pyscript · WebReflection · Sep 30, 2025 · Sep 15, 2025
diff --git a/docs/index.js b/docs/index.js
diff --git a/docs/index.js.map b/docs/index.js.map
diff --git a/esm/interpreter/micropython.js b/esm/interpreter/micropython.js
@@ -3,7 +3,7 @@ import fetch from '@webreflection/fetch';
 import { createProgress, writeFile } from './_utils.js';
 import { getFormat, loader, loadProgress, registerJSModule, run, runAsync, runEvent } from './_python.js';
 import { stdio, buffered } from './_io.js';
-import { absoluteURL, fixedRelative } from '../utils.js';
+import { absoluteURL, fixedRelative, js_modules } from '../utils.js';
 import mip from '../python/mip.js';
 import { zip } from '../3rd-party.js';
 
@@ -37,6 +37,7 @@ export default {
         url = url.replace(/\.m?js$/, '.wasm');
         progress('Loading MicroPython');
         const interpreter = await get(loadMicroPython({ linebuffer: false, stderr, stdout, url }));
+        globalThis[js_modules].set('-T-', this.transform.bind(this, interpreter));
         const py_imports = importPackages.bind(this, interpreter, baseURL);
         loader.set(interpreter, py_imports);
         await loadProgress(this, progress, interpreter, config, baseURL);

diff --git a/esm/interpreter/pyodide.js b/esm/interpreter/pyodide.js
@@ -1,7 +1,7 @@
 import { createProgress, writeFile } from './_utils.js';
 import { getFormat, loader, loadProgress, registerJSModule, run, runAsync, runEvent } from './_python.js';
 import { stdio } from './_io.js';
-import { IDBMapSync, isArray, fixedRelative } from '../utils.js';
+import { IDBMapSync, isArray, fixedRelative, js_modules } from '../utils.js';
 
 const type = 'pyodide';
 const toJsOptions = { dict_converter: Object.fromEntries };
@@ -124,6 +124,7 @@ export default {
         const interpreter = await get(
             loadPyodide({ stderr, stdout, ...options }),
         );
+        globalThis[js_modules].set('-T-', this.transform.bind(this, interpreter));
         if (config.debug) interpreter.setDebug(true);
         const py_imports = importPackages.bind(interpreter);
         if (index_urls) indexURLs.set(interpreter, index_urls);

diff --git a/package.json b/package.json
@@ -95,6 +95,6 @@
         "to-json-callback": "^0.1.1"
     },
     "worker": {
-        "blob": "sha256-9Jm1+L4Uur4gkfKpJGU+YQkR+/qFKhZtxE3UMQEjUbw="
+        "blob": "sha256-793NDYXZ46XOi7y/2zZMFwpOtxJESk/tvuGnDaYZotI="
     }
 }
diff --git a/rollup/build_xworker.cjs b/rollup/build_xworker.cjs
@@ -14,7 +14,9 @@ const PACKAGE_JSON = resolve(join(__dirname, "..", "package.json"));
 
 const coincident = [
     "import coincident from 'coincident/window/main';",
-    'const { Worker } = coincident({ transfer: false });',
+    "const js_modules = Symbol.for('polyscript.js_modules');",
+    "let transform;",
+    'const { Worker } = coincident({ transfer: false, transform: value => (transform || (transform = globalThis[js_modules]?.get("-T-")))?.(value) ?? value });',
 ];
 
 for (const file of readdirSync(DIST_DIR)) {

diff --git a/test/worker/sync.html b/test/worker/sync.html
@@ -0,0 +1,23 @@
+<!doctype html>
+<html lang="en">
+    <head>
+        <meta charset="UTF-8" />
+        <meta name="viewport" content="width=device-width,initial-scale=1.0" />
+        <title>python workers</title>
+        <script type="module">
+            import "/dist/index.js";
+        </script>
+    </head>
+    <body>
+        <script type="micropython">
+            from polyscript import XWorker
+
+            def handle_data(data):
+              print("main", data)
+              return (1, 2, 3)
+
+            w = XWorker('./sync.py', type='pyodide')
+            w.sync.data = handle_data
+        </script>
+    </body>
+</html>
diff --git a/test/worker/sync.py b/test/worker/sync.py
@@ -0,0 +1,3 @@
+from polyscript import xworker
+
+print("worker", xworker.sync.data(memoryview(b"hello")))
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		from polyscript import xworker

		print("worker", xworker.sync.data(memoryview(b"hello")))