feat: MkDocs

.github/workflows/cd.yml

@@ -13,7 +13,7 @@ jobs:
 
     steps:
       - name: Run checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up environment
         uses: ./.github/actions/environment

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
 
     steps:
       - name: Run checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up environment
         uses: ./.github/actions/environment

.github/workflows/pages.yml

@@ -0,0 +1,29 @@
+name: GitHub Pages
+
+on:
+  push:
+    branches:
+      - prod
+
+jobs:
+  delivery:
+    name: Delivery
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+
+    steps:
+      - name: Run checkout
+        uses: actions/checkout@v6
+
+      - name: Configure Git
+        run: |
+          git config --global user.name "github-pages[bot]"
+          git config --global user.email "github-pages[bot]@users.noreply.github.com"
+
+      - name: Set up environment
+        uses: ./.github/actions/environment
+
+      - name: Deploy MkDocs
+        shell: bash
+        run: uv run mkdocs gh-deploy --force

Makefile

@@ -16,3 +16,6 @@ mypy:
 
 pytest:
 	uv run pytest
+
+mkdocs:
+	uv run mkdocs serve

README.md

@@ -5,22 +5,13 @@
 [![PyPI - Downloads](https://img.shields.io/pypi/dm/python-cq.svg?color=blue)](https://pypistats.org/packages/python-cq)
 [![Ruff](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ruff/main/assets/badge/v2.json)](https://github.com/astral-sh/ruff)
 
-Lightweight library for separating Python code according to **Command and Query Responsibility Segregation** principles.
+Documentation: https://python-cq.remimd.dev
 
-Dependency injection is handled by [python-injection](https://github.com/100nm/python-injection).
-
-Easy to use with [FastAPI](https://github.com/fastapi/fastapi).
+Python package designed to organize your code following CQRS principles. It builds on top of [python-injection](https://github.com/100nm/python-injection) for dependency injection.
 
 ## Installation
 
 ⚠️ _Requires Python 3.12 or higher_
-
 ```bash
 pip install python-cq
 ```
-
-## Resources
-
-* [**Writing Application Layer**](https://github.com/100nm/python-cq/tree/prod/documentation/writing-application-layer.md)
-* [**Pipeline**](https://github.com/100nm/python-cq/tree/prod/documentation/pipeline.md)
-* [**FastAPI Example**](https://github.com/100nm/python-cq/tree/prod/documentation/fastapi-example.md)

cq/_core/handler.py

@@ -90,6 +90,10 @@ def subscribe(self, input_type: type[I], factory: HandlerFactory[[I], O]) -> Sel
         return self
 
 
+class _Decorator(Protocol):
+    def __call__[T](self, wrapped: T, /) -> T: ...
+
+
 @dataclass(repr=False, eq=False, frozen=True, slots=True)
 class HandlerDecorator[I, O]:
     registry: HandlerRegistry[I, O]
@@ -104,16 +108,16 @@ def __call__(
             /,
             *,
             threadsafe: bool | None = ...,
-        ) -> Callable[[HandlerType[[I], O]], HandlerType[[I], O]]: ...
+        ) -> _Decorator: ...
 
         @overload
-        def __call__(
+        def __call__[T](
             self,
-            input_or_handler_type: HandlerType[[I], O],
+            input_or_handler_type: T,
             /,
             *,
             threadsafe: bool | None = ...,
-        ) -> HandlerType[[I], O]: ...
+        ) -> T: ...
 
         @overload
         def __call__(
@@ -122,11 +126,11 @@ def __call__(
             /,
             *,
             threadsafe: bool | None = ...,
-        ) -> Callable[[HandlerType[[I], O]], HandlerType[[I], O]]: ...
+        ) -> _Decorator: ...
 
