Add test for invalid hiwire refs

src/tests/test_pyodide.py

@@ -1685,3 +1685,54 @@ def f2():
     assert dedent("\n".join(msg.splitlines()[1:-1])) == "\n".join(
         expected.splitlines()[2:]
     )
+
+@run_in_pyodide
+def test_hiwire_invalid_ref(selenium):
+    import pyodide_js
+    from pyodide.ffi import JsException
+    from pyodide.code import run_js
+    import pytest
+
+    _hiwire_get = pyodide_js._module._hiwire_get
+    _hiwire_incref = pyodide_js._module._hiwire_incref
+    _hiwire_decref = pyodide_js._module._hiwire_decref
+    _api = pyodide_js._api
+
+    _hiwire_incref(0)
+    assert not _api.fail_test
+    _hiwire_decref(0)
+    assert not _api.fail_test
+    expected = r"Pyodide internal error: Argument to hiwire_get is falsy \(but error indicator is not set\)\."
+    with pytest.raises(JsException, match=expected):
+        _hiwire_get(0)
+    assert _api.fail_test
+    _api.fail_test = False
+
+    with pytest.raises(AssertionError, match="This is a message"):
+        run_js(
+            """
+            const msgptr = pyodide._module.stringToNewUTF8("This is a message");
+            const AssertionError = pyodide._module.HEAP32[pyodide._module._PyExc_AssertionError/4];
+            pyodide._module._PyErr_SetString(AssertionError, msgptr);
+            pyodide._module._free(msgptr);
+            try {
+                pyodide._module._hiwire_get(0);
+            } finally {
+                pyodide._module._PyErr_Clear();
+            }
+            """
+        )
+    msg = "hiwire_{} on invalid reference 77. This is most likely due to use after free. It may also be due to memory corruption."
+    with pytest.raises(JsException, match=msg.format("get")):
+        _hiwire_get(77)
+    assert _api.fail_test
+    _api.fail_test = False
+    with pytest.raises(JsException, match=msg.format("incref")):
+        _hiwire_incref(77)
+    assert _api.fail_test
+    _api.fail_test = False
+    with pytest.raises(JsException, match=msg.format("decref")):
+        _hiwire_decref(77)
+    assert _api.fail_test
+    _api.fail_test = False
+