Add tests for base model Document (#5)

todo/tests/unit/models/common/test_document.py

@@ -0,0 +1,58 @@
+from typing import ClassVar
+from unittest import TestCase
+from bson import ObjectId
+from pydantic import Field
+from todo.models.common.document import Document
+
+
+class DocumentTests(TestCase):
+    def test_subclass_without_collection_name_raises_error(self):
+        with self.assertRaises(TypeError) as context:
+
+            class InvalidDocument(Document):
+                pass
+
+        self.assertIn("must define a static `collection_name` field as a string", str(context.exception))
+
+    def test_subclass_with_invalid_collection_name_type_raises_error(self):
+        with self.assertRaises(TypeError):
+
+            class InvalidDocument(Document):
+                collection_name: ClassVar[str] = 123
+
+    def test_subclass_with_valid_collection_name(self):
+        try:
+
+            class ValidDocument(Document):
+                collection_name: ClassVar[str] = "valid_collection"
+        except TypeError as e:
+            print(e)
+            self.fail("TypeError raised for valid Document subclass")
+
+    def test_id_field_alias(self):
+        class TestDocument(Document):
+            collection_name: ClassVar[str] = "test_collection"
+
+        obj_id = ObjectId()
+        doc = TestDocument.model_validate({"_id": obj_id})
+        self.assertEqual(doc.id, obj_id)
+        self.assertEqual(doc.model_dump(mode="json", by_alias=True)["_id"], str(obj_id))
+
+    def test_json_encoder_serializes_objectid(self):
+        class TestDocument(Document):
+            collection_name: ClassVar[str] = "test_collection"
+
+        obj_id = ObjectId()
+        doc = TestDocument(id=obj_id)
+        serialized = doc.model_dump_json()
+        self.assertIn(str(obj_id), serialized)
+
+    def test_populate_by_name_behavior(self):
+        class TestDocument(Document):
+            collection_name: ClassVar[str] = "test_collection"
+            field_one: str = Field(..., alias="fieldOne")
+
+        data = {"_id": ObjectId(), "fieldOne": "value"}
+        doc = TestDocument.model_validate(data)
+        self.assertEqual(doc.field_one, "value")
+        self.assertEqual(doc.model_dump(by_alias=True)["fieldOne"], "value")