python-dependency-injector/tests/unit/providers/test_singletons.py

"""Dependency injector singleton providers unit tests."""

import unittest2 as unittest

from dependency_injector import (
    providers,
    errors,
)


class Example(object):

    def __init__(self, init_arg1=None, init_arg2=None, init_arg3=None,
                 init_arg4=None):
        self.init_arg1 = init_arg1
        self.init_arg2 = init_arg2
        self.init_arg3 = init_arg3
        self.init_arg4 = init_arg4

        self.attribute1 = None
        self.attribute2 = None


class SingletonTests(unittest.TestCase):

    def test_is_provider(self):
        self.assertTrue(providers.is_provider(providers.Singleton(Example)))

    def test_init_with_callable(self):
        self.assertTrue(providers.Singleton(credits))

    def test_init_with_not_callable(self):
        self.assertRaises(errors.Error, providers.Singleton, 123)

    def test_init_with_valid_provided_type(self):
        class ExampleProvider(providers.Singleton):
            provided_type = Example

        example_provider = ExampleProvider(Example, 1, 2)

        self.assertIsInstance(example_provider(), Example)

    def test_init_with_valid_provided_subtype(self):
        class ExampleProvider(providers.Singleton):
            provided_type = Example

        class NewExampe(Example):
            pass

        example_provider = ExampleProvider(NewExampe, 1, 2)

        self.assertIsInstance(example_provider(), NewExampe)

    def test_init_with_invalid_provided_type(self):
        class ExampleProvider(providers.Singleton):
            provided_type = Example

        with self.assertRaises(errors.Error):
            ExampleProvider(list)

    def test_call(self):
        provider = providers.Singleton(Example)

        instance1 = provider()
        instance2 = provider()

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

    def test_call_with_init_positional_args(self):
        provider = providers.Singleton(Example, 'i1', '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.assertIs(instance1, instance2)
        self.assertIsInstance(instance1, Example)
        self.assertIsInstance(instance2, Example)

    def test_call_with_init_keyword_args(self):
        provider = providers.Singleton(Example, init_arg1='i1', 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.assertIs(instance1, instance2)
        self.assertIsInstance(instance1, Example)
        self.assertIsInstance(instance2, Example)

    def test_call_with_init_positional_and_keyword_args(self):
        provider = providers.Singleton(Example, 'i1', 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.assertIs(instance1, instance2)
        self.assertIsInstance(instance1, Example)
        self.assertIsInstance(instance2, Example)

    def test_call_with_attributes(self):
        provider = providers.Singleton(Example)
        provider.add_attributes(attribute1='a1', 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.assertIs(instance1, instance2)
        self.assertIsInstance(instance1, Example)
        self.assertIsInstance(instance2, Example)

    def test_call_with_context_args(self):
        provider = providers.Singleton(Example)

        instance = provider(11, 22)

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

    def test_call_with_context_kwargs(self):
        provider = providers.Singleton(Example, init_arg1=1)

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

        # Instance is created earlier
        instance1 = provider(init_arg1=11, init_arg2=22)
        self.assertEqual(instance1.init_arg1, 1)
        self.assertEqual(instance1.init_arg2, 22)

    def test_call_with_context_args_and_kwargs(self):
        provider = providers.Singleton(Example, 11)

        instance = provider(22, init_arg3=33, init_arg4=44)

        self.assertEqual(instance.init_arg1, 11)
        self.assertEqual(instance.init_arg2, 22)
        self.assertEqual(instance.init_arg3, 33)
        self.assertEqual(instance.init_arg4, 44)

    def test_fluent_interface(self):
        provider = providers.Singleton(Example) \
            .add_args(1, 2) \
            .add_kwargs(init_arg3=3, init_arg4=4) \
            .add_attributes(attribute1=5, attribute2=6)

        instance = provider()

        self.assertEqual(instance.init_arg1, 1)
        self.assertEqual(instance.init_arg2, 2)
        self.assertEqual(instance.init_arg3, 3)
        self.assertEqual(instance.init_arg4, 4)
        self.assertEqual(instance.attribute1, 5)
        self.assertEqual(instance.attribute2, 6)

    def test_call_overridden(self):
        provider = providers.Singleton(Example)
        overriding_provider1 = providers.Singleton(dict)
        overriding_provider2 = providers.Singleton(object)

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

        instance1 = provider()
        instance2 = provider()

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

    def test_reset(self):
        provider = providers.Singleton(object)

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

        provider.reset()

