Schemas (#429)

* Add single container prototype

* Add multiple containers prototype

* Add integration tests

* Implement from_*() methods and add tests

* Prototype inline injections

* Add integration test for inline providers

* Refactor integration tests

* Add integration test for reordered schema

* Remove unused imports from tests

* Refactor schema module

* Update tests to match latest schemas

* Add mypy_boto3_s3 to the test requirements

* Add boto3 to the test requirements

* Add set_provides for Callable, Factory, and Singleton providers

* Fix warnings in tests

* Add typing stubs for Callable, Factory, and Singleton .set_provides() attributes

* Fix singleton children to have optional provides

* Implement provider to provider resolving

* Fix pypy3 tests

* Implement boto3 session use case and add tests

* Implement lazy initialization and improve copying for Callable, Factory, Singleton, and Coroutine providers

* Fix Python 2 tests

* Add region name for boto3 integration example

* Remove f-strings from set_provides()

* Fix schema flake8 errors

* Implement lazy initialization and improve copying for Delegate provider

* Implement lazy initialization and improve copying for Object provider

* Speed up wiring tests

* Implement lazy initialization and improve copying for FactoryAggregate provider

* Implement lazy initialization and improve copying for Selector provider

* Implement lazy initialization and improve copying for Dependency provider

* Implement lazy initialization and improve copying for Resource provider

* Implement lazy initialization and improve copying for Configuration provider

* Implement lazy initialization and improve copying for ProvidedInstance provider

* Implement lazy initialization and improve copying for AttributeGetter provider

* Implement lazy initialization and improve copying for ItemGetter provider

* Implement lazy initialization and improve copying for MethodCaller provder

* Update changelog

* Fix typing in wiring module

* Fix wiring module loader uninstallation issue

* Fix provided instance providers error handing in asynchronous mode

Co-authored-by: Roman Mogylatov <rmk@Romans-MacBook-Pro.local>

docs/main/changelog.rst

@@ -7,6 +7,14 @@ that were made in every particular version.
 From version 0.7.6 *Dependency Injector* framework strictly 
 follows `Semantic versioning`_
 
+Development version
+-------------------
+- Implement providers' lazy initialization.
+- Improve providers' copying.
+- Improve typing in wiring module.
+- Fix wiring module loader uninstallation issue.
+- Fix provided instance providers error handing in asynchronous mode.
+
 4.30.0
 ------
 - Remove restriction to wire a dynamic container.

requirements-dev.txt

@@ -12,5 +12,7 @@ fastapi
 pydantic
 numpy
 scipy
+boto3
+mypy_boto3_s3
 
 -r requirements-ext.txt

src/dependency_injector/containers.pyi

@@ -1,3 +1,4 @@
+from pathlib import Path
 from typing import (
     Generic,
     Type,
@@ -34,6 +35,7 @@ class Container:
     def __init__(self) -> None: ...
     def __deepcopy__(self, memo: Optional[Dict[str, Any]]) -> Provider: ...
     def __setattr__(self, name: str, value: Union[Provider, Any]) -> None: ...
+    def __getattr__(self, name: str) -> Provider: ...
     def __delattr__(self, name: str) -> None: ...
     def set_providers(self, **providers: Provider): ...
     def set_provider(self, name: str, provider: Provider) -> None: ...
@@ -48,6 +50,9 @@ class Container:
     def apply_container_providers_overridings(self) -> None: ...
     def reset_singletons(self) -> SingletonResetContext[C_Base]: ...
     def check_dependencies(self) -> None: ...
+    def from_schema(self, schema: Dict[Any, Any]) -> None: ...
+    def from_yaml_schema(self, filepath: Union[Path, str], loader: Optional[Any]=None) -> None: ...
+    def from_json_schema(self, filepath: Union[Path, str]) -> None: ...
     @overload
     def resolve_provider_name(self, provider: Provider) -> str: ...
     @classmethod

src/dependency_injector/containers.pyx

@@ -1,5 +1,6 @@
 """Containers module."""
 
+import json
 import sys
 
 try:
@@ -7,6 +8,11 @@ try:
 except ImportError:
     asyncio = None
 
+try:
+    import yaml
+except ImportError:
+    yaml = None
+
 import six
 
 from . import providers, errors
@@ -330,6 +336,39 @@ class DynamicContainer(Container):
             f'{", ".join(undefined_names)}',
         )
 
+    def from_schema(self, schema):
+        """Build container providers from schema."""
+        from .schema import build_schema
+        for name, provider in build_schema(schema).items():
+            self.set_provider(name, provider)
+
+    def from_yaml_schema(self, filepath, loader=None):
+        """Build container providers from YAML schema.
+
+        You can specify type of loader as a second argument. By default, method
+        uses ``SafeLoader``.
+        """
+        if yaml is None:
+            raise errors.Error(
+                'Unable to load yaml schema - PyYAML is not installed. '
+                'Install PyYAML or install Dependency Injector with yaml extras: '
+                '"pip install dependency-injector[yaml]"'
+            )
+
+        if loader is None:
+            loader = yaml.SafeLoader
+
+        with open(filepath) as file:
+            schema = yaml.load(file, loader)
+
+        self.from_schema(schema)
+
+    def from_json_schema(self, filepath):
+        """Build container providers from JSON schema."""
+        with open(filepath) as file:
+            schema = json.load(file)
+        self.from_schema(schema)
+
     def resolve_provider_name(self, provider):
         """Try to resolve provider name."""
         for provider_name, container_provider in self.providers.items():

src/dependency_injector/providers.pxd

@@ -203,7 +203,7 @@ cdef class Dict(Provider):
 
 
 cdef class Resource(Provider):
-    cdef object __initializer
+    cdef object __provides
     cdef bint __initialized
     cdef object __shutdowner
     cdef object __resource
@@ -235,27 +235,27 @@ cdef class Selector(Provider):
 # Provided instance
 
 cdef class ProvidedInstance(Provider):
-    cdef Provider __provider
+    cdef object __provides
 
     cpdef object _provide(self, tuple args, dict kwargs)
 
 
 cdef class AttributeGetter(Provider):
-    cdef Provider __provider
-    cdef object __attribute
+    cdef object __provides
+    cdef object __name
 
     cpdef object _provide(self, tuple args, dict kwargs)
 
 
 cdef class ItemGetter(Provider):
-    cdef Provider __provider
-    cdef object __item
+    cdef object __provides
+    cdef object __name
 
     cpdef object _provide(self, tuple args, dict kwargs)
 
 
 cdef class MethodCaller(Provider):
-    cdef Provider __provider
+    cdef object __provides
     cdef tuple __args
     cdef int __args_len
     cdef tuple __kwargs

src/dependency_injector/providers.pyi

@@ -79,7 +79,9 @@ class Provider(Generic[T]):
 
 
 class Object(Provider[T]):
-    def __init__(self, provides: T) -> None: ...
+    def __init__(self, provides: Optional[T] = None) -> None: ...
+    def provides(self) -> Optional[T]: ...
+    def set_provides(self, provides: Optional[T]) -> Object: ...
 
 
 class Self(Provider[T]):
@@ -94,16 +96,21 @@ class Delegate(Provider[Provider]):
     def __init__(self, provides: Optional[Provider] = None) -> None: ...
     @property
     def provides(self) -> Optional[Provider]: ...
-    def set_provides(self, provides: Optional[Provider]): ...
+    def set_provides(self, provides: Optional[Provider]) -> Delegate: ...
 
