common : add reasoning_format = none support to gpt-oss (#21094)

Author: aldehir

common/chat.cpp

@@ -971,6 +971,7 @@ static common_chat_params common_chat_params_init_gpt_oss(const common_chat_temp
     auto has_tools           = inputs.tools.is_array() && !inputs.tools.empty();
     auto has_response_format = !inputs.json_schema.is_null() && inputs.json_schema.is_object();
     auto include_grammar     = has_response_format || (has_tools && inputs.tool_choice != COMMON_CHAT_TOOL_CHOICE_NONE);
+    auto extract_reasoning   = inputs.reasoning_format != COMMON_REASONING_FORMAT_NONE;
 
     auto parser = build_chat_peg_parser([&](common_chat_peg_builder & p) {
         auto start           = p.rule("start", p.literal("<|start|>assistant"));
@@ -979,7 +980,13 @@ static common_chat_params common_chat_params_init_gpt_oss(const common_chat_temp
         auto channel         = p.literal("<|channel|>") + (p.literal("commentary") | p.literal("analysis"));
         auto constrain_type  = p.chars("[A-Za-z0-9_-]", 1, -1);
 
-        auto analysis = p.rule("analysis", p.literal("<|channel|>analysis<|message|>") + p.reasoning(content) + end);
+        if (extract_reasoning) {
+            p.rule("analysis", p.literal("<|channel|>analysis<|message|>") + p.reasoning(content) + end);
+        } else {
+            p.rule("analysis", p.content(p.literal("<|channel|>analysis<|message|>") + content + end));
+        }
+
+        auto analysis = p.ref("analysis");
         auto preamble = p.rule("preamble", p.literal("<|channel|>commentary<|message|>") + p.content(content) + end);
         auto final_msg = p.rule("final", p.literal("<|channel|>final<|message|>") + p.content(content));
         auto any = p.rule("any", preamble | analysis);

tests/test-chat.cpp

@@ -2796,6 +2796,14 @@ static void test_template_output_peg_parsers(bool detailed_debug) {
             .expect(message_assist_thoughts)
             .run();
 
+        // Analysis channel (reasoning) with final channel (content) with reasoning_format = none
+        tst.test(
+               "<|channel|>analysis<|message|>I'm\nthinking<|end|><|start|>assistant<|channel|>final<|message|>Hello, world!\nWhat's "
+               "up?")
+            .reasoning_format(COMMON_REASONING_FORMAT_NONE)
+            .expect_content("<|channel|>analysis<|message|>I'm\nthinking<|end|>Hello, world!\nWhat's up?")
+            .run();
+
         // Analysis channel only (partial) - still works when reasoning format is set
         tst.test("<|channel|>analysis<|message|>I'm\nthinking")
             .reasoning_format(COMMON_REASONING_FORMAT_AUTO)
@@ -2805,24 +2813,28 @@ static void test_template_output_peg_parsers(bool detailed_debug) {
 
         // Tool call with recipient in role header: " to=functions.NAME<|channel|>analysis<|message|>JSON"
         tst.test(" to=functions.special_function<|channel|>analysis<|message|>{\"arg1\": 1}")
+            .reasoning_format(COMMON_REASONING_FORMAT_AUTO)
             .tools({ special_function_tool })
             .expect(message_assist_call)
             .run();
 
         // Tool call with recipient in channel header: "<|channel|>analysis to=functions.NAME<|message|>JSON"
         tst.test("<|channel|>analysis to=functions.special_function<|message|>{\"arg1\": 1}")
+            .reasoning_format(COMMON_REASONING_FORMAT_AUTO)
             .tools({ special_function_tool })
             .expect(message_assist_call)
             .run();
 
         // Tool call with constraint: " to=functions.NAME<|channel|>analysis <|constrain|>json<|message|>JSON"
         tst.test(" to=functions.special_function<|channel|>analysis <|constrain|>json<|message|>{\"arg1\": 1}")
+            .reasoning_format(COMMON_REASONING_FORMAT_AUTO)
             .tools({ special_function_tool })
             .expect(message_assist_call)
             .run();
 
         // Tool call in commentary channel (channel header variant)
         tst.test("<|channel|>commentary to=functions.special_function<|message|>{\"arg1\": 1}")
+            .reasoning_format(COMMON_REASONING_FORMAT_AUTO)
             .tools({ special_function_tool })
             .expect(message_assist_call)
             .run();