python-dependency-injector/tests/test_providers.py

"""Objects providers unittests."""

import unittest2 as unittest

from objects.providers import Provider
from objects.providers import Delegate
from objects.providers import Factory
from objects.providers import Singleton
from objects.providers import ExternalDependency
from objects.providers import Class
from objects.providers import Object
from objects.providers import Function
from objects.providers import Value
from objects.providers import Callable
from objects.providers import Config

from objects.injections import KwArg
from objects.injections import Attribute
from objects.injections import Method

from objects.utils import is_provider

from objects.errors import Error


class ProviderTests(unittest.TestCase):

    """Provider test cases."""

    def setUp(self):
        """Set test cases environment up."""
        self.provider = Provider()

    def test_is_provider(self):
        """Test `is_provider` check."""
        self.assertTrue(is_provider(self.provider))

    def test_call(self):
        """Test call."""
        self.assertRaises(NotImplementedError, self.provider.__call__)

    def test_delegate(self):
        """Test creating of provider delegation."""
        delegate1 = self.provider.delegate()

        self.assertIsInstance(delegate1, Delegate)
        self.assertIs(delegate1(), self.provider)

        delegate2 = self.provider.delegate()

        self.assertIsInstance(delegate2, Delegate)
        self.assertIs(delegate2(), self.provider)

        self.assertIsNot(delegate1, delegate2)

    def test_override(self):
        """Test provider overriding."""
        overriding_provider = Provider()
        self.provider.override(overriding_provider)
        self.assertTrue(self.provider.is_overridden)

    def test_override_with_not_provider(self):
        """Test provider overriding with not provider instance."""
        self.assertRaises(Error, self.provider.override, object())

    def test_last_overriding(self):
        """Test getting last overriding provider."""
        overriding_provider1 = Provider()
        overriding_provider2 = Provider()

        self.provider.override(overriding_provider1)
        self.assertIs(self.provider.last_overriding, overriding_provider1)

        self.provider.override(overriding_provider2)
        self.assertIs(self.provider.last_overriding, overriding_provider2)

    def test_last_overriding_of_not_overridden_provider(self):
        """Test getting last overriding from not overridden provider."""
        try:
            self.provider.last_overriding
        except Error:
            pass
        else:
            self.fail('Got en error in {}'.format(
                str(self.test_last_overriding_of_not_overridden_provider)))

    def test_reset_last_overriding(self):
        """Test reseting of last overriding provider."""
        overriding_provider1 = Provider()
        overriding_provider2 = Provider()

        self.provider.override(overriding_provider1)
        self.provider.override(overriding_provider2)

        self.assertIs(self.provider.last_overriding, overriding_provider2)

        self.provider.reset_last_overriding()
        self.assertIs(self.provider.last_overriding, overriding_provider1)

        self.provider.reset_last_overriding()
        self.assertFalse(self.provider.is_overridden)

    def test_reset_last_overriding_of_not_overridden_provider(self):
        """Test resetting of last overriding on not overridden provier."""
        self.assertRaises(Error, self.provider.reset_last_overriding)

    def test_reset_override(self):
        """Test reset of provider's override."""
        overriding_provider = Provider()
        self.provider.override(overriding_provider)

        self.assertTrue(self.provider.is_overridden)
        self.assertIs(self.provider.last_overriding, overriding_provider)

        self.provider.reset_override()

        self.assertFalse(self.provider.is_overridden)
        try:
            self.provider.last_overriding
        except Error:
            pass
        else:
            self.fail('Got en error in {}'.format(
                str(self.test_last_overriding_of_not_overridden_provider)))


class DelegateTests(unittest.TestCase):

    """Delegate test cases."""

