python-dependency-injector/tests/test_injections.py

"""Objects injections unittests."""

import unittest2 as unittest

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

from objects.providers import NewInstance

from objects.providers import Error


class InjectionTests(unittest.TestCase):

    """Injection test cases."""

    def test_init(self):
        """Test Injection creation and initialization."""
        injection = Injection('some_arg_name', 'some_value')
        self.assertEqual(injection.name, 'some_arg_name')
        self.assertEqual(injection.injectable, 'some_value')

    def test_value_with_scalar_injectable(self):
        """Test Injection value property with scalar value."""
        injection = Injection('some_arg_name', 'some_value')
        self.assertEqual(injection.value, 'some_value')

    def test_value_with_provider_injectable(self):
        """Test Injection value property with provider."""
        injection = Injection('some_arg_name', NewInstance(object))
        self.assertIsInstance(injection.value, object)


class KwArgTests(unittest.TestCase):

    """Keyword arg injection test cases."""

    def test_init(self):
        """Test KwArg creation and initialization."""
        injection = KwArg('some_arg_name', 'some_value')
        self.assertEqual(injection.name, 'some_arg_name')
        self.assertEqual(injection.injectable, 'some_value')


class AttributeTests(unittest.TestCase):

    """Attribute injection test cases."""

    def test_init(self):
        """Test Attribute creation and initialization."""
        injection = Attribute('some_arg_name', 'some_value')
        self.assertEqual(injection.name, 'some_arg_name')
        self.assertEqual(injection.injectable, 'some_value')


class MethodTests(unittest.TestCase):

    """Method injection test cases."""

    def test_init(self):
        """Test Method creation and initialization."""
        injection = Method('some_arg_name', 'some_value')
        self.assertEqual(injection.name, 'some_arg_name')
        self.assertEqual(injection.injectable, 'some_value')


class InjectTests(unittest.TestCase):

    """Inject decorator test cases."""

    def test_decorated(self):
        """Test `inject()` decorated callback."""
        provider1 = NewInstance(object)
        provider2 = NewInstance(list)

        @inject(KwArg('a', provider1))
        @inject(KwArg('b', provider2))
        def test(a, b):
            return a, b

        a1, b1 = test()
        a2, b2 = test()

        self.assertIsInstance(a1, object)
        self.assertIsInstance(a2, object)
        self.assertIsNot(a1, a2)

        self.assertIsInstance(b1, list)
        self.assertIsInstance(b2, list)
        self.assertIsNot(b1, b2)

    def test_decorated_kwargs_priority(self):
        """Test `inject()` decorated callback kwargs priority."""
        provider1 = NewInstance(object)
        provider2 = NewInstance(list)
        object_a = object()

        @inject(KwArg('a', provider1))
        @inject(KwArg('b', provider2))
        def test(a, b):
            return a, b

        a1, b1 = test(a=object_a)
        a2, b2 = test(a=object_a)

        self.assertIsInstance(a1, object)
        self.assertIsInstance(a2, object)
        self.assertIs(a1, object_a)
        self.assertIs(a2, object_a)

        self.assertIsInstance(b1, list)
        self.assertIsInstance(b2, list)
        self.assertIsNot(b1, b2)

    def test_decorated_with_args(self):
        """Test `inject()` decorated callback with args."""
        provider = NewInstance(list)
        object_a = object()

        @inject(KwArg('b', provider))
        def test(a, b):
            return a, b

        a1, b1 = test(object_a)
        a2, b2 = test(object_a)

        self.assertIsInstance(a1, object)
        self.assertIsInstance(a2, object)
        self.assertIs(a1, object_a)
        self.assertIs(a2, object_a)

        self.assertIsInstance(b1, list)
        self.assertIsInstance(b2, list)
        self.assertIsNot(b1, b2)

    def test_decorate_with_not_injection(self):
        """Test `inject()` decorator with not an injection instance."""
        self.assertRaises(Error, inject, object)