refactoring: ♻️ More precise exceptions

Author: remimd

injection/core/module.py

@@ -27,7 +27,12 @@
 
 from injection.common.event import Event, EventChannel, EventListener
 from injection.common.lazy import LazyMapping
-from injection.exceptions import ModuleError, NoInjectable
+from injection.exceptions import (
+    ModuleCircularUseError,
+    ModuleError,
+    ModuleNotUsedError,
+    NoInjectable,
+)
 
 __all__ = ("Injectable", "Module", "ModulePriorities")
 
@@ -73,24 +78,29 @@ class ModuleEvent(Event, ABC):
     on_module: Module
 
 
-@dataclass(frozen=True)
+@dataclass(frozen=True, slots=True)
 class ModuleEventProxy(ModuleEvent):
     event: Event
 
     def __str__(self) -> str:
         return f"`{self.on_module}` has propagated an event: {self.origin}"
 
-    @cached_property
-    def origin(self) -> Event:
+    def __iter__(self) -> Iterator[Event]:
         if isinstance(self.event, ModuleEventProxy):
-            return self.event.origin
+            yield from self.event
 
-        return self.event
+        yield self.event
+
+    @property
+    def origin(self) -> Event:
+        return next(self.__iter__())
 
     @property
     def is_circular(self) -> bool:
-        origin = self.origin
-        return isinstance(origin, ModuleEvent) and origin.on_module is self.on_module
+        return any(
+            isinstance(event, ModuleEvent) and event.on_module is self.on_module
+            for event in self
+        )
 
     @property
     def previous_module(self) -> Module | None:
@@ -381,7 +391,7 @@ def on_event(self, event: Event, /):
         self_event = ModuleEventProxy(self, event)
 
         if self_event.is_circular:
-            raise ModuleError(
+            raise ModuleCircularUseError(
                 "Circular dependency between two modules: "
                 f"`{self_event.previous_module}` and `{self}`."
             )
@@ -399,7 +409,7 @@ def __move_module(self, module: Module, priority: ModulePriorities):
         try:
             self.__modules.move_to_end(module, last=last)
         except KeyError as exc:
-            raise ModuleError(
+            raise ModuleNotUsedError(
                 f"`{module}` can't be found in the modules used by `{self}`."
             ) from exc
 

injection/exceptions.py

@@ -1,6 +1,3 @@
-__all__ = ("InjectionError", "ModuleError", "NoInjectable")
-
-
 class InjectionError(Exception):
     ...
 
@@ -11,3 +8,11 @@ class NoInjectable(KeyError, InjectionError):
 
 class ModuleError(InjectionError):
     ...
+
+
+class ModuleCircularUseError(ModuleError):
+    ...
+
+
+class ModuleNotUsedError(KeyError, ModuleError):
+    ...

poetry.lock

@@ -1,10 +1,11 @@
+from contextlib import suppress
 from typing import Any
 
 import pytest
 
 from injection import Module, ModulePriorities
 from injection.core import Injectable
-from injection.exceptions import ModuleError
+from injection.exceptions import ModuleCircularUseError, ModuleError, ModuleNotUsedError
 
 
 class SomeClass:
@@ -86,13 +87,28 @@ def test_use_with_self_raise_module_error(self, module, event_history):
 
         event_history.assert_length(0)
 
-    def test_use_with_circular_dependency_raise_module_error(self, module):
+    def test_use_with_circular_dependency_raise_module_circular_use_error(self, module):
         second_module = Module()
         module.use(second_module)
 
-        with pytest.raises(ModuleError):
+        with pytest.raises(ModuleCircularUseError):
             second_module.use(module)
 
+    def test_use_with_deep_circular_dependency_raise_module_circular_use_error(
+        self,
+        module,
+    ):
+        second_module = Module()
+        third_module = Module()
+
+        module.use(second_module)
+
+        with suppress(ModuleCircularUseError):
+            second_module.use(module)
+
+        with pytest.raises(ModuleCircularUseError):
+            module.use(third_module)
+
     def test_use_with_module_already_in_use_raise_module_error(
         self,
         module,
@@ -178,5 +194,5 @@ def test_change_priority_with_success(self, module, event_history):
     def test_change_priority_with_module_not_found(self, module, event_history):
         second_module = Module()
 
-        with pytest.raises(ModuleError):
+        with pytest.raises(ModuleNotUsedError):
             module.change_priority(second_module, ModulePriorities.HIGH)

tests/core/test_module.py

@@ -3,8 +3,6 @@
 
 from injection.common.event import Event, EventListener
 
-__all__ = ("EventHistory",)
-
 
 @dataclass(repr=False, eq=False, frozen=True, slots=True)
 class EventHistory(EventListener):