chore: unit test for cohere and handle stop curl

engine/extensions/remote-engine/remote_engine.cc

@@ -35,6 +35,7 @@ size_t StreamWriteCallback(char* ptr, size_t size, size_t nmemb,
     status["has_error"] = true;
     status["is_stream"] = true;
     status["status_code"] = k400BadRequest;
+    context->need_stop = false;
     (*context->callback)(std::move(status), std::move(check_error));
     return size * nmemb;
   }
@@ -58,7 +59,8 @@ size_t StreamWriteCallback(char* ptr, size_t size, size_t nmemb,
       status["is_done"] = true;
       status["has_error"] = false;
       status["is_stream"] = true;
-      status["status_code"] = 200;
+      status["status_code"] = k200OK;
+      context->need_stop = false;
       (*context->callback)(std::move(status), Json::Value());
       break;
     }
@@ -169,6 +171,15 @@ CurlResponse RemoteEngine::MakeStreamingChatCompletionRequest(
 
   curl_slist_free_all(headers);
   curl_easy_cleanup(curl);
+  if (context.need_stop) {
+    CTL_DBG("No stop message received, need to stop");
+    Json::Value status;
+    status["is_done"] = true;
+    status["has_error"] = false;
+    status["is_stream"] = true;
+    status["status_code"] = k200OK;
+    (*context.callback)(std::move(status), Json::Value());
+  }
   return response;
 }
 
@@ -626,6 +637,9 @@ void RemoteEngine::HandleChatCompletion(
 
       try {
         response_json["stream"] = false;
+        if (!response_json.isMember("model")) {
+          response_json["model"] = model;
+        }
         response_str = renderer_.Render(template_str, response_json);
       } catch (const std::exception& e) {
         throw std::runtime_error("Template rendering error: " +
@@ -649,6 +663,7 @@ void RemoteEngine::HandleChatCompletion(
       Json::Value error;
       error["error"] = "Failed to parse response";
       callback(std::move(status), std::move(error));
+      LOG_WARN << "Failed to parse response: " << response_str;
       return;
     }
 

engine/extensions/remote-engine/remote_engine.h

@@ -24,6 +24,7 @@ struct StreamContext {
   std::string model;
   extensions::TemplateRenderer& renderer;
   std::string stream_template;
+  bool need_stop = true;
 };
 struct CurlResponse {
   std::string body;

engine/extensions/template_renderer.cc

@@ -50,9 +50,6 @@ std::string TemplateRenderer::Render(const std::string& tmpl,
 
     LOG_DEBUG << "Result: " << result;
 
-    // Validate JSON
-    auto parsed = nlohmann::json::parse(result);
-
     return result;
   } catch (const std::exception& e) {
     LOG_ERROR << "Template rendering failed: " << e.what();
@@ -133,4 +130,4 @@ std::string TemplateRenderer::RenderFile(const std::string& template_path,
                              e.what());
   }
 }
-}  // namespace remote_engine
+}  // namespace extensions

engine/test/components/test_remote_engine.cc

@@ -181,6 +181,239 @@ TEST_F(RemoteEngineTest, AnthropicResponse) {
   EXPECT_TRUE(res_json["choices"][0]["message"]["content"].isNull());
 }
 