    def setUp(self):
        """Set test cases environment up."""
        self.delegated = Provider()
        self.delegate = Delegate(delegated=self.delegated)

    def test_is_provider(self):
        """Test `is_provider` check."""
        self.assertTrue(is_provider(self.delegate))

    def test_init_with_not_provider(self):
        """Test that delegate accepts only another provider as delegated."""
        self.assertRaises(Error, Delegate, delegated=object())

    def test_call(self):
        """ Test returning of delegated provider."""
        delegated1 = self.delegate()
        delegated2 = self.delegate()

        self.assertIs(delegated1, self.delegated)
        self.assertIs(delegated2, self.delegated)


class FactoryTests(unittest.TestCase):

    """Factory test cases."""

    class Example(object):

        """Example class for Factory provider tests."""

        def __init__(self, init_arg1=None, init_arg2=None):
            """Initializer.

            :param init_arg1:
            :param init_arg2:
            :return:
            """
            self.init_arg1 = init_arg1
            self.init_arg2 = init_arg2

            self.attribute1 = None
            self.attribute2 = None

            self.method1_value = None
            self.method2_value = None

        def method1(self, value):
            """Setter method 1."""
            self.method1_value = value

        def method2(self, value):
            """Setter method 2."""
            self.method2_value = value

    def test_is_provider(self):
        """Test `is_provider` check."""
        self.assertTrue(is_provider(Factory(self.Example)))

    def test_init_with_callable(self):
        """Test creation of provider with a callable."""
        self.assertTrue(Factory(credits))

    def test_init_with_not_callable(self):
        """Test creation of provider with not a callable."""
        self.assertRaises(Error, Factory, 123)

    def test_call(self):
        """Test creation of new instances."""
        provider = Factory(self.Example)
        instance1 = provider()
        instance2 = provider()

        self.assertIsNot(instance1, instance2)
        self.assertIsInstance(instance1, self.Example)
        self.assertIsInstance(instance2, self.Example)

    def test_call_with_init_args(self):
        """Test creation of new instances with init args injections."""
        provider = Factory(self.Example,
                           KwArg('init_arg1', 'i1'),
                           KwArg('init_arg2', 'i2'))

        instance1 = provider()
        instance2 = provider()

        self.assertEqual(instance1.init_arg1, 'i1')
        self.assertEqual(instance1.init_arg2, 'i2')

        self.assertEqual(instance2.init_arg1, 'i1')
        self.assertEqual(instance2.init_arg2, 'i2')

        self.assertIsNot(instance1, instance2)
        self.assertIsInstance(instance1, self.Example)
        self.assertIsInstance(instance2, self.Example)

    def test_call_with_attributes(self):
        """Test creation of new instances with attribute injections."""
        provider = Factory(self.Example,
                           Attribute('attribute1', 'a1'),
                           Attribute('attribute2', 'a2'))

        instance1 = provider()
        instance2 = provider()

        self.assertEqual(instance1.attribute1, 'a1')
        self.assertEqual(instance1.attribute2, 'a2')

        self.assertEqual(instance2.attribute1, 'a1')
        self.assertEqual(instance2.attribute2, 'a2')

        self.assertIsNot(instance1, instance2)
        self.assertIsInstance(instance1, self.Example)
        self.assertIsInstance(instance2, self.Example)

    def test_call_with_methods(self):
        """Test creation of new instances with method injections."""
        provider = Factory(self.Example,
                           Method('method1', 'm1'),
                           Method('method2', 'm2'))

        instance1 = provider()
        instance2 = provider()

        self.assertEqual(instance1.method1_value, 'm1')
        self.assertEqual(instance1.method2_value, 'm2')

        self.assertEqual(instance2.method1_value, 'm1')
        self.assertEqual(instance2.method2_value, 'm2')

        self.assertIsNot(instance1, instance2)
        self.assertIsInstance(instance1, self.Example)
        self.assertIsInstance(instance2, self.Example)

    def test_call_with_context_args(self):
        """Test creation of new instances with context args."""
        provider = Factory(self.Example)
        instance = provider(11, 22)

        self.assertEqual(instance.init_arg1, 11)
        self.assertEqual(instance.init_arg2, 22)