 
 class Dependency(Provider[T]):
     def __init__(self, instance_of: Type[T] = object, default: Optional[Union[Provider, Any]] = None) -> None: ...
     def __getattr__(self, name: str) -> Any: ...
+
     @property
     def instance_of(self) -> Type[T]: ...
+    def set_instance_of(self, instance_of: Type[T]) -> Dependency[T]: ...
+
     @property
     def default(self) -> Provider[T]: ...
+    def set_default(self, default: Optional[Union[Provider, Any]]) -> Dependency[T]: ...
+
     @property
     def is_defined(self) -> bool: ...
     def provided_by(self, provider: Provider) -> OverridingContext[P]: ...
@@ -131,9 +138,10 @@ class DependenciesContainer(Object):
 
 
 class Callable(Provider[T]):
-    def __init__(self, provides: _Callable[..., T], *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[_Callable[..., T]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @property
-    def provides(self) -> T: ...
+    def provides(self) -> Optional[T]: ...
+    def set_provides(self, provides: Optional[_Callable[..., T]]) -> Callable[T]: ...
     @property
     def args(self) -> Tuple[Injection]: ...
     def add_args(self, *args: Injection) -> Callable[T]: ...
@@ -207,7 +215,19 @@ class Configuration(Object[Any]):
     def __exit__(self, *exc_info: Any) -> None: ...
     def __getattr__(self, item: str) -> ConfigurationOption: ...
     def __getitem__(self, item: Union[str, Provider]) -> ConfigurationOption: ...
+
     def get_name(self) -> str: ...
+    def set_name(self, name: str) -> Configuration: ...
+
+    def get_default(self) -> _Dict[Any, Any]: ...
+    def set_default(self, default: _Dict[Any, Any]): ...
+
+    def get_strict(self) -> bool: ...
+    def set_strict(self, strict: bool) -> Configuration: ...
+
+    def get_children(self) -> _Dict[str, ConfigurationOption]: ...
+    def set_children(self, children: _Dict[str, ConfigurationOption]) -> Configuration: ...
+
     def get(self, selector: str) -> Any: ...
     def set(self, selector: str, value: Any) -> OverridingContext[P]: ...
     def reset_cache(self) -> None: ...
@@ -221,11 +241,12 @@ class Configuration(Object[Any]):
 
 class Factory(Provider[T]):
     provided_type: Optional[Type]
-    def __init__(self, provides: _Callable[..., T], *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[_Callable[..., T]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @property
     def cls(self) -> T: ...
     @property
     def provides(self) -> T: ...
+    def set_provides(self, provides: Optional[_Callable[..., T]]) -> Factory[T]: ...
     @property
     def args(self) -> Tuple[Injection]: ...
     def add_args(self, *args: Injection) -> Factory[T]: ...
@@ -266,15 +287,17 @@ class FactoryAggregate(Provider):
 
     @property
     def factories(self) -> _Dict[str, Factory]: ...
+    def set_factories(self, **factories: Factory) -> FactoryAggregate: ...
 
 
 class BaseSingleton(Provider[T]):
     provided_type = Optional[Type]
-    def __init__(self, provides: _Callable[..., T], *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[_Callable[..., T]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @property
     def cls(self) -> T: ...
     @property
     def provides(self) -> T: ...
+    def set_provides(self, provides: Optional[_Callable[..., T]]) -> BaseSingleton[T]: ...
     @property
     def args(self) -> Tuple[Injection]: ...
     def add_args(self, *args: Injection) -> BaseSingleton[T]: ...
@@ -340,19 +363,20 @@ class Dict(Provider[_Dict]):
 
 class Resource(Provider[T]):
     @overload
-    def __init__(self, initializer: Type[resources.Resource[T]], *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[Type[resources.Resource[T]]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @overload
-    def __init__(self, initializer: Type[resources.AsyncResource[T]], *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[Type[resources.AsyncResource[T]]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @overload
-    def __init__(self, initializer: _Callable[..., _Iterator[T]], *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[_Callable[..., _Iterator[T]]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @overload
-    def __init__(self, initializer: _Callable[..., _AsyncIterator[T]], *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[_Callable[..., _AsyncIterator[T]]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @overload
-    def __init__(self, initializer: _Callable[..., _Coroutine[Injection, Injection, T]], *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[_Callable[..., _Coroutine[Injection, Injection, T]]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @overload
-    def __init__(self, initializer: _Callable[..., T], *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[_Callable[..., T]] = None, *args: Injection, **kwargs: Injection) -> None: ...
     @property
-    def initializer(self) -> _Callable[..., Any]: ...
+    def provides(self) -> Optional[_Callable[..., Any]]: ...
+    def set_provides(self, provides: Optional[Any]) -> Resource[T]: ...
     @property
     def args(self) -> Tuple[Injection]: ...
     def add_args(self, *args: Injection) -> Resource[T]: ...
@@ -383,32 +407,47 @@ class Container(Provider[T]):
 
 
 class Selector(Provider[Any]):
-    def __init__(self, selector: _Callable[..., Any], **providers: Provider): ...
+    def __init__(self, selector: Optional[_Callable[..., Any]] = None, **providers: Provider): ...
     def __getattr__(self, name: str) -> Provider: ...
+
+    @property
+    def selector(self) -> Optional[_Callable[..., Any]]: ...
+    def set_selector(self, selector: Optional[_Callable[..., Any]]) -> Selector: ...
+
     @property
     def providers(self) -> _Dict[str, Provider]: ...
+    def set_providers(self, **providers: Provider) -> Selector: ...
 
 
 class ProvidedInstanceFluentInterface:
     def __getattr__(self, item: Any) -> AttributeGetter: ...
     def __getitem__(self, item: Any) -> ItemGetter: ...
     def call(self, *args: Injection, **kwargs: Injection) -> MethodCaller: ...
+    @property
+    def provides(self) -> Optional[Provider]: ...
+    def set_provides(self, provides: Optional[Provider]) -> ProvidedInstanceFluentInterface: ...
 
 
 class ProvidedInstance(Provider, ProvidedInstanceFluentInterface):
-    def __init__(self, provider: Provider) -> None: ...
+    def __init__(self, provides: Optional[Provider] = None) -> None: ...
 
 
 class AttributeGetter(Provider, ProvidedInstanceFluentInterface):
-    def __init__(self, provider: Provider, attribute: str) -> None: ...
+    def __init__(self, provides: Optional[Provider] = None, name: Optional[str] = None) -> None: ...
+    @property
+    def name(self) -> Optional[str]: ...
+    def set_name(self, name: Optional[str]) -> ProvidedInstanceFluentInterface: ...
 
 
 class ItemGetter(Provider, ProvidedInstanceFluentInterface):
-    def __init__(self, provider: Provider, item: str) -> None: ...
+    def __init__(self, provides: Optional[Provider] = None, name: Optional[str] = None) -> None: ...
+    @property
+    def name(self) -> Optional[str]: ...
+    def set_name(self, name: Optional[str]) -> ProvidedInstanceFluentInterface: ...
 
 
 class MethodCaller(Provider, ProvidedInstanceFluentInterface):
-    def __init__(self, provider: Provider, *args: Injection, **kwargs: Injection) -> None: ...
+    def __init__(self, provides: Optional[Provider] = None, *args: Injection, **kwargs: Injection) -> None: ...
 
 
 class OverridingContext(Generic[T]):

