Merge pull request #658 from fadedDexofan/fix/protocol-inspection

fix: resolve `__init__` introspection when `Protocol` is first in bases

Author: Tishka17

src/dishka/provider/make_factory.py

@@ -92,8 +92,22 @@ def _is_bound_method(obj: Any) -> bool:
     return ismethod(obj) and bool(obj.__self__)
 
 
+def _resolve_init(tp: type) -> Any:
+    init = tp.__init__  # type: ignore[misc]
+    if init is not _protocol_init:
+        return init
+    for cls in tp.__mro__:
+        if cls is object:
+            continue
+        init_candidate = cls.__dict__.get("__init__")
+        if init_candidate is not None and init_candidate is not _protocol_init:
+            return init_candidate
+    return init
+
+
 def _get_init_members(tp: type) -> MembersStorage[str, None]:
-    type_hints = get_all_type_hints(tp.__init__)  # type: ignore[misc, no-untyped-call]
+    real_init = _resolve_init(tp)
+    type_hints = get_all_type_hints(real_init)  # type: ignore[no-untyped-call]
     if "__init__" in tp.__dict__:
         overridden = frozenset(type_hints)
     else:
@@ -256,7 +270,7 @@ def _make_factory_by_class(
     if not provides:
         provides = source
 
-    init = strip_alias(source).__init__
+    init = _resolve_init(strip_alias(source))
     if missing_hints := _params_without_hints(init, skip_self=True):
         raise MissingHintsError(source, missing_hints, append_init=True)
     # we need to fix concrete generics and normal classes as well

tests/unit/container/test_resolve.py

@@ -1,3 +1,6 @@
+import math
+from typing import Protocol
+
 import pytest
 
 from dishka import (
@@ -7,6 +10,7 @@
     make_container,
     provide,
 )
+from dishka.provider import provide_all
 from ..sample_providers import (
     A_VALUE,
     ClassA,
@@ -144,3 +148,135 @@ def test_kwargs():
 
     container = make_container(provider)
     assert container.get(str) == "ok"
+
+
+class _Dep:
+    pass
+
+
+def test_provide_multiple_protocols_before_base():
+    class Proto1(Protocol):
+        pass
+
+    class Proto2(Protocol):
+        pass
+
+    class Base:
+        def __init__(self, dep: _Dep) -> None:
+            self.dep = dep
+
+    class Multi(Proto1, Proto2, Base):
+        pass
+
+    provider = Provider(scope=Scope.APP)
+    provider.provide(_Dep)
+    provider.provide(Multi)
+
+    container = make_container(provider)
+    result = container.get(Multi)
+    assert isinstance(result, Multi)
+    assert isinstance(result.dep, _Dep)
+
+
+def test_provide_own_init_overrides_protocol_stub():
+    class Proto(Protocol):
+        pass
+
+    class Base:
+        def __init__(self, dep: _Dep) -> None:
+            self.dep = dep
+
+    class Impl(Proto, Base):
+        def __init__(self, dep: _Dep) -> None:
+            self.own_dep = dep
+
+    provider = Provider(scope=Scope.APP)
+    provider.provide(_Dep)
+    provider.provide(Impl)
+
+    container = make_container(provider)
+    result = container.get(Impl)
+    assert isinstance(result, Impl)
+    assert isinstance(result.own_dep, _Dep)
+
+
+def test_provide_protocol_with_explicit_init():
+    class ProtoWithInit(Protocol):
+        def __init__(self, dep: _Dep) -> None: ...
+
+    class Impl(ProtoWithInit):
+        def __init__(self, dep: _Dep) -> None:
+            self.dep = dep
+
+    provider = Provider(scope=Scope.APP)
+    provider.provide(_Dep)
+    provider.provide(Impl)
+
+    container = make_container(provider)
+    result = container.get(Impl)
+    assert isinstance(result, Impl)
+    assert isinstance(result.dep, _Dep)
+
+
+def test_provide_deep_hierarchy_with_protocol():
+    class Proto(Protocol):
+        pass
+
+    class GrandBase:
+        def __init__(self, dep: _Dep) -> None:
+            self.dep = dep
+
+    class Base(GrandBase):
+        pass
+
+    class Impl(Proto, Base):
+        pass
+
+    provider = Provider(scope=Scope.APP)
+    provider.provide(_Dep)
+    provider.provide(Impl)
+
+    container = make_container(provider)
+    result = container.get(Impl)
+    assert isinstance(result, Impl)
+    assert isinstance(result.dep, _Dep)
+
+
+def test_provide_all_as_provider_method():
+    def a() -> int:
+        return 100
+
+    def b(num: int) -> float:
+        return num / 2
+
+    provider = Provider(scope=Scope.APP)
+    provider.provide_all(a, b)
+
+    container = make_container(provider)
+
+    hundred = container.get(int)
+    assert hundred == 100
+
+    fifty = container.get(float)
+    assert math.isclose(fifty, 50.0, abs_tol=1e-9)
+
+
+def test_provide_all_in_class():
+    class MyProvider(Provider):
+        scope = Scope.APP
+
+        def a(self) -> int:
+            return 100
+
+        def b(self, num: int) -> float:
+            return num / 2
+
+        abcd = provide_all(a, b)
+
+    container = make_container(MyProvider())
+
+    hundred = container.get(int)
+    assert hundred == 100
+
+    fifty = container.get(float)
+    assert math.isclose(fifty, 50.0, abs_tol=1e-9)

