nixos-and-flakes-book/docs/.vitepress/vitepress-pdf.config.ts

import { defineUserConfig } from "vitepress-export-pdf";
import config from './config'


// convert `config.themeConfig?.sidebar` to a list of routes
let routeOrder = [];
const sidebar = config.locales.root.themeConfig?.sidebar;
if (sidebar) {
  sidebar.forEach((it) => {
    if (it.items) {
      it.items.forEach((subItem) => {
        routeOrder.push(subItem.link.replace(/\.md$/, ""));
      });
    }
  });
}

// print routeOrder in terminal
console.log("routeOrder: ", routeOrder);

export default defineUserConfig({
  routePatterns: ["!/zh/**"],  // exclude zh-CN pages
	sorter: (pageA, pageB) => {
		const aIndex = routeOrder.findIndex(route => route === pageA.path);
		const bIndex = routeOrder.findIndex(route => route === pageB.path);
		const index = aIndex - bIndex;
		// console.log(`sorter: ${pageA.path} vs ${pageB.path} = ${index}`);
		return index;
	},
	urlOrigin: "https://nixos-and-flakes.thiscute.world/",
});