Write unit tests with pytest and TestClient

[Navashub]

Description

The project has no automated tests. Add a pytest test suite covering the core CRUD flows.

What to do

• Add pip install pytest httpx to dependencies
• Create a tests/ folder with __init__.py and test_tasks.py, test_users.py
• Use FastAPI's TestClient with an in-memory SQLite database (not tasks.db)
• Write tests for at minimum:
  • Create a user → assert 200, assert name in response
  • Create a task for that user → assert 200, assert completed is False
  • Get all tasks → assert list contains the created task
  • Update task to completed → assert completed is True
  • Delete the task → assert 200, assert task no longer returned

Acceptance Criteria

• pytest runs and all tests pass
• Tests use a separate test database, not the development tasks.db
• No test leaves data behind (use TestClient with a fresh DB per session)

Hints

• Override the get_db dependency in tests to point at a test database
• FastAPI docs on testing: https://fastapi.tiangolo.com/tutorial/testing/

Difficulty

🟡 Intermediate