python-dependency-injector/tests/test_injections.py

"""Dependency injector injections unittests."""

import warnings

import unittest2 as unittest

from dependency_injector import injections
from dependency_injector import providers
from dependency_injector import errors


class InjectTests(unittest.TestCase):
    """Inject decorator test cases."""

    def test_decorated_args(self):
        """Test `inject()` decoration with args."""
        provider1 = providers.Factory(object)
        provider2 = providers.Factory(list)

        @injections.inject(provider1, 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_args_several_times(self):
        """Test `inject()` decoration with args several times."""
        provider1 = providers.Factory(object)
        provider2 = providers.Factory(list)

        @injections.inject(provider2)
        @injections.inject(provider1)
        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_context_args(self):
        """Test `inject()` decoration with context args."""
        provider1 = providers.Factory(object)
        provider2 = providers.Factory(list)

        @injections.inject(provider1)
        def test(a, b):
            return a, b

        a1, b1 = test(provider2())
        a2, b2 = test(provider2())

        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(self):
        """Test `inject()` decoration with kwargs."""
        provider1 = providers.Factory(object)
        provider2 = providers.Factory(list)

        @injections.inject(a=provider1)
        @injections.inject(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 = providers.Factory(object)
        provider2 = providers.Factory(list)
        object_a = object()

        @injections.inject(a=provider1)
        @injections.inject(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 = providers.Factory(list)
        object_a = object()

        @injections.inject(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_class_method(self):
        """Test `inject()` decorator with class method."""
        class Test(object):
            """Test class."""

            @injections.inject(arg1=123)
            @injections.inject(arg2=456)
            def some_method(self, arg1, arg2):
                """Some test method."""
                return arg1, arg2

        test_object = Test()
        arg1, arg2 = test_object.some_method()

        self.assertEquals(arg1, 123)
        self.assertEquals(arg2, 456)

    def test_decorate_class_with_init(self):
        """Test `inject()` decorator that decorate class with __init__."""
        @injections.inject(arg1=123)
        @injections.inject(arg2=456)
        class Test(object):
            """Test class."""

            def __init__(self, arg1, arg2):
                """Init."""
                self.arg1 = arg1
                self.arg2 = arg2

        test_object = Test()

        self.assertEquals(test_object.arg1, 123)
        self.assertEquals(test_object.arg2, 456)

    def test_decorate_class_without_init(self):
        """Test `inject()` decorator that decorate class without __init__."""
        with self.assertRaises(errors.Error):
            @injections.inject(arg1=123)
            class Test(object):
                """Test class."""


class InjectDeprecationTests(unittest.TestCase):
    """Deprecation of `@inject()` tests."""

    def test_deprecation_warning_on_usage(self):
        """Test that DeprecationWarning is produced when `@inject` is used."""
        with warnings.catch_warnings(record=True) as caught_warnings:
            warnings.simplefilter('always')

            @injections.inject(1)
            def _example(arg):
                pass

            warnings.simplefilter('default')

        self.assertEquals(len(caught_warnings), 1)
        self.assertEquals(caught_warnings[-1].category, DeprecationWarning)
        self.assertIn('Call to a deprecated decorator',
                      str(caught_warnings[-1].message))
        self.assertIn('@dependency_injector.injections.inject',
                      str(caught_warnings[-1].message))