esbuild-wasm-bundler/serve.tsx

import bundler from "./mod.ts";
import {Root} from "./introspect.ts"

const transpiled:Map<string, string> = new Map();

const ServeJS =(inText:string)=> new Response(inText, {headers:{"content-type":"application/javascript"}});

const htmlFile = Deno.readTextFileSync(Deno.cwd()+"/index.html");

Deno.serve(async(req)=>{
    const url = new URL(req.url);
    const index = url.pathname.lastIndexOf(".");
    if(index > -1)
    {
        const ext = url.pathname.substring(index+1);
        if(ext === "ts" || ext == "tsx" || ext == "js" || ext == "jsx")
        {
            if(ext == "js")
            {
                const lookup = transpiled.get(url.pathname);
                if(lookup)
                {
                    return ServeJS(lookup);
                }
            }
            else
            {
                const lookup = transpiled.get(url.pathname.substring(0, index)+".js");
                if(lookup)
                {
                    return ServeJS(lookup);
                }
            }
            try
            {
                const results = await bundler({
                    entryPoints:["."+url.pathname],
                    outdir:"/",
                    entryNames: `[dir][name]`,
                    splitting: true
                });
                results.outputFiles?.forEach(output=>{
                    transpiled.set(output.path, output.text);
                })
                return ServeJS(results.outputFiles[0].text);
            }
            catch(e)
            {
                return new Response("404", {status:404});
            }
        }

    }
    return new Response(htmlFile, {headers:{"content-type": "text/html"}});
});