src/dependency_injector/schema.py

@@ -0,0 +1,231 @@
+"""Schema module."""
+
+import builtins
+import importlib
+from typing import Dict, Any, Type, Optional
+
+from . import containers, providers
+
+
+ContainerSchema = Dict[Any, Any]
+ProviderSchema = Dict[Any, Any]
+
+
+class SchemaProcessorV1:
+
+    def __init__(self, schema: ContainerSchema) -> None:
+        self._schema = schema
+        self._container = containers.DynamicContainer()
+
+    def process(self):
+        """Process schema."""
+        self._create_providers(self._schema['container'])
+        self._setup_injections(self._schema['container'])
+
+    def get_providers(self):
+        """Return providers."""
+        return self._container.providers
+
+    def _create_providers(
+            self,
+            provider_schema: ProviderSchema,
+            container: Optional[containers.Container] = None,
+    ) -> None:
+        if container is None:
+            container = self._container
+        for provider_name, data in provider_schema.items():
+            provider = None
+
+            if 'provider' in data:
+                provider_type = _get_provider_cls(data['provider'])
+                args = []
+
+                # provides = data.get('provides')
+                # if provides:
+                #     provides = _import_string(provides)
+                #     if provides:
+                #         args.append(provides)
+
+                provider = provider_type(*args)
+
+            if provider is None:
+                provider = providers.Container(containers.DynamicContainer)
+
+            container.set_provider(provider_name, provider)
+
+            if isinstance(provider, providers.Container):
+                self._create_providers(provider_schema=data, container=provider)
+
+    def _setup_injections(  # noqa: C901
+            self,
+            provider_schema: ProviderSchema,
+            container: Optional[containers.Container] = None,
+    ) -> None:
+        if container is None:
+            container = self._container
+
+        for provider_name, data in provider_schema.items():
+            provider = getattr(container, provider_name)
+            args = []
+            kwargs = {}
+
+            provides = data.get('provides')
+            if provides:
+                if isinstance(provides, str) and provides.startswith('container.'):
+                    provides = self._resolve_provider(provides[len('container.'):])
+                else:
+                    provides = _import_string(provides)
+                provider.set_provides(provides)
+
+            arg_injections = data.get('args')
+            if arg_injections:
+                for arg in arg_injections:
+                    injection = None
+
+                    if isinstance(arg, str) and arg.startswith('container.'):
+                        injection = self._resolve_provider(arg[len('container.'):])
+
+                    # TODO: refactoring
+                    if isinstance(arg, dict):
+                        provider_args = []
+                        provider_type = _get_provider_cls(arg.get('provider'))
+                        provides = arg.get('provides')
+                        if provides:
+                            if isinstance(provides, str) and provides.startswith('container.'):
+                                provides = self._resolve_provider(provides[len('container.'):])
+                            else:
+                                provides = _import_string(provides)
+                            provider_args.append(provides)
+                        for provider_arg in arg.get('args', []):
+                            if isinstance(provider_arg, str) \
+                                    and provider_arg.startswith('container.'):
+                                provider_args.append(
+                                    self._resolve_provider(provider_arg[len('container.'):]),
+                                )
+                        injection = provider_type(*provider_args)
+
+                    if not injection:
+                        injection = arg
+
+                    args.append(injection)
+            if args:
+                provider.add_args(*args)
+
+            kwarg_injections = data.get('kwargs')
+            if kwarg_injections:
+                for name, arg in kwarg_injections.items():
+                    injection = None
+
+                    if isinstance(arg, str) and arg.startswith('container.'):
+                        injection = self._resolve_provider(arg[len('container.'):])
+
+                    # TODO: refactoring
+                    if isinstance(arg, dict):
+                        provider_args = []
+                        provider_type = _get_provider_cls(arg.get('provider'))
+                        provides = arg.get('provides')
+                        if provides:
+                            if isinstance(provides, str) and provides.startswith('container.'):
+                                provides = self._resolve_provider(provides[len('container.'):])
+                            else:
+                                provides = _import_string(provides)
+                            provider_args.append(provides)
+                        for provider_arg in arg.get('args', []):
+                            if isinstance(provider_arg, str) \
+                                    and provider_arg.startswith('container.'):
+                                provider_args.append(
+                                    self._resolve_provider(provider_arg[len('container.'):]),
+                                )
+                        injection = provider_type(*provider_args)
+
+                    if not injection:
+                        injection = arg
+
+                    kwargs[name] = injection
+            if kwargs:
+                provider.add_kwargs(**kwargs)
+
+            if isinstance(provider, providers.Container):
+                self._setup_injections(provider_schema=data, container=provider)
+
+    def _resolve_provider(self, name: str) -> Optional[providers.Provider]:
+        segments = name.split('.')
+        try:
+            provider = getattr(self._container, segments[0])
+        except AttributeError:
+            return None
+
+        for segment in segments[1:]:
+            parentheses = ''
+            if '(' in segment and ')' in segment:
+                parentheses = segment[segment.find('('):segment.rfind(')')+1]
+                segment = segment.replace(parentheses, '')
+
+            try:
+                provider = getattr(provider, segment)
+            except AttributeError:
+                # TODO
+                return None
+
+            if parentheses:
+                # TODO
+                provider = provider()
+
+        return provider
+
+
+def build_schema(schema: ContainerSchema) -> Dict[str, providers.Provider]:
+    """Build provider schema."""
+    schema_processor = SchemaProcessorV1(schema)
+    schema_processor.process()
+    return schema_processor.get_providers()
+
+
+def _get_provider_cls(provider_cls_name: str) -> Type[providers.Provider]:
+    std_provider_type = _fetch_provider_cls_from_std(provider_cls_name)
+    if std_provider_type:
+        return std_provider_type
+
+    custom_provider_type = _import_provider_cls(provider_cls_name)
+    if custom_provider_type:
+        return custom_provider_type
+
+    raise SchemaError(f'Undefined provider class "{provider_cls_name}"')
+
+
+def _fetch_provider_cls_from_std(provider_cls_name: str) -> Optional[Type[providers.Provider]]:
+    return getattr(providers, provider_cls_name, None)
+
+
+def _import_provider_cls(provider_cls_name: str) -> Optional[Type[providers.Provider]]:
+    try:
+        cls = _import_string(provider_cls_name)
+    except (ImportError, ValueError) as exception:
+        raise SchemaError(f'Can not import provider "{provider_cls_name}"') from exception
+    except AttributeError:
+        return None
+    else:
+        if isinstance(cls, type) and not issubclass(cls, providers.Provider):
+            raise SchemaError(f'Provider class "{cls}" is not a subclass of providers base class')
+        return cls
+
+
+def _import_string(string_name: str) -> Optional[object]:
+    segments = string_name.split('.')
+
+    if len(segments) == 1:
+        member = getattr(builtins, segments[0], None)
+        if member:
+            return member
+
+    module_name = '.'.join(segments[:-1])
+    if not module_name:
+        return None
+
+    member = segments[-1]
+    module = importlib.import_module(module_name)
+    return getattr(module, member, None)
+
+
+class SchemaError(Exception):
+    """Schema-related error."""

src/dependency_injector/wiring.py

@@ -771,7 +771,7 @@ class ProvidedInstance(Modifier):
 
     def modify(
             self,
-            provider: providers.ConfigurationOption,
+            provider: providers.Provider,
             providers_map: ProvidersMap,
     ) -> providers.Provider:
         provider = provider.provided
@@ -860,7 +860,7 @@ class AutoLoader:
 
     @property
     def installed(self):
-        return self._path_hook is not None
+        return self._path_hook in sys.path_hooks
 
     def install(self):
         if self.installed:

tests/unit/containers/test_declarative_py2_py3.py

@@ -412,7 +412,7 @@ class DeclarativeContainerTests(unittest.TestCase):
         class Services(containers.DeclarativeContainer):
             a = providers.Dependency()
             c = providers.Factory(C, a=a)
-            b = providers.Factory(B, fa=a.delegate())
+            b = providers.Factory(B, fa=a.provider)
 
         a = providers.Factory(A)
         assert isinstance(Services(a=a).c().a, A)  # ok

tests/unit/providers/test_async_py36.py

@@ -655,6 +655,32 @@ class ProvidedInstanceTests(AsyncTestCase):
         self.assertIs(instance2.resource, RESOURCE1)
         self.assertIs(instance1.resource, instance2.resource)
 
+    def test_provided_attribute_error(self):
+        async def raise_exception():
+            raise RuntimeError()
+
+        class TestContainer(containers.DeclarativeContainer):
+            client = providers.Factory(raise_exception)
+
+        container = TestContainer()
+
+        with self.assertRaises(RuntimeError):
+            self._run(container.client.provided.attr())
+
+    def test_provided_attribute_undefined_attribute(self):
+        class TestClient:
+            def __init__(self, resource):
+                self.resource = resource
+
+        class TestContainer(containers.DeclarativeContainer):
+            resource = providers.Resource(init_resource, providers.Object(RESOURCE1))
+            client = providers.Factory(TestClient, resource=resource)
+
+        container = TestContainer()
+
+        with self.assertRaises(AttributeError):
+            self._run(container.client.provided.attr())
+
     def test_provided_item(self):
         class TestClient:
             def __init__(self, resource):
@@ -685,6 +711,28 @@ class ProvidedInstanceTests(AsyncTestCase):
         self.assertIs(instance2.resource, RESOURCE1)
         self.assertIs(instance1.resource, instance2.resource)
 
+    def test_provided_item_error(self):
+        async def raise_exception():
+            raise RuntimeError()
+
+        class TestContainer(containers.DeclarativeContainer):
+            client = providers.Factory(raise_exception)
+
+        container = TestContainer()
+
+        with self.assertRaises(RuntimeError):
+            self._run(container.client.provided['item']())
+
+    def test_provided_item_undefined_item(self):
+        class TestContainer(containers.DeclarativeContainer):
+            resource = providers.Resource(init_resource, providers.Object(RESOURCE1))
+            client = providers.Factory(dict, resource=resource)
+
+        container = TestContainer()
+
+        with self.assertRaises(KeyError):
+            self._run(container.client.provided['item']())
+
     def test_provided_method_call(self):
         class TestClient:
             def __init__(self, resource):
@@ -715,6 +763,31 @@ class ProvidedInstanceTests(AsyncTestCase):
         self.assertIs(instance2.resource, RESOURCE1)
         self.assertIs(instance1.resource, instance2.resource)
 
