RFC: Transitioning Config Loading from jiti to Node Native

[chenjiahan]

Background

Currently, configuration files are loaded with jiti, which relies on Babel. This approach is relatively slow (at least ~70ms slower compared to native).

Using Node's native loader provides better performance and stricter behavior, but comes with some requirements:

• Requires Node v22.18+ with built-in TypeScript support
• Import specifiers must include file extensions
• When using TypeScript, package.json must set "type": "module"
• Importing JSON requires with { type: "json" }

Proposal

• Short term: Introduce a new CLI option --config-loader auto.

  • It will try the faster native loader first.
  • If that fails, it will gracefully fall back to jiti for compatibility.
  • Over time, auto will become the default behavior across Rstack tools.

• Long term: Once Node v22.18+ adoption is widespread, we plan to drop jiti.

  • This will reduce installation size.
  • It will align more closely with Node’s official module loading standards.
  • Estimated timeline: ~2 years.

Related

• PR: Add support for --config-loader auto

[Timeless0911]

The auto mode has become the default configuration loading behavior of Rslib in v0.14.0.