From b7d9f53dbea90193c628a0e9ecb8c7d9a292cee2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Edgar=20Ram=C3=ADrez-Mondrag=C3=B3n?= <edgarrm358@gmail.com>
Date: Fri, 8 Mar 2024 14:18:15 -0600
Subject: [PATCH 1/3] Add failing test

---
 tests/core/test_typing.py | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/tests/core/test_typing.py b/tests/core/test_typing.py
index 59bfa41ab..37b74a888 100644
--- a/tests/core/test_typing.py
+++ b/tests/core/test_typing.py
@@ -263,6 +263,27 @@ def test_object_arrays_remove_types(caplog: pytest.LogCaptureFixture):
         )
 
 
+def test_conform_object_additional_properties():
+    schema = PropertiesList(
+        Property(
+            "object",
+            PropertiesList(additional_properties=True),
+        ),
+    ).to_dict()
+
+    record = {"object": {"extra": "value"}}
+    expected_output = {"object": {"extra": "value"}}
+
+    actual_output = conform_record_data_types(
+        "test_stream",
+        record,
+        schema,
+        TypeConformanceLevel.RECURSIVE,
+        logger,
+    )
+    assert actual_output == expected_output
+
+
 def test_conform_primitives():
     assert (
         _conform_primitive_property(

From 42302e2cb9bfe345f267f058c5c0c1acce50b590 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Edgar=20Ram=C3=ADrez-Mondrag=C3=B3n?= <edgarrm358@gmail.com>
Date: Fri, 8 Mar 2024 14:23:53 -0600
Subject: [PATCH 2/3] Implement fix

---
 singer_sdk/helpers/_typing.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/singer_sdk/helpers/_typing.py b/singer_sdk/helpers/_typing.py
index fdaaecd6e..ccaa41412 100644
--- a/singer_sdk/helpers/_typing.py
+++ b/singer_sdk/helpers/_typing.py
@@ -421,6 +421,8 @@ def _conform_record_data_types(  # noqa: PLR0912
     for property_name, elem in input_object.items():
         property_path = property_name if parent is None else f"{parent}.{property_name}"
         if property_name not in schema["properties"]:
+            if schema.get("additionalProperties"):
+                output_object[property_name] = elem
             unmapped_properties.append(property_path)
             continue
 

From ba222ac83c8cb20301bc249d12e9910d6002712d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Edgar=20Ram=C3=ADrez-Mondrag=C3=B3n?= <edgarrm358@gmail.com>
Date: Fri, 8 Mar 2024 14:38:40 -0600
Subject: [PATCH 3/3] Some refactoring

---
 singer_sdk/helpers/_typing.py | 55 +++++++++++++++++++++++------------
 1 file changed, 37 insertions(+), 18 deletions(-)

diff --git a/singer_sdk/helpers/_typing.py b/singer_sdk/helpers/_typing.py
index ccaa41412..74ed59cf5 100644
--- a/singer_sdk/helpers/_typing.py
+++ b/singer_sdk/helpers/_typing.py
@@ -393,7 +393,7 @@ def conform_record_data_types(
 
 
 # TODO: This is in dire need of refactoring. It's a mess.
-def _conform_record_data_types(  # noqa: PLR0912
+def _conform_record_data_types(
     input_object: dict[str, t.Any],
     schema: dict,
     level: TypeConformanceLevel,
@@ -429,24 +429,14 @@ def _conform_record_data_types(  # noqa: PLR0912
         property_schema = schema["properties"][property_name]
         if isinstance(elem, list) and is_uniform_list(property_schema):
             if level == TypeConformanceLevel.RECURSIVE:
-                item_schema = property_schema["items"]
-                output = []
-                for item in elem:
-                    if is_object_type(item_schema) and isinstance(item, dict):
-                        (
-                            output_item,
-                            sub_unmapped_properties,
-                        ) = _conform_record_data_types(
-                            item,
-                            item_schema,
-                            level,
-                            property_path,
-                        )
-                        unmapped_properties.extend(sub_unmapped_properties)
-                        output.append(output_item)
-                    else:
-                        output.append(_conform_primitive_property(item, item_schema))
+                output, sub_unmapped_properties = _conform_uniform_list(
+                    elem,
+                    path=property_path,
+                    schema=property_schema,
+                    level=level,
+                )
                 output_object[property_name] = output
+                unmapped_properties.extend(sub_unmapped_properties)
             else:
                 output_object[property_name] = elem
         elif (
@@ -475,6 +465,35 @@ def _conform_record_data_types(  # noqa: PLR0912
     return output_object, unmapped_properties
 
 
+def _conform_uniform_list(
+    element: list,
+    *,
+    path: str,
+    schema: dict,
+    level: TypeConformanceLevel,
+) -> tuple[list, list[str]]:
+    item_schema = schema["items"]
+    unmapped_properties = []
+    output = []
+    for item in element:
+        if is_object_type(item_schema) and isinstance(item, dict):
+            (
+                output_item,
+                sub_unmapped_properties,
+            ) = _conform_record_data_types(
+                item,
+                item_schema,
+                level,
+                path,
+            )
+            unmapped_properties.extend(sub_unmapped_properties)
+            output.append(output_item)
+        else:
+            output.append(_conform_primitive_property(item, item_schema))
+
+    return output, unmapped_properties
+
+
 def _conform_primitive_property(  # noqa: PLR0911
     elem: t.Any,  # noqa: ANN401
     property_schema: dict,