Turbopack: support module workers (vercel#72614)

- Also process `new Worker()` if there are options
- Then remove the `type: module` from the options at runtime (as Webpack
also does apparently). The alternative would be to keep the `type:
module` and ESM imports instead in the worker.

test/e2e/app-dir/worker/app/page.js → test/e2e/app-dir/worker/app/classic/page.js

@@ -7,7 +7,7 @@ export default function Home() {
     <div>
       <button
         onClick={() => {
-          const worker = new Worker(new URL('./worker', import.meta.url))
+          const worker = new Worker(new URL('../worker', import.meta.url))
           worker.addEventListener('message', (event) => {
             setState(event.data)
           })

test/e2e/app-dir/worker/app/module/page.js

@@ -0,0 +1,24 @@
+'use client'
+import { useState } from 'react'
+
+export default function Home() {
+  const [state, setState] = useState('default')
+  return (
+    <div>
+      <button
+        onClick={() => {
+          const worker = new Worker(new URL('../worker', import.meta.url), {
+            type: 'module',
+          })
+          worker.addEventListener('message', (event) => {
+            setState(event.data)
+          })
+        }}
+      >
+        Get web worker data
+      </button>
+      <p>Worker state: </p>
+      <p id="worker-state">{state}</p>
+    </div>
+  )
+}

test/e2e/app-dir/worker/worker.test.ts

@@ -12,7 +12,19 @@ describe('app dir - workers', () => {
   }
 
   it('should support web workers with dynamic imports', async () => {
-    const browser = await next.browser('/')
+    const browser = await next.browser('/classic')
+    expect(await browser.elementByCss('#worker-state').text()).toBe('default')
+
+    await browser.elementByCss('button').click()
+
+    await check(
+      async () => browser.elementByCss('#worker-state').text(),
+      'worker.ts:worker-dep'
+    )
+  })
+
+  it('should support module web workers with dynamic imports', async () => {
+    const browser = await next.browser('/module')
     expect(await browser.elementByCss('#worker-state').text()).toBe('default')
 
     await browser.elementByCss('button').click()

turbopack/crates/turbopack-ecmascript-runtime/js/src/browser/runtime/base/runtime-base.ts

@@ -239,7 +239,7 @@ function resolveAbsolutePath(modulePath?: string): string {
 }
 
 function getWorkerBlobURL(chunks: ChunkPath[]): string {
-  let bootstrap = `TURBOPACK_WORKER_LOCATION = ${JSON.stringify(location.origin)};importScripts(${chunks.map(c => (`TURBOPACK_WORKER_LOCATION + ${JSON.stringify(getChunkRelativeUrl(c))}`)).join(", ")});`;
+  let bootstrap = `self.TURBOPACK_WORKER_LOCATION = ${JSON.stringify(location.origin)};importScripts(${chunks.map(c => (`self.TURBOPACK_WORKER_LOCATION + ${JSON.stringify(getChunkRelativeUrl(c))}`)).join(", ")});`;
   let blob = new Blob([bootstrap], { type: "text/javascript" });
   return URL.createObjectURL(blob);
 }

turbopack/crates/turbopack-ecmascript/src/references/mod.rs

@@ -1407,7 +1407,7 @@ async fn handle_call<G: Fn(Vec<Effect>) + Send + Sync>(
             }
             JsValue::WellKnownFunction(WellKnownFunctionKind::WorkerConstructor) => {
                 let args = linked_args(args).await?;
-                if let [url @ JsValue::Url(_, JsValueUrlKind::Relative)] = &args[..] {
+                if let Some(url @ JsValue::Url(_, JsValueUrlKind::Relative)) = args.first() {
                     let pat = js_value_to_pattern(url);
                     if !pat.has_constant_parts() {
                         let (args, hints) = explain_args(&args);

turbopack/crates/turbopack-ecmascript/src/references/worker.rs

@@ -1,5 +1,6 @@
 use anyhow::{bail, Result};
 use swc_core::{
+    common::util::take::Take,
     ecma::ast::{Expr, ExprOrSpread, Lit, NewExpr},
     quote_expr,
 };
@@ -65,7 +66,7 @@ impl WorkerAssetReference {
         );
 
         let Some(module) = *module.first_module().await? else {
-            bail!("Expected worker to resolve to a module");
+            return Ok(None);
         };
         let Some(chunkable) = ResolvedVc::try_downcast::<Box<dyn ChunkableModule>>(module).await?
         else {
@@ -133,13 +134,23 @@ impl CodeGenerateable for WorkerAssetReference {
         let visitor = create_visitor!(path, visit_mut_expr(expr: &mut Expr) {
             let message = if let Expr::New(NewExpr { args, ..}) = expr {
                 if let Some(args) = args {
-                    match args.iter_mut().next() {
+                    match args.first_mut() {
                         Some(ExprOrSpread { spread: None, expr }) => {
                             let item_id = Expr::Lit(Lit::Str(item_id.to_string().into()));
                             *expr = quote_expr!(
                                 "__turbopack_require__($item_id)",
                                 item_id: Expr = item_id
                             );
+
+                            if let Some(opts) = args.get_mut(1) {
+                                if opts.spread.is_none(){
+                                    *opts.expr = *quote_expr!(
+                                        "{...$opts, type: undefined}",
+                                        opts: Expr = (*opts.expr).take()
+                                    );
+                                }
+
+                            }
                             return;
                         }
                         // These are SWC bugs: https://github.com/swc-project/swc/issues/5394