Fixed a bug causing cache() to raise a TypeError when attempting …

…to cache a function call that contains an argument that is a list containing a dictionary (#3).

CHANGELOG.md

@@ -1,6 +1,10 @@
 ## Changelog 🔄
 All notable changes to `persist-cache` will be documented here. This project adheres to [Keep a Changelog](https://keepachangelog.com/en/1.1.0/) and [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.3.1] - 2024-03-20
+### Fixed
+- Fixed a bug causing `cache()` to raise a `TypeError` when attempting to cache a function call that contains an argument that is a list containing a dictionary ([#3](https://github.com/umarbutler/persist-cache/issues/3)) ([fe7aa6c](https://github.com/umarbutler/persist-cache/commit/fe7aa6ccd2f7fbeebaa53e4c1cc0230f6ef35cb4)).
+
 ## [0.3.0] - 2024-03-19
 ### Changed
 - Ceased delimiting hashes and the length of the input with hyphens as the hashes already have a fixed size so there is no possibility of collision.

src/persist_cache/serialization.py

@@ -56,7 +56,7 @@ def directly_msgpackable(data: Any) -> bool:
     # - It is of a type specified by `ABSOLUTELY_DIRECTLY_MSGPACKABLE_TYPES`.
     if (isinstance(data, str) and not any(data.startswith(str_signature) for str_signature in STR_SIGNATURES)) \
         or isinstance(data, int) and -2**63 <= data <= 2**64-1 \
-        or (isinstance(data, list) and all(directly_msgpackable(d) for d in data) and (len(data) == 0 or data[0] not in LISTED_SIGNATURES)) \
+        or (isinstance(data, list) and all(directly_msgpackable(d) for d in data) and (len(data) == 0 or not isinstance(data[0], str) or data[0] not in LISTED_SIGNATURES)) \
         or (isinstance(data, dict) and all(directly_msgpackable(k) and directly_msgpackable(v) for k, v in data.items())) \
         or isinstance(data, ABSOLUTELY_DIRECTLY_MSGPACKABLE_TYPES):
         return True