Merge remote-tracking branch 'canassa/feat/metadata-fields'

tests/test_metadata.py

@@ -0,0 +1,34 @@
+import datetime
+from dataclasses import dataclass, field
+
+import pytest
+from marshmallow import fields, ValidationError
+
+from dataclasses_json import DataClassJsonMixin
+
+
+@dataclass
+class Car(DataClassJsonMixin):
+    license_number: str = field(metadata={'mm': fields.String(required=False)})
+
+
+@dataclass
+class StringDate(DataClassJsonMixin):
+    string_date: datetime.datetime = field(metadata={'mm': fields.String(required=False)})
+
+
+car_schema = Car.schema()
+string_date_schema = StringDate.schema()
+
+
+class TestMetadataField:
+
+    def test_validation_error_raises(self):
+        with pytest.raises(ValidationError) as e:
+            car_schema.load({'license_number': 123})
+        assert e.value.messages == {'license_number': ['Not a valid string.']}
+
+    def test_mm_field_takes_precedence_over_types(self):
+        obj = string_date_schema.load({'string_date': 'yesterday'})
+        assert isinstance(obj, StringDate)
+        assert obj.string_date == 'yesterday'