-    def __call__(
+    def __call__[T](
         self,
-        input_or_handler_type: type[I] | HandlerType[[I], O] | None = None,
+        input_or_handler_type: type[I] | T | None = None,
         /,
         *,
         threadsafe: bool | None = None,

cq/middlewares/scope.py

@@ -21,13 +21,13 @@ class InjectionScopeMiddleware:
 
     async def __call__(self, *args: Any, **kwargs: Any) -> MiddlewareResult[Any]:
         async with AsyncExitStack() as stack:
-            cm = adefine_scope(self.scope_name, threadsafe=self.threadsafe)
             try:
-                await stack.enter_async_context(cm)
+                await stack.enter_async_context(
+                    adefine_scope(self.scope_name, threadsafe=self.threadsafe)
+                )
 
             except ScopeAlreadyDefinedError:
                 if not self.exist_ok:
                     raise
 
-            del cm
             yield

docs/CNAME

@@ -0,0 +1 @@
+python-cq.remimd.dev

docs/guides/configuring.md

@@ -0,0 +1,71 @@
+# Configuring a Bus
+
+Each bus can be customized with listeners and middlewares. To do so, create a factory function decorated with `@injectable` that returns the configured bus.
+```python
+from cq import CommandBus, MiddlewareResult, new_command_bus
+from injection import injectable
+
+async def listener(message: MessageType):
+    ...
+
+async def middleware(message: MessageType) -> MiddlewareResult[ReturnType]:
+    # do something before the handler is executed
+    return_value = yield
+    # do something after the handler is executed
+
+@injectable
+def command_bus_factory() -> CommandBus:
+    bus = new_command_bus()
+    bus.add_listeners(listener)
+    bus.add_middlewares(middleware)
+    return bus
+```
+
+The same pattern applies to `QueryBus` and `EventBus` using `new_query_bus()` and `new_event_bus()`.
+
+## Listeners
+
+Listeners are executed before the handler(s). They receive the message and can perform side effects such as logging or validation.
+```python
+async def log_listener(message: MessageType):
+    print(f"Received: {message}")
+```
+
+## Middlewares
+
+Middlewares wrap around handler execution, allowing you to run logic before and after a handler processes a message.
+```python
+async def timing_middleware(message: Any) -> MiddlewareResult[Any]:
+    start = time.time()
+    yield
+    print(f"Execution time: {time.time() - start}s")
+```
+
+For commands and queries, middlewares run once around the single handler. For events, middlewares run around each handler individually.
+
+!!! note
+    The generator was chosen to keep both the input message and the return value read-only.
+
+## Class-based listeners and middlewares
+
+For more flexibility, listeners and middlewares can be defined as classes with a `__call__` method. This allows you to inject dependencies and configure their behavior.
+```python
+from cq import MiddlewareResult
+from dataclasses import dataclass
+
+@dataclass
+class LogListener:
+    logger: Logger
+
+    async def __call__(self, message: Any):
+        self.logger.info(f"Received: {message}")
+
+@dataclass
+class TimingMiddleware:
+    metrics: MetricsService
+
+    async def __call__(self, message: Any) -> MiddlewareResult[Any]:
+        start = time.time()
+        yield
+        self.metrics.record(time.time() - start)
+```

docs/guides/dispatching.md

@@ -0,0 +1,52 @@
+# Dispatching messages
+
+To dispatch messages to their handlers, **python-cq** provides three bus classes: `CommandBus`, `QueryBus`, and `EventBus`.
+
+Each bus can take a generic parameter to specify the return type of the `dispatch` method.
+
+## Retrieving a bus
+
+Bus instances are available through [python-injection](https://github.com/100nm/python-injection)'s dependency injection:
+
+```python
+from cq import CommandBus
+from injection import inject
+
+@inject
+async def create_user(bus: CommandBus[None]):
+    command = CreateUserCommand(name="John", email="[email protected]")
+    await bus.dispatch(command)
+```
+
+## CommandBus
+
+Use the CommandBus to dispatch commands. It returns the value produced by the handler.
+```python
+from cq import CommandBus
+
+bus: CommandBus[None]
+command = CreateUserCommand(name="John", email="[email protected]")
+await bus.dispatch(command)
+```
+
+## QueryBus
+
+Use the QueryBus to dispatch queries. It returns the value produced by the handler.
+```python
+from cq import QueryBus
+
+bus: QueryBus[User]
+query = GetUserByIdQuery(user_id)
+user = await bus.dispatch(query)
+```
+
+## EventBus
+
+Use the EventBus to dispatch events. Since events can be handled by multiple handlers (or none), it does not return a value.
+```python
+from cq import EventBus
+
+bus: EventBus
+event = UserCreatedEvent(user_id)
+await bus.dispatch(event)
+```