    def test_call_with_context_kwargs(self):
        """Test creation of new instances with context kwargs."""
        provider = Factory(self.Example,
                           KwArg('init_arg1', 1))

        instance1 = provider(init_arg2=22)
        self.assertEqual(instance1.init_arg1, 1)
        self.assertEqual(instance1.init_arg2, 22)

        instance1 = provider(init_arg1=11, init_arg2=22)
        self.assertEqual(instance1.init_arg1, 11)
        self.assertEqual(instance1.init_arg2, 22)

    def test_call_overridden(self):
        """Test creation of new instances on overridden provider."""
        provider = Factory(self.Example)
        overriding_provider1 = Factory(dict)
        overriding_provider2 = Factory(list)

        provider.override(overriding_provider1)
        provider.override(overriding_provider2)

        instance1 = provider()
        instance2 = provider()

        self.assertIsNot(instance1, instance2)
        self.assertIsInstance(instance1, list)
        self.assertIsInstance(instance2, list)


class SingletonTests(unittest.TestCase):

    """Singleton test cases."""

    def test_call(self):
        """Test creation and returning of single object."""
        provider = Singleton(object)

        instance1 = provider()
        instance2 = provider()

        self.assertIsInstance(instance1, object)
        self.assertIsInstance(instance2, object)
        self.assertIs(instance1, instance2)

    def test_reset(self):
        """Test creation and reset of single object."""
        provider = Singleton(object)

        instance1 = provider()
        self.assertIsInstance(instance1, object)

        provider.reset()

        instance2 = provider()
        self.assertIsInstance(instance1, object)

        self.assertIsNot(instance1, instance2)


class ExternalDependencyTests(unittest.TestCase):

    """ExternalDependency test cases."""

    def setUp(self):
        """Set test cases environment up."""
        self.provider = ExternalDependency(instance_of=list)

    def test_init_with_not_class(self):
        """Test creation with not a class."""
        self.assertRaises(Error, ExternalDependency, object())

    def test_is_provider(self):
        """Test `is_provider` check."""
        self.assertTrue(is_provider(self.provider))

    def test_call_overridden(self):
        """Test call of overridden external dependency."""
        self.provider.provided_by(Factory(list))
        self.assertIsInstance(self.provider(), list)

    def test_call_overridden_but_not_instance_of(self):
        """Test call of overridden external dependency, but not instance of."""
        self.provider.provided_by(Factory(dict))
        self.assertRaises(Error, self.provider)

    def test_call_not_overridden(self):
        """Test call of not satisfied external dependency."""
        self.assertRaises(Error, self.provider)


class StaticProvidersTests(unittest.TestCase):

    """Static providers test cases."""

    def test_is_provider(self):
        """Test `is_provider` check."""
        self.assertTrue(is_provider(Class(object)))
        self.assertTrue(is_provider(Object(object())))
        self.assertTrue(is_provider(Function(map)))
        self.assertTrue(is_provider(Value(123)))

    def test_call_class_provider(self):
        """Test Class provider call."""
        self.assertIs(Class(dict)(), dict)

    def test_call_object_provider(self):
        """Test Object provider call."""
        obj = object()
        self.assertIs(Object(obj)(), obj)

    def test_call_function_provider(self):
        """Test Function provider call."""
        self.assertIs(Function(map)(), map)

    def test_call_value_provider(self):
        """Test Value provider call."""
        self.assertEqual(Value(123)(), 123)

    def test_call_overridden_class_provider(self):
        """Test overridden Class provider call."""
        cls_provider = Class(dict)
        cls_provider.override(Object(list))
        self.assertIs(cls_provider(), list)

    def test_call_overridden_object_provider(self):
        """Test overridden Object provider call."""
        obj1 = object()
        obj2 = object()
        obj_provider = Object(obj1)
        obj_provider.override(Object(obj2))
        self.assertIs(obj_provider(), obj2)

    def test_call_overridden_function_provider(self):
        """Test overridden Function provider call."""
        function_provider = Function(len)
        function_provider.override(Function(sum))
        self.assertIs(function_provider(), sum)

    def test_call_overridden_value_provider(self):
        """Test overridden Value provider call."""
        value_provider = Value(123)
        value_provider.override(Value(321))
        self.assertEqual(value_provider(), 321)


class CallableTests(unittest.TestCase):