+    def test_provided_method_call_parent_error(self):
+        async def raise_exception():
+            raise RuntimeError()
+
+        class TestContainer(containers.DeclarativeContainer):
+            client = providers.Factory(raise_exception)
+
+        container = TestContainer()
+
+        with self.assertRaises(RuntimeError):
+            self._run(container.client.provided.method.call()())
+
+    def test_provided_method_call_error(self):
+        class TestClient:
+            def method(self):
+                raise RuntimeError()
+
+        class TestContainer(containers.DeclarativeContainer):
+            client = providers.Factory(TestClient)
+
+        container = TestContainer()
+
+        with self.assertRaises(RuntimeError):
+            self._run(container.client.provided.method.call()())
+
 
 class DependencyTests(AsyncTestCase):
 
@@ -996,7 +1069,7 @@ class AsyncProvidersWithAsyncDependenciesTests(AsyncTestCase):
         container = Container()
         service = self._run(container.service())
 
-        self.assertEquals(service, {'service': 'ok', 'db': {'db': 'ok'}})
+        self.assertEqual(service, {'service': 'ok', 'db': {'db': 'ok'}})
 
 
 class AsyncProviderWithAwaitableObjectTests(AsyncTestCase):

tests/unit/providers/test_base_py2_py3.py

@@ -1,6 +1,7 @@
 """Dependency injector base providers unit tests."""
 
 import unittest
+import warnings
 
 from dependency_injector import (
     containers,
@@ -21,13 +22,14 @@ class ProviderTests(unittest.TestCase):
         self.assertRaises(NotImplementedError, self.provider.__call__)
 
     def test_delegate(self):
-        delegate1 = self.provider.delegate()
+        with warnings.catch_warnings():
+            warnings.simplefilter('ignore')
+            delegate1 = self.provider.delegate()
+            delegate2 = self.provider.delegate()
 
         self.assertIsInstance(delegate1, providers.Delegate)
         self.assertIs(delegate1(), self.provider)
 
-        delegate2 = self.provider.delegate()
-
         self.assertIsInstance(delegate2, providers.Delegate)
         self.assertIs(delegate2(), self.provider)
 
@@ -150,6 +152,17 @@ class ObjectProviderTests(unittest.TestCase):
     def test_is_provider(self):
         self.assertTrue(providers.is_provider(providers.Object(object())))
 
+    def test_init_optional_provides(self):
+        instance = object()
+        provider = providers.Object()
+        provider.set_provides(instance)
+        self.assertIs(provider.provides, instance)
+        self.assertIs(provider(), instance)
+
+    def test_set_provides_returns_self(self):
+        provider = providers.Object()
+        self.assertIs(provider.set_provides(object()), provider)
+
     def test_provided_instance_provider(self):
         provider = providers.Object(object())
         self.assertIsInstance(provider.provided, providers.ProvidedInstance)
@@ -289,6 +302,16 @@ class DelegateTests(unittest.TestCase):
     def test_is_provider(self):
         self.assertTrue(providers.is_provider(self.delegate))
 
+    def test_init_optional_provides(self):
+        provider = providers.Delegate()
+        provider.set_provides(self.delegated)
+        self.assertIs(provider.provides, self.delegated)
+        self.assertIs(provider(), self.delegated)
+
+    def test_set_provides_returns_self(self):
+        provider = providers.Delegate()
+        self.assertIs(provider.set_provides(self.delegated), provider)
+
     def test_init_with_not_provider(self):
         self.assertRaises(errors.Error, providers.Delegate, object())
 
@@ -312,6 +335,24 @@ class DependencyTests(unittest.TestCase):
     def setUp(self):
         self.provider = providers.Dependency(instance_of=list)
 
+    def test_init_optional(self):
+        list_provider = providers.List(1, 2, 3)
+        provider = providers.Dependency()
+        provider.set_instance_of(list)
+        provider.set_default(list_provider)
+
+        self.assertIs(provider.instance_of, list)
+        self.assertIs(provider.default, list_provider)
+        self.assertEqual(provider(), [1, 2, 3])
+
+    def test_set_instance_of_returns_self(self):
+        provider = providers.Dependency()
+        self.assertIs(provider.set_instance_of(list), provider)
+
+    def test_set_default_returns_self(self):
+        provider = providers.Dependency()
+        self.assertIs(provider.set_default(providers.Provider()), provider)
+
     def test_init_with_not_class(self):
         self.assertRaises(TypeError, providers.Dependency, object())
 

tests/unit/providers/test_callables_py2_py3.py

@@ -22,6 +22,16 @@ class CallableTests(unittest.TestCase):
     def test_init_with_not_callable(self):
         self.assertRaises(errors.Error, providers.Callable, 123)
 
+    def test_init_optional_provides(self):
+        provider = providers.Callable()
+        provider.set_provides(object)
+        self.assertIs(provider.provides, object)
+        self.assertIsInstance(provider(), object)
+
+    def test_set_provides_returns_self(self):
+        provider = providers.Callable()
+        self.assertIs(provider.set_provides(object), provider)
+
     def test_provided_instance_provider(self):
         provider = providers.Callable(_example)
         self.assertIsInstance(provider.provided, providers.ProvidedInstance)

tests/unit/providers/test_configuration_py2_py3.py

@@ -28,6 +28,28 @@ class ConfigTests(unittest.TestCase):
     def tearDown(self):
         del self.config
 
+    def test_init_optional(self):
+        provider = providers.Configuration()
+        provider.set_name('myconfig')
+        provider.set_default({'foo': 'bar'})
+        provider.set_strict(True)
+
+        self.assertEqual(provider.get_name(), 'myconfig')
+        self.assertEqual(provider.get_default(), {'foo': 'bar'})
+        self.assertTrue(provider.get_strict())
+
+    def test_set_name_returns_self(self):
+        provider = providers.Configuration()
+        self.assertIs(provider.set_name('myconfig'), provider)
+
+    def test_set_default_returns_self(self):
+        provider = providers.Configuration()
+        self.assertIs(provider.set_default({}), provider)
+
+    def test_set_strict_returns_self(self):
+        provider = providers.Configuration()
+        self.assertIs(provider.set_strict(True), provider)
+
     def test_default_name(self):
         config = providers.Configuration()
         self.assertEqual(config.get_name(), 'config')

tests/unit/providers/test_coroutines_py35.py

@@ -1,8 +1,8 @@
 """Dependency injector coroutine providers unit tests."""
 
 import asyncio
-
 import unittest
+import warnings
 
 from dependency_injector import (
     providers,
@@ -43,6 +43,16 @@ class CoroutineTests(AsyncTestCase):
     def test_init_with_not_coroutine(self):
         self.assertRaises(errors.Error, providers.Coroutine, lambda: None)
 
+    def test_init_optional_provides(self):
+        provider = providers.Coroutine()
+        provider.set_provides(_example)
+        self.assertIs(provider.provides, _example)
+        self.assertEqual(run(provider(1, 2, 3, 4)), (1, 2, 3, 4))
+
+    def test_set_provides_returns_self(self):
+        provider = providers.Coroutine()
+        self.assertIs(provider.set_provides(_example), provider)
+
     def test_call_with_positional_args(self):
         provider = providers.Coroutine(_example, 1, 2, 3, 4)
         self.assertTupleEqual(self._run(provider()), (1, 2, 3, 4))
@@ -232,9 +242,12 @@ class AbstractCoroutineTests(AsyncTestCase):
                               providers.Coroutine)
 
     def test_call_overridden_by_coroutine(self):
-        @asyncio.coroutine
-        def _abstract_example():
-            raise RuntimeError('Should not be raised')
+        with warnings.catch_warnings():
+            warnings.simplefilter('ignore')
+
+            @asyncio.coroutine
+            def _abstract_example():
+                raise RuntimeError('Should not be raised')
 
         provider = providers.AbstractCoroutine(_abstract_example)
         provider.override(providers.Coroutine(_example))
@@ -242,9 +255,12 @@ class AbstractCoroutineTests(AsyncTestCase):
         self.assertTrue(self._run(provider(1, 2, 3, 4)), (1, 2, 3, 4))
 
     def test_call_overridden_by_delegated_coroutine(self):
-        @asyncio.coroutine
-        def _abstract_example():
-            raise RuntimeError('Should not be raised')
+        with warnings.catch_warnings():
+            warnings.simplefilter('ignore')
+
+            @asyncio.coroutine
+            def _abstract_example():
+                raise RuntimeError('Should not be raised')
 
         provider = providers.AbstractCoroutine(_abstract_example)
         provider.override(providers.DelegatedCoroutine(_example))

tests/unit/providers/test_factories_py2_py3.py

@@ -34,6 +34,16 @@ class FactoryTests(unittest.TestCase):
     def test_init_with_not_callable(self):
         self.assertRaises(errors.Error, providers.Factory, 123)
 
