allow non-tool call json in llama 3.x parser

Author: ochafik

common/chat.cpp

@@ -1177,7 +1177,18 @@ static void common_chat_parse_llama_3_1(common_chat_msg_parser & builder, bool w
         }
     } else if (auto tc = builder.try_consume_json_with_dumped_args({{"parameters"}})) {
         if (!builder.add_tool_call(tc->value, "parameters")) {
-            builder.move_to(initial_pos);
+            auto has_unknown_keys = false;
+            for (const auto & [key, value] : tc->value.items()) {
+                if (key != "parameters" && key != "name" && key != "type") {
+                    has_unknown_keys = true;
+                    break;
+                }
+            }
+            if (has_unknown_keys) {
+                builder.move_to(initial_pos);
+            } else {
+                throw common_chat_msg_partial_exception("incomplete tool call");
+            }
         }
     }
     builder.add_content(builder.consume_rest());

tests/test-chat.cpp

@@ -1074,6 +1074,24 @@ static void test_template_output_parsers() {
                 "<|python_tag|>{\"type\": \"function\", \"name\": \"special_function\", \"parameters\": {\"arg1\": 1}}",
                 /* is_partial= */ false,
                 {COMMON_CHAT_FORMAT_LLAMA_3_X}));
+        assert_equals(
+            simple_assist_msg("{\"something\": \"else\"}"),
+            common_chat_parse(
+                "{\"something\": \"else\"}",
+                /* is_partial= */ false,
+                {COMMON_CHAT_FORMAT_LLAMA_3_X}));
+        assert_equals(
+            message_assist_empty,
+            common_chat_parse(
+                "{\"some",
+                /* is_partial= */ true,
+                {COMMON_CHAT_FORMAT_LLAMA_3_X}));
+        assert_equals(
+            message_assist_empty,
+            common_chat_parse(
+                "{\"parameters\": {\"arg1\": 1}",
+                /* is_partial= */ true,
+                {COMMON_CHAT_FORMAT_LLAMA_3_X}));
 
         // test_templates(tmpls.get(), end_tokens, message_assist, tools, R"(?)", /* expect_grammar_triggered= */ false);
         test_templates(tmpls.get(), end_tokens, message_assist_call_code_interpreter, llama_3_1_tools,