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

        self.assertIsNot(instance1, instance2)

    def test_repr(self):
        provider = providers.Singleton(Example)

        self.assertEqual(repr(provider),
                         '<dependency_injector.providers.creational.'
                         'Singleton({0}) at {1}>'.format(
                             repr(Example),
                             hex(id(provider))))


class DelegatedSingletonTests(unittest.TestCase):

    def test_inheritance(self):
        self.assertIsInstance(providers.DelegatedSingleton(object),
                              providers.Singleton)

    def test_is_provider(self):
        self.assertTrue(
            providers.is_provider(providers.DelegatedSingleton(object)))

    def test_is_delegated_provider(self):
        provider = providers.DelegatedSingleton(object)
        self.assertIs(provider.provide_injection(), provider)


class ThreadLocalSingletonTests(unittest.TestCase):

    def test_is_provider(self):
        self.assertTrue(
            providers.is_provider(providers.ThreadLocalSingleton(Example)))

    def test_init_with_callable(self):
        self.assertTrue(providers.ThreadLocalSingleton(credits))

    def test_init_with_not_callable(self):
        self.assertRaises(errors.Error, providers.ThreadLocalSingleton, 123)

    def test_init_with_valid_provided_type(self):
        class ExampleProvider(providers.ThreadLocalSingleton):
            provided_type = Example

        example_provider = ExampleProvider(Example, 1, 2)

        self.assertIsInstance(example_provider(), Example)

    def test_init_with_valid_provided_subtype(self):
        class ExampleProvider(providers.ThreadLocalSingleton):
            provided_type = Example

        class NewExampe(Example):
            pass

        example_provider = ExampleProvider(NewExampe, 1, 2)

        self.assertIsInstance(example_provider(), NewExampe)

    def test_init_with_invalid_provided_type(self):
        class ExampleProvider(providers.ThreadLocalSingleton):
            provided_type = Example

        with self.assertRaises(errors.Error):
            ExampleProvider(list)

    def test_call(self):
        provider = providers.ThreadLocalSingleton(Example)

        instance1 = provider()
        instance2 = provider()

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

    def test_call_with_init_positional_args(self):
        provider = providers.ThreadLocalSingleton(Example, 'i1', '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.assertIs(instance1, instance2)
        self.assertIsInstance(instance1, Example)
        self.assertIsInstance(instance2, Example)

    def test_call_with_init_keyword_args(self):
        provider = providers.ThreadLocalSingleton(Example,
                                                  init_arg1='i1',
                                                  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.assertIs(instance1, instance2)
        self.assertIsInstance(instance1, Example)
        self.assertIsInstance(instance2, Example)

    def test_call_with_init_positional_and_keyword_args(self):
        provider = providers.ThreadLocalSingleton(Example,
                                                  'i1',
                                                  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.assertIs(instance1, instance2)
        self.assertIsInstance(instance1, Example)
        self.assertIsInstance(instance2, Example)

    def test_call_with_attributes(self):
        provider = providers.ThreadLocalSingleton(Example)
        provider.add_attributes(attribute1='a1', 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.assertIs(instance1, instance2)
        self.assertIsInstance(instance1, Example)
        self.assertIsInstance(instance2, Example)

    def test_call_with_context_args(self):
        provider = providers.ThreadLocalSingleton(Example)

        instance = provider(11, 22)

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

    def test_call_with_context_kwargs(self):
        provider = providers.ThreadLocalSingleton(Example, init_arg1=1)

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

        # Instance is created earlier
        instance1 = provider(init_arg1=11, init_arg2=22)
        self.assertEqual(instance1.init_arg1, 1)
        self.assertEqual(instance1.init_arg2, 22)

    def test_call_with_context_args_and_kwargs(self):
        provider = providers.ThreadLocalSingleton(Example, 11)

        instance = provider(22, init_arg3=33, init_arg4=44)

        self.assertEqual(instance.init_arg1, 11)
        self.assertEqual(instance.init_arg2, 22)
        self.assertEqual(instance.init_arg3, 33)
        self.assertEqual(instance.init_arg4, 44)

    def test_fluent_interface(self):
        provider = providers.ThreadLocalSingleton(Example) \
            .add_args(1, 2) \
            .add_kwargs(init_arg3=3, init_arg4=4) \
            .add_attributes(attribute1=5, attribute2=6)

        instance = provider()

        self.assertEqual(instance.init_arg1, 1)
        self.assertEqual(instance.init_arg2, 2)
        self.assertEqual(instance.init_arg3, 3)
        self.assertEqual(instance.init_arg4, 4)
        self.assertEqual(instance.attribute1, 5)
        self.assertEqual(instance.attribute2, 6)

    def test_call_overridden(self):
        provider = providers.ThreadLocalSingleton(Example)
        overriding_provider1 = providers.ThreadLocalSingleton(dict)
        overriding_provider2 = providers.ThreadLocalSingleton(object)

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

        instance1 = provider()
        instance2 = provider()

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

    def test_reset(self):
        provider = providers.ThreadLocalSingleton(object)

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

        provider.reset()

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

        self.assertIsNot(instance1, instance2)

    def test_repr(self):
        provider = providers.ThreadLocalSingleton(Example)

        self.assertEqual(repr(provider),
                         '<dependency_injector.providers.creational.'
                         'ThreadLocalSingleton({0}) at {1}>'.format(
                             repr(Example),
                             hex(id(provider))))


class DelegatedThreadLocalSingletonTests(unittest.TestCase):

    def test_inheritance(self):
        self.assertIsInstance(providers.DelegatedThreadLocalSingleton(object),
                              providers.ThreadLocalSingleton)

    def test_is_provider(self):
        self.assertTrue(
            providers.is_provider(
                providers.DelegatedThreadLocalSingleton(object)))

    def test_is_delegated_provider(self):
        provider = providers.DelegatedThreadLocalSingleton(object)
        self.assertIs(provider.provide_injection(), provider)