add type check in viewkeys / viewvalues / viewitems method on dict

src/runtime/dict.cpp

@@ -91,16 +91,28 @@ Box* dictKeys(BoxedDict* self) {
 }
 
 Box* dictViewKeys(BoxedDict* self) {
+    if (!isSubclass(self->cls, dict_cls)) {
+        raiseExcHelper(TypeError, "descriptor 'viewkeys' requires a 'dict' object but received a '%s'",
+                       getTypeName(self)->c_str());
+    }
     BoxedDictView* rtn = new BoxedDictView(self, dict_keys_cls);
     return rtn;
 }
 
 Box* dictViewValues(BoxedDict* self) {
+    if (!isSubclass(self->cls, dict_cls)) {
+        raiseExcHelper(TypeError, "descriptor 'viewvalues' requires a 'dict' object but received a '%s'",
+                       getTypeName(self)->c_str());
+    }
     BoxedDictView* rtn = new BoxedDictView(self, dict_values_cls);
     return rtn;
 }
 
 Box* dictViewItems(BoxedDict* self) {
+    if (!isSubclass(self->cls, dict_cls)) {
+        raiseExcHelper(TypeError, "descriptor 'viewitems' requires a 'dict' object but received a '%s'",
+                       getTypeName(self)->c_str());
+    }
     BoxedDictView* rtn = new BoxedDictView(self, dict_items_cls);
     return rtn;
 }

test/tests/dict.py

@@ -197,13 +197,19 @@ print sorted(d.items())
 # viewkeys / viewvalues / viewitems
 
 d = {}
+keys = d.keys()
+viewkeys = d.viewkeys()
 
 print list(d.viewkeys())
 print list(d.viewvalues())
 print list(d.viewitems())
+print 'keys of d: ', keys
+print 'viewkeys of d: ', list(viewkeys)
 
 d['a'] = 1
 
 print list(d.viewkeys())
 print list(d.viewvalues())
 print list(d.viewitems())
+print 'keys of d: ', keys
+print 'viewkeys of d: ', list(viewkeys)