core/tests/test_loader.py

"""Test to verify that we can load components."""
# pylint: disable=protected-access
import unittest

import homeassistant.loader as loader
import homeassistant.components.http as http

from tests.common import get_test_home_assistant, MockModule


class TestLoader(unittest.TestCase):
    """Test the loader module."""

    # pylint: disable=invalid-name
    def setUp(self):
        """Setup tests."""
        self.hass = get_test_home_assistant()

    # pylint: disable=invalid-name
    def tearDown(self):
        """Stop everything that was started."""
        self.hass.stop()

    def test_set_component(self):
        """Test if set_component works."""
        loader.set_component('switch.test_set', http)

        self.assertEqual(http, loader.get_component('switch.test_set'))

    def test_get_component(self):
        """Test if get_component works."""
        self.assertEqual(http, loader.get_component('http'))

        self.assertIsNotNone(loader.get_component('switch.test'))

    def test_load_order_component(self):
        """Test if we can get the proper load order of components."""
        loader.set_component('mod1', MockModule('mod1'))
        loader.set_component('mod2', MockModule('mod2', ['mod1']))
        loader.set_component('mod3', MockModule('mod3', ['mod2']))

        self.assertEqual(
            ['mod1', 'mod2', 'mod3'], loader.load_order_component('mod3'))

        # Create circular dependency
        loader.set_component('mod1', MockModule('mod1', ['mod3']))

        self.assertEqual([], loader.load_order_component('mod3'))

        # Depend on non-existing component
        loader.set_component('mod1', MockModule('mod1', ['nonexisting']))

        self.assertEqual([], loader.load_order_component('mod1'))

        # Try to get load order for non-existing component
        self.assertEqual([], loader.load_order_component('mod1'))