feat: enable new tree shaking in production

[chenjiahan]

Summary

Rsbuild v0.5.0 will enable the Rspack's new tree shaking in production build. This will significantly optimize the tree shaking algorithm, making the bundle size smaller in the production build.

If you encounter any issues with the new tree shaking in your project, you can report it to the Rspack repository through an issue. You can also manually switch to old tree shaking:

// rsbuild.config.ts
import { defineConfig } from '@rsbuild/core';

export default defineConfig({
  tools: {
    rspack: {
      experiments: {
        rspackFuture: {
          newTreeshaking: false,
        },
      },
    },
  },
});

Note that Rsbuild only enable new tree shaking in production build, because Rspack still has some problems when using it in dev mode. Such as web-infra-dev/rspack#5887

Related Links

web-infra-dev/rspack#5887

Checklist

• Tests updated.
• Documentation updated.