Better resolution of mappings in transform (#3392)

Author: kddejong

src/cfnlint/template/transforms/_language_extensions.py

@@ -364,7 +364,7 @@ def value(
 
         if mapping:
             try:
-                t_map[1].value(cfn)
+                t_map[1].value(cfn, params, only_params)
             except _ResolveError:
                 try:
                     t_map[2].value(cfn)

test/unit/module/template/transforms/test_language_extensions.py

@@ -188,7 +188,12 @@ def setUp(self) -> None:
                             "Development": "1",
                             "Stage": ["1", "2"],
                             "Production": ["1", "2", "3"],
-                        }
+                        },
+                        "Instances": {
+                            "Development": "A",
+                            "Stage": ["A", "B"],
+                            "Production": ["A", "B", "C"],
+                        },
                     },
                 },
             }
@@ -289,6 +294,17 @@ def test_find_in_map_values_without_default(self):
         with self.assertRaises(_ResolveError):
             map.value(self.cfn, None, False, False)
 
+    def test_second_key_resolution(self):
+        map = _ForEachValueFnFindInMap("a", ["Config", {"Ref": "Value"}, "Production"])
+
+        self.assertEqual(
+            map.value(self.cfn, {"Value": "DBInstances"}, False, True), ["1", "2", "3"]
+        )
+
+        self.assertEqual(
+            map.value(self.cfn, {"Value": "Instances"}, False, True), ["A", "B", "C"]
+        )
+
     def test_find_in_map_values_without_default_resolve_error(self):
         map = _ForEachValueFnFindInMap(
             "a", ["Bucket", "Production", {"Ref": "SSMParameter"}]