Preserve dialect-specific ARRAY types instead of adapting to generic ARRAY

CHANGES.rst

@@ -5,6 +5,11 @@ Version history
 
 - Added autoincrement to primary key columns to prevent missing field errors.
   (`#473 <https://github.com/agronholm/sqlacodegen/issues/473>`_; PR by @jtmonroe)
+- Preserve dialect-specific ``ARRAY`` types (e.g. ``postgresql.ARRAY``) instead
+  of adapting them to the generic ``sqlalchemy.ARRAY``. The generic type does
+  not implement operators like ``.contains()``, so adapting silently broke
+  PostgreSQL array queries on generated models.
+  (`#441 <https://github.com/agronholm/sqlacodegen/issues/441>`_)
 
 **4.0.3**
 

src/sqlacodegen/generators.py

@@ -1036,6 +1036,12 @@ def fix_enum_column(col_name: str, enum_type: Enum) -> None:
                         column.server_default = None
 
     def get_adapted_type(self, coltype: Any) -> Any:
+        # Keep dialect-specific ARRAY subclasses; the generic sqlalchemy.ARRAY
+        # is missing operators like .contains() (GH-441).
+        if isinstance(coltype, ARRAY) and type(coltype) is not ARRAY:
+            coltype.item_type = self.get_adapted_type(coltype.item_type)
+            return coltype
+
         compiled_type = coltype.compile(self.bind.engine.dialect)
         for supercls in coltype.__class__.__mro__:
             if not supercls.__name__.startswith("_") and hasattr(

tests/test_generator_tables.py

@@ -130,7 +130,8 @@ def test_arrays(generator: CodeGenerator) -> None:
     validate_code(
         generator.generate(),
         """\
-        from sqlalchemy import ARRAY, Column, Double, Integer, MetaData, Table
+        from sqlalchemy import Column, Double, Integer, MetaData, Table
+        from sqlalchemy.dialects.postgresql import ARRAY
 
         metadata = MetaData()
 
@@ -144,6 +145,36 @@ def test_arrays(generator: CodeGenerator) -> None:
     )
 
 
+@pytest.mark.parametrize("engine", ["postgresql"], indirect=["engine"])
+def test_array_preserves_dialect_for_runtime_operators(
+    generator: CodeGenerator,
+) -> None:
+    """Regression test for GH-441."""
+    Table(
+        "simple_items",
+        generator.metadata,
+        Column("id", postgresql.TEXT, primary_key=True),
+        Column("tags", postgresql.ARRAY(postgresql.TEXT)),
+    )
+
+    validate_code(
+        generator.generate(),
+        """\
+        from sqlalchemy import Column, MetaData, Table, Text
+        from sqlalchemy.dialects.postgresql import ARRAY
+
+        metadata = MetaData()
+
+
+        t_simple_items = Table(
+            'simple_items', metadata,
+            Column('id', Text, primary_key=True),
+            Column('tags', ARRAY(Text()))
+        )
+        """,
+    )
+
+
 @pytest.mark.parametrize("engine", ["postgresql"], indirect=["engine"])
 def test_jsonb(generator: CodeGenerator) -> None:
     Table(