+TEST_F(RemoteEngineTest, CohereRequest) {
+  std::string tpl =
+      R"({ 
+      {% for key, value in input_request %}
+        {% if key == "messages" %}  
+          {% if input_request.messages.0.role == "system" %}
+            "preamble": "{{ input_request.messages.0.content }}",
+            {% if length(input_request.messages) > 2 %}
+            "chatHistory": [
+              {% for message in input_request.messages %}
+                {% if not loop.is_first and not loop.is_last %}
+                  {"role": {% if message.role == "user" %} "USER" {% else %} "CHATBOT" {% endif %}, "content": "{{ message.content }}" } {% if loop.index < length(input_request.messages) - 2 %},{% endif %}
+                {% endif %}
+              {% endfor %}
+            ],
+            {% endif %}
+            "message": "{{ last(input_request.messages).content }}"
+          {% else %}
+           {% if length(input_request.messages) > 2 %}
+            "chatHistory": [
+              {% for message in input_request.messages %}
+                {% if not loop.is_last %}
+                  { "role": {% if message.role == "user" %} "USER" {% else %} "CHATBOT" {% endif %}, "content": "{{ message.content }}" } {% if loop.index < length(input_request.messages) - 2 %},{% endif %}
+                {% endif %}
+              {% endfor %}
+            ],
+            {% endif %}
+            "message": "{{ last(input_request.messages).content }}"
+          {% endif %}
+          {% if not loop.is_last %},{% endif %} 
+        {% else if key == "system" or key == "model" or key == "temperature" or key == "store" or key == "max_tokens" or key == "stream" or key == "presence_penalty" or key == "metadata" or key == "frequency_penalty" or key == "tools" or key == "tool_choice" or key == "logprobs" or key == "top_logprobs" or key == "logit_bias" or key == "n" or key == "modalities" or key == "prediction" or key == "response_format" or key == "service_tier" or key == "seed" or key == "stop" or key == "stream_options" or key == "top_p" or key == "parallel_tool_calls" or key == "user" %}
+          "{{ key }}": {{ tojson(value) }}   
+          {% if not loop.is_last %},{% endif %} 
+        {% endif %}      
+      {% endfor %} })";
+  {
+    std::string message_with_system = R"({
+    "engine" : "cohere",
+	  "max_tokens" : 1024,
+    "messages": [        
+        {"role": "system", "content": "You are a seasoned data scientist at a Fortune 500 company."},
+        {"role": "user", "content": "Hello, world"},
+        {"role": "assistant", "content": "The man who is widely credited with discovering gravity is Sir Isaac Newton"},
+        {"role": "user", "content": "How are you today?"}
+    ],
+    "model": "command-r-plus-08-2024",
+    "stream" : true
+})";
+
+    auto data = json_helper::ParseJsonString(message_with_system);
+
+    extensions::TemplateRenderer rdr;
+    auto res = rdr.Render(tpl, data);
+
+    auto res_json = json_helper::ParseJsonString(res);
+    EXPECT_EQ(data["model"].asString(), res_json["model"].asString());
+    EXPECT_EQ(data["max_tokens"].asInt(), res_json["max_tokens"].asInt());
+    for (auto const& msg : data["messages"]) {
+      if (msg["role"].asString() == "system") {
+        EXPECT_EQ(msg["content"].asString(), res_json["preamble"].asString());
+      }
+    }
+    EXPECT_EQ(res_json["message"].asString(), "How are you today?");
+  }
+
+  {
+    std::string message_without_system = R"({
+      "messages": [
+          {"role": "user", "content": "Hello, world"}
+      ],
+      "model": "command-r-plus-08-2024",
+      "max_tokens": 1024,
+  })";
+
+    auto data = json_helper::ParseJsonString(message_without_system);
+
+    extensions::TemplateRenderer rdr;
+    auto res = rdr.Render(tpl, data);
+
+    auto res_json = json_helper::ParseJsonString(res);
+    EXPECT_EQ(data["model"].asString(), res_json["model"].asString());
+    EXPECT_EQ(data["max_tokens"].asInt(), res_json["max_tokens"].asInt());
+    EXPECT_EQ(data["messages"][0]["content"].asString(),
+              res_json["message"].asString());
+  }
+}
+
+TEST_F(RemoteEngineTest, CohereResponse) {
+  std::string tpl = R"(
+  {% if input_request.stream %} 
+    {"object": "chat.completion.chunk", 
+    "model": "{{ input_request.model }}", 
+    "choices": [{"index": 0, "delta": { {% if input_request.event_type == "text-generation" %} "role": "assistant", "content": "{{ input_request.text }}" {% else %} "role": "assistant", "content": null {% endif %} }, 
