Add support of positional argument injections for Callable provider

Also current commit contains:
- Some refactoring of internals
- Additional unit tests for Factory and Singleton providers

dependency_injector/injections.py

@@ -1,11 +1,14 @@
 """Injections module."""
 
 import sys
+import itertools
+
 import six
 
 from .utils import is_provider
-from .utils import ensure_is_injection
+from .utils import is_injection
-from .utils import get_injectable_kwargs
+from .utils import is_arg_injection
+from .utils import is_kwarg_injection
 
 from .errors import Error
 
@@ -77,11 +80,7 @@ def inject(*args, **kwargs):
     :type injection: Injection
     :return: (callable) -> (callable)
     """
-    injections = tuple(KwArg(name, value)
+    injections = _parse_kwargs_injections(args, kwargs)
-                       for name, value in six.iteritems(kwargs))
-    if args:
-        injections += tuple(ensure_is_injection(injection)
-                            for injection in args)
 
     def decorator(callback_or_cls):
         """Dependency injection decorator."""
@@ -107,10 +106,41 @@ def inject(*args, **kwargs):
         def decorated(*args, **kwargs):
             """Decorated with dependency injection callback."""
             return callback(*args,
-                            **get_injectable_kwargs(kwargs,
+                            **_get_injectable_kwargs(kwargs,
-                                                    decorated.injections))
+                                                     decorated.injections))
 
         decorated.injections = injections
 
         return decorated
     return decorator
+
+
+def _parse_args_injections(args):
+    """Parse positional argument injections according to current syntax."""
+    return tuple(Arg(arg) if not is_injection(arg) else arg
+                 for arg in args
+                 if not is_injection(arg) or is_arg_injection(arg))
+
+
+def _parse_kwargs_injections(args, kwargs):
+    """Parse keyword argument injections according to current syntax."""
+    kwarg_injections = tuple(injection
+                             for injection in args
+                             if is_kwarg_injection(injection))
+    if kwargs:
+        kwarg_injections += tuple(KwArg(name, value)
+                                  for name, value in six.iteritems(kwargs))
+    return kwarg_injections
+
+
+def _get_injectable_args(context_args, arg_injections):
+    """Return tuple of positional arguments, patched with injections."""
+    return itertools.chain((arg.value for arg in arg_injections), context_args)
+
+
+def _get_injectable_kwargs(context_kwargs, kwarg_injections):
+    """Return dictionary of keyword arguments, patched with injections."""
+    injectable_kwargs = dict((kwarg.name, kwarg.value)
+                             for kwarg in kwarg_injections)
+    injectable_kwargs.update(context_kwargs)
+    return injectable_kwargs

dependency_injector/providers.py

@@ -2,17 +2,14 @@
 
 import six
 
-from .injections import Arg
+from .injections import _parse_args_injections
-from .injections import KwArg
+from .injections import _parse_kwargs_injections
+from .injections import _get_injectable_args
+from .injections import _get_injectable_kwargs
 
 from .utils import ensure_is_provider
-from .utils import is_injection
-from .utils import is_arg_injection
-from .utils import is_kwarg_injection
 from .utils import is_attribute_injection
 from .utils import is_method_injection
-from .utils import get_injectable_args
-from .utils import get_injectable_kwargs
 from .utils import GLOBAL_LOCK
 
 from .errors import Error
@@ -116,15 +113,8 @@ class Factory(Provider):
             raise Error('Factory provider expects to get callable, ' +
                         'got {0} instead'.format(str(provides)))
         self.provides = provides
-        self.args = tuple(Arg(arg) if not is_injection(arg) else arg
+        self.args = _parse_args_injections(args)
-                          for arg in args
+        self.kwargs = _parse_kwargs_injections(args, kwargs)
-                          if not is_injection(arg) or is_arg_injection(arg))
-        self.kwargs = tuple(injection
-                            for injection in args
-                            if is_kwarg_injection(injection))
-        if kwargs:
-            self.kwargs += tuple(KwArg(name, value)
-                                 for name, value in six.iteritems(kwargs))
         self.attributes = tuple(injection
                                 for injection in args
                                 if is_attribute_injection(injection))
@@ -135,8 +125,8 @@ class Factory(Provider):
 
     def _provide(self, *args, **kwargs):
         """Return provided instance."""
-        instance = self.provides(*get_injectable_args(args, self.args),
+        instance = self.provides(*_get_injectable_args(args, self.args),
-                                 **get_injectable_kwargs(kwargs, self.kwargs))
+                                 **_get_injectable_kwargs(kwargs, self.kwargs))
         for attribute in self.attributes:
             setattr(instance, attribute.name, attribute.value)
         for method in self.methods:
@@ -258,21 +248,21 @@ class Callable(Provider):
     with some predefined dependency injections.
     """
 