tests/unit/container/test_with_parents.py

@@ -303,3 +303,32 @@ class MyProvider(Provider):
     container = make_container(MyProvider())
 
     assert isinstance(container.get(IntRepo), ConcreteRepo)
+
+
+class _Dep:
+    pass
+
+
+def test_protocol_first_with_parents() -> None:
+    class Proto(Protocol):
+        pass
+
+    class Base:
+        def __init__(self, dep: _Dep) -> None:
+            self.dep = dep
+
+    class Impl(Proto, Base):
+        pass
+
+    provider = Provider(scope=Scope.APP)
+    provider.provide(_Dep)
+    provider.provide(WithParents[Impl])
+
+    container = make_container(provider)
+    result = container.get(Impl)
+    assert isinstance(result, Impl)
+    assert isinstance(result.dep, _Dep)
+    assert container.get(Proto) is result
+    assert container.get(Base) is result
+
+

tests/unit/test_provider.py

@@ -1,4 +1,3 @@
-import math
 from collections.abc import (
     AsyncGenerator,
     AsyncIterable,
@@ -28,7 +27,6 @@
     Scope,
     alias,
     decorate,
-    make_container,
     provide,
 )
 from dishka._adaptix.feature_requirement import HAS_TV_DEFAULT
@@ -479,46 +477,6 @@ def decorator(self, param: int) -> str:
         decorate(decorator)
 
 
-def test_provide_all_as_provider_method():
-    def a() -> int:
-        return 100
-
-    def b(num: int) -> float:
-        return num / 2
-
-    provider = Provider(scope=Scope.APP)
-    provider.provide_all(a, b)
-
-    container = make_container(provider)
-
-    hundred = container.get(int)
-    assert hundred == 100
-
-    fifty = container.get(float)
-    assert math.isclose(fifty, 50.0, abs_tol=1e-9)
-
-
-def test_provide_all_in_class():
-    class MyProvider(Provider):
-        scope = Scope.APP
-
-        def a(self) -> int:
-            return 100
-
-        def b(self, num: int) -> float:
-            return num / 2
-
-        abcd = provide_all(a, b)
-
-    container = make_container(MyProvider())
-
-    hundred = container.get(int)
-    assert hundred == 100
-
-    fifty = container.get(float)
-    assert math.isclose(fifty, 50.0, abs_tol=1e-9)
-
-
 make_factory_by_source = partial(
     make_factory,
     provides=None,