How to run a fetch inside a Vite Plugin - vite

Question

Am creating a vite plugin which will enable me to generate a sitemap for my website but am not finding how to make a fetch request using one of their many hooks. Am using simplecrawler module to run the fetch inside the plugin but it doesn't seem to work.
import type { Plugin, ResolvedConfig } from "vite";
import crawler from "simplecrawler";
const crawl = async (port:number): Promise<string[]> => {
return new Promise((resolve)=> {
const links: Set<string> = new Set();
const Crawler = new crawler(`http://localhost:${port}`);
Crawler.on("fetchcomplete", (queueItem, _responseBody, response) => {
if (response.headers["content-type"] === "text/html") {
links.add(queueItem.url);
}
});
Crawler.on("complete", () => {
const paths = [...links].map((link) => {
return new URL(link).pathname;
});
resolve(paths);
});
Crawler.start()
});
};
const plugin = ():Plugin =>{
const moduleId = `virtual:sitemap`;
const resolvedModuleId = `\0${moduleId}`;
let config: ResolvedConfig;
return {
name: "vite-plugin-svelte-sitemap",
resolveId: id => {
if (id === moduleId){
return resolvedModuleId
}
return id
},
configResolved: resolvedConfig => {
config = resolvedConfig;
},
buildStart: ()=>{
return async ()=>{
let port = config.server.port !== undefined ? config.server.port : (config.mode === "development" ? 5173 : 4173);
let urls = await crawl(port);
console.log(urls);
}
}
}
}
export default plugin;
So far, this is what I have been able to come up with