+    {% if input_request.event_type == "stream-end" %} "finish_reason": "{{ input_request.finish_reason }}" {% else %} "finish_reason": null {% endif %} }]
+    } 
+  {% else %} 
+    {"id": "{{ input_request.generation_id }}", 
+    "created": null, 
+    "object": "chat.completion", 
+    "model": "{{ input_request.model }}", 
+    "choices": [{ "index": 0, "message": { "role": "assistant", "content": {% if not input_request.text %} null {% else  %}  "{{input_request.text}}" {% endif %}, "refusal": null }, "logprobs": null, "finish_reason": "{{ input_request.finish_reason }}" } ], "usage": { "prompt_tokens": {{ input_request.meta.tokens.input_tokens }}, "completion_tokens": {{ input_request.meta.tokens.output_tokens }}, "total_tokens": {{ input_request.meta.tokens.input_tokens + input_request.meta.tokens.output_tokens }}, "prompt_tokens_details": { "cached_tokens": 0 }, "completion_tokens_details": { "reasoning_tokens": 0, "accepted_prediction_tokens": 0, "rejected_prediction_tokens": 0 } }, "system_fingerprint": "fp_6b68a8204b"} {% endif %})";
+  std::string message = R"({
+   "event_type": "text-generation",
+   "text": " help"
+})";
+  auto data = json_helper::ParseJsonString(message);
+  data["stream"] = true;
+  data["model"] = "cohere";
+  extensions::TemplateRenderer rdr;
+  auto res = rdr.Render(tpl, data);
+  auto res_json = json_helper::ParseJsonString(res);
+  EXPECT_EQ(res_json["choices"][0]["delta"]["content"].asString(), " help");
+
+  message = R"(
+  {
+  "event_type": "stream-end",
+  "response": {
+    "text": "Hello! How can I help you today?",
+    "generation_id": "29f14a5a-11de-4cae-9800-25e4747408ea",
+    "chat_history": [
+      {
+        "role": "USER",
+        "message": "hello world!"
+      },
+      {
+        "role": "CHATBOT",
+        "message": "Hello! How can I help you today?"
+      }
+    ],
+    "finish_reason": "COMPLETE",
+    "meta": {
+      "api_version": {
+        "version": "1"
+      },
+      "billed_units": {
+        "input_tokens": 3,
+        "output_tokens": 9
+      },
+      "tokens": {
+        "input_tokens": 69,
+        "output_tokens": 9
+      }
+    }
+  },
+  "finish_reason": "COMPLETE"
+  })";
+  data = json_helper::ParseJsonString(message);
+  data["stream"] = true;
+  data["model"] = "cohere";
+  res = rdr.Render(tpl, data);
+  res_json = json_helper::ParseJsonString(res);
+  EXPECT_TRUE(res_json["choices"][0]["delta"]["content"].isNull());
+
+  // non-stream
+  message = R"(
+  {
+  "text": "Isaac Newton was born on 25 December 1642 (Old Style) \n\nor 4 January 1643 (New Style).",
+  "generation_id": "0385c7cf-4247-43a3-a450-b25b547a31e1",
+  "citations": [
+    {
+      "start": 25,
+      "end": 41,
+      "text": "25 December 1642",
+      "document_ids": [
+        "web-search_0"
+      ]
+    }
+  ],
+  "search_queries": [
+    {
+      "text": "Isaac Newton birth year",
+      "generation_id": "9a497980-c3e2-4460-b81c-ef44d293f95d"
+    }
+  ],
+  "search_results": [
+    {
+      "connector": {
+        "id": "web-search"
+      },
+      "document_ids": [
+        "web-search_0"
+      ],
+      "search_query": {
+        "text": "Isaac Newton birth year",
+        "generation_id": "9a497980-c3e2-4460-b81c-ef44d293f95d"
+      }
+    }
+  ],
+  "finish_reason": "COMPLETE",
+  "chat_history": [
+    {
+      "role": "USER",
+      "message": "Who discovered gravity?"
+    },
+    {
+      "role": "CHATBOT",
+      "message": "The man who is widely credited with discovering gravity is Sir Isaac Newton"
+    },
+    {
+      "role": "USER",
+      "message": "What year was he born?"
+    },
+    {
+      "role": "CHATBOT",
+      "message": "Isaac Newton was born on 25 December 1642 (Old Style) or 4 January 1643 (New Style)."
+    }
+  ],
+  "meta": {
+    "api_version": {
+      "version": "1"
+    },
+    "billed_units": {
+      "input_tokens": 31738,
+      "output_tokens": 35
+    },
+    "tokens": {
+      "input_tokens": 32465,
+      "output_tokens": 205
+    }
+  }
+}
+  )";
+
+  data = json_helper::ParseJsonString(message);
+  data["stream"] = false;
+  data["model"] = "cohere";
+  res = rdr.Render(tpl, data);
+  res_json = json_helper::ParseJsonString(res);
+  EXPECT_EQ(res_json["choices"][0]["message"]["content"].asString(),
+            "Isaac Newton was born on 25 December 1642 (Old Style) \n\nor 4 "
+            "January 1643 (New Style).");
+}
+
 TEST_F(RemoteEngineTest, HeaderTemplate) {
   {
     std::string header_template =