Support new language extension foreach capabilities (#3033)

Author: kddejong

src/cfnlint/template/transforms/_language_extensions.py

@@ -195,13 +195,14 @@ def _walk(self, item: Any, params: MutableMapping[str, Any], cfn: Any):
     def _replace_string_params(
         self, s: str, params: Mapping[str, Any]
     ) -> Tuple[bool, str]:
-        pattern = r"\${[a-zA-Z0-9\.:]+}"
+        pattern = r"(\$|&){[a-zA-Z0-9\.:]+}"
         if not re.search(pattern, s):
             return (True, s)
 
         new_s = deepcopy(s)
         for k, v in params.items():
             new_s = re.sub(rf"\$\{{{k}\}}", v, new_s)
+            new_s = re.sub(rf"\&\{{{k}\}}", re.sub("[^0-9a-zA-Z]+", "", v), new_s)
 
         if isinstance(s, str_node):
             new_s = str_node(new_s, s.start_mark, s.end_mark)

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

@@ -241,7 +241,21 @@ def setUp(self) -> None:
                                 },
                             }
                         },
-                    ]
+                    ],
+                    "Fn::ForEach::SpecialCharacters": [
+                        "Identifier",
+                        ["a-b", "c-d"],
+                        {
+                            "S3Bucket&{Identifier}": {
+                                "Type": "AWS::S3::Bucket",
+                                "Properties": {
+                                    "BucketName": {
+                                        "Fn::Sub": "bucket-name-&{Identifier}"
+                                    },
+                                },
+                            }
+                        },
+                    ],
                 },
                 "Outputs": {
                     "Fn::ForEach::BucketOutputs": [
@@ -318,6 +332,18 @@ def setUp(self) -> None:
                     },
                     "Type": "AWS::S3::Bucket",
                 },
+                "S3Bucketab": {
+                    "Properties": {
+                        "BucketName": "bucket-name-ab",
+                    },
+                    "Type": "AWS::S3::Bucket",
+                },
+                "S3Bucketcd": {
+                    "Properties": {
+                        "BucketName": "bucket-name-cd",
+                    },
+                    "Type": "AWS::S3::Bucket",
+                },
             },
             "Transforms": ["AWS::LanguageExtensions"],
         }
@@ -331,6 +357,7 @@ def test_transform(self):
         self.assertDictEqual(
             template,
             self.result,
+            template,
         )
 
     def test_transform_findinmap_function(self):
@@ -373,7 +400,7 @@ def test_bad_collection_ref(self):
         cfn = Template(filename="", template=template_obj, regions=["us-east-1"])
         matches, template = language_extension(cfn)
         self.assertListEqual(matches, [])
-        self.assertTrue(len(template["Resources"]) == 2)
+        self.assertTrue(len(template["Resources"]) == 4)
         self.assertTrue("S3BucketA" in template["Resources"])
 
     def test_duplicate_key(self):