+    def test_init_optional_provides(self):
+        provider = providers.Factory()
+        provider.set_provides(object)
+        self.assertIs(provider.provides, object)
+        self.assertIsInstance(provider(), object)
+
+    def test_set_provides_returns_self(self):
+        provider = providers.Factory()
+        self.assertIs(provider.set_provides(object), provider)
+
     def test_init_with_valid_provided_type(self):
         class ExampleProvider(providers.Factory):
             provided_type = Example
@@ -502,6 +512,26 @@ class FactoryAggregateTests(unittest.TestCase):
                 example_a=providers.Factory(self.ExampleA),
                 example_b=object())
 
+    def test_init_optional_factories(self):
+        provider = providers.FactoryAggregate()
+        provider.set_factories(
+            example_a=self.example_a_factory,
+            example_b=self.example_b_factory,
+        )
+        self.assertEqual(
+            provider.factories,
+            {
+                'example_a': self.example_a_factory,
+                'example_b': self.example_b_factory,
+            },
+        )
+        self.assertIsInstance(provider('example_a'), self.ExampleA)
+        self.assertIsInstance(provider('example_b'), self.ExampleB)
+
+    def test_set_provides_returns_self(self):
+        provider = providers.FactoryAggregate()
+        self.assertIs(provider.set_factories(example_a=self.example_a_factory), provider)
+
     def test_call(self):
         object_a = self.factory_aggregate('example_a',
                                           1, 2, init_arg3=3, init_arg4=4)

tests/unit/providers/test_provided_instance_py2_py3.py

@@ -126,6 +126,44 @@ class ProvidedInstanceTests(unittest.TestCase):
         )
 
 
+class LazyInitTests(unittest.TestCase):
+
+    def test_provided_instance(self):
+        provides = providers.Object(object())
+        provider = providers.ProvidedInstance()
+        provider.set_provides(provides)
+        self.assertIs(provider.provides, provides)
+        self.assertIs(provider.set_provides(providers.Provider()), provider)
+
+    def test_attribute_getter(self):
+        provides = providers.Object(object())
+        provider = providers.AttributeGetter()
+        provider.set_provides(provides)
+        provider.set_name('__dict__')
+        self.assertIs(provider.provides, provides)
+        self.assertEqual(provider.name, '__dict__')
+        self.assertIs(provider.set_provides(providers.Provider()), provider)
+        self.assertIs(provider.set_name('__dict__'), provider)
+
+    def test_item_getter(self):
+        provides = providers.Object({'foo': 'bar'})
+        provider = providers.ItemGetter()
+        provider.set_provides(provides)
+        provider.set_name('foo')
+        self.assertIs(provider.provides, provides)
+        self.assertEqual(provider.name, 'foo')
+        self.assertIs(provider.set_provides(providers.Provider()), provider)
+        self.assertIs(provider.set_name('foo'), provider)
+
+    def test_method_caller(self):
+        provides = providers.Object(lambda: 42)
+        provider = providers.MethodCaller()
+        provider.set_provides(provides)
+        self.assertIs(provider.provides, provides)
+        self.assertEqual(provider(), 42)
+        self.assertIs(provider.set_provides(providers.Provider()), provider)
+
+
 class ProvidedInstancePuzzleTests(unittest.TestCase):
 
     def test_puzzled(self):

tests/unit/providers/test_resource_py35.py

@@ -29,6 +29,16 @@ class ResourceTests(unittest.TestCase):
     def test_is_provider(self):
         self.assertTrue(providers.is_provider(providers.Resource(init_fn)))
 
+    def test_init_optional_provides(self):
+        provider = providers.Resource()
+        provider.set_provides(init_fn)
+        self.assertIs(provider.provides, init_fn)
+        self.assertEqual(provider(), (tuple(), dict()))
+
+    def test_set_provides_returns_self(self):
+        provider = providers.Resource()
+        self.assertIs(provider.set_provides(init_fn), provider)
+
     def test_provided_instance_provider(self):
         provider = providers.Resource(init_fn)
         self.assertIsInstance(provider.provided, providers.ProvidedInstance)

tests/unit/providers/test_selector_py2_py3.py

@@ -16,6 +16,28 @@ class SelectorTests(unittest.TestCase):
     def test_is_provider(self):
         self.assertTrue(providers.is_provider(providers.Selector(self.selector)))
 
+    def test_init_optional(self):
+        one = providers.Object(1)
+        two = providers.Object(2)
+
+        provider = providers.Selector()
+        provider.set_selector(self.selector)
+        provider.set_providers(one=one, two=two)
+
+        self.assertEqual(provider.providers, {'one': one, 'two': two})
+        with self.selector.override('one'):
+            self.assertEqual(provider(), one())
+        with self.selector.override('two'):
+            self.assertEqual(provider(), two())
+
+    def test_set_selector_returns_self(self):
+        provider = providers.Selector()
+        self.assertIs(provider.set_selector(self.selector), provider)
+
+    def test_set_providers_returns_self(self):
+        provider = providers.Selector()
+        self.assertIs(provider.set_providers(one=providers.Provider()), provider)
+
     def test_provided_instance_provider(self):
         provider = providers.Selector(self.selector)
         self.assertIsInstance(provider.provided, providers.ProvidedInstance)

tests/unit/providers/test_singletons_py2_py3.py

@@ -36,6 +36,16 @@ class _BaseSingletonTestCase(object):
     def test_init_with_not_callable(self):
         self.assertRaises(errors.Error, self.singleton_cls, 123)
 
+    def test_init_optional_provides(self):
+        provider = self.singleton_cls()
+        provider.set_provides(object)
+        self.assertIs(provider.provides, object)
+        self.assertIsInstance(provider(), object)
+
+    def test_set_provides_returns_self(self):
+        provider = self.singleton_cls()
+        self.assertIs(provider.set_provides(object), provider)
+
     def test_init_with_valid_provided_type(self):
         class ExampleProvider(self.singleton_cls):
             provided_type = Example

tests/unit/samples/schemasample/container-boto3-session.yml

@@ -0,0 +1,27 @@
+version: "1"
+
+container:
+
+  config:
+    provider: Configuration
+
+  session:
+    provider: Singleton
+    provides: boto3.session.Session
+    kwargs:
+      aws_access_key_id: container.config.aws_access_key_id
+      aws_secret_access_key: container.config.aws_secret_access_key
+      aws_session_token: container.config.aws_session_token
+      region_name: container.config.aws_region_name
+
+  s3_client:
+    provider: Factory
+    provides: container.session.provided.client.call()
+    kwargs:
+      service_name: s3
+
+  sqs_client:
+    provider: Factory
+    provides: container.session.provided.client.call()
+    kwargs:
+      service_name: sqs

tests/unit/samples/schemasample/container-multiple-inline.yml

@@ -0,0 +1,58 @@
+version: "1"
+
+container:
+
+  core:
+    config:
+      provider: Configuration
+
+  gateways:
+    database_client:
+      provider: Singleton
+      provides: sqlite3.connect
+      args:
+        - provider: Callable
+          provides: schemasample.utils.return_
+          args:
+            - container.core.config.database.dsn
+
+    s3_client:
+      provider: Singleton
+      provides: boto3.client
+      kwargs:
+        service_name: s3
+        aws_access_key_id: container.core.config.aws.access_key_id
+        aws_secret_access_key: container.core.config.aws.secret_access_key
+
+  services:
+    user:
+      provider: Factory
+      provides: schemasample.services.UserService
+      kwargs:
+        db:
+          provider: Callable
+          provides: schemasample.utils.return_
+          args:
+            - container.gateways.database_client
+
+    auth:
+      provider: Factory
+      provides: schemasample.services.AuthService
+      kwargs:
+        db:
+          provider: Callable
+          provides: schemasample.utils.return_
+          args:
+            - container.gateways.database_client
+        token_ttl: container.core.config.auth.token_ttl.as_int()
+
+    photo:
+      provider: Factory
+      provides: schemasample.services.PhotoService
+      kwargs:
+        db:
+          provider: Callable
+          provides: schemasample.utils.return_
+          args:
+            - container.gateways.database_client
+        s3: container.gateways.s3_client

