client should backoff when receiving final chunk

Author: cwaldren-ld

contract-tests/sse-contract-tests/src/event_outbox.cpp

@@ -67,7 +67,7 @@ EventOutbox::RequestType EventOutbox::build_request(
     RequestType req;
 
     req.set(http::field::host, callback_host_);
-    req.method(http::verb::get);
+    req.method(http::verb::post);
     req.target(callback_url_ + "/" + std::to_string(counter));
 
     nlohmann::json json;

libs/server-sent-events/src/client.cpp

@@ -303,6 +303,12 @@ class FoxyClient : public Client,
             logger_("read HTTP response body aborted (shutting down)");
             return;
         }
+        if (body_parser_->is_done()) {
+            // The server can indicate that the chunk encoded response is done
+            // by sending a final chunk + CRLF. The body parser will have
+            // detected this. The correct response is to attempt to reconnect.
+            return do_backoff("receiving final chunk");
+        }
         if (!ec) {
             log_and_update_last_read(amount);
             return session_->async_read_some(