Don't replace Default values in SAM (#3874)

Author: kddejong

src/cfnlint/template/transforms/_sam.py

@@ -151,6 +151,10 @@ def _replace_variables_with_language_extension(self):
         if "AWS::LanguageExtensions" in transforms:
             parameters = {}
             for k, v in self._template.get("Parameters", {}).items():
+                p_type = v.get("Type")
+                if isinstance(p_type, str):
+                    if p_type.startswith("AWS::SSM::Parameter::"):
+                        continue
                 if isinstance(v, dict) and v.get("Default"):
                     parameters[k] = v.get("Default")
 

test/fixtures/templates/good/transform/language_extension.yaml

@@ -10,6 +10,9 @@ Parameters:
   AutoPublishAliasParameter:
     Type: String
     Default: TestAliasRef
+  VpcId:
+    Type: "AWS::SSM::Parameter::Value<AWS::EC2::VPC::Id>"
+    Default: "/network/vpc/primary/id"
 Mappings:
   StackIdMap01:
     teststack1:
@@ -63,3 +66,9 @@ Resources:
         def handler(event, context):
           print("Hello, world!")
       AutoPublishAlias: !Ref AutoPublishAliasParameter
+
+  SecurityGroups:
+    Type: AWS::EC2::SecurityGroup
+    Properties:
+      GroupDescription: Example security group
+      VpcId: !Ref VpcId