Filter out empty dialect kwargs (#468)

Author: sheinbergon

CHANGES.rst

@@ -1,13 +1,15 @@
 Version history
 ===============
 
-**Unreleased**
+**4.0.2**
 
 - Fixed rendering of inherited keyword arguments for dialect-specific types that use
   ``**kwargs`` in their initializers (such as MySQL ``CHAR`` with ``collation``) while
   preserving existing ``*args`` rendering behavior (PR by @hyoj0942)
 - Fixed missing metadata argument when rendering plain tables with the SQLModel
 - Added support for self-referential tables in the SQLModel generator (PR by @sheinbergon)
+- Fixed empty dialect kwargs (e.g. ``postgresql_include=[]``) being included in
+  rendered indexes, tables, and columns (PR by @sheinbergon)
 
 **4.0.1**
 

src/sqlacodegen/generators.py

@@ -427,6 +427,7 @@ def render_index(self, index: Index) -> str:
         kwargs = {
             key: repr(value) if isinstance(value, str) else value
             for key, value in sorted(index.kwargs.items(), key=lambda item: item[0])
+            if value not in ([], {})
         }
         if index.unique:
             kwargs["unique"] = True
@@ -778,6 +779,9 @@ def _add_dialect_kwargs_and_info(
             except Exception:
                 continue
 
+            if isinstance(value, list | dict) and not value:
+                continue
+
             # Render values:
             # - callable context (values_for_dict=False): produce a string expression.
             #   primitives use repr(value); custom objects stringify then repr().

tests/test_generator_declarative.py

@@ -3161,3 +3161,75 @@ class MyTable(Base):
             tags: Mapped[list[TagEnum]] = mapped_column(ARRAY(Enum(TagEnum, values_callable=lambda cls: [member.value for member in cls], name='tag_enum', schema='custom_schema')), nullable=False)
         """,
     )
+
+
+def test_index_with_empty_kwargs(generator: CodeGenerator) -> None:
+    simple_items = Table(
+        "simple_items",
+        generator.metadata,
+        Column("id", INTEGER, primary_key=True),
+        Column("name", VARCHAR),
+    )
+    simple_items.indexes.add(
+        Index(
+            "idx_name",
+            simple_items.c.name,
+            postgresql_using="gist",
+            postgresql_include=[],
+        )
+    )
+
+    validate_code(
+        generator.generate(),
+        """\
+from typing import Optional
+
+from sqlalchemy import Index, Integer, String
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
+
+class Base(DeclarativeBase):
+    pass
+
+
+class SimpleItems(Base):
+    __tablename__ = 'simple_items'
+    __table_args__ = (
+        Index('idx_name', 'name', postgresql_using='gist'),
+    )
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    name: Mapped[Optional[str]] = mapped_column(String)
+        """,
+    )
+
+
+@pytest.mark.parametrize("generator", [["include_dialect_options"]], indirect=True)
+def test_include_dialect_options_empty_values_skipped(
+    generator: CodeGenerator,
+) -> None:
+    Table(
+        "t_opts3",
+        generator.metadata,
+        Column("id", INTEGER, primary_key=True),
+        mysql_engine="InnoDB",
+        mysql_partition_by=[],
+        mysql_PROPERTIES={},
+    )
+
+    validate_code(
+        generator.generate(),
+        """\
+from sqlalchemy import Integer
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
+
+class Base(DeclarativeBase):
+    pass
+
+
+class TOpts3(Base):
+    __tablename__ = 't_opts3'
+    __table_args__ = {'mysql_engine': 'InnoDB'}
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+        """,
+    )