feat: add type annotations to errors and hash modules

- Add type annotations to errors.py (suggest method)
- Add type annotations to hash.py (key_hash, uuid_from_buffer)
- Enable strict mypy checking for these modules
- Now 3 modules under strict checking: content_registry, errors, hash

Increases type coverage incrementally following gradual adoption strategy.

Related #1266

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: dimitri-yatsenko

pyproject.toml

@@ -166,6 +166,8 @@ check_untyped_defs = true
 [[tool.mypy.overrides]]
 module = [
     "datajoint.content_registry",
+    "datajoint.errors",
+    "datajoint.hash",
 ]
 disallow_untyped_defs = true
 disallow_incomplete_defs = true
@@ -185,10 +187,8 @@ module = [
     "datajoint.declare",
     "datajoint.dependencies",
     "datajoint.diagram",
-    "datajoint.errors",
     "datajoint.expression",
     "datajoint.gc",
-    "datajoint.hash",
     "datajoint.heading",
     "datajoint.jobs",
     "datajoint.lineage",

src/datajoint/errors.py

@@ -11,13 +11,13 @@
 class DataJointError(Exception):
     """Base class for errors specific to DataJoint internal operation."""
 
-    def suggest(self, *args) -> "DataJointError":
+    def suggest(self, *args: object) -> "DataJointError":
         """
         Regenerate the exception with additional arguments.
 
         Parameters
         ----------
-        *args : any
+        *args : object
             Additional arguments to append to the exception.
 
         Returns

src/datajoint/hash.py

@@ -1,8 +1,11 @@
+from __future__ import annotations
+
 import hashlib
 import uuid
+from typing import Any
 
 
-def key_hash(mapping):
+def key_hash(mapping: dict[str, Any]) -> str:
     """
     32-byte hash of the mapping's key values sorted by the key name.
     This is often used to convert a long primary key value into a shorter hash.
@@ -13,7 +16,7 @@ def key_hash(mapping):
     return hashed.hexdigest()
 
 
-def uuid_from_buffer(buffer=b"", *, init_string=""):
+def uuid_from_buffer(buffer: bytes = b"", *, init_string: str = "") -> uuid.UUID:
     """
     Compute MD5 hash of buffer data, returned as UUID.