fix: address PR #1311 review comments

- Replace bare except: with except ImportError: in diagram.py
- Replace assert statements with explicit raises in blob.py
- Replace assert False with explicit raises in expression.py and declare.py
- Implement hash verification in objectref.py

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

Author: dimitri-yatsenko

src/datajoint/blob.py

@@ -159,7 +159,8 @@ def unpack(self, blob):
             self._pos += len(prefix)
             blob_size = self.read_value()
             blob = compression[prefix](self._blob[self._pos :])
-            assert len(blob) == blob_size
+            if len(blob) != blob_size:
+                raise DataJointError(f"Blob size mismatch: expected {blob_size}, got {len(blob)}")
             self._blob = blob
             self._pos = 0
         blob_format = self.read_zero_terminated_string()
@@ -363,7 +364,8 @@ def read_int(self):
     @staticmethod
     def pack_int(v):
         n_bytes = v.bit_length() // 8 + 1
-        assert 0 < n_bytes <= 0xFFFF, "Integers are limited to 65535 bytes"
+        if not (0 < n_bytes <= 0xFFFF):
+            raise DataJointError("Integers are limited to 65535 bytes")
         return b"\x0a" + np.uint16(n_bytes).tobytes() + v.to_bytes(n_bytes, byteorder="little", signed=True)
 
     def read_bool(self):

src/datajoint/declare.py

@@ -673,7 +673,7 @@ def substitute_special_type(match: dict, category: str, foreign_key_sql: list[st
             match["type"] = sql_type
         # else: type passes through as-is (json, date, datetime, char, varchar, enum)
     else:
-        assert False, f"Unknown special type: {category}"
+        raise DataJointError(f"Unknown special type: {category}")
 
 
 def compile_attribute(line: str, in_key: bool, foreign_key_sql: list[str], context: dict) -> tuple[str, str, str | None]:

src/datajoint/diagram.py

@@ -23,14 +23,14 @@
     from matplotlib import pyplot as plt
 
     plot_active = True
-except:
+except ImportError:
     plot_active = False
 
 try:
     from networkx.drawing.nx_pydot import pydot_layout
 
     diagram_active = True
-except:
+except ImportError:
     diagram_active = False
 
 

src/datajoint/expression.py

@@ -1085,12 +1085,12 @@ def make_sql(self):
         return "({sql1})  UNION ({sql2})".format(sql1=sql1, sql2=sql2)
 
     def from_clause(self):
-        """The union does not use a FROM clause"""
-        assert False
+        """The union does not use a FROM clause."""
+        raise NotImplementedError("Union does not use a FROM clause")
 
     def where_clause(self):
-        """The union does not use a WHERE clause"""
-        assert False
+        """The union does not use a WHERE clause."""
+        raise NotImplementedError("Union does not use a WHERE clause")
 
     def __len__(self):
         return self.connection.query(

src/datajoint/objectref.py

@@ -15,6 +15,7 @@
 import fsspec
 
 from .errors import DataJointError
+from .hash_registry import compute_hash
 from .storage import StorageBackend
 
 
@@ -366,8 +367,10 @@ def _verify_file(self) -> bool:
 
         # Check hash if available
         if self.hash:
-            # TODO: Implement hash verification
-            pass
+            content = self._backend.get_buffer(self.path)
+            actual_hash = compute_hash(content)
+            if actual_hash != self.hash:
+                raise IntegrityError(f"Hash mismatch for {self.path}: expected {self.hash}, got {actual_hash}")
 
         return True