Preserve query string on redirect

CHANGELOG.md

@@ -14,6 +14,7 @@ Using the following categories, list your changes in this order:
 ### Added
 
 -   Support Python 3.13.
+-   Django `settings.py:SERVESTATIC_PRESERVE_QUERY_STRING_ON_REDIRECT` will forward the request query string when issuing redirects.
 
 ## [2.0.1] - 2024-09-13
 

docs/src/django-settings.md

@@ -204,6 +204,16 @@ This setting is only effective if the `ServeStatic` storage backend is being use
 
 ---
 
+## `SERVESTATIC_PRESERVE_QUERY_STRING_ON_REDIRECT`
+
+**Default:** `False`
+
+Set to `True` to preserve the request query string when issuing redirects.
+
+By default, ServeStatic will strip the query string when issuing a redirect. If this setting is enabled, the query string will instead be forwarded to the redirect location.
+
+---
+
 ## `SERVESTATIC_MANIFEST_STRICT`
 
 **Default:** `True`

src/servestatic/base.py

@@ -48,6 +48,7 @@ def __init__(
         add_headers_function: Callable[[Headers, str, str], None] | None = None,
         index_file: str | bool | None = None,
         immutable_file_test: Callable | str | None = None,
+        preserve_query_string_on_redirect: bool | None = None,
     ):
         self.autorefresh = autorefresh
         self.max_age = max_age
@@ -60,6 +61,7 @@ def __init__(
         self.application = application
         self.files = {}
         self.directories = []
+        self.preserve_query_string_on_redirect = preserve_query_string_on_redirect
 
         if index_file is True:
             self.index_file: str | None = "index.html"
@@ -236,4 +238,8 @@ def redirect(self, from_url, to_url):
             msg = f"Cannot handle redirect: {from_url} > {to_url}"
             raise ValueError(msg)
         headers = {"Cache-Control": f"max-age={self.max_age}, public"} if self.max_age is not None else {}
-        return Redirect(relative_url, headers=headers)
+        return Redirect(
+            relative_url,
+            headers=headers,
+            preserve_query_string=self.preserve_query_string_on_redirect,
+        )

src/servestatic/middleware.py

@@ -73,6 +73,11 @@ def __init__(self, get_response=None, settings=django_settings):
         force_script_name = getattr(settings, "FORCE_SCRIPT_NAME", None)
         static_url = getattr(settings, "STATIC_URL", None)
         root = getattr(settings, "SERVESTATIC_ROOT", None)
+        preserve_query_string_on_redirect = getattr(
+            django_settings,
+            "SERVESTATIC_PRESERVE_QUERY_STRING_ON_REDIRECT",
+            False,
+        )
 
         super().__init__(
             application=None,
@@ -84,6 +89,7 @@ def __init__(self, get_response=None, settings=django_settings):
             add_headers_function=add_headers_function,
             index_file=self.index_file,
             immutable_file_test=immutable_file_test,
+            preserve_query_string_on_redirect=preserve_query_string_on_redirect,
         )
 
         if self.static_prefix is None:

src/servestatic/responders.py

@@ -315,12 +315,20 @@ def get_path_and_headers(self, request_headers):
 
 
 class Redirect:
-    def __init__(self, location, headers=None):
+    def __init__(self, location, headers=None, preserve_query_string=False):
         headers = list(headers.items()) if headers else []
         headers.append(("Location", quote(location.encode("utf8"))))
         self.response = Response(HTTPStatus.FOUND, headers, None)
+        self.preserve_query_string = preserve_query_string
 
     def get_response(self, method, request_headers):
+        query_string = request_headers.get("QUERY_STRING")
+        if query_string and self.preserve_query_string:
+            headers = list(self.response.headers)
+            name, value = headers[-1]
+            value = "{}?{}".format(value, query_string)
+            headers[-1] = (name, value)
+            return Response(self.response.status, headers, None)
         return self.response
 
     async def aget_response(self, method, request_headers):

tests/test_servestatic.py

@@ -16,7 +16,7 @@
 import pytest
 
 from servestatic import ServeStatic
-from servestatic.responders import StaticFile
+from servestatic.responders import Redirect, StaticFile
 
 from .utils import AppServer, Files
 
@@ -376,3 +376,15 @@ def test_chunked_file_size_matches_range_with_range_header():
     while response.file.read(1):
         file_size += 1
     assert file_size == 14
+
+
+def test_redirect_strips_query_string_by_default():
+    responder = Redirect("/redirect/to/here/")
+    response = responder.get_response("GET", {"QUERY_STRING": "foo=1&bar=2"})
+    assert response.headers[0] == ("Location", "/redirect/to/here/")
+
+
+def test_redirect_preserves_query_string_if_configured():
+    responder = Redirect("/redirect/to/here/", preserve_query_string=True)
+    response = responder.get_response("GET", {"QUERY_STRING": "foo=1&bar=2"})
+    assert response.headers[0] == ("Location", "/redirect/to/here/?foo=1&bar=2")