tests/unit/samples/schemasample/container-multiple-reordered.yml

@@ -0,0 +1,43 @@
+version: "1"
+
+container:
+
+  services:
+    user:
+      provider: Factory
+      provides: schemasample.services.UserService
+      kwargs:
+        db: container.gateways.database_client
+
+    auth:
+      provider: Factory
+      provides: schemasample.services.AuthService
+      kwargs:
+        db: container.gateways.database_client
+        token_ttl: container.core.config.auth.token_ttl.as_int()
+
+    photo:
+      provider: Factory
+      provides: schemasample.services.PhotoService
+      kwargs:
+        db: container.gateways.database_client
+        s3: container.gateways.s3_client
+
+  gateways:
+    database_client:
+      provider: Singleton
+      provides: sqlite3.connect
+      args:
+        - container.core.config.database.dsn
+
+    s3_client:
+      provider: Singleton
+      provides: boto3.client
+      kwargs:
+        service_name: s3
+        aws_access_key_id: core.config.aws.access_key_id
+        aws_secret_access_key: core.config.aws.secret_access_key
+
+  core:
+    config:
+      provider: Configuration

tests/unit/samples/schemasample/container-multiple.yml

@@ -0,0 +1,43 @@
+version: "1"
+
+container:
+
+  core:
+    config:
+      provider: Configuration
+
+  gateways:
+    database_client:
+      provider: Singleton
+      provides: sqlite3.connect
+      args:
+        - container.core.config.database.dsn
+
+    s3_client:
+      provider: Singleton
+      provides: boto3.client
+      kwargs:
+        service_name: s3
+        aws_access_key_id: container.core.config.aws.access_key_id
+        aws_secret_access_key: container.core.config.aws.secret_access_key
+
+  services:
+    user:
+      provider: Factory
+      provides: schemasample.services.UserService
+      kwargs:
+        db: container.gateways.database_client
+
+    auth:
+      provider: Factory
+      provides: schemasample.services.AuthService
+      kwargs:
+        db: container.gateways.database_client
+        token_ttl: container.core.config.auth.token_ttl.as_int()
+
+    photo:
+      provider: Factory
+      provides: schemasample.services.PhotoService
+      kwargs:
+        db: container.gateways.database_client
+        s3: container.gateways.s3_client

tests/unit/samples/schemasample/container-single.yml

@@ -0,0 +1,39 @@
+version: "1"
+
+container:
+  config:
+    provider: Configuration
+
+  database_client:
+    provider: Singleton
+    provides: sqlite3.connect
+    args:
+      - container.config.database.dsn
+
+  s3_client:
+    provider: Singleton
+    provides: boto3.client
+    kwargs:
+      service_name: s3
+      aws_access_key_id: container.config.aws.access_key_id
+      aws_secret_access_key: container.config.aws.secret_access_key
+
+  user_service:
+    provider: Factory
+    provides: schemasample.services.UserService
+    kwargs:
+      db: container.database_client
+
+  auth_service:
+    provider: Factory
+    provides: schemasample.services.AuthService
+    kwargs:
+      db: container.database_client
+      token_ttl: container.config.auth.token_ttl.as_int()
+
+  photo_service:
+    provider: Factory
+    provides: schemasample.services.PhotoService
+    kwargs:
+      db: container.database_client
+      s3: container.s3_client

tests/unit/samples/schemasample/services.py

@@ -0,0 +1,56 @@
+"""Services module."""
+
+import logging
+import sqlite3
+from typing import Dict
+
+from mypy_boto3_s3 import S3Client
+
+
+class BaseService:
+
+    def __init__(self) -> None:
+        self.logger = logging.getLogger(
+            f'{__name__}.{self.__class__.__name__}',
+        )
+
+
+class UserService(BaseService):
+
+    def __init__(self, db: sqlite3.Connection) -> None:
+        self.db = db
+        super().__init__()
+
+    def get_user(self, email: str) -> Dict[str, str]:
+        self.logger.debug('User %s has been found in database', email)
+        return {'email': email, 'password_hash': '...'}
+
+
+class AuthService(BaseService):
+
+    def __init__(self, db: sqlite3.Connection, token_ttl: int) -> None:
+        self.db = db
+        self.token_ttl = token_ttl
+        super().__init__()
+
+    def authenticate(self, user: Dict[str, str], password: str) -> None:
+        assert password is not None
+        self.logger.debug(
+            'User %s has been successfully authenticated',
+            user['email'],
+        )
+
+
+class PhotoService(BaseService):
+
+    def __init__(self, db: sqlite3.Connection, s3: S3Client) -> None:
+        self.db = db
+        self.s3 = s3
+        super().__init__()
+
+    def upload_photo(self, user: Dict[str, str], photo_path: str) -> None:
+        self.logger.debug(
+            'Photo %s has been successfully uploaded by user %s',
+            photo_path,
+            user['email'],
+        )

tests/unit/samples/schemasample/utils.py

@@ -0,0 +1,2 @@
+def return_(instance):
+    return instance

tests/unit/samples/wiringsamples/imports.py

@@ -0,0 +1,13 @@
+"""Test module for wiring."""
+
+import sys
+
+if 'pypy' not in sys.version.lower():
+    import numpy  # noqa
+    from numpy import *  # noqa
+
+    import scipy  # noqa
+    from scipy import *  # noqa
+
+    import builtins  # noqa
+    from builtins import *  # noqa

tests/unit/samples/wiringsamples/module.py

@@ -1,7 +1,6 @@
 """Test module for wiring."""
 
 from decimal import Decimal
-import sys
 from typing import Callable
 
 from dependency_injector import providers
@@ -129,16 +128,3 @@ def test_class_decorator(service: Service = Provide[Container.service]):
 
 def test_container(container: Container = Provide[Container]):
     return container.service()
-
-
-# Import tests
-
-if 'pypy' not in sys.version.lower():
-    import numpy  # noqa
-    from numpy import *  # noqa
-
-    import scipy  # noqa
-    from scipy import *  # noqa
-
-    import builtins  # noqa
-    from builtins import *  # noqa

tests/unit/schema/__init__.py

@@ -0,0 +1 @@
+"""Schema tests."""

tests/unit/schema/test_containers_api_py36.py

@@ -0,0 +1,162 @@
+import contextlib
+import json
+import os.path
+import tempfile
+import unittest
+
+import yaml
+from dependency_injector import containers, providers, errors
+
+
+class FromSchemaTests(unittest.TestCase):
+
+    def test(self):
+        container = containers.DynamicContainer()
+        container.from_schema(
+            {
+                'version': '1',
+                'container': {
+                    'provider1': {
+                        'provider': 'Factory',
+                        'provides': 'list',
+                        'args': [1, 2, 3],
+                    },
+                    'provider2': {
+                        'provider': 'Factory',
+                        'provides': 'dict',
+                        'kwargs': {
+                            'one': 'container.provider1',
+                            'two': 2,
+                        },
+                    },
+                },
+            },
+        )
+
+        self.assertIsInstance(container.provider1, providers.Factory)
+        self.assertIs(container.provider1.provides, list)
+        self.assertEqual(container.provider1.args, (1, 2, 3))
+
+        self.assertIsInstance(container.provider2, providers.Factory)
+        self.assertIs(container.provider2.provides, dict)
+        self.assertEqual(container.provider2.kwargs, {'one': container.provider1, 'two': 2})
+
+
+class FromYamlSchemaTests(unittest.TestCase):
+
+    def test(self):
+        container = containers.DynamicContainer()
+
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            schema_path = os.path.join(tmp_dir, 'schema.yml')
+            with open(schema_path, 'w') as file:
+                file.write("""
+                version: "1"
+                container:
+                  provider1:
+                    provider: Factory
+                    provides: list
+                    args:
+                      - 1
+                      - 2
+                      - 3
+                  provider2:
+                    provider: Factory
+                    provides: dict
+                    kwargs:
+                      one: container.provider1
+                      two: 2
+                """)
+
+            container.from_yaml_schema(schema_path)
+
+        self.assertIsInstance(container.provider1, providers.Factory)
+        self.assertIs(container.provider1.provides, list)
+        self.assertEqual(container.provider1.args, (1, 2, 3))
+
+        self.assertIsInstance(container.provider2, providers.Factory)
+        self.assertIs(container.provider2.provides, dict)
+        self.assertEqual(container.provider2.kwargs, {'one': container.provider1, 'two': 2})
+
+    def test_with_loader(self):
+        container = containers.DynamicContainer()
+
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            schema_path = os.path.join(tmp_dir, 'schema.yml')
+            with open(schema_path, 'w') as file:
+                file.write("""
+                version: "1"
+                container:
+                  provider:
+                    provider: Factory
+                    provides: list
+                    args: [1, 2, 3]
+                """)
+
+            container.from_yaml_schema(schema_path, loader=yaml.Loader)
+
+        self.assertIsInstance(container.provider, providers.Factory)
+        self.assertIs(container.provider.provides, list)
+        self.assertEqual(container.provider.args, (1, 2, 3))
+
+    def test_no_yaml_installed(self):
+        @contextlib.contextmanager
+        def no_yaml_module():
+            containers.yaml = None
+            yield
+            containers.yaml = yaml
+
+        container = containers.DynamicContainer()
+        with no_yaml_module():
+            with self.assertRaises(errors.Error) as error:
+                container.from_yaml_schema('./no-yaml-installed.yml')
+
+        self.assertEqual(
+            error.exception.args[0],
+            'Unable to load yaml schema - PyYAML is not installed. '
+            'Install PyYAML or install Dependency Injector with yaml extras: '
+            '"pip install dependency-injector[yaml]"',
+        )
+
+
+class FromJsonSchemaTests(unittest.TestCase):
+
+    def test(self):
+        container = containers.DynamicContainer()
+
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            schema_path = os.path.join(tmp_dir, 'schema.json')
+            with open(schema_path, 'w') as file:
+                file.write(
+                    json.dumps(
+                        {
+                            'version': '1',
+                            'container': {
+                                'provider1': {
+                                    'provider': 'Factory',
+                                    'provides': 'list',
+                                    'args': [1, 2, 3],
+                                },
+                                'provider2': {
+                                    'provider': 'Factory',
+                                    'provides': 'dict',
+                                    'kwargs': {
+                                        'one': 'container.provider1',
+                                        'two': 2,
+                                    },
+                                },
+                            },
+                        },
+                        indent=4,
+                    ),
+                )
+
+            container.from_json_schema(schema_path)
+
+        self.assertIsInstance(container.provider1, providers.Factory)
+        self.assertIs(container.provider1.provides, list)
+        self.assertEqual(container.provider1.args, (1, 2, 3))
+
+        self.assertIsInstance(container.provider2, providers.Factory)
+        self.assertIs(container.provider2.provides, dict)
+        self.assertEqual(container.provider2.kwargs, {'one': container.provider1, 'two': 2})