-    __slots__ = ('callback', 'kwargs')
+    __slots__ = ('callback', 'args', 'kwargs')
 
-    def __init__(self, callback, **kwargs):
+    def __init__(self, callback, *args, **kwargs):
         """Initializer."""
         if not callable(callback):
             raise Error('Callable expected, got {0}'.format(str(callback)))
         self.callback = callback
-        self.kwargs = tuple(KwArg(name, value)
+        self.args = _parse_args_injections(args)
-                            for name, value in six.iteritems(kwargs))
+        self.kwargs = _parse_kwargs_injections(args, kwargs)
         super(Callable, self).__init__()
 
     def _provide(self, *args, **kwargs):
         """Return provided instance."""
-        return self.callback(*args, **get_injectable_kwargs(kwargs,
+        return self.callback(*_get_injectable_args(args, self.args),
-                                                            self.kwargs))
+                             **_get_injectable_kwargs(kwargs, self.kwargs))
 
 
 class Config(Provider):

dependency_injector/utils.py

@@ -1,7 +1,6 @@
 """Utils module."""
 
 import threading
-import itertools
 
 import six
 
@@ -87,16 +86,3 @@ def ensure_is_catalog_bundle(instance):
         raise Error('Expected catalog bundle instance, '
                     'got {0}'.format(str(instance)))
     return instance
-
-
-def get_injectable_args(context_args, arg_injections):
-    """Return tuple of positional args, patched with injections."""
-    return itertools.chain((arg.value for arg in arg_injections), context_args)
-
-
-def get_injectable_kwargs(context_kwargs, kwarg_injections):
-    """Return dictionary of keyword args, patched with injections."""
-    kwargs = dict((kwarg.name, kwarg.value)
-                  for kwarg in kwarg_injections)
-    kwargs.update(context_kwargs)
-    return kwargs

tests/test_injections.py

@@ -161,10 +161,6 @@ class InjectTests(unittest.TestCase):
         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(di.Error, di.inject, object)
-
     def test_decorate_class_method(self):
         """Test `inject()` decorator with class method."""
         class Test(object):

tests/test_providers.py

@@ -7,7 +7,8 @@ import dependency_injector as di
 class Example(object):
     """Example class for Factory provider tests."""
 
-    def __init__(self, init_arg1=None, init_arg2=None):
+    def __init__(self, init_arg1=None, init_arg2=None, init_arg3=None,
+                 init_arg4=None):
         """Initializer.
 
         :param init_arg1:
@@ -16,6 +17,8 @@ class Example(object):
         """
         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
@@ -304,11 +307,13 @@ class FactoryTests(unittest.TestCase):
 
     def test_call_with_context_args(self):
         """Test creation of new instances with context args."""
-        provider = di.Factory(Example)
+        provider = di.Factory(Example, 11, 22)
-        instance = provider(11, 22)
+        instance = provider(33, 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_call_with_context_kwargs(self):
         """Test creation of new instances with context kwargs."""
@@ -319,9 +324,19 @@ class FactoryTests(unittest.TestCase):
         self.assertEqual(instance1.init_arg1, 1)
         self.assertEqual(instance1.init_arg2, 22)
 
-        instance1 = provider(init_arg1=11, init_arg2=22)
+        instance2 = provider(init_arg1=11, init_arg2=22)
-        self.assertEqual(instance1.init_arg1, 11)
+        self.assertEqual(instance2.init_arg1, 11)
-        self.assertEqual(instance1.init_arg2, 22)
+        self.assertEqual(instance2.init_arg2, 22)
+
+    def test_call_with_context_args_and_kwargs(self):
+        """Test creation of new instances with context args and kwargs."""
+        provider = di.Factory(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_call_overridden(self):
         """Test creation of new instances on overridden provider."""
@@ -521,6 +536,16 @@ class SingletonTests(unittest.TestCase):
         self.assertEqual(instance1.init_arg1, 1)
         self.assertEqual(instance1.init_arg2, 22)
 
+    def test_call_with_context_args_and_kwargs(self):
+        """Test getting of instances with context args and kwargs."""
+        provider = di.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_call_overridden(self):
         """Test getting of instances on overridden provider."""
         provider = di.Singleton(Example)
@@ -653,52 +678,82 @@ class StaticProvidersTests(unittest.TestCase):
 class CallableTests(unittest.TestCase):
     """Callable test cases."""
 
