fix: change conditional logic in _choose_redirect_arg for `TestClie…

…nt` (encode#2783).

starlette/testclient.py

@@ -449,16 +449,16 @@ def _choose_redirect_arg(
         self, follow_redirects: bool | None, allow_redirects: bool | None
     ) -> bool | httpx._client.UseClientDefault:
         redirect: bool | httpx._client.UseClientDefault = httpx._client.USE_CLIENT_DEFAULT
+        if allow_redirects is not None and follow_redirects is not None:
+            raise RuntimeError(  # pragma: no cover
+                "Cannot use both `allow_redirects` and `follow_redirects`."
+            )
         if allow_redirects is not None:
             message = "The `allow_redirects` argument is deprecated. Use `follow_redirects` instead."
             warnings.warn(message, DeprecationWarning)
             redirect = allow_redirects
         if follow_redirects is not None:
             redirect = follow_redirects
-        elif allow_redirects is not None and follow_redirects is not None:
-            raise RuntimeError(  # pragma: no cover
-                "Cannot use both `allow_redirects` and `follow_redirects`."
-            )
         return redirect
 
     def request(  # type: ignore[override]