Fix ty type checker errors in vgi source and tests

- test_streaming_decorator.py: Fix method override by using correct
  parameter name 'batch' instead of 'b'
- vgi/arguments.py: Restructure type_bound normalization for better
  type narrowing (if/else instead of ternary)
- vgi/function.py: Use getattr() instead of hasattr() for __orig_bases__
  to make iteration type-safe
- vgi/worker.py: Cast dynamic type() result to type[CatalogInterface]

Reduces ty diagnostics from 17 to 14 (remaining are pyarrow stub issues).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: rustyconover

tests/table_in_out/test_streaming_decorator.py

@@ -172,10 +172,10 @@ def test_equivalent_output(self) -> None:
         """@streaming decorated function should produce same output as manual."""
 
         class ManualEcho(TableInOutGenerator):
-            def process(self, b: pa.RecordBatch) -> OutputGenerator:
+            def process(self, batch: pa.RecordBatch) -> OutputGenerator:
                 """Manual process without decorator."""
                 _ = yield None
-                current: pa.RecordBatch | None = b
+                current: pa.RecordBatch | None = batch
                 while True:
                     # Combined yield-and-receive (correct pattern)
                     current = yield Output(current)

vgi/arguments.py

@@ -1136,9 +1136,10 @@ def validate_type_bound(self, field_type: pa.DataType) -> None:
             return
 
         # Normalize to sequence
-        predicates: list[TypeBoundPredicate] = (
-            [self.type_bound] if callable(self.type_bound) else list(self.type_bound)
-        )
+        if callable(self.type_bound):
+            predicates: list[TypeBoundPredicate] = [self.type_bound]
+        else:
+            predicates = list(self.type_bound)
 
         # OR logic: at least one predicate must pass
         if not any(predicate(field_type) for predicate in predicates):

vgi/function.py

@@ -295,8 +295,9 @@ def _get_init_input_type(cls) -> type["FunctionInitInput"]:
             return cls._init_input_type_cache[cls]
 
         for base in cls.__mro__:
-            if hasattr(base, "__orig_bases__"):
-                for orig_base in base.__orig_bases__:
+            orig_bases = getattr(base, "__orig_bases__", None)
+            if orig_bases is not None:
+                for orig_base in orig_bases:
                     origin = get_origin(orig_base)
                     if origin is not None and origin.__name__ == "Function":
                         args = get_args(orig_base)

vgi/worker.py

@@ -212,13 +212,16 @@ def _get_catalog_interface(cls) -> type[CatalogInterface] | None:
             from vgi.catalog import ReadOnlyCatalogInterface
 
             # Create a dynamic subclass with the worker's functions
-            cls._default_catalog_interface = type(
-                f"{cls.__name__}Catalog",
-                (ReadOnlyCatalogInterface,),
-                {
-                    "catalog_name": cls.catalog_name,
-                    "functions": list(cls.functions),
-                },
+            cls._default_catalog_interface = cast(
+                type[CatalogInterface],
+                type(
+                    f"{cls.__name__}Catalog",
+                    (ReadOnlyCatalogInterface,),
+                    {
+                        "catalog_name": cls.catalog_name,
+                        "functions": list(cls.functions),
+                    },
+                ),
             )
 
         return cls._default_catalog_interface