fix an issue when searching for Ref in tojsonstring (#3107)

Author: kddejong

src/cfnlint/languageExtensions.py

@@ -24,16 +24,24 @@ def validate_type(self, fn_object_val, matches, tree, intrinsic_function):
             matches.append(RuleMatch(tree[:], message.format("/".join(map(str, tree)))))
         return matches
 
+    def _find_in_obj(self, obj):
+        if isinstance(obj, dict):
+            for k, v in obj.items():
+                if k == "Ref":
+                    yield v
+                    return
+                yield from self._find_in_obj(v)
+
+        if isinstance(obj, list):
+            for v in obj:
+                yield from self._find_in_obj(v)
+
     def validate_pseudo_parameters(
         self, fn_object_val, matches, tree, pseudo_params, intrinsic_function
     ):
         if isinstance(fn_object_val, dict):
             ref = "Ref"
-            ref_list = [
-                val[ref]
-                for _, val in fn_object_val.items()
-                if hasattr(val, "__iter__") and ref in val
-            ]
+            ref_list = self._find_in_obj(fn_object_val)
             for ref in ref_list:
                 if ref in pseudo_params:
                     message = (

src/cfnlint/rules/functions/ForEach.py

@@ -27,8 +27,7 @@ def match(self, cfn):
         for for_each in for_eaches:
             has_language_extensions_transform = cfn.has_language_extensions_transform()
 
-            LanguageExtensions.validate_transform_is_declared(
-                self,
+            LanguageExtensions().validate_transform_is_declared(
                 has_language_extensions_transform,
                 matches,
                 for_each[:-1],

src/cfnlint/rules/functions/Length.py

@@ -26,8 +26,7 @@ def match(self, cfn):
         fn_length_objects = cfn.search_deep_keys(intrinsic_function)
         for fn_length_object in fn_length_objects:
             tree = fn_length_object[:-1]
-            LanguageExtensions.validate_transform_is_declared(
-                self,
+            LanguageExtensions().validate_transform_is_declared(
                 has_language_extensions_transform,
                 matches,
                 tree,

src/cfnlint/rules/functions/ToJsonString.py

@@ -27,18 +27,16 @@ def match(self, cfn):
         for fn_toJsonString_object in fn_toJsonString_objects:
             tree = fn_toJsonString_object[:-1]
             fn_toJsonString_object_value = fn_toJsonString_object[-1]
-            LanguageExtensions.validate_transform_is_declared(
-                self,
+            LanguageExtensions().validate_transform_is_declared(
                 has_language_extensions_transform,
                 matches,
                 tree,
                 intrinsic_function,
             )
-            LanguageExtensions.validate_type(
-                self, fn_toJsonString_object_value, matches, tree, intrinsic_function
+            LanguageExtensions().validate_type(
+                fn_toJsonString_object_value, matches, tree, intrinsic_function
             )
-            LanguageExtensions.validate_pseudo_parameters(
-                self,
+            LanguageExtensions().validate_pseudo_parameters(
                 fn_toJsonString_object_value,
                 matches,
                 tree,