    """Callable test cases."""

    def example(self, arg1, arg2, arg3):
        """Example callback."""
        return arg1, arg2, arg3

    def setUp(self):
        """Set test cases environment up."""
        self.provider = Callable(self.example,
                                 KwArg('arg1', 'a1'),
                                 KwArg('arg2', 'a2'),
                                 KwArg('arg3', 'a3'))

    def test_init_with_not_callable(self):
        """Test creation of provider with not callable."""
        self.assertRaises(Error, Callable, 123)

    def test_is_provider(self):
        """Test `is_provider` check."""
        self.assertTrue(is_provider(self.provider))

    def test_call(self):
        """Test provider call."""
        self.assertEqual(self.provider(), ('a1', 'a2', 'a3'))

    def test_call_with_args(self):
        """Test provider call with kwargs priority."""
        provider = Callable(self.example,
                            KwArg('arg3', 'a3'))
        self.assertEqual(provider(1, 2), (1, 2, 'a3'))

    def test_call_with_kwargs_priority(self):
        """Test provider call with kwargs priority."""
        self.assertEqual(self.provider(arg1=1, arg3=3), (1, 'a2', 3))

    def test_call_overridden(self):
        """Test overridden provider call."""
        overriding_provider1 = Value((1, 2, 3))
        overriding_provider2 = Value((3, 2, 1))

        self.provider.override(overriding_provider1)
        self.provider.override(overriding_provider2)

        result1 = self.provider()
        result2 = self.provider()

        self.assertEqual(result1, (3, 2, 1))
        self.assertEqual(result2, (3, 2, 1))


class ConfigTests(unittest.TestCase):

    """Config test cases."""

    def setUp(self):
        """Set test cases environment up."""
        self.initial_data = dict(key='value',
                                 category=dict(setting='setting_value'))
        self.provider = Config(self.initial_data)

    def test_is_provider(self):
        """Test `is_provider` check."""
        self.assertTrue(is_provider(self.provider))

    def test_init_without_initial_value(self):
        """Test provider's creation with no initial value."""
        self.assertEqual(Config()(), dict())

    def test_call(self):
        """Test returning of config value."""
        self.assertEqual(self.provider(), self.initial_data)

    def test_update_from(self):
        """Test update of config value."""
        self.assertEqual(self.provider(), self.initial_data)

        self.initial_data['key'] = 'other_value'
        self.provider.update_from(self.initial_data)
        self.assertEqual(self.provider(), self.initial_data)

    def test_call_child(self):
        """Test returning of child config values."""
        category = self.provider.category
        category_setting = self.provider.category.setting

        self.assertTrue(is_provider(category))
        self.assertTrue(is_provider(category_setting))

        self.assertEqual(category(), self.initial_data['category'])
        self.assertEqual(category_setting(),
                         self.initial_data['category']['setting'])

    def test_call_deferred_child_and_update_from(self):
        """Test returning of deferred child config values."""
        self.provider = Config()
        category = self.provider.category
        category_setting = self.provider.category.setting

        self.assertTrue(is_provider(category))
        self.assertTrue(is_provider(category_setting))

        self.provider.update_from(self.initial_data)

        self.assertEqual(category(), self.initial_data['category'])
        self.assertEqual(category_setting(),
                         self.initial_data['category']['setting'])

    def test_call_deferred_child_with_empty_value(self):
        """Test returning of deferred child config values."""
        self.provider = Config()
        category_setting = self.provider.category.setting
        self.assertRaises(Error, category_setting)