Unify validation and remove Container.validate_provider

docs/dev/key-concepts.md

@@ -65,8 +65,7 @@ Container provides methods for resolving dependencies:
 
 1. `resolve_provider(provider)` - Resolve a specific provider instance
 2. `resolve(SomeType)` - Resolve by type
-3. `validate_provider(provider)` - Validate that the provider's dependency graph is wired correctly without creating real instances (useful at startup)
-4. `validate()` - Walk the entire provider graph and detect circular dependencies (raises `RuntimeError` with the cycle path if found)
+3. `validate()` - Walk the entire provider graph and detect missing dependencies, missing alias sources, and circular dependencies — without creating real instances (useful at startup)
 
 You can also pass `validate=True` to `Container(...)` to run validation automatically at creation time:
 

modern_di/container.py

@@ -102,9 +102,6 @@ def resolve_provider(self, provider: "AbstractProvider[types.T]") -> types.T:
 
         return provider.resolve(self)
 
-    def validate_provider(self, provider: "AbstractProvider[types.T]") -> types.T:
-        return typing.cast(types.T, provider.validate(self))
-
     def validate(self) -> None:
         visiting: set[int] = set()
         visited: set[int] = set()

modern_di/providers/abstract.py

@@ -28,8 +28,5 @@ def __init__(
     @abc.abstractmethod
     def resolve(self, container: "Container") -> typing.Any: ...  # noqa: ANN401
 
-    @abc.abstractmethod
-    def validate(self, container: "Container") -> dict[str, typing.Any]: ...
-
     def get_dependencies(self, container: "Container") -> dict[str, "AbstractProvider[typing.Any]"]:  # noqa: ARG002
         return {}

modern_di/providers/alias.py

@@ -34,14 +34,5 @@ def _find_source(self, container: "Container") -> "AbstractProvider[types.T_co]"
     def get_dependencies(self, container: "Container") -> dict[str, "AbstractProvider[typing.Any]"]:
         return {"source": self._find_source(container)}
 
-    def validate(self, container: "Container") -> dict[str, typing.Any]:
-        source = self._find_source(container)
-        return {
-            "bound_type": self.bound_type,
-            "source_type": self._source_type,
-            "source": source.validate(container),
-            "self": self,
-        }
-
     def resolve(self, container: "Container") -> types.T_co:
         return container.resolve_provider(self._find_source(container))

modern_di/providers/container_provider.py

@@ -17,8 +17,5 @@ def __init__(self) -> None:
     def resolve(self, container: "Container") -> "Container":
         return container
 
-    def validate(self, container: "Container") -> dict[str, typing.Any]:  # noqa: ARG002
-        return {"self": self}
-
 
 container_provider = _ContainerProvider()

modern_di/providers/context_provider.py

@@ -25,9 +25,6 @@ def __init__(
     def __repr__(self) -> str:
         return f"ContextProvider(context_type={self._context_type!r}, scope={self.scope!r})"
 
-    def validate(self, container: "Container") -> dict[str, typing.Any]:  # noqa: ARG002
-        return {"bound_type": self.bound_type, "self": self}
-
     def resolve(self, container: "Container") -> types.T_co | None:
         container = container.find_container(self.scope)
         return container.context_registry.find_context(self._context_type)

modern_di/providers/factory.py

@@ -123,20 +123,6 @@ def get_dependencies(self, container: "Container") -> dict[str, "AbstractProvide
         provider_kwargs, _ = self._ensure_kwargs_cached(scoped_container, cache_item)
         return provider_kwargs
 
-    def validate(self, container: "Container") -> dict[str, typing.Any]:
-        container = container.find_container(self.scope)
-        cache_item = container.cache_registry.fetch_cache_item(self)
-        provider_kwargs, static_kwargs = self._ensure_kwargs_cached(container, cache_item)
-        validated_kwargs: dict[str, typing.Any] = {k: v.validate(container) for k, v in provider_kwargs.items()}
-        validated_kwargs.update(static_kwargs)
-        return {
-            "bound_type": self.bound_type,
-            "creator": self._creator,
-            "self": self,
-            "kwargs": validated_kwargs,
-            "cache_settings": self.cache_settings,
-        }
-
     def resolve(self, container: "Container") -> types.T_co:
         container = container.find_container(self.scope)
         cache_item = container.cache_registry.fetch_cache_item(self)

skills/modern-di/testing.md

@@ -116,6 +116,6 @@ Check that all dependencies can be resolved without creating real objects:
 ```python
 def test_wiring():
     container = Container(scope=Scope.APP, groups=[Dependencies])
-    container.validate_provider(Dependencies.users_repository)
-    # Raises RuntimeError if any dependency is missing
+    container.validate()
+    # Raises if any provider has missing dependencies, missing alias sources, or circular deps
 ```

tests/providers/test_alias.py

@@ -33,7 +33,6 @@ def test_alias_delegates_to_source() -> None:
 
 def test_alias_resolve_provider() -> None:
     container = Container(groups=[MyGroup])
-    container.validate_provider(MyGroup.abstract_repo)
     instance = container.resolve_provider(MyGroup.abstract_repo)
     assert isinstance(instance, PostgresRepository)
 
