fix(#56): error in handling multiple query parameters (#57)

* handling duplicate query parameters

Fix: #56

Signed-off-by: yhl-cs <yuhl18@zju.edu.cn>

* test(refactor): better http multiple query params tesing

* test(refactor): better ws multiple query params tesing

* docs: add comments for why need to shallow clone the `query_params`

* docs: add changelog

---------

Signed-off-by: yhl-cs <yuhl18@zju.edu.cn>
Co-authored-by: yu.hanlin <yu.hanlin@jingjiamicro.com>
Co-authored-by: WSH032 <614337162@qq.com>

Author: 3 people

CHANGELOG.md

@@ -23,6 +23,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- [#57](https://github.com/WSH032/fastapi-proxy-lib/pull/57) - fix: error in handling multiple query parameters (#56). Thanks [@yhl-cs](https://github.com/yhl-cs)!
+
+    Now `fastapi-proxy-lib` can handle multiple query parameters (e.g. `foo?a=1&a=2`) correctly. Previously, it would only keep the last one (e.g. `foo?a=2`).
+
 ## [0.2.0] - 2025-01-15
 
 ### Added

src/fastapi_proxy_lib/core/http.py

@@ -267,7 +267,9 @@ async def send_request_to_target(  # pyright: ignore [reportIncompatibleMethodOv
         proxy_request = client.build_request(
             method=request.method,
             url=target_url,
-            params=request.query_params,
+            # TODO, FIXME: do not shallow clone (i.e, `tuple(...)`) the query_params,
+            # see: <https://github.com/WSH032/fastapi-proxy-lib/pull/57#issuecomment-2750153934>
+            params=tuple(request.query_params.multi_items()),
             headers=proxy_header,
             content=request_content,  # FIXME: 一个已知问题是，流式响应头包含'transfer-encoding': 'chunked'，但有些服务器会400拒绝这个头
             # cookies=request.cookies,  # NOTE: headers中已有的cookie优先级高，所以这里不需要

src/fastapi_proxy_lib/core/websocket.py

@@ -493,7 +493,11 @@ async def send_request_to_target(  # pyright: ignore [reportIncompatibleMethodOv
         client_request_headers: "HeaderTypes" = _change_client_header(
             headers=websocket.headers, target_url=target_url
         )
-        client_request_params: "QueryParamTypes" = websocket.query_params
+        # TODO, FIXME: do not shallow clone (i.e, `tuple(...)`) the query_params,
+        # see: <https://github.com/WSH032/fastapi-proxy-lib/pull/57#issuecomment-2750153934>
+        client_request_params: "QueryParamTypes" = tuple(
+            websocket.query_params.multi_items()
+        )
 
         # TODO: 是否可以不检查http版本?
         check_result = check_http_version(websocket.scope, SUPPORTED_WS_HTTP_VERSIONS)

tests/test_http.py

@@ -158,6 +158,37 @@ async def test_if_the_header_is_properly_handled(
         )
         assert "close" in proxy_resp.headers["connection"]
 
+    @pytest.mark.anyio()
+    async def test_if_the_multiple_query_params_forwarding_is_correct(
+        self, tool_4_test_fixture: Tool4TestFixture
+    ) -> None:
+        """See: <https://github.com/WSH032/fastapi-proxy-lib/issues/56>."""
+        client_for_conn_to_proxy_server = (
+            tool_4_test_fixture.client_for_conn_to_proxy_server
+        )
+        proxy_server_base_url = tool_4_test_fixture.proxy_server_base_url
+
+        query_params = httpx.QueryParams(
+            [
+                ("key1", "value1"),
+                # NOTE: following two keys are same
+                ("key2", "value2"),
+                ("key2", "value3"),
+            ]
+        )
+        # We only need to send the query_params to any endpoint
+        await client_for_conn_to_proxy_server.get(
+            proxy_server_base_url + "get/echo_headers_and_params",
+            params=query_params,
+        )
+
+        target_server_recv_request = tool_4_test_fixture.get_request()
+
+        # Check is the multiple query_params are forwarded correctly
+        assert sorted(target_server_recv_request.query_params.multi_items()) == sorted(
+            query_params.multi_items()
+        )
+
     @pytest.mark.anyio()
     async def test_if_the_proxy_forwarding_is_correct(
         self, tool_4_test_fixture: Tool4TestFixture

tests/test_ws.py

@@ -175,6 +175,31 @@ async def test_ws_proxy(self, tool_4_test_fixture: Tool4TestFixture) -> None:
             await ws.send_bytes(b"foo")
             assert await ws.receive_bytes() == b"foo"
 
+        ########## Test multiple query params ##########
+        # see: <https://github.com/WSH032/fastapi-proxy-lib/issues/56>
+
+        query_params = httpx.QueryParams(
+            [
+                ("key1", "value1"),
+                # NOTE: following two keys are same
+                ("key2", "value2"),
+                ("key2", "value3"),
+            ]
+        )
+        # We only need to send the query_params to any endpoint
+        async with aconnect_ws(
+            proxy_server_base_url + "just_close_with_1001",
+            client_for_conn_to_proxy_server,
+            params=query_params,
+        ):
+            pass
+
+        target_starlette_ws = get_request()
+        # Check is the multiple query_params are forwarded correctly
+        assert sorted(target_starlette_ws.query_params.multi_items()) == sorted(
+            query_params.multi_items()
+        )
+
         ########## 测试子协议 ##########
 
         async with aconnect_ws(