Always copy profile (#274)

Author: hoffa

samtranslator/model/connector_profiles/profile.py

@@ -1,3 +1,4 @@
+import copy
 import json
 import os
 import re
@@ -10,7 +11,9 @@
 
 
 def get_profile(source_type: str, dest_type: str):
-    return PROFILE["Permissions"].get(source_type, {}).get(dest_type)
+    profile = PROFILE["Permissions"].get(source_type, {}).get(dest_type)
+    # Ensure not passing a mutable shared variable
+    return copy.deepcopy(profile)
 
 
 def verify_profile_variables_replaced(obj: Any) -> None:

tests/model/connector_profiles/test_profile.py

@@ -2,7 +2,11 @@
 
 from parameterized import parameterized
 
-from samtranslator.model.connector_profiles.profile import profile_replace, verify_profile_variables_replaced
+from samtranslator.model.connector_profiles.profile import (
+    get_profile,
+    profile_replace,
+    verify_profile_variables_replaced,
+)
 
 
 class TestProfile(TestCase):
@@ -235,3 +239,9 @@ def test_verify_not_replaced(self, profile, error_includes):
         with self.assertRaises(ValueError) as ctx:
             verify_profile_variables_replaced(profile)
         self.assertIn(error_includes, str(ctx.exception))
+
+    def test_get_profile_copied(self):
+        d1 = get_profile("AWS::Lambda::Function", "AWS::DynamoDB::Table")
+        d1["Type"] = "overridden"
+        d2 = get_profile("AWS::Lambda::Function", "AWS::DynamoDB::Table")
+        self.assertNotEqual(d1, d2)