loading assets.
• JavaScript bundling is separate: Propshaft only handles traditional assets, while JavaScript can be bundled by modern tools.

Migration Tips

For existing Rails applications, moving from Sprockets to Propshaft involves:

1. Removing Sprockets gems (sprockets-rails) and adding propshaft.
2. Adjusting asset paths and configurations as needed.
3. Configuring your JavaScript bundler separately if using advanced JavaScript setups.

Full migration instruction here.

This switch in Rails 8 is a step toward simplifying the asset pipeline, reducing build times, and making Rails apps faster and more modular.