feat(web): Add possibility to parse query params

ludic/web/responses.py

@@ -1,6 +1,7 @@
 import inspect
 from collections.abc import Callable
-from typing import Any, ParamSpec, TypeVar, get_origin
+from types import NoneType, UnionType
+from typing import Any, ParamSpec, TypeVar, get_args, get_origin
 
 from starlette._utils import is_async_callable
 from starlette.concurrency import run_in_threadpool
@@ -107,7 +108,7 @@ async def prepare_response(
     return response
 
 
-async def extract_from_request(
+async def extract_from_request(  # noqa
     handler: Callable[..., Any],
     request: Request | WebSocket,
 ) -> dict[str, Any]:
@@ -132,6 +133,14 @@ async def extract_from_request(
         ):
             async with request.form() as form:
                 handler_kwargs[name] = param.annotation(form)
+        elif isinstance(param.annotation, UnionType):
+            if (args := get_args(param.annotation)) and (
+                len(args) != 2 or args[1] is not NoneType
+            ):
+                raise TypeError(
+                    f"Request handler has an invalid signature: {param.annotation!r}"
+                )
+            handler_kwargs[name] = request.query_params.get(name)
         elif issubclass(param.annotation, FormData):
             async with request.form() as form:
                 handler_kwargs[name] = form

tests/web/test_routing.py

@@ -0,0 +1,53 @@
+import pytest
+from starlette.testclient import TestClient
+
+from ludic.html import div
+from ludic.web import LudicApp
+from ludic.web.datastructures import Headers
+
+app = LudicApp()
+
+
+@app.get("/mandatory-param/{test}")
+def mandatory_param(test: str) -> div:
+    return div(test)
+
+
+@app.get("/extract-headers/")
+def extract_headers(headers: Headers) -> div:
+    return div(headers["X-Foo"])
+
+
+@app.get("/kw-only-params")
+def kw_only_params(*, bar: str | None) -> div:
+    return div(bar or "nothing")
+
+
+@app.get("/invalid-signature")
+def invalid_signature(*, bar: str | int) -> div:
+    return div(bar or "nothing")
+
+
+def test_mandatory_param() -> None:
+    with TestClient(app) as client:
+        response = client.get("/mandatory-param/value")
+        assert response.content.decode("utf-8") == "<div>value</div>"
+
+
+def test_extract_headers() -> None:
+    with TestClient(app) as client:
+        response = client.get("/extract-headers", headers={"X-Foo": "x-foo-value"})
+        assert response.content.decode("utf-8") == "<div>x-foo-value</div>"
+
+
+def test_kw_only_params() -> None:
+    with TestClient(app) as client:
+        response = client.get("/kw-only-params?bar=something")
+        assert response.content.decode("utf-8") == "<div>something</div>"
+        response = client.get("/kw-only-params")
+        assert response.content.decode("utf-8") == "<div>nothing</div>"
+
+
+def test_invalid_signature() -> None:
+    with TestClient(app) as client, pytest.raises(TypeError):
+        client.get("/invalid-signature?bar=something")