Warn about requestCookies=[]

scrapy_zyte_api/_params.py

@@ -211,8 +211,23 @@ def _set_http_request_cookies_from_request(
 ):
     api_params.setdefault("experimental", {})
     if "requestCookies" in api_params["experimental"]:
-        if api_params["experimental"]["requestCookies"] is False:
+        request_cookies = api_params["experimental"]["requestCookies"]
+        if request_cookies is False:
             del api_params["experimental"]["requestCookies"]
+        elif not request_cookies and isinstance(request_cookies, list):
+            logger.warning(
+                (
+                    "Request %(request)r is overriding automatic request "
+                    "cookie mapping by explicitly setting "
+                    "experimental.requestCookies to []. If this was your "
+                    "intention, please use False instead of []. Otherwise, "
+                    "stop defining experimental.requestCookies in your "
+                    "request to let automatic mapping work."
+                ),
+                {
+                    "request": request,
+                },
+            )
         return
     output_cookies = []
     input_cookies = _get_all_cookies(request, cookie_jars)

tests/test_api_requests.py

@@ -1933,6 +1933,33 @@ def test_automap_header_settings(settings, headers, meta, expected, warnings, ca
             [],
             [],
         ),
+        # Setting requestCookies to [] disables automatic mapping, but logs a
+        # a warning recommending to either use False to achieve the same or
+        # remove the parameter to let automated mapping work.
+        (
+            {
+                "ZYTE_API_EXPERIMENTAL_COOKIES_ENABLED": True,
+            },
+            REQUEST_INPUT_COOKIES_MINIMAL_DICT,
+            {},
+            {
+                "experimental": {
+                    "requestCookies": [],
+                }
+            },
+            {
+                "httpResponseBody": True,
+                "httpResponseHeaders": True,
+                "experimental": {
+                    "requestCookies": [],
+                    "responseCookies": True,
+                },
+            },
+            [
+                "is overriding automatic request cookie mapping",
+            ],
+            [],
+        ),
         # Cookies work for browser and automatic extraction requests as well.
         (
             {