feat: ✨ set_constant can raise ValueError (#269)

Author: remimd

documentation/basic-usage.md

@@ -34,8 +34,7 @@ from injection import set_constant
 class ServiceC:
     """ class implementation """
 
-service_c = ServiceC()
-set_constant(service_c)
+service_c = set_constant(ServiceC())
 ```
 
 Or here is the decorator `constant` which is equivalent:

documentation/entrypoint.md

@@ -59,7 +59,7 @@ def entrypoint[**P, T](self: AsyncEntrypoint[P, T], conf: Conf) -> Entrypoint[P,
         f"{keyword}: {name}"
         for name in self.profile_loader.required_module_names(profile)
     }
-    module_loader = PythonModuleLoader.from_keywords(keyword, *keywords)
+    module_loader = PythonModuleLoader.from_keywords(*keywords)
     return (
         self.inject()
         .decorate(adefine_scope(Scope.LIFESPAN, kind="shared"))

injection/__init__.pyi

@@ -374,7 +374,7 @@ class Module:
         *,
         alias: bool = ...,
         mode: Mode | ModeStr = ...,
-    ) -> Self:
+    ) -> T:
         """
         Function for registering a specific instance to be injected. This is useful for
         registering global variables. The difference with the singleton decorator is

injection/_core/module.py

@@ -532,16 +532,21 @@ def set_constant[T](
         *,
         alias: bool = False,
         mode: Mode | ModeStr = Mode.get_default(),
-    ) -> Self:
-        hints = on if alias else (type(instance), on)
+    ) -> T:
+        if not alias:
+            on = (type(instance), on)
+
+        elif not on:
+            raise ValueError("`on` must be provided when `alias` is `True`.")
+
         self.injectable(
             lambda: instance,
             ignore_type_hint=True,
             inject=False,
-            on=hints,
+            on=on,
             mode=mode,
         )
-        return self
+        return instance
 
     def reserve_scoped_slot[T](
         self,

tests/core/test_module.py

@@ -188,7 +188,7 @@ class C(B): ...
             is module.get_instance(C)
         )
 
-    def test_set_constant_with_success_with_type_alias(self, module):
+    def test_set_constant_with_type_alias(self, module):
         type HelloWorld = str
         value = "Hello world!"
 
@@ -197,6 +197,12 @@ def test_set_constant_with_success_with_type_alias(self, module):
         assert module.get_instance(str) is NotImplemented
         assert module.get_instance(HelloWorld) is value
 
+    def test_set_constant_with_alias_and_no_on_raise_value_error(self, module):
+        value = "Hello world!"
+
+        with pytest.raises(ValueError):
+            module.set_constant(value, alias=True)
+
     """
     reserve_scoped_slot
     """