Expose annotations types + make nurse.get() raise when service is not registered

.pre-commit-config.yaml

@@ -13,3 +13,8 @@ repos:
         entry: poetry run ruff format
         language: system
         types: [file, python]
+      - id: pyright
+        name: pyright
+        entry: poetry run pyright
+        language: system
+        types: [file, python]

nurse/__init__.py

@@ -1,4 +1,5 @@
-from nurse.api import clear, get, inject, serve
+from nurse.api import clear, get, serve
+from nurse.exceptions import ServiceNotFound
 
 __version__ = "0.5.0"
-__all__ = ["clear", "get", "inject", "serve"]
+__all__ = ["clear", "get", "serve", "ServiceNotFound"]

nurse/api.py

@@ -1,10 +1,14 @@
-from inspect import iscoroutinefunction, isfunction
-from nurse.exceptions import DependencyError
 from .service_catalog import ServiceCatalog
-from typing import List
+from typing import TypeVar
+from nurse.exceptions import ServiceNotFound
 
+TDependencyInterface = TypeVar("TDependencyInterface")
 
-def serve(user_class, through=None) -> None:
+
+def serve(
+    service_instance: TDependencyInterface,
+    through: type[TDependencyInterface] | None = None,
+) -> None:
     """
     Add an instance of a user-defined class to Nurse's services catalog.
     By default, a dependency is registered for its concrete type, but an interface can be provided.
@@ -13,13 +17,17 @@ def serve(user_class, through=None) -> None:
     :param through: An interface used to access the user class
                    (must be a direct or indirect parent class)
     """
+    if through is not None:
+        _through = through
+    else:
+        _through = service_instance.__class__
 
-    through = through or user_class.__class__
-
-    if not issubclass(user_class.__class__, through):
-        raise ValueError(f"Class {user_class} must be a subclass of {through}.")
+    if not issubclass(service_instance.__class__, _through):
+        raise ValueError(
+            f"Service instance of type '{service_instance.__class__}' must be a subclass of {_through}."
+        )
 
-    ServiceCatalog.get_instance()._services[through] = user_class
+    ServiceCatalog.get_instance().services[_through] = service_instance
 
 
 def clear() -> None:
@@ -29,7 +37,7 @@ def clear() -> None:
     ServiceCatalog.get_instance().clear()
 
 
-def get(service_type):
+def get(service_instance_class: type[TDependencyInterface]) -> TDependencyInterface:
     """
     Retrieve a service from the service catalog.
 
@@ -39,105 +47,9 @@ def get(service_type):
 
     ssh_client = nurse.get(SSHClient)
     """
-    return ServiceCatalog.get_instance()._services.get(service_type)
-
-
-def inject(*items_to_inject: List[str]):
-    """
-    A decorator that injects dependencies into every instances of a user-defined class or method
-
-    :Example:
-
-    class SSHClient:
-
-        def connect(self):
-            pass
-
-    @nurse.inject("ssh_client")
-    class Server:
-        ssh_client: SSHClient
-
-    server = Server()
-    server.ssh_client.connect()
-
-
-    @nurse.inject("client")
-    def send(client: SSHClient):
-        client.send("Hello World !")
-
-    nurse.serve(SSHClient())
-    send()
-
-
-    @nurse.inject("client")
-    async def send(client: SSHClient):
-        await client.send("Hello World !")
-
-    nurse.serve(SSHClient())
-    asyncio.run(send())
-    """
-
-    def decorator(decorated):
-        service_catalog = ServiceCatalog.get_instance()
-        if isinstance(decorated, type):
-            return inject_class(decorated, service_catalog, items_to_inject)
-        elif iscoroutinefunction(decorated):
-            return inject_async_function(decorated, service_catalog, items_to_inject)
-        elif isfunction(decorated):
-            return inject_function(decorated, service_catalog, items_to_inject)
-
-        raise NotImplementedError("user-defined class or function can't be injected.")
-
-    return decorator
-
-
-def inject_class(decorated_class, service_catalog, field_to_inject):
-    def init_decorator(self, *args, **kwargs):
-        for param_to_inject in field_to_inject:
-            service = get_service(service_catalog, decorated_class, param_to_inject)
-            setattr(self, param_to_inject, service)
-
-        return init_decorator.decorated_init(self, *args, **kwargs)
-
-    init_decorator.decorated_init = decorated_class.__init__
-    decorated_class.__init__ = init_decorator
-
-    return decorated_class
-
-
-def inject_function(decorated_func, service_catalog, args_to_inject):
-    def decorator(*args, **kwargs):
-        injected_args = {}
-        for param_to_inject in args_to_inject:
-            service = get_service(service_catalog, decorated_func, param_to_inject)
-            injected_args.setdefault(param_to_inject, service)
-
-        return decorated_func(*args, **injected_args, **kwargs)
-
-    return decorator
-
-
-def inject_async_function(decorated_func, service_catalog, args_to_inject):
-    async def decorator(*args, **kwargs):
-        injected_args = {}
-        for param_to_inject in args_to_inject:
-            service = get_service(service_catalog, decorated_func, param_to_inject)
-            injected_args.setdefault(param_to_inject, service)
-
-        return await decorated_func(*args, **injected_args, **kwargs)
-
-    return decorator
-
-
-def get_service(service_catalog: ServiceCatalog, decorated_obj, param_to_inject: str):
-    service_type = decorated_obj.__annotations__.get(param_to_inject)
-    if not service_type:
-        raise DependencyError(f"Args `{param_to_inject}` must be typed to be injected.")
-
-    service = service_catalog._services.get(service_type)
-    if not service:
-        raise DependencyError(
-            f"Dependency `{service_type.__name__}` for `{param_to_inject}` was not found."
+    service = ServiceCatalog.get_instance().services.get(service_instance_class)
+    if service is None:
+        raise ServiceNotFound(
+            f"No service exists for '{service_instance_class.__class__}'"
         )
-
     return service

nurse/exceptions.py

@@ -1,6 +1,2 @@
-class DependencyError(Exception):
-    def __init__(self, message: str) -> None:
-        self.message = message
-
-    def __str__(self) -> str:
-        return self.message
+class ServiceNotFound(Exception):
+    pass

nurse/service_catalog.py

@@ -1,16 +1,19 @@
+from typing import Any, Optional
+
+
 class ServiceCatalog:
     """
     A singleton service catalog.
     """
 
-    __slots__ = ("_services",)
-    instance = None
+    __slots__ = ("services",)
+    instance: Optional["ServiceCatalog"] = None
 
     def __init__(self) -> None:
-        self._services = {}
+        self.services = dict[Any, Any]()
 
     def clear(self) -> None:
-        self._services.clear()
+        self.services.clear()
 
     @classmethod
     def get_instance(cls) -> "ServiceCatalog":

pyproject.toml

@@ -19,6 +19,7 @@ pytest = "^8.0"
 ruff = "^0.7.3"
 pre-commit = "^4.0.1"
 pytest-cov = "^6.0.0"
+pyright = "^1.1.388"
 
 [build-system]
 requires = ["poetry-core"]
@@ -39,3 +40,15 @@ line-length = 88
 # It would be preferable to use python's standard "project.requires-python"
 # but poetry does not comply with it.
 target-version = "py311"
+
+
+[tool.pyright]
+venvPath = "."
+venv = ".venv"
+typeCheckingMode = "strict"
+include = ["nurse/**"]
+exclude = [
+    "**/__pycache__",
+]
+
+executionEnvironments = [{ root = "nurse" }]