adds tool calling test

tests/test_litellm/llms/heroku/test_heroku_chat_transformation.py

@@ -80,4 +80,87 @@ class TestHerokuChatConfig:
         assert request.headers["Authorization"] == f"Bearer {os.environ['HEROKU_API_KEY']}"
         assert request.headers["Content-Type"] == "application/json"
 
-        assert response.choices[0].message.content == "It's me, Mia! How are you?"
+        assert response.choices[0].message.content == "It's me, Mia! How are you?"
+
+    @pytest.mark.respx()
+    def test_heroku_tool_calling(self, respx_mock):
+        """Test that the Heroku tool calling API is called correctly"""
+        config = HerokuChatConfig()
+        headers = {}
+        api_key = "fake-heroku-key"
+
+        litellm.disable_aiohttp_transport = True
+
+        model = "heroku/claude-4-sonnet"
+
+        respx_mock.post("https://us.inference.heroku.com/v1/chat/completions").respond(
+            json={
+                "id": "chatcmpl-1859428879fc791b17d73",
+                "object": "chat.completion",
+                "created": 1754506683,
+                "model": "claude-4-sonnet",
+                "system_fingerprint": "heroku-inf-cp42st",
+                "choices": [
+                    {
+                    "index": 0,
+                    "message": {
+                        "role": "assistant",
+                        "refusal": None,
+                        "tool_calls": [
+                        {
+                            "id": "tooluse_dV3Vtnb-S9-Z_YFicSv2Gw",
+                            "type": "function",
+                            "function": {
+                            "name": "get_current_weather",
+                            "arguments": "{\"location\":\"Portland, OR\"}"
+                            }
+                        }
+                        ],
+                        "content": "Let me check the current weather in Portland for you."
+                    },
+                    "finish_reason": "tool_calls"
+                    }
+                ],
+                "usage": {
+                    "prompt_tokens": 354,
+                    "completion_tokens": 69,
+                    "total_tokens": 423
+                }
+            },
+            status_code=200,
+        )
+
+        response = completion(
+            model=model,
+            messages=[{"role": "user", "content": "What's the weather in Portland?"}],
+            tools=[{
+                "type": "function", 
+                "function": {
+                    "name": "get_current_weather", 
+                    "description": "Get the current weather in a given location",
+                    "parameters": {
+                        "type": "object",
+                        "properties": {
+                            "location": {
+                                "type": "string",
+                                "description": "The city and state, e.g. Portland, OR"
+                            }
+                        },
+                        "required": [
+                            "location"
+                        ]
+                    }
+                }
+            }],
+            tool_choice="auto",
+        )
+        print(response)
+        assert response.choices[0].message.content == "Let me check the current weather in Portland for you."
+        assert response.choices[0].message.tool_calls[0].id == "tooluse_dV3Vtnb-S9-Z_YFicSv2Gw"
+        assert response.choices[0].message.tool_calls[0].type == "function"
+        assert response.choices[0].message.tool_calls[0].function.name == "get_current_weather"
+        assert response.choices[0].message.tool_calls[0].function.arguments == "{\"location\":\"Portland, OR\"}"
+
+        assert response.usage.prompt_tokens == 354
+        assert response.usage.completion_tokens == 69
+        assert response.usage.total_tokens == 423