feat: serialize sqlalchemy relations

Makefile

@@ -19,5 +19,5 @@ lint:
 	isort alcherializer tests
 
 test:
-	python -m pytest -p no:warnings --cov=alcherializer -v
+	python -m pytest -p no:warnings --cov=alcherializer -vv
 	coverage html

alcherializer/serializer.py

@@ -4,6 +4,7 @@
 )
 
 import sqlalchemy
+from sqlalchemy.ext.declarative import DeclarativeMeta
 
 from alcherializer import fields
 from alcherializer.exceptions import MalformedMetaClassException
@@ -32,7 +33,7 @@ def data(self) -> Dict[str, Any]:
         for instance in instances:
             obj_dict = {}
             for key in self.fields.keys():
-                obj_dict[key] = getattr(instance, key)
+                obj_dict[key] = self._get_instance_field_value(instance, key)
 
             results.append(obj_dict)
 
@@ -77,8 +78,10 @@ def _get_fields(self) -> Dict[str, Any]:
                 continue
 
             columns[key] = {
-                "type": value.type,
-                "required": value.nullable is False,
+                "type": value.type if hasattr(value, "type") else value,
+                "required": value.nullable is False
+                if hasattr(value, "nullable")
+                else False,
                 "validator": self._get_field_validator(key, value),
             }
 
@@ -102,3 +105,24 @@ def _get_field_validator(self, key: str, field):
             return fields.BooleanField(key, field)
 
         return fields.BaseField(key, field)
+
+    def _get_instance_field_value(self, instance, field: str) -> Any:
+        value = getattr(instance, field)
+        if isinstance(value.__class__, DeclarativeMeta):
+            serializer = self.fields[field]["validator"]
+            if isinstance(serializer, Serializer):
+                serializer.instance = value
+                return serializer.data
+
+        if (
+            isinstance(value, list)
+            and len(value) > 0
+            and isinstance(value[0].__class__, DeclarativeMeta)
+        ):
+            serializer = self.fields[field]["validator"]
+            if isinstance(serializer, Serializer):
+                serializer.instance = value
+                serializer.many = True
+                return serializer.data
+
+        return value

tests/unit/serializer/test_data.py

@@ -1,5 +1,6 @@
 import sqlalchemy
 from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import relationship
 
 from alcherializer import Serializer
 
@@ -66,3 +67,107 @@ class Meta:
 
     serializer = MySerializer(model)
     assert serializer.data == {"id": 1}
+
+
+def test_data_get_related_one_to_one_model() -> None:
+    class MyRelatedModel(declarative_base()):
+        id = sqlalchemy.Column(
+            sqlalchemy.Integer, primary_key=True, nullable=False
+        )
+        hello = sqlalchemy.Column(sqlalchemy.String, nullable=False)
+
+        __tablename__ = "my_related_model"
+
+    class MyModel(declarative_base()):
+        id = sqlalchemy.Column(
+            sqlalchemy.Integer, primary_key=True, nullable=False
+        )
+        name = sqlalchemy.Column(sqlalchemy.String, nullable=False)
+        related_id = sqlalchemy.Column(
+            sqlalchemy.Integer, sqlalchemy.ForeignKey(MyRelatedModel.id)
+        )
+
+        related = relationship(MyRelatedModel, uselist=False)
+
+        __tablename__ = "my_model"
+
+    class MyRelatedModelSerializer(Serializer):
+        class Meta:
+            model = MyRelatedModel
+
+    class MyModelSerializer(Serializer):
+        related = MyRelatedModelSerializer()
+
+        class Meta:
+            model = MyModel
+            fields = ["id", "name", "related"]
+
+    model = MyModel(
+        id=1,
+        name="my name",
+        related=MyRelatedModel(
+            id=1,
+            hello="world",
+        ),
+    )
+
+    serializer = MyModelSerializer(model)
+    assert serializer.data == {
+        "id": 1,
+        "name": "my name",
+        "related": {"id": 1, "hello": "world"},
+    }
+
+
+def test_data_get_related_has_many_models() -> None:
+    class MyRelatedModel(declarative_base()):
+        id = sqlalchemy.Column(
+            sqlalchemy.Integer, primary_key=True, nullable=False
+        )
+        hello = sqlalchemy.Column(sqlalchemy.String, nullable=False)
+
+        __tablename__ = "my_related_model"
+
+    class MyModel(declarative_base()):
+        id = sqlalchemy.Column(
+            sqlalchemy.Integer, primary_key=True, nullable=False
+        )
+        name = sqlalchemy.Column(sqlalchemy.String, nullable=False)
+        related_id = sqlalchemy.Column(
+            sqlalchemy.Integer, sqlalchemy.ForeignKey(MyRelatedModel.id)
+        )
+
+        related = relationship(MyRelatedModel, uselist=False)
+
+        __tablename__ = "my_model"
+
+    class MyRelatedModelSerializer(Serializer):
+        class Meta:
+            model = MyRelatedModel
+
+    class MyModelSerializer(Serializer):
+        related = MyRelatedModelSerializer()
+
+        class Meta:
+            model = MyModel
+            fields = ["id", "name", "related"]
+
+    model = MyModel(
+        id=1,
+        name="my name",
+        related=[
+            MyRelatedModel(
+                id=1,
+                hello="world",
+            ),
+        ],
+    )
+
+    serializer = MyModelSerializer(model)
+    assert serializer.data == {
+        "id": 1,
+        "name": "my name",
+        "related": [
+            {"id": 1, "hello": "world"},
+        ],
+    }