Convert JS exceptions to Python.

Author: PetterS

module.c

@@ -2,6 +2,47 @@
 
 #include "third-party/quickjs.h"
 
+static PyObject* JSException = NULL;
+
+static PyObject* quickjs_to_python(JSContext* context, JSValue value) {
+ int tag = JS_VALUE_GET_TAG(value);
+PyObject *return_value = NULL;
+
+if (tag == JS_TAG_INT) {
+return_value = Py_BuildValue("i", JS_VALUE_GET_INT(value));
+} else if (tag == JS_TAG_BOOL) {
+return_value = Py_BuildValue("O", JS_VALUE_GET_BOOL(value) ? Py_True : Py_False);
+} else if (tag == JS_TAG_NULL) {
+return_value = Py_None;
+} else if (tag == JS_TAG_UNDEFINED) {
+return_value = Py_None;
+} else if (tag == JS_TAG_UNINITIALIZED) {
+return_value = Py_None;
+} else if (tag == JS_TAG_EXCEPTION) {
+ JSValue exception = JS_GetException(context);
+ JSValue error_string = JS_ToString(context, exception);
+ const char *cstring = JS_ToCString(context, error_string);
+ PyErr_Format(JSException, "%s", cstring);
+JS_FreeCString(context, cstring);
+ JS_FreeValue(context, error_string);
+ JS_FreeValue(context, exception);
+} else if (tag == JS_TAG_FLOAT64) {
+return_value = Py_BuildValue("d", JS_VALUE_GET_FLOAT64(value));
+} else if (tag == JS_TAG_STRING) {
+const char *cstring = JS_ToCString(context, value);
+return_value = Py_BuildValue("s", cstring);
+JS_FreeCString(context, cstring);
+} else {
+// TODO: Raise exception.
+}
+
+JS_FreeValue(context, value);
+if (return_value == Py_None) {
+Py_RETURN_NONE;
+}
+return return_value;
+}
+
 static PyObject *test(PyObject *self, PyObject *args) {
 return Py_BuildValue("i", 42);
 }
@@ -35,36 +76,7 @@ static PyObject *context_eval(ContextData *self, PyObject *args) {
 return NULL;
 }
 JSValue value = JS_Eval(self->context, code, strlen(code), "<input>", JS_EVAL_TYPE_GLOBAL);
-int tag = JS_VALUE_GET_TAG(value);
-PyObject *return_value = NULL;
-
-if (tag == JS_TAG_INT) {
-return_value = Py_BuildValue("i", JS_VALUE_GET_INT(value));
-} else if (tag == JS_TAG_BOOL) {
-return_value = Py_BuildValue("O", JS_VALUE_GET_BOOL(value) ? Py_True : Py_False);
-} else if (tag == JS_TAG_NULL) {
-// None
-} else if (tag == JS_TAG_UNDEFINED) {
-// None
-} else if (tag == JS_TAG_UNINITIALIZED) {
-// None
-} else if (tag == JS_TAG_EXCEPTION) {
-// TODO: Raise exception.
-} else if (tag == JS_TAG_FLOAT64) {
-return_value = Py_BuildValue("d", JS_VALUE_GET_FLOAT64(value));
-} else if (tag == JS_TAG_STRING) {
-const char *cstring = JS_ToCString(self->context, value);
-return_value = Py_BuildValue("s", cstring);
-JS_FreeCString(self->context, cstring);
-} else {
-// TODO: Raise exception.
-}
-
-JS_FreeValue(self->context, value);
-if (return_value == NULL) {
-Py_RETURN_NONE;
-}
-return return_value;
+ return quickjs_to_python(self->context, value);
 }
 
 static PyMethodDef context_methods[] = {
@@ -104,7 +116,13 @@ PyMODINIT_FUNC PyInit__quickjs(void) {
 return NULL;
 }
 
+ JSException = PyErr_NewException("_quickjs.JSException", NULL, NULL);
+ if (JSException == NULL) {
+ return NULL;
+ }
+
 Py_INCREF(&Context);
 PyModule_AddObject(module, "Context", (PyObject *)&Context);
+ PyModule_AddObject(module, "JSException", JSException);
 return module;
 }

quickjs/__init__.py

@@ -6,3 +6,4 @@ def test():
 
 
 Context = _quickjs.Context
+JSException = _quickjs.JSException

test_quickjs.py

@@ -37,3 +37,16 @@ def test_wrong_type(self):
  def test_context_between_calls(self):
  self.context.eval("x = 40; y = 2;")
  self.assertEqual(self.context.eval("x + y"), 42)
+
+ def test_function(self):
+ self.context.eval("""
+ function special(x) {
+ return 40 + x;
+ }
+ """)
+ self.assertEqual(self.context.eval("special(2)"), 42)
+
+
+ def test_error(self):
+ with self.assertRaisesRegex(quickjs.JSException, "ReferenceError: missing is not defined"):
+ self.context.eval("missing + missing")