Data type converter: Support converting elements of collections (ARRAY)

src/crate/client/converter.py

@@ -27,8 +27,7 @@
 from copy import deepcopy
 from datetime import datetime
 from enum import Enum
-from typing import Any, Callable, Dict, Optional, Union
-
+from typing import Any, Callable, Dict, Optional, Union, List
 
 InputVal = Any
 
@@ -128,8 +127,17 @@ def get_mapping_key(type_: Union[CrateDatatypeIdentifier, int]) -> int:
             return type_
 
     def convert(self, type_: int, value: Optional[Any]) -> Optional[Any]:
-        converter = self.get(type_)
-        return converter(value)
+        if isinstance(type_, List):
+            type_, inner_type = type_
+            assert type_ == 100, f"Type {type_} not implemented as collection type"
+            if value is None:
+                result = self.convert(inner_type, None)
+            else:
+                result = [self.convert(inner_type, item) for item in value]
+        else:
+            converter = self.get(type_)
+            result = converter(value)
+        return result
 
 
 class DefaultTypeConverter(Converter):

src/crate/client/test_cursor.py

@@ -92,3 +92,45 @@ def test_execute_with_converter(self):
         self.assertEqual(result, ['foo', '10.10.10.1', 1658167836758, "B'0110'"])
 
         conn.close()
+
+    def test_execute_array_with_converter(self):
+        client = ClientMocked()
+        conn = connect(client=client)
+        converter = Cursor.get_default_converter()
+        cursor = conn.cursor(converter=converter)
+
+        conn.client.set_next_response({
+            "col_types": [4, [100, 5]],
+            "cols": ["name", "address"],
+            "rows": [["foo", ["10.10.10.1", "10.10.10.2"]]],
+            "rowcount": 1,
+            "duration": 123
+        })
+
+        cursor.execute("")
+        result = cursor.fetchone()
+        self.assertEqual(result, [
+            'foo',
+            [IPv4Address('10.10.10.1'), IPv4Address('10.10.10.2')],
+        ])
+
+    def test_execute_nested_array_with_converter(self):
+        client = ClientMocked()
+        conn = connect(client=client)
+        converter = Cursor.get_default_converter()
+        cursor = conn.cursor(converter=converter)
+
+        conn.client.set_next_response({
+            "col_types": [4, [100, [100, 5]]],
+            "cols": ["name", "address_buckets"],
+            "rows": [["foo", [["10.10.10.1", "10.10.10.2"], ["10.10.10.3"], [], None]]],
+            "rowcount": 1,
+            "duration": 123
+        })
+
+        cursor.execute("")
+        result = cursor.fetchone()
+        self.assertEqual(result, [
+            'foo',
+            [[IPv4Address('10.10.10.1'), IPv4Address('10.10.10.2')], [IPv4Address('10.10.10.3')], [], None],
+        ])