tests/unit/schema/test_integration_py36.py

@@ -0,0 +1,293 @@
+import sqlite3
+import unittest
+
+from dependency_injector import containers
+
+# Runtime import
+import os
+_TOP_DIR = os.path.abspath(
+    os.path.sep.join((
+        os.path.dirname(__file__),
+        '../',
+    )),
+)
+_SAMPLES_DIR = os.path.abspath(
+    os.path.sep.join((
+        os.path.dirname(__file__),
+        '../samples/',
+    )),
+)
+import sys
+sys.path.append(_SAMPLES_DIR)
+
+from schemasample.services import UserService, AuthService, PhotoService
+
+
+class TestSchemaSingleContainer(unittest.TestCase):
+
+    def test(self):
+        container = containers.DynamicContainer()
+        container.from_yaml_schema(f'{_SAMPLES_DIR}/schemasample/container-single.yml')
+        container.config.from_dict({
+            'database': {
+                'dsn': ':memory:',
+            },
+            'aws': {
+                'access_key_id': 'KEY',
+                'secret_access_key': 'SECRET',
+            },
+            'auth': {
+                'token_ttl': 3600,
+            },
+        })
+
+        # User service
+        user_service1 = container.user_service()
+        user_service2 = container.user_service()
+        self.assertIsInstance(user_service1, UserService)
+        self.assertIsInstance(user_service2, UserService)
+        self.assertIsNot(user_service1, user_service2)
+
+        self.assertIsInstance(user_service1.db, sqlite3.Connection)
+        self.assertIsInstance(user_service2.db, sqlite3.Connection)
+        self.assertIs(user_service1.db, user_service2.db)
+
+        # Auth service
+        auth_service1 = container.auth_service()
+        auth_service2 = container.auth_service()
+        self.assertIsInstance(auth_service1, AuthService)
+        self.assertIsInstance(auth_service2, AuthService)
+        self.assertIsNot(auth_service1, auth_service2)
+
+        self.assertIsInstance(auth_service1.db, sqlite3.Connection)
+        self.assertIsInstance(auth_service2.db, sqlite3.Connection)
+        self.assertIs(auth_service1.db, auth_service2.db)
+        self.assertIs(auth_service1.db, container.database_client())
+        self.assertIs(auth_service2.db, container.database_client())
+
+        self.assertEqual(auth_service1.token_ttl, 3600)
+        self.assertEqual(auth_service2.token_ttl, 3600)
+
+        # Photo service
+        photo_service1 = container.photo_service()
+        photo_service2 = container.photo_service()
+        self.assertIsInstance(photo_service1, PhotoService)
+        self.assertIsInstance(photo_service2, PhotoService)
+        self.assertIsNot(photo_service1, photo_service2)
+
+        self.assertIsInstance(photo_service1.db, sqlite3.Connection)
+        self.assertIsInstance(photo_service2.db, sqlite3.Connection)
+        self.assertIs(photo_service1.db, photo_service2.db)
+        self.assertIs(photo_service1.db, container.database_client())
+        self.assertIs(photo_service2.db, container.database_client())
+
+        self.assertIs(photo_service1.s3, photo_service2.s3)
+        self.assertIs(photo_service1.s3, container.s3_client())
+        self.assertIs(photo_service2.s3, container.s3_client())
+
+
+class TestSchemaMultipleContainers(unittest.TestCase):
+
+    def test(self):
+        container = containers.DynamicContainer()
+        container.from_yaml_schema(f'{_SAMPLES_DIR}/schemasample/container-multiple.yml')
+        container.core.config.from_dict({
+            'database': {
+                'dsn': ':memory:',
+            },
+            'aws': {
+                'access_key_id': 'KEY',
+                'secret_access_key': 'SECRET',
+            },
+            'auth': {
+                'token_ttl': 3600,
+            },
+        })
+
+        # User service
+        user_service1 = container.services.user()
+        user_service2 = container.services.user()
+        self.assertIsInstance(user_service1, UserService)
+        self.assertIsInstance(user_service2, UserService)
+        self.assertIsNot(user_service1, user_service2)
+
+        self.assertIsInstance(user_service1.db, sqlite3.Connection)
+        self.assertIsInstance(user_service2.db, sqlite3.Connection)
+        self.assertIs(user_service1.db, user_service2.db)
+
+        # Auth service
+        auth_service1 = container.services.auth()
+        auth_service2 = container.services.auth()
+        self.assertIsInstance(auth_service1, AuthService)
+        self.assertIsInstance(auth_service2, AuthService)
+        self.assertIsNot(auth_service1, auth_service2)
+
+        self.assertIsInstance(auth_service1.db, sqlite3.Connection)
+        self.assertIsInstance(auth_service2.db, sqlite3.Connection)
+        self.assertIs(auth_service1.db, auth_service2.db)
+        self.assertIs(auth_service1.db, container.gateways.database_client())
+        self.assertIs(auth_service2.db, container.gateways.database_client())
+
+        self.assertEqual(auth_service1.token_ttl, 3600)
+        self.assertEqual(auth_service2.token_ttl, 3600)
+
+        # Photo service
+        photo_service1 = container.services.photo()
+        photo_service2 = container.services.photo()
+        self.assertIsInstance(photo_service1, PhotoService)
+        self.assertIsInstance(photo_service2, PhotoService)
+        self.assertIsNot(photo_service1, photo_service2)
+
+        self.assertIsInstance(photo_service1.db, sqlite3.Connection)
+        self.assertIsInstance(photo_service2.db, sqlite3.Connection)
+        self.assertIs(photo_service1.db, photo_service2.db)
+        self.assertIs(photo_service1.db, container.gateways.database_client())
+        self.assertIs(photo_service2.db, container.gateways.database_client())
+
+        self.assertIs(photo_service1.s3, photo_service2.s3)
+        self.assertIs(photo_service1.s3, container.gateways.s3_client())
+        self.assertIs(photo_service2.s3, container.gateways.s3_client())
+
+
+class TestSchemaMultipleContainersReordered(unittest.TestCase):
+
+    def test(self):
+        container = containers.DynamicContainer()
+        container.from_yaml_schema(f'{_SAMPLES_DIR}/schemasample/container-multiple-reordered.yml')
+        container.core.config.from_dict({
+            'database': {
+                'dsn': ':memory:',
+            },
+            'aws': {
+                'access_key_id': 'KEY',
+                'secret_access_key': 'SECRET',
+            },
+            'auth': {
+                'token_ttl': 3600,
+            },
+        })
+
+        # User service
+        user_service1 = container.services.user()
+        user_service2 = container.services.user()
+        self.assertIsInstance(user_service1, UserService)
+        self.assertIsInstance(user_service2, UserService)
+        self.assertIsNot(user_service1, user_service2)
+
+        self.assertIsInstance(user_service1.db, sqlite3.Connection)
+        self.assertIsInstance(user_service2.db, sqlite3.Connection)
+        self.assertIs(user_service1.db, user_service2.db)
+
+        # Auth service
+        auth_service1 = container.services.auth()
+        auth_service2 = container.services.auth()
+        self.assertIsInstance(auth_service1, AuthService)
+        self.assertIsInstance(auth_service2, AuthService)
+        self.assertIsNot(auth_service1, auth_service2)
+
+        self.assertIsInstance(auth_service1.db, sqlite3.Connection)
+        self.assertIsInstance(auth_service2.db, sqlite3.Connection)
+        self.assertIs(auth_service1.db, auth_service2.db)
+        self.assertIs(auth_service1.db, container.gateways.database_client())
+        self.assertIs(auth_service2.db, container.gateways.database_client())
+
+        self.assertEqual(auth_service1.token_ttl, 3600)
+        self.assertEqual(auth_service2.token_ttl, 3600)
+
+        # Photo service
+        photo_service1 = container.services.photo()
+        photo_service2 = container.services.photo()
+        self.assertIsInstance(photo_service1, PhotoService)
+        self.assertIsInstance(photo_service2, PhotoService)
+        self.assertIsNot(photo_service1, photo_service2)
+
+        self.assertIsInstance(photo_service1.db, sqlite3.Connection)
+        self.assertIsInstance(photo_service2.db, sqlite3.Connection)
+        self.assertIs(photo_service1.db, photo_service2.db)
+        self.assertIs(photo_service1.db, container.gateways.database_client())
+        self.assertIs(photo_service2.db, container.gateways.database_client())
+
+        self.assertIs(photo_service1.s3, photo_service2.s3)
+        self.assertIs(photo_service1.s3, container.gateways.s3_client())
+        self.assertIs(photo_service2.s3, container.gateways.s3_client())
+
+
+class TestSchemaMultipleContainersWithInlineProviders(unittest.TestCase):
+
+    def test(self):
+        container = containers.DynamicContainer()
+        container.from_yaml_schema(f'{_SAMPLES_DIR}/schemasample/container-multiple-inline.yml')
+        container.core.config.from_dict({
+            'database': {
+                'dsn': ':memory:',
+            },
+            'aws': {
+                'access_key_id': 'KEY',
+                'secret_access_key': 'SECRET',
+            },
+            'auth': {
+                'token_ttl': 3600,
+            },
+        })
+
+        # User service
+        user_service1 = container.services.user()
+        user_service2 = container.services.user()
+        self.assertIsInstance(user_service1, UserService)
+        self.assertIsInstance(user_service2, UserService)
+        self.assertIsNot(user_service1, user_service2)
+
+        self.assertIsInstance(user_service1.db, sqlite3.Connection)
+        self.assertIsInstance(user_service2.db, sqlite3.Connection)
+        self.assertIs(user_service1.db, user_service2.db)
+
+        # Auth service
+        auth_service1 = container.services.auth()
+        auth_service2 = container.services.auth()
+        self.assertIsInstance(auth_service1, AuthService)
+        self.assertIsInstance(auth_service2, AuthService)
+        self.assertIsNot(auth_service1, auth_service2)
+
+        self.assertIsInstance(auth_service1.db, sqlite3.Connection)
+        self.assertIsInstance(auth_service2.db, sqlite3.Connection)
+        self.assertIs(auth_service1.db, auth_service2.db)
+        self.assertIs(auth_service1.db, container.gateways.database_client())
+        self.assertIs(auth_service2.db, container.gateways.database_client())
+
+        self.assertEqual(auth_service1.token_ttl, 3600)
+        self.assertEqual(auth_service2.token_ttl, 3600)
+
+        # Photo service
+        photo_service1 = container.services.photo()
+        photo_service2 = container.services.photo()
+        self.assertIsInstance(photo_service1, PhotoService)
+        self.assertIsInstance(photo_service2, PhotoService)
+        self.assertIsNot(photo_service1, photo_service2)
+
+        self.assertIsInstance(photo_service1.db, sqlite3.Connection)
+        self.assertIsInstance(photo_service2.db, sqlite3.Connection)
+        self.assertIs(photo_service1.db, photo_service2.db)
+        self.assertIs(photo_service1.db, container.gateways.database_client())
+        self.assertIs(photo_service2.db, container.gateways.database_client())
+
+        self.assertIs(photo_service1.s3, photo_service2.s3)
+        self.assertIs(photo_service1.s3, container.gateways.s3_client())
+        self.assertIs(photo_service2.s3, container.gateways.s3_client())
+
+
+class TestSchemaBoto3Session(unittest.TestCase):
+
+    def test(self):
+        container = containers.DynamicContainer()
+        container.from_yaml_schema(f'{_SAMPLES_DIR}/schemasample/container-boto3-session.yml')
+        container.config.from_dict(
+            {
+                'aws_access_key_id': 'key',
+                'aws_secret_access_key': 'secret',
+                'aws_session_token': 'token',
+                'aws_region_name': 'us-east-1',
+            },
+        )
+
+        self.assertEqual(container.s3_client().__class__.__name__, 'S3')
+        self.assertEqual(container.sqs_client().__class__.__name__, 'SQS')

