tools(fix): Fix Storage iterator (ethereum#369)

docs/CHANGELOG.md

@@ -14,6 +14,7 @@ Test fixtures for use by clients are available for each release on the [Github r
 - 🔀 Rename test fixtures names to match the corresponding pytest node ID as generated using `fill` ([#342](https://github.com/ethereum/execution-spec-tests/pull/342)).
 - 💥 Replace "=" with "_" in pytest node ids and test fixture names ([#342](https://github.com/ethereum/execution-spec-tests/pull/342)).
 - ✨ Fork objects used to write tests can now be compared using the `>`, `>=`, `<`, `<=` operators, to check for a fork being newer than, newer than or equal, older than, older than or equal, respectively when compared against other fork ([#367](https://github.com/ethereum/execution-spec-tests/pull/367))
+- 🐞 Storage type iterator is now fixed ([#369](https://github.com/ethereum/execution-spec-tests/pull/369))
 
 ### 🔧 EVM Tools
 

src/ethereum_test_tools/common/types.py

@@ -402,7 +402,7 @@ def key_value_to_string(value: int) -> str:
             hex_str = "0" + hex_str
         return "0x" + hex_str
 
-    def __init__(self, input: StorageDictType = {}, start_slot: int = 0):
+    def __init__(self, input: StorageDictType | "Storage" = {}, start_slot: int = 0):
         """
         Initializes the storage using a given mapping which can have
         keys and values either as string or int.
@@ -420,6 +420,10 @@ def __len__(self) -> int:
         """Returns number of elements in the storage"""
         return len(self.data)
 
+    def __iter__(self) -> Iterator[int]:
+        """Returns iterator of the storage"""
+        return iter(self.data)
+
     def __contains__(self, key: str | int | bytes) -> bool:
         """Checks for an item in the storage"""
         key = Storage.parse_key_value(key)

src/ethereum_test_tools/tests/test_types.py

@@ -52,6 +52,10 @@ def test_storage():
     assert 10 in s.data
     assert s.data[10] == 10
 
+    iter_s = iter(Storage({10: 20, "11": "21"}))
+    assert next(iter_s) == 10
+    assert next(iter_s) == 11
+
     s["10"] = "0x10"
     s["0x10"] = "10"
     assert s.data[10] == 16