feat(event_handler): add decorator for HTTP HEAD verb

aws_lambda_powertools/event_handler/api_gateway.py

@@ -1222,6 +1222,63 @@ def lambda_handler(event, context):
             middlewares,
         )
 
+    def head(
+        self,
+        rule: str,
+        cors: Optional[bool] = None,
+        compress: bool = False,
+        cache_control: Optional[str] = None,
+        summary: Optional[str] = None,
+        description: Optional[str] = None,
+        responses: Optional[Dict[int, OpenAPIResponse]] = None,
+        response_description: str = _DEFAULT_OPENAPI_RESPONSE_DESCRIPTION,
+        tags: Optional[List[str]] = None,
+        operation_id: Optional[str] = None,
+        include_in_schema: bool = True,
+        security: Optional[List[Dict[str, List[str]]]] = None,
+        middlewares: Optional[List[Callable]] = None,
+    ):
+        """Head route decorator with HEAD `method`
+
+        Examples
+        --------
+        Simple example with a custom lambda handler using the Tracer capture_lambda_handler decorator
+
+        ```python
+        from aws_lambda_powertools import Tracer
+        from aws_lambda_powertools.event_handler import APIGatewayRestResolver, Response, content_types
+
+        tracer = Tracer()
+        app = APIGatewayRestResolver()
+
+        @app.head("/head-call")
+        def simple_head():
+            return Response(status_code=200,
+                            content_type=content_types.APPLICATION_JSON,
+                            headers={"Content-Length": "123"})
+
+        @tracer.capture_lambda_handler
+        def lambda_handler(event, context):
+            return app.resolve(event, context)
+        ```
+        """
+        return self.route(
+            rule,
+            "HEAD",
+            cors,
+            compress,
+            cache_control,
+            summary,
+            description,
+            responses,
+            response_description,
+            tags,
+            operation_id,
+            include_in_schema,
+            security,
+            middlewares,
+        )
+
     def _push_processed_stack_frame(self, frame: str):
         """
         Add Current Middleware to the Middleware Stack Frames

docs/core/event_handler/api_gateway.md

@@ -221,7 +221,7 @@ You can use named decorators to specify the HTTP method that should be handled i
     --8<-- "examples/event_handler_rest/src/http_methods.json"
     ```
 
-If you need to accept multiple HTTP methods in a single function, you can use the `route` method and pass a list of HTTP methods.
+If you need to accept multiple HTTP methods in a single function, or support a HTTP method for which no decorator exists (e.g. [TRACE](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/TRACE)), you can use the `route` method and pass a list of HTTP methods.
 
 ```python hl_lines="15" title="Handling multiple HTTP Methods"
 --8<-- "examples/event_handler_rest/src/http_methods_multiple.py"
@@ -524,12 +524,12 @@ Behind the scenes, the [data validation](#data-validation) feature auto-generate
 
 There are some important **caveats** that you should know before enabling it:
 
-| Caveat                                               | Description                                                                                                                                                                              |
-| ------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| Swagger UI is **publicly accessible by default**         | When using `enable_swagger` method, you can [protect sensitive API endpoints by implementing a custom middleware](#customizing-swagger-ui) using your preferred authorization mechanism. |
-| **No micro-functions support** yet                       | Swagger UI is enabled on a per resolver instance which will limit its accuracy here.                                                                                                     |
-| You need to expose a **new route**                       | You'll need to expose the following path to Lambda: `/swagger`; ignore if you're routing this path already.                         |
-| JS and CSS  files are **embedded within Swagger HTML**   | If you are not using an external CDN to serve Swagger UI assets, we embed JS and CSS directly into the HTML. To enhance performance, please consider enabling the `compress` option to minimize the size of HTTP requests. |
+| Caveat                                                 | Description                                                                                                                                                                                                                |
+| ------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| Swagger UI is **publicly accessible by default**       | When using `enable_swagger` method, you can [protect sensitive API endpoints by implementing a custom middleware](#customizing-swagger-ui) using your preferred authorization mechanism.                                   |
+| **No micro-functions support** yet                     | Swagger UI is enabled on a per resolver instance which will limit its accuracy here.                                                                                                                                       |
+| You need to expose a **new route**                     | You'll need to expose the following path to Lambda: `/swagger`; ignore if you're routing this path already.                                                                                                                |
+| JS and CSS  files are **embedded within Swagger HTML** | If you are not using an external CDN to serve Swagger UI assets, we embed JS and CSS directly into the HTML. To enhance performance, please consider enabling the `compress` option to minimize the size of HTTP requests. |
 
 ```python hl_lines="12-13" title="enabling_swagger.py"
 --8<-- "examples/event_handler_rest/src/enabling_swagger.py"
@@ -835,8 +835,8 @@ As a practical example, let's refactor our correlation ID middleware so it accep
 
 These are native middlewares that may become native features depending on customer demand.
 
-| Middleware                                                                                                                | Purpose                                                                                                                                    |
-| ------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------ |
+| Middleware                                                                                                                | Purpose                                                                                                                                 |
+| ------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------- |
 | [SchemaValidationMiddleware](/lambda/python/latest/api/event_handler/middlewares/schema_validation.html){target="_blank"} | Validates API request body and response against JSON Schema, using [Validation utility](../../utilities/validation.md){target="_blank"} |
 
 #### Being a good citizen
@@ -1053,7 +1053,7 @@ When you're describing your API, declare security schemes at the top level, and
 OpenAPI 3 lets you describe APIs protected using the following security schemes:
 
 | Security Scheme                                                                                                                                                                         | Type            | Description                                                                                                                                                                                                                                                                         |
-|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | [HTTP auth](https://www.iana.org/assignments/http-authschemes/http-authschemes.xhtml){target="_blank"}                                                                                  | `HTTPBase`      | HTTP authentication schemes using the Authorization header (e.g: [Basic auth](https://swagger.io/docs/specification/authentication/basic-authentication/){target="_blank"}, [Bearer](https://swagger.io/docs/specification/authentication/bearer-authentication/){target="_blank"}) |
 | [API keys](https://swagger.io/docs/specification/authentication/api-keys/https://swagger.io/docs/specification/authentication/api-keys/){target="_blank"} (e.g: query strings, cookies) | `APIKey`        | API keys in headers, query strings or [cookies](https://swagger.io/docs/specification/authentication/cookie-authentication/){target="_blank"}.                                                                                                                                      |
 | [OAuth 2](https://swagger.io/docs/specification/authentication/oauth2/){target="_blank"}                                                                                                | `OAuth2`        | Authorization protocol that gives an API client limited access to user data on a web server.                                                                                                                                                                                        |

tests/functional/event_handler/test_api_gateway.py

@@ -291,12 +291,16 @@ def delete_func():
     def patch_func():
         raise RuntimeError()
 
+    @app.head("/no_matching_head")
+    def head_func():
+        raise RuntimeError()
+
     def handler(event, context):
         return app.resolve(event, context)
 
     # Also check the route configurations
     routes = app._static_routes
-    assert len(routes) == 5
+    assert len(routes) == 6
     for route in routes:
         if route.func == get_func:
             assert route.method == "GET"
@@ -308,6 +312,8 @@ def handler(event, context):
             assert route.method == "DELETE"
         elif route.func == patch_func:
             assert route.method == "PATCH"
+        elif route.func == head_func:
+            assert route.method == "HEAD"
 
     # WHEN calling the handler
     # THEN return a 404