test: add test for enum reflection

duckdb_engine/__init__.py

@@ -463,6 +463,7 @@ def get_multi_indexes(
 
     def initialize(self, connection: "Connection") -> None:
         DefaultDialect.initialize(self, connection)
+        self.supports_native_enum = True
 
     def create_connect_args(self, url: URL) -> Tuple[tuple, dict]:
         opts = url.translate_connect_args(database="database")

duckdb_engine/tests/test_basic.py

@@ -362,10 +362,63 @@ def test_table_reflect(session: Session, engine: Engine) -> None:
     user_table = Table("test", meta)
     insp = inspect(engine)
 
+    reflect_table(insp, user_table, None)
+
+
+def reflect_table(insp: Inspector, *args: Any, **kwargs: Any) -> None:
     reflect_table = (
         insp.reflecttable if hasattr(insp, "reflecttable") else insp.reflect_table
     )
-    reflect_table(user_table, None)
+    return reflect_table(*args, **kwargs)
+
+
+@mark.xfail(raises=AssertionError, reason="not yet supported by duckdb")
+def test_enum_type_format(engine: Engine) -> None:
+    importorskip("duckdb", "0.6.1")
+
+    sql = [
+        "CREATE TYPE enum_t AS ENUM('a', 'b');",
+        "CREATE TABLE tmp (enum_col enum_t);",
+    ]
+    with engine.connect() as conn:
+        for s in sql:
+            conn.execute(text(s))
+
+        (column,) = conn.execute(
+            text("select * from duckdb_columns() where column_name = 'enum_col'")
+        )
+        (type_actual,) = conn.execute(
+            text("select * from duckdb_types() where type_name = 'enum_t'"),
+        )
+
+        type_oid = type_actual["type_oid"]
+        data_type_id = column["data_type_id"]
+
+        (result,) = conn.execute(
+            text("SELECT pg_catalog.format_type(:type_oid, 0)"), {"type_oid": type_oid}
+        )
+
+        assert result[0] == "enum"
+
+        assert type_oid == data_type_id
+
+
+def test_enum_reflection(session: Session, engine: Engine) -> None:
+    importorskip("duckdb", "0.6.1")
+
+    sql = [
+        "CREATE TYPE enum_t AS ENUM('a', 'b');",
+        "CREATE TABLE tmp (enum_col enum_t);",
+        "INSERT INTO tmp VALUES ('b');",
+        "INSERT INTO tmp VALUES ('a');",
+    ]
+
+    with engine.connect() as conn:
+        for s in sql:
+            conn.execute(text(s))
+
+    tmp = Table("tmp", MetaData())
+    reflect_table(inspect(engine), tmp, include_columns=[])
 
 
 def test_fetch_df_chunks() -> None: