Add task and label database repository for get task API

todo/repositories/__init__.py

@@ -0,0 +1 @@
+# Added this because without this file Django isn't able to auto detect the test files

todo/repositories/common/mongo_repository.py

@@ -0,0 +1,20 @@
+from abc import ABC
+
+from todo_project.db.config import DatabaseManager
+
+
+class MongoRepository(ABC):
+    collection = None
+    collection_name = None
+    database_manager = DatabaseManager()
+
+    def __init_subclass__(cls, **kwargs):
+        super().__init_subclass__(**kwargs)
+        if not hasattr(cls, "collection_name") or not isinstance(cls.collection_name, str):
+            raise TypeError(f"Class {cls.__name__} must define a static `collection_name` field as a string.")
+
+    @classmethod
+    def get_collection(cls):
+        if cls.collection is None:
+            cls.collection = cls.database_manager.get_collection(cls.collection_name)
+        return cls.collection

todo/repositories/label_repository.py

@@ -0,0 +1,17 @@
+from typing import List
+
+from bson import ObjectId
+from todo.models.label import LabelModel
+from todo.repositories.common.mongo_repository import MongoRepository
+
+
+class LabelRepository(MongoRepository):
+    collection_name = LabelModel.collection_name
+
+    @classmethod
+    def list_by_ids(cls, ids: List[ObjectId]) -> List[LabelModel]:
+        if len(ids) == 0:
+            return []
+        labels_collection = cls.get_collection()
+        labels_cursor = labels_collection.find({"_id": {"$in": ids}})
+        return [LabelModel(**label) for label in labels_cursor]

todo/repositories/task_repository.py

@@ -0,0 +1,18 @@
+from typing import List
+from todo.models.task import TaskModel
+from todo.repositories.common.mongo_repository import MongoRepository
+
+
+class TaskRepository(MongoRepository):
+    collection_name = TaskModel.collection_name
+
+    @classmethod
+    def list(cls, page: int, limit: int) -> List[TaskModel]:
+        tasks_collection = cls.get_collection()
+        tasks_cursor = tasks_collection.find().skip((page - 1) * limit).limit(limit)
+        return [TaskModel(**task) for task in tasks_cursor]
+
+    @classmethod
+    def count(cls) -> int:
+        tasks_collection = cls.get_collection()
+        return tasks_collection.count_documents({})

todo/tests/fixtures/label.py

@@ -18,3 +18,5 @@
         "createdBy": "qMbT6M2GB65W7UHgJS4g",
     },
 ]
+
+label_models = [LabelModel(**data) for data in label_db_data]

todo/tests/fixtures/task.py

@@ -35,3 +35,5 @@
         "updatedBy": "qMbT6M2GB65W7UHgJS4g",
     },
 ]
+
+tasks_models = [TaskModel(**data) for data in tasks_db_data]

todo/tests/unit/repositories/__init__.py

@@ -0,0 +1 @@
+# Added this because without this file Django isn't able to auto detect the test files

todo/tests/unit/repositories/common/__init__.py

@@ -0,0 +1 @@
+# Added this because without this file Django isn't able to auto detect the test files

todo/tests/unit/repositories/common/test_mongo_repository.py

@@ -0,0 +1,57 @@
+from unittest import TestCase
+from unittest.mock import MagicMock, patch
+from todo.repositories.common.mongo_repository import MongoRepository
+from todo_project.db.config import DatabaseManager
+
+
+class MongoRepositoryTests(TestCase):
+    def test_subclass_without_collection_name_raises_error(self):
+        with self.assertRaises(TypeError) as context:
+
+            class InvalidRepository(MongoRepository):
+                pass
+
+        self.assertIn(
+            "Class InvalidRepository must define a static `collection_name` field as a string.", str(context.exception)
+        )
+
+    def test_subclass_with_invalid_collection_name_raises_error(self):
+        with self.assertRaises(TypeError) as context:
+
+            class InvalidRepository(MongoRepository):
+                collection_name = 123
+
+        self.assertIn(
+            "Class InvalidRepository must define a static `collection_name` field as a string.", str(context.exception)
+        )
+
+    def test_subclass_with_valid_collection_name_passes(self):
+        try:
+
+            class ValidRepository(MongoRepository):
+                collection_name = "valid_collection"
+        except TypeError:
+            self.fail("TypeError raised for a valid subclass with collection_name")
+
+    @patch.object(DatabaseManager, "get_collection")
+    def test_get_collection_initializes_collection(self, mock_get_collection):
+        class TestRepository(MongoRepository):
+            collection_name = "test_collection"
+
+        mock_get_collection.return_value = MagicMock()
+
+        collection = TestRepository.get_collection()
+        mock_get_collection.assert_called_once_with("test_collection")
+        self.assertEqual(TestRepository.collection, collection)
+
+    @patch.object(DatabaseManager, "get_collection")
+    def test_get_collection_uses_cached_collection(self, mock_get_collection):
+        class TestRepository(MongoRepository):
+            collection_name = "test_collection"
+
+        mock_get_collection.return_value = MagicMock()
+
+        TestRepository.get_collection()
+        TestRepository.get_collection()
+
+        mock_get_collection.assert_called_once_with("test_collection")

