prefetch-plugin.ts

import type { HtmlTagDescriptor, Plugin } from 'vite';

export function prefetch(): Plugin {
  return {
    name: 'prefetch',

    enforce: 'post',
    apply: 'build',

    transformIndexHtml: (html, ctx) => {
      const tags = Object.keys(ctx.bundle)
        .filter((v) => !v.toString().endsWith('webp'))
        .map(
          (chunkName) =>
            ({
              injectTo: 'head',
              tag: 'link',
              attrs: {
                rel: 'prefetch',
                href: `/${chunkName}`,
              },
            } as HtmlTagDescriptor),
        );

      return {
        html,
        tags,
      };
    },
  };
}