Add getter for Proxy handler objects (#4676)

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

docs/02.API-REFERENCE.md

@@ -5791,7 +5791,7 @@ These APIs all depend on build option (`JERRY_BUILTIN_PROXY`).
 
 **Summary**
 
-Gets the target object of a Proxy object
+Gets the target object of a Proxy object.
 
 *Notes*:
 - This API depends on a build option (`JERRY_BUILTIN_PROXY`) and can be checked
@@ -5804,7 +5804,7 @@ Gets the target object of a Proxy object
 
 ```c
 jerry_value_t
-jerry_get_proxy_target (jerry_value_t proxy_value)
+jerry_get_proxy_target (jerry_value_t proxy_value);
 ```
 
 - `proxy_value` - Proxy object value
@@ -5838,6 +5838,60 @@ jerry_get_proxy_target (jerry_value_t proxy_value)
 
 - [jerry_create_proxy](#jerry_create_proxy)
 - [jerry_create_special_proxy](#jerry_create_special_proxy)
+- [jerry_get_proxy_handler](#jerry_get_proxy_handler)
+
+## jerry_get_proxy_handler
+
+**Summary**
+
+Gets the handler object of a Proxy object.
+
+*Notes*:
+- This API depends on a build option (`JERRY_BUILTIN_PROXY`) and can be checked
+  in runtime with the `JERRY_FEATURE_PROXY` feature enum value,
+  see: [jerry_is_feature_enabled](#jerry_is_feature_enabled).
+- The es.next profile enables this by default.
+
+
+**Prototype**
+
+```c
+jerry_value_t
+jerry_get_proxy_handler (jerry_value_t proxy_value);
+```
+
+- `proxy_value` - Proxy object value
+- return value
+  - type error - if proxy_value is not a Proxy object
+  - handler object - otherwise
+
+*New in version [[NEXT_RELEASE]]*.
+
+**Example**
+
+```c
+{
+  jerry_value_t target = jerry_create_object ();
+  jerry_value_t handler = jerry_create_object ();
+  jerry_value_t proxy = jerry_create_proxy (target, handler);
+
+  jerry_release_value (target);
+  jerry_release_value (handler);
+
+  handler = jerry_get_proxy_handler (proxy);
+
+  // ... usage of the handler
+
+  jerry_release_value (handler);
+  jerry_release_value (proxy);
+}
+```
+
+**See also**
+
+- [jerry_create_proxy](#jerry_create_proxy)
+- [jerry_create_special_proxy](#jerry_create_special_proxy)
+- [jerry_get_proxy_target](#jerry_get_proxy_target)
 
 
 # Acquire and release API values

jerry-core/api/jerry.c

@@ -5023,9 +5023,43 @@ jerry_get_proxy_target (jerry_value_t proxy_value) /**< proxy value */
   JERRY_UNUSED (proxy_value);
 #endif /* JERRY_BUILTIN_PROXY */
 
-  return jerry_throw (ecma_raise_type_error (ECMA_ERR_MSG ("Passed value is not a proxy object")));
+  return jerry_throw (ecma_raise_type_error (ECMA_ERR_MSG (ecma_error_argument_is_not_a_proxy)));
 } /* jerry_get_proxy_target */
 
+/**
+ * Get the handler object of a Proxy object
+ *
+ * @return type error - if proxy_value is not a Proxy object
+ *         handler object - otherwise
+ */
+jerry_value_t
+jerry_get_proxy_handler (jerry_value_t proxy_value) /**< proxy value */
+{
+  jerry_assert_api_available ();
+
+#if JERRY_BUILTIN_PROXY
+  if (ecma_is_value_object (proxy_value))
+  {
+    ecma_object_t *object_p = ecma_get_object_from_value (proxy_value);
+
+    if (ECMA_OBJECT_IS_PROXY (object_p))
+    {
+      ecma_proxy_object_t *proxy_object_p = (ecma_proxy_object_t *) object_p;
+
+      if (!ecma_is_value_null (proxy_object_p->handler))
+      {
+        ecma_ref_object (ecma_get_object_from_value (proxy_object_p->handler));
+      }
+      return proxy_object_p->handler;
+    }
+  }
+#else /* !JERRY_BUILTIN_PROXY */
+  JERRY_UNUSED (proxy_value);
+#endif /* JERRY_BUILTIN_PROXY */
+
+  return jerry_throw (ecma_raise_type_error (ECMA_ERR_MSG (ecma_error_argument_is_not_a_proxy)));
+} /* jerry_get_proxy_handler */
+
 /**
  * Validate UTF-8 string
  *

jerry-core/ecma/base/ecma-errors.c

@@ -118,6 +118,11 @@ const char * const ecma_error_class_is_non_configurable = "Prototype property of
  */
 const char * const ecma_error_argument_is_not_an_object = "Argument is not an object";
 
+/**
+ * Error message, argument is not a Proxy object
+ */
+const char * const ecma_error_argument_is_not_a_proxy = "Argument is not a Proxy object";
+
 /**
  * Error message, target is not a constructor
  */

jerry-core/ecma/base/ecma-errors.h

@@ -63,6 +63,7 @@ extern const char * const ecma_error_arraybuffer_is_detached;
 extern const char * const ecma_error_cannot_convert_to_object;
 extern const char * const ecma_error_class_is_non_configurable;
 extern const char * const ecma_error_argument_is_not_an_object;
+extern const char * const ecma_error_argument_is_not_a_proxy;
 extern const char * const ecma_error_target_is_not_a_constructor;
 extern const char * const ecma_error_argument_is_not_an_regexp;
 extern const char * const ecma_error_invalid_array_length;

jerry-core/include/jerryscript-core.h

@@ -324,6 +324,7 @@ void jerry_get_bigint_digits (jerry_value_t value, uint64_t *digits_p, uint32_t
  * Proxy functions.
  */
 jerry_value_t jerry_get_proxy_target (jerry_value_t proxy_value);
+jerry_value_t jerry_get_proxy_handler (jerry_value_t proxy_value);
 
 /**
  * Input validator functions.

tests/unit-core/test-proxy.c

@@ -340,21 +340,31 @@ main (void)
   target = jerry_create_object ();
   handler = jerry_create_object ();
   proxy = jerry_create_proxy (target, handler);
-  jerry_release_value (handler);
 
   {
     jerry_value_t res = jerry_get_proxy_target (proxy);
     TEST_ASSERT (res == target);
     jerry_release_value (res);
 
+    res = jerry_get_proxy_handler (proxy);
+    TEST_ASSERT (res == handler);
+    jerry_release_value (res);
+
     res = jerry_get_proxy_target (target);
     TEST_ASSERT (jerry_value_is_error (res));
     res = jerry_get_value_from_error (res, true);
     TEST_ASSERT (jerry_get_error_type (res) == JERRY_ERROR_TYPE);
     jerry_release_value (res);
+
+    res = jerry_get_proxy_handler (handler);
+    TEST_ASSERT (jerry_value_is_error (res));
+    res = jerry_get_value_from_error (res, true);
+    TEST_ASSERT (jerry_get_error_type (res) == JERRY_ERROR_TYPE);
+    jerry_release_value (res);
   }
 
   jerry_release_value (proxy);
+  jerry_release_value (handler);
   jerry_release_value (target);
 
   test_proxy_native ();