todo/tests/unit/repositories/test_label_repository.py

@@ -0,0 +1,42 @@
+from unittest import TestCase
+from unittest.mock import patch, MagicMock
+from pymongo.collection import Collection
+from todo.models.label import LabelModel
+from todo.repositories.label_repository import LabelRepository
+from todo.tests.fixtures.label import label_db_data
+
+
+class LabelRepositoryTests(TestCase):
+    def setUp(self):
+        self.label_ids = [label_data["_id"] for label_data in label_db_data]
+        self.label_data = label_db_data
+
+        self.patcher_get_collection = patch("todo.repositories.label_repository.LabelRepository.get_collection")
+        self.mock_get_collection = self.patcher_get_collection.start()
+        self.mock_collection = MagicMock(spec=Collection)
+        self.mock_get_collection.return_value = self.mock_collection
+
+    def tearDown(self):
+        self.patcher_get_collection.stop()
+
+    def test_list_by_ids_returns_label_models(self):
+        self.mock_collection.find.return_value = self.label_data
+
+        result = LabelRepository.list_by_ids(self.label_ids)
+
+        self.assertEqual(len(result), len(self.label_data))
+        self.assertTrue(all(isinstance(label, LabelModel) for label in result))
+
+    def test_list_by_ids_returns_empty_list_if_not_found(self):
+        self.mock_collection.find.return_value = []
+
+        result = LabelRepository.list_by_ids([self.label_ids[0]])
+
+        self.assertEqual(result, [])
+
+    def test_list_by_ids_skips_db_call_for_empty_input(self):
+        result = LabelRepository.list_by_ids([])
+
+        self.assertEqual(result, [])
+        self.mock_get_collection.assert_not_called()
+        self.mock_collection.assert_not_called()

todo/tests/unit/repositories/test_task_repository.py

@@ -0,0 +1,51 @@
+from unittest import TestCase
+from unittest.mock import patch, MagicMock
+from pymongo.collection import Collection
+from todo.models.task import TaskModel
+from todo.repositories.task_repository import TaskRepository
+from todo.tests.fixtures.task import tasks_db_data
+
+
+class TaskRepositoryTests(TestCase):
+    def setUp(self):
+        self.task_data = tasks_db_data
+
+        self.patcher_get_collection = patch("todo.repositories.task_repository.TaskRepository.get_collection")
+        self.mock_get_collection = self.patcher_get_collection.start()
+        self.mock_collection = MagicMock(spec=Collection)
+        self.mock_get_collection.return_value = self.mock_collection
+
+    def tearDown(self):
+        self.patcher_get_collection.stop()
+
+    def test_list_applies_pagination_correctly(self):
+        self.mock_collection.find.return_value.skip.return_value.limit.return_value = self.task_data
+
+        page = 1
+        limit = 10
+        result = TaskRepository.list(page, limit)
+
+        self.assertEqual(len(result), len(self.task_data))
+        self.assertTrue(all(isinstance(task, TaskModel) for task in result))
+
+        self.mock_collection.find.assert_called_once()
+        self.mock_collection.find.return_value.skip.assert_called_once_with(0)
+        self.mock_collection.find.return_value.skip.return_value.limit.assert_called_once_with(limit)
+
+    def test_list_returns_empty_list_for_no_tasks(self):
+        self.mock_collection.find.return_value.skip.return_value.limit.return_value = []
+
+        result = TaskRepository.list(2, 10)
+
+        self.assertEqual(result, [])
+        self.mock_collection.find.assert_called_once()
+        self.mock_collection.find.return_value.skip.assert_called_once_with(10)
+        self.mock_collection.find.return_value.skip.return_value.limit.assert_called_once_with(10)
+
+    def test_count_returns_total_task_count(self):
+        self.mock_collection.count_documents.return_value = 42
+
+        result = TaskRepository.count()
+
+        self.assertEqual(result, 42)
+        self.mock_collection.count_documents.assert_called_once_with({})