Fix from jsmod import *

docs/project/changelog.md

@@ -39,6 +39,9 @@ myst:
   it can be raised in Python.
   {pr}`3868`
 
+- {{ Fix }} `from jsmodule import *` now works.
+  {pr}`3903`
+
 - {{ Enhancement }} When a `JsProxy` of an array is passed to Python builtin
   functions that use the `PySequence_*` APIs, it now works as expected. Also
   `jsarray * n` repeats the array `n` times and `jsarray + iterable` returns a

src/js/pyodide.ts

@@ -88,7 +88,20 @@ function finalizeBootstrap(API: any, config: ConfigType) {
 
   // Set up key Javascript modules.
   let importhook = API._pyodide._importhook;
-  importhook.register_js_finder();
+  function jsFinderHook(o: object) {
+    if ("__all__" in o) {
+      return;
+    }
+    Object.defineProperty(o, "__all__", {
+      get: () =>
+        pyodide.toPy(
+          Object.getOwnPropertyNames(o).filter((name) => name !== "__all__"),
+        ),
+      enumerable: false,
+      configurable: true,
+    });
+  }
+  importhook.register_js_finder.callKwargs({ hook: jsFinderHook });
   importhook.register_js_module("js", config.jsglobals);
 
   let pyodide = API.makePublicAPI();

src/py/_pyodide/_importhook.py

@@ -1,5 +1,5 @@
 import sys
-from collections.abc import Sequence
+from collections.abc import Callable, Sequence
 from importlib.abc import Loader, MetaPathFinder
 from importlib.machinery import ModuleSpec
 from importlib.util import spec_from_loader
@@ -12,6 +12,7 @@
 class JsFinder(MetaPathFinder):
     def __init__(self) -> None:
         self.jsproxies: dict[str, Any] = {}
+        self.hook: Callable[[JsProxy], None] = lambda _: None
 
     def find_spec(
         self,
@@ -69,6 +70,7 @@ def register_js_module(self, name: str, jsproxy: Any) -> None:
             raise TypeError(
                 f"Argument 'jsproxy' must be a JsProxy, not {type(jsproxy).__name__!r}"
             )
+        self.hook(jsproxy)
         self.jsproxies[name] = jsproxy
 
     def unregister_js_module(self, name: str) -> None:
@@ -114,7 +116,7 @@ def is_package(self, fullname: str) -> bool:
 unregister_js_module = jsfinder.unregister_js_module
 
 
-def register_js_finder() -> None:
+def register_js_finder(*, hook: Callable[[JsProxy], None]) -> None:
     """A bootstrap function, called near the end of Pyodide initialization.
 
     It is called in ``loadPyodide`` in ``pyodide.js`` once ``_pyodide_core`` is ready
@@ -129,7 +131,7 @@ def register_js_finder() -> None:
     for importer in sys.meta_path:
         if isinstance(importer, JsFinder):
             raise RuntimeError("JsFinder already registered")
-
+    jsfinder.hook = hook
     sys.meta_path.append(jsfinder)
 
 

src/tests/test_jsproxy.py

@@ -663,6 +663,56 @@ def test_unregister_jsmodule_error(selenium):
     )
 
 
+@pytest.mark.skip_refcount_check
+@pytest.mark.skip_pyproxy_check
+@run_in_pyodide
+def test_jsmod_import_star1(selenium):
+    import sys
+    from typing import Any
+
+    from pyodide.code import run_js
+
+    run_js("pyodide.registerJsModule('xx', {a: 2, b: 7, f(x){ return x + 1; }});")
+    g: dict[str, Any] = {}
+    exec("from xx import *", g)
+    try:
+        assert "a" in g
+        assert "b" in g
+        assert "f" in g
+        assert "__all__" not in g
+        assert g["a"] == 2
+        assert g["b"] == 7
+        assert g["f"](9) == 10
+    finally:
+        sys.modules.pop("xx", None)
+        run_js("pyodide.unregisterJsModule('xx');")
+
+
+@pytest.mark.skip_refcount_check
+@pytest.mark.skip_pyproxy_check
+@run_in_pyodide
+def test_jsmod_import_star2(selenium):
+    import sys
+    from typing import Any
+
+    from pyodide.code import run_js
+
+    run_js(
+        "pyodide.registerJsModule('xx', {a: 2, b: 7, f(x){ return x + 1; }, __all__ : pyodide.toPy(['a'])});"
+    )
+    g: dict[str, Any] = {}
+    exec("from xx import *", g)
+    try:
+        assert "a" in g
+        assert "b" not in g
+        assert "f" not in g
+        assert "__all__" not in g
+        assert g["a"] == 2
+    finally:
+        sys.modules.pop("xx", None)
+        run_js("pyodide.unregisterJsModule('xx');")
+
+
 @pytest.mark.skip_refcount_check
 @pytest.mark.skip_pyproxy_check
 def test_nested_import(selenium_standalone):