Add tests for task repository (#5)

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({})