Support AWS::Lambda::Alias type resolving

samcli/lib/intrinsic_resolver/intrinsics_symbol_table.py

@@ -160,15 +160,24 @@ def get_default_pseudo_resolver(self):
     def get_default_attribute_resolver(self):
         return {"Ref": lambda logical_id: logical_id, "Arn": self.arn_resolver}
 
-    @staticmethod
-    def get_default_type_resolver():
+    def handle_function_alias_type(self, logical_id):
+        node = self._resources.get(logical_id).get("Properties").get("FunctionName")
+
+        function_id = self.resolve_symbols(node.get("Ref"), IntrinsicResolver.REF)
+        functionArn = self.arn_resolver(function_id)
+        return functionArn
+
+    def get_default_type_resolver(self):
         return {
             "AWS::ApiGateway::RestApi": {
                 "RootResourceId": "/"  # It usually used as a reference to the parent id of the RestApi,
             },
             "AWS::Lambda::LayerVersion": {
                 IntrinsicResolver.REF: lambda logical_id: {IntrinsicResolver.REF: logical_id}
             },
+            "AWS::Lambda::Alias": {
+                IntrinsicResolver.REF: self.handle_function_alias_type,
+            },
             "AWS::Serverless::LayerVersion": {
                 IntrinsicResolver.REF: lambda logical_id: {IntrinsicResolver.REF: logical_id}
             },

tests/unit/lib/intrinsic_resolver/test_intrinsics_symbol_table.py

@@ -1,12 +1,11 @@
 from unittest import TestCase
-
 from unittest.mock import patch
 
 from parameterized import parameterized
 
-from samcli.lib.intrinsic_resolver.invalid_intrinsic_exception import InvalidSymbolException
 from samcli.lib.intrinsic_resolver.intrinsic_property_resolver import IntrinsicResolver
 from samcli.lib.intrinsic_resolver.intrinsics_symbol_table import IntrinsicsSymbolTable
+from samcli.lib.intrinsic_resolver.invalid_intrinsic_exception import InvalidSymbolException
 
 
 class TestIntrinsicsSymbolTablePseudoProperties(TestCase):
@@ -91,6 +90,25 @@ def test_default_type_resolver_function(self):
 
         self.assertEqual(result, "MyApi")
 
+    def test_default_type_resolver_function_alias(self):
+        template = {
+            "Resources": {
+                "TestFunction17441592": {
+                    "Type": "AWS::Lambda::Function",
+                },
+                "TestFunctionAlias31D71541": {
+                    "Type": "AWS::Lambda::Alias",
+                    "Properties": {
+                        "FunctionName": {"Ref": "TestFunction17441592"},
+                    },
+                },
+            }
+        }
+        symbol_resolver = IntrinsicsSymbolTable(template=template)
+        result = symbol_resolver.resolve_symbols("TestFunctionAlias31D71541", "Ref")
+
+        self.assertEqual(result, "arn:aws:lambda:us-east-1:123456789012:function:TestFunction17441592")
+
     def test_custom_attribute_resolver(self):
         template = {"Resources": {"MyApi": {"Type": "AWS::ApiGateway::RestApi"}}}
         common_attribute_resolver = {"Arn": "test"}