conference-room-booking-system/backend/tests/services/test_users.py

"""Unit tests for the backend.services.users module."""

from unittest.mock import AsyncMock
from unittest.mock import MagicMock

import pytest
from sqlalchemy import select
from sqlalchemy.exc import SQLAlchemyError
from sqlalchemy.ext.asyncio import AsyncSession

from backend.models import User  # Add this import for the User model
from backend.services.users import get_users


@pytest.mark.asyncio
@pytest.mark.parametrize("mock_logger", ["backend.services.users"], indirect=True)
async def test_get_users_success(
    async_session: AsyncSession, sample_users: list[User], mock_logger: MagicMock
) -> None:
    """Test successful retrieval of all users from the database.

    Args:
        async_session: The asynchronous database session.
        sample_users: The list of sample user objects to return.
        mock_logger: The mocked logger instance.
    """
    mock_scalars_result = AsyncMock()
    mock_scalars_result.all = MagicMock(return_value=sample_users)
    mock_scalars = AsyncMock(return_value=mock_scalars_result)
    async_session.scalars = mock_scalars  # type: ignore [method-assign]

    result: list[User] = await get_users(async_session)

    assert isinstance(result, list)
    assert len(result) == 2
    assert result == sample_users
    async_session.scalars.assert_called_once()
    assert async_session.scalars.call_args.args[0].compare(select(User))


@pytest.mark.asyncio
@pytest.mark.parametrize("mock_logger", ["backend.services.users"], indirect=True)
async def test_get_users_empty(
    async_session: AsyncSession, mock_logger: MagicMock
) -> None:
    """Test retrieval of users when the database is empty.

    Args:
        async_session: The asynchronous database session.
        mock_logger: The mocked logger instance.
    """
    mock_scalars_result = AsyncMock()
    mock_scalars_result.all = MagicMock(return_value=[])
    mock_scalars = AsyncMock(return_value=mock_scalars_result)
    async_session.scalars = mock_scalars  # type: ignore [method-assign]

    result: list[User] = await get_users(async_session)

    assert isinstance(result, list)
    assert len(result) == 0
    async_session.scalars.assert_called_once()
    assert async_session.scalars.call_args.args[0].compare(select(User))


@pytest.mark.asyncio
@pytest.mark.parametrize("mock_logger", ["backend.services.users"], indirect=True)
async def test_get_users_database_error(
    async_session: AsyncSession, mock_logger: MagicMock
) -> None:
    """Test handling of database errors in get_users.

    Verifies that get_users raises an exception on database failure.

    Args:
        async_session: The asynchronous database session.
        mock_logger: The mocked logger instance.
    """
    async_session.scalars = AsyncMock(  # type: ignore [method-assign]
        side_effect=SQLAlchemyError("Database error")
    )

    with pytest.raises(SQLAlchemyError):
        await get_users(async_session)
    async_session.scalars.assert_called_once()