-    def example(self, arg1, arg2, arg3):
+    def example(self, arg1, arg2, arg3, arg4):
         """Example callback."""
-        return arg1, arg2, arg3
+        return arg1, arg2, arg3, arg4
 
-    def setUp(self):
+    def test_init_with_callable(self):
-        """Set test cases environment up."""
+        """Test creation of provider with a callable."""
-        self.provider = di.Callable(self.example,
+        self.assertTrue(di.Callable(self.example))
-                                    arg1='a1',
-                                    arg2='a2',
-                                    arg3='a3')
 
     def test_init_with_not_callable(self):
-        """Test creation of provider with not callable."""
+        """Test creation of provider with not a callable."""
         self.assertRaises(di.Error, di.Callable, 123)
 
-    def test_is_provider(self):
-        """Test `is_provider` check."""
-        self.assertTrue(di.is_provider(self.provider))
-
     def test_call(self):
-        """Test provider call."""
+        """Test call."""
-        self.assertEqual(self.provider(), ('a1', 'a2', 'a3'))
+        provider = di.Callable(lambda: True)
+        self.assertTrue(provider())
 
-    def test_call_with_args(self):
+    def test_call_with_positional_args(self):
-        """Test provider call with kwargs priority."""
+        """Test call with positional args.
+
+        New simplified syntax.
+        """
+        provider = di.Callable(self.example, 1, 2, 3, 4)
+        self.assertTupleEqual(provider(), (1, 2, 3, 4))
+
+    def test_call_with_keyword_args(self):
+        """Test call with keyword args.
+
+        New simplified syntax.
+        """
+        provider = di.Callable(self.example, arg1=1, arg2=2, arg3=3, arg4=4)
+        self.assertTupleEqual(provider(), (1, 2, 3, 4))
+
+    def test_call_with_positional_and_keyword_args(self):
+        """Test call with positional and keyword args.
+
+        Simplified syntax of positional and keyword arg injections.
+        """
+        provider = di.Callable(self.example, 1, 2, arg3=3, arg4=4)
+        self.assertTupleEqual(provider(), (1, 2, 3, 4))
+
+    def test_call_with_positional_and_keyword_args_extended_syntax(self):
+        """Test call with positional and keyword args.
+
+        Extended syntax of positional and keyword arg injections.
+        """
         provider = di.Callable(self.example,
-                               arg3='a3')
+                               di.Arg(1),
-        self.assertEqual(provider(1, 2), (1, 2, 'a3'))
+                               di.Arg(2),
+                               di.KwArg('arg3', 3),
+                               di.KwArg('arg4', 4))
+        self.assertTupleEqual(provider(), (1, 2, 3, 4))
 
-    def test_call_with_kwargs_priority(self):
+    def test_call_with_context_args(self):
-        """Test provider call with kwargs priority."""
+        """Test call with context args."""
-        self.assertEqual(self.provider(arg1=1, arg3=3), (1, 'a2', 3))
+        provider = di.Callable(self.example, 1, 2)
+        self.assertTupleEqual(provider(3, 4), (1, 2, 3, 4))
+
+    def test_call_with_context_kwargs(self):
+        """Test call with context kwargs."""
+        provider = di.Callable(self.example,
+                               di.KwArg('arg1', 1))
+        self.assertTupleEqual(provider(arg2=2, arg3=3, arg4=4), (1, 2, 3, 4))
+
+    def test_call_with_context_args_and_kwargs(self):
+        """Test call with context args and kwargs."""
+        provider = di.Callable(self.example, 1)
+        self.assertTupleEqual(provider(2, arg3=3, arg4=4), (1, 2, 3, 4))
 
     def test_call_overridden(self):
-        """Test overridden provider call."""
+        """Test creation of new instances on overridden provider."""
-        overriding_provider1 = di.Value((1, 2, 3))
+        provider = di.Callable(self.example)
-        overriding_provider2 = di.Value((3, 2, 1))
+        provider.override(di.Value((4, 3, 2, 1)))
+        provider.override(di.Value((1, 2, 3, 4)))
 
-        self.provider.override(overriding_provider1)
+        self.assertTupleEqual(provider(), (1, 2, 3, 4))
-        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):