From 66f0f173f36f7f3c67c1cb60b7859e2c7573d1b7 Mon Sep 17 00:00:00 2001
From: Wanderrful <wanderrful@gmail.com>
Date: Thu, 17 Sep 2020 18:38:38 -0500
Subject: [PATCH] #100 Propagate meta dict to Nested dataclasses

---
 src/desert/_make.py |  5 +++--
 tests/test_make.py  | 16 ++++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/desert/_make.py b/src/desert/_make.py
index 088386c..d250cf5 100644
--- a/src/desert/_make.py
+++ b/src/desert/_make.py
@@ -130,7 +130,7 @@ def class_schema(
             attributes[field.name] = field_for_schema(
                 hints.get(field.name, field.type),
                 _get_field_default(field),
-                field.metadata,
+                {**meta, **field.metadata},
             )
 
     cls_schema = type(
@@ -289,7 +289,8 @@ def field_for_schema(
 
     if field is None:
         nested = forward_reference or class_schema(typ)
-        field = marshmallow.fields.Nested(nested)
+        params = {k: v for k, v in metadata.items() if type(k) is str}
+        field = marshmallow.fields.Nested(nested, **params)
 
     field.metadata.update(metadata)
 
diff --git a/tests/test_make.py b/tests/test_make.py
index 0e1aa01..cfda7c8 100644
--- a/tests/test_make.py
+++ b/tests/test_make.py
@@ -191,6 +191,22 @@ class B:
     assert data == B(A(5))
 
 
+def test_nested_unknown(module):
+    """Schemas will propagate meta to Nested dataclasses."""
+
+    @module.dataclass
+    class A:
+        x: int
+
+    @module.dataclass
+    class B:
+        y: A
+
+    data = desert.schema_class(B, meta={"unknown": marshmallow.EXCLUDE})().load({"y": {"x": 5, "z": 3}})
+
+    assert data == B(A(5))
+
+
 def test_optional(module):
     """Setting an optional type makes the default None."""