esbuild-wasm-bundler/mod.ts

import * as ESBuild from "https://deno.land/x/esbuild@v0.19.2/wasm.js";
import * as Mapper from "https://esm.sh/esbuild-plugin-importmaps@1.0.0"; // https://github.com/andstellar/esbuild-plugin-importmaps

export const Root = new URL(`file://${Deno.cwd().replaceAll("\\", "/")}`).toString()+"/";
console.log("running at", Root);

type Resolver = Parameters<ESBuild.PluginBuild["onResolve"]>[1];

const prefix = "/_dot_importer_/";
const Resolver:Resolver =(args)=>
{
  console.log("RESOLVE");
  console.log("in:", args);

  let resolveRoot = args.importer||Root;
  if(resolveRoot.startsWith(prefix))
  {
    resolveRoot = resolveRoot.substring(prefix.length)
  }

  const output:ESBuild.OnResolveResult = {
    path:prefix + new URL(args.path, resolveRoot).href,
    namespace:"http",
  }

  console.log("out:", output);
  return output;
}

const FetchTSX =async(inPath:string):Promise<ESBuild.OnLoadResult>=>
{
  console.log("fetching", inPath);
  const result = await fetch(inPath);
  const contents = await result.text();
  return { contents, loader: `tsx` };
}

const resolvePlugin:ESBuild.Plugin = {
  name: "resolve-plugin",
  setup(build) {
    build.onResolve({ filter: /^\.\/.*$/ }, Resolver);
    build.onResolve({ filter: /^(\.\.\/).*$/ }, Resolver);

    build.onLoad({ filter: /.*/, namespace:"http" }, async(args)=> {
      console.log("LOAD WEB");
      console.log("in:", args);
      const fetchPath = args.path.substring(prefix.length);

      console.log("fetching", fetchPath);
      const result = await fetch(fetchPath);
      const contents = await result.text();
      return { contents, loader: `tsx` };
    });
  },
};

type ImportMap = Parameters<typeof Mapper.importmapPlugin>[0];

  await ESBuild.initialize({ worker: false });
  const result = await ESBuild.build({
    //entryPoints: ["./app.tsx"],
    entryPoints: ["./deep/deep.tsx"],
    //entryPoints: ["http://localhost:4507/deep/deep.tsx"],
    bundle: true,
    minify: true,
    format: "esm",
    jsx: "automatic",
    jsxImportSource: "react",
    plugins:[
      resolvePlugin,
      Mapper.importmapPlugin({
        imports:{
          "react":"https://esm.sh/preact@10.22.0/compat"
        }
      }) as ESBuild.Plugin
    ]
  });
  ESBuild.stop();

for(const item of result.outputFiles)
{
  //console.log(item.text)
}