tests/unit/wiring/test_wiring_py36.py

@@ -437,6 +437,7 @@ class AutoLoaderTest(unittest.TestCase):
     def test_register_container(self):
         register_loader_containers(self.container)
         importlib.reload(module)
+        importlib.import_module('wiringsamples.imports')
 
         service = module.test_function()
         self.assertIsInstance(service, Service)

tests/unit/wiring/test_wiring_string_ids_py36.py

@@ -1,4 +1,6 @@
+import contextlib
 from decimal import Decimal
+import importlib
 import unittest
 
 from dependency_injector.wiring import (
@@ -6,6 +8,8 @@ from dependency_injector.wiring import (
     Provide,
     Provider,
     Closing,
+    register_loader_containers,
+    unregister_loader_containers,
 )
 from dependency_injector import containers, providers, errors
 
@@ -409,27 +413,27 @@ class WiringAsyncInjectionsTest(AsyncTestCase):
         self.assertEqual(asyncinjections.resource2.shutdown_counter, 2)
 
 
-# class AutoLoaderTest(unittest.TestCase):
-#
-#     container: Container
-#
-#     def setUp(self) -> None:
-#         self.container = Container(config={'a': {'b': {'c': 10}}})
-#         importlib.reload(module)
-#
-#     def tearDown(self) -> None:
-#         with contextlib.suppress(ValueError):
-#             unregister_loader_containers(self.container)
-#
-#         self.container.unwire()
-#
-#     @classmethod
-#     def tearDownClass(cls) -> None:
-#         importlib.reload(module)
-#
-#     def test_register_container(self):
-#         register_loader_containers(self.container)
-#         importlib.reload(module)
-#
-#         service = module.test_function()
-#         self.assertIsInstance(service, Service)
+class AutoLoaderTest(unittest.TestCase):
+
+    container: Container
+
+    def setUp(self) -> None:
+        self.container = Container(config={'a': {'b': {'c': 10}}})
+        importlib.reload(module)
+
+    def tearDown(self) -> None:
+        with contextlib.suppress(ValueError):
+            unregister_loader_containers(self.container)
+
+        self.container.unwire()
+
+    @classmethod
+    def tearDownClass(cls) -> None:
+        importlib.reload(module)
+
+    def test_register_container(self):
+        register_loader_containers(self.container)
+        importlib.reload(module)
+
+        service = module.test_function()
+        self.assertIsInstance(service, Service)

tox.ini

@@ -10,6 +10,8 @@ deps=
     fastapi
     numpy
     scipy
+    boto3
+    mypy_boto3_s3
 extras=
     yaml
     pydantic
@@ -68,6 +70,8 @@ commands=
 deps=
     httpx
     fastapi
+    boto3
+    mypy_boto3_s3
 extras=
     yaml
     flask