Add JS_GetClassName (#1215)

Author: caturria

quickjs.c

@@ -3610,6 +3610,15 @@ bool JS_IsRegisteredClass(JSRuntime *rt, JSClassID class_id)
             rt->class_array[class_id].class_id != 0);
 }
 
+JSAtom JS_GetClassName(JSRuntime *rt, JSClassID class_id)
+{
+    if (JS_IsRegisteredClass(rt, class_id)) {
+        return JS_DupAtomRT(rt, rt->class_array[class_id].class_id);
+    } else {
+        return JS_ATOM_NULL;
+    }
+}
+
 /* create a new object internal class. Return -1 if error, 0 if
    OK. The finalizer can be NULL if none is needed. */
 static int JS_NewClass1(JSRuntime *rt, JSClassID class_id,

quickjs.h

@@ -634,6 +634,8 @@ JS_EXTERN JSClassID JS_NewClassID(JSRuntime *rt, JSClassID *pclass_id);
 JS_EXTERN JSClassID JS_GetClassID(JSValueConst v);
 JS_EXTERN int JS_NewClass(JSRuntime *rt, JSClassID class_id, const JSClassDef *class_def);
 JS_EXTERN bool JS_IsRegisteredClass(JSRuntime *rt, JSClassID class_id);
+/* Returns the class name or JS_ATOM_NULL if `id` is not a registered class. Must be freed with JS_FreeAtom. */
+JS_EXTERN JSAtom JS_GetClassName(JSRuntime *rt, JSClassID class_id);
 
 /* value handling */