tests and changes for coverage

Author: altendky

src/desert/_make.py

@@ -213,10 +213,7 @@ def field_for_schema(
     if default is not marshmallow.missing:
         desert_metadata.setdefault("default", default)
         desert_metadata.setdefault("allow_none", True)
-        if not desert_metadata.get(
-            "required"
-        ):  # 'missing' must not be set for required fields.
-            desert_metadata.setdefault("missing", default)
+        desert_metadata.setdefault("missing", default)
 
     field = None
 
@@ -256,7 +253,7 @@ def field_for_schema(
                 values=field_for_schema(arguments[1]),
             )
         elif typing_inspect.is_optional_type(typ):
-            subtyp = next(t for t in arguments if t is not NoneType)
+            [subtyp] = (t for t in arguments if t is not NoneType)
             # Treat optional types as types with a None default
             metadata[_DESERT_SENTINEL]["default"] = metadata.get("default", None)
             metadata[_DESERT_SENTINEL]["missing"] = metadata.get("missing", None)

tests/test_make.py

@@ -1,12 +1,15 @@
 import dataclasses
 import datetime
+import decimal
 import enum
+import re
 import sys
 import types
 import typing as t
 
 import attr
 import marshmallow
+import marshmallow.fields
 import pytest
 
 import desert
@@ -282,6 +285,40 @@ class A:
     assert attr.fields(A).x.metadata["foo"] == 1
 
 
+def test_non_init(module):
+    """Non-init attributes are not included in schema"""
+
+    @module.dataclass
+    class A:
+        x: int
+        y: str = module.field(default="can't init this", init=False)
+
+    schema = desert.schema_class(A)()
+
+    assert "y" not in schema.fields
+
+
+def test_metadata_marshmallow_field_loads(module):
+    """Marshmallow field can be specified via metadata dict"""
+
+    @module.dataclass
+    class A:
+        x: decimal.Decimal = module.field(
+            metadata={"marshmallow_field": marshmallow.fields.Decimal(as_string=True)}
+        )
+
+    schema = desert.schema_class(A)()
+
+    assert schema.loads('{"x": "1.3"}') == A(decimal.Decimal("1.3"))
+
+
+def test_get_field_default_raises_for_non_field():
+    """Not attrs and not dataclasses field raises"""
+
+    with pytest.raises(TypeError, match=re.escape("None")):
+        desert._make._get_field_default(field=None)
+
+
 @pytest.mark.parametrize(argnames=["value"], argvalues=[["X"], [5]])
 def test_union(module, value, assert_dump_load):
     """Deserialize one of several types."""