fix: apply the session-level proxy when no per-request proxy is given

The per-request proxy resolution never fell back to the session default, so FetcherSession(proxy=...) was silently ignored, and requests went direct. Same fix in the sync and async paths, with regression tests asserting on the proxy that reaches curl_cffi.

Closes #295

tests/fetchers/sync/test_requests_session.py

@@ -1,7 +1,9 @@
 import pytest
-
+from unittest.mock import patch, MagicMock
+from curl_cffi.curl import CurlError
 
 from scrapling.engines.static import _SyncSessionLogic as FetcherSession, FetcherClient
+from scrapling.engines.toolbelt import ProxyRotator
 
 
 class TestFetcherSession:
@@ -9,11 +11,7 @@ class TestFetcherSession:
 
     def test_fetcher_session_creation(self):
         """Test FetcherSession creation"""
-        session = FetcherSession(
-            timeout=30,
-            retries=3,
-            stealthy_headers=True
-        )
+        session = FetcherSession(timeout=30, retries=3, stealthy_headers=True)
 
         assert session._default_timeout == 30
         assert session._default_retries == 3
@@ -43,3 +41,44 @@ class TestFetcherSession:
         # Should not have context manager methods
         assert client.__enter__ is None
         assert client.__exit__ is None
+
+    def test_session_level_proxy_is_applied(self):
+        """Session-level proxy must reach the request, not be silently dropped (#295)"""
+        proxy = "http://10.255.255.1:9999"
+
+        with FetcherSession(proxy=proxy) as session:
+            with (
+                patch.object(session._curl_session, "request") as mocked_request,
+                patch("scrapling.engines.static.ResponseFactory.from_http_request", return_value=MagicMock()),
+            ):
+                session.get("http://example.com")
+
+            assert mocked_request.call_args.kwargs["proxy"] == proxy
+
+    def test_per_request_proxy_overrides_session_proxy(self):
+        """A per-request proxy must take precedence over the session-level proxy"""
+        request_proxy = "http://10.255.255.2:9999"
+
+        with FetcherSession(proxy="http://10.255.255.1:9999") as session:
+            with (
+                patch.object(session._curl_session, "request") as mocked_request,
+                patch("scrapling.engines.static.ResponseFactory.from_http_request", return_value=MagicMock()),
+            ):
+                session.get("http://example.com", proxy=request_proxy)
+
+            assert mocked_request.call_args.kwargs["proxy"] == request_proxy
+
+    def test_proxy_rotates_per_retry_attempt(self):
+        """With a rotator, every retry attempt must pull a fresh proxy"""
+        rotator = ProxyRotator(["http://p1:8080", "http://p2:8080"])
+
+        with FetcherSession(proxy_rotator=rotator, retries=2, retry_delay=0) as session:
+            with (
+                patch.object(session._curl_session, "request") as mocked_request,
+                patch("scrapling.engines.static.ResponseFactory.from_http_request", return_value=MagicMock()),
+            ):
+                mocked_request.side_effect = [CurlError("transient"), MagicMock()]
+                session.get("http://example.com")
+
+            proxies_used = [call.kwargs["proxy"] for call in mocked_request.call_args_list]
+            assert proxies_used == ["http://p1:8080", "http://p2:8080"]