@@ -99,7 +98,7 @@ class G(Group):
 
     container = Container(groups=[G])
     with pytest.raises(AliasSourceNotRegisteredError, match="PostgresRepository"):
-        container.validate_provider(G.abstract)
+        container.resolve_provider(G.abstract)
 
 
 def test_alias_missing_source_raises_on_container_validate() -> None:

tests/providers/test_container_provider.py

@@ -7,7 +7,6 @@ def test_container_provider_direct_resolving() -> None:
 
     request_container = app_container.build_child_container(scope=Scope.REQUEST)
     assert request_container.resolve_provider(providers.container_provider) is request_container
-    request_container.validate_provider(providers.container_provider)
 
 
 def test_container_provider_sub_dependency() -> None:

tests/providers/test_context_provider.py

@@ -22,8 +22,7 @@ class MyGroup(Group):
 
 def test_context_provider() -> None:
     now = datetime.datetime.now(tz=datetime.timezone.utc)
-    app_container = Container(context={datetime.datetime: now})
-    app_container.validate_provider(MyGroup.context_provider)
+    app_container = Container(groups=[MyGroup], context={datetime.datetime: now})
     instance1 = app_container.resolve_provider(MyGroup.context_provider)
     instance2 = app_container.resolve_provider(MyGroup.context_provider)
     assert instance1 is instance2 is now

tests/providers/test_factory.py

@@ -46,7 +46,6 @@ class MyGroup(Group):
 def test_app_factory() -> None:
     app_container = Container(groups=[MyGroup])
     instance1 = app_container.resolve_provider(MyGroup.app_factory)
-    app_container.validate_provider(MyGroup.app_factory)
     instance2 = app_container.resolve(dependency_type=SimpleCreator)
     assert isinstance(instance1, SimpleCreator)
     assert isinstance(instance2, SimpleCreator)
@@ -64,7 +63,7 @@ def test_app_factory_skip_creator_parsing() -> None:
 def test_app_factory_unresolvable() -> None:
     app_container = Container(groups=[MyGroup])
     with pytest.raises(ArgumentResolutionError, match="Argument dep1 of type <class 'str'> cannot be resolved") as exc:
-        app_container.validate_provider(MyGroup.app_factory_unresolvable)
+        app_container.resolve_provider(MyGroup.app_factory_unresolvable)
     assert exc.value.arg_name == "dep1"
     assert exc.value.arg_type is str
 
@@ -78,16 +77,16 @@ def test_func_with_union_factory() -> None:
 def test_func_with_broken_annotation() -> None:
     app_container = Container(groups=[MyGroup])
     with pytest.raises(ArgumentResolutionError, match="Argument dep1 of type None cannot be resolved"):
-        app_container.validate_provider(MyGroup.func_with_broken_annotation)
+        app_container.resolve_provider(MyGroup.func_with_broken_annotation)
 
 
 def test_request_factory() -> None:
     app_container = Container(groups=[MyGroup])
     request_container = app_container.build_child_container(scope=Scope.REQUEST)
-    request_container.validate_provider(MyGroup.request_factory)
+    request_container.resolve_provider(MyGroup.request_factory)
     instance1 = request_container.resolve_provider(MyGroup.request_factory)
     instance2 = request_container.resolve_provider(MyGroup.request_factory)
-    request_container.validate_provider(MyGroup.request_factory)
+    request_container.resolve_provider(MyGroup.request_factory)
     assert instance1 is not instance2
 
     request_container = app_container.build_child_container(scope=Scope.REQUEST)

tests/test_container.py

@@ -1,5 +1,6 @@
 import copy
 import dataclasses
+import typing
 
 import pytest
 
@@ -11,6 +12,7 @@
     ProviderNotRegisteredError,
     ScopeSkippedError,
 )
+from modern_di.providers.abstract import AbstractProvider
 
 
 def test_container_prevent_copy() -> None:
@@ -125,3 +127,43 @@ class ValidGroup(Group):
 
     container = Container(groups=[ValidGroup])
     container.validate()  # should not raise
+
+
+def test_validate_memoizes_diamond() -> None:
+    @dataclasses.dataclass(kw_only=True, slots=True)
+    class Bottom:
+        pass
+
+    @dataclasses.dataclass(kw_only=True, slots=True)
+    class Left:
+        bottom: Bottom
+
+    @dataclasses.dataclass(kw_only=True, slots=True)
+    class Right:
+        bottom: Bottom
+
+    @dataclasses.dataclass(kw_only=True, slots=True)
+    class Top:
+        left: Left
+        right: Right
+
+    bottom_provider = providers.Factory(creator=Bottom)
+    call_count = 0
+    original_get_dependencies = bottom_provider.get_dependencies
+
+    def counting_get_dependencies(container: Container) -> dict[str, AbstractProvider[typing.Any]]:
+        nonlocal call_count
+        call_count += 1
+        return original_get_dependencies(container)
+
+    bottom_provider.get_dependencies = counting_get_dependencies  # ty: ignore[invalid-assignment]
+
+    class DiamondGroup(Group):
+        bottom = bottom_provider
+        left = providers.Factory(creator=Left)
+        right = providers.Factory(creator=Right)
+        top = providers.Factory(creator=Top)
+
+    container = Container(groups=[DiamondGroup])
+    container.validate()
+    assert call_count == 1