[FEATURE] Avoid redirections when requesting without trailing slash (#4963)

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# Description

When requesting `http://localhost:6900/datasets`, the server will
redirect to `http://localhost:6900/datasets/`. We can skip this
redirection and return the static content in the same request.



**Type of change**

(Please delete options that are not relevant. Remember to title the PR
according to the type of change)

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)

**How Has This Been Tested**

(Please describe the tests that you ran to verify your changes. And
ideally, reference `tests`)

- [ ] Test A
- [ ] Test B

**Checklist**

- [ ] I followed the style guidelines of this project
- [ ] I did a self-review of my code
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] I filled out [the contributor form](https://tally.so/r/n9XrxK)
(see text above)
- [ ] I have added relevant notes to the `CHANGELOG.md` file (See
https://keepachangelog.com/)

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: frascuchon

argilla-server/.gitignore

@@ -165,6 +165,5 @@ cython_debug/
 # Misc
 .DS_Store
 
-
 # Generated static files
 src/argilla_server/static/

argilla-server/src/argilla_server/_app.py

@@ -51,6 +51,7 @@ def create_server_app() -> FastAPI:
         description="Argilla API",
         docs_url=None,
         redoc_url=None,
+        redirect_slashes=False,
         version=str(argilla_version),
     )
 
@@ -77,7 +78,7 @@ async def redirect_api():
     # This if-else clause is needed to simplify the test dependencies setup. Otherwise we cannot override dependencies
     # easily. We can review this once we have separate fastapi application for the api and the webapp.
     if settings.base_url and settings.base_url != "/":
-        _app = FastAPI(docs_url=None, redoc_url=None, openapi_url=None)
+        _app = FastAPI(docs_url=None, redoc_url=None, openapi_url=None, redirect_slashes=False)
         _app.mount(settings.base_url, app)
         return _app
     else:

argilla-server/src/argilla_server/static_rewrite.py

@@ -12,11 +12,14 @@
 #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
+import os
+import stat
 from typing import Union
 
+import anyio
 from fastapi.staticfiles import StaticFiles
 from starlette.exceptions import HTTPException
-from starlette.responses import Response
+from starlette.responses import FileResponse, RedirectResponse, Response
 from starlette.types import Scope
 
 
@@ -25,7 +28,9 @@ class RewriteStaticFiles(StaticFiles):
 
     async def get_response(self, path: str, scope: Scope) -> Response:
         try:
-            response = await super().get_response(path, scope)
+            response = await self._get_response_internal(path, scope)
+            if response.status_code == 307:
+                return RedirectResponse(url=f"{scope['path']}/")
             return await self._handle_response(response, scope)
         except HTTPException as ex:
             return await self._handle_response(ex, scope)
@@ -40,3 +45,40 @@ async def _handle_response(
         if isinstance(response_or_error, HTTPException):
             raise response_or_error
         return response_or_error
+
+    async def _get_response_internal(self, path: str, scope: Scope) -> Response:
+        """
+        Returns an HTTP response, given the incoming path, method and request headers.
+
+        This method is the same as the one in the parent class, but it handles folder path
+        without trailing slash differently. Instead of returning a 307 response, it returns
+        a 200 response with the content of the folder index file.
+        """
+        if scope["method"] not in ("GET", "HEAD"):
+            raise HTTPException(status_code=405)
+
+        try:
+            full_path, stat_result = await anyio.to_thread.run_sync(self.lookup_path, path)
+        except PermissionError:
+            raise HTTPException(status_code=401)
+        except OSError:
+            raise
+
+        if stat_result and stat.S_ISREG(stat_result.st_mode):
+            # We have a static file to serve.
+            return self.file_response(full_path, stat_result, scope)
+
+        elif stat_result and stat.S_ISDIR(stat_result.st_mode) and self.html:
+            # We're in HTML mode, and have got a directory URL.
+            # Check if we have 'index.html' file to serve.
+            index_path = os.path.join(path, "index.html")
+            full_path, stat_result = await anyio.to_thread.run_sync(self.lookup_path, index_path)
+            if stat_result is not None and stat.S_ISREG(stat_result.st_mode):
+                return self.file_response(full_path, stat_result, scope)
+
+        if self.html:
+            # Check for '404.html' if we're in HTML mode.
+            full_path, stat_result = await anyio.to_thread.run_sync(self.lookup_path, "404.html")
+            if stat_result and stat.S_ISREG(stat_result.st_mode):
+                return FileResponse(full_path, stat_result=stat_result, status_code=404)
+        raise HTTPException(status_code=404)