fix: use raw_response.text instead of .json() for LegacyAPIResponse compat

LegacyAPIResponse (returned by with_raw_response in some openai SDK
versions) does not expose a .json() method, causing AttributeError on
all non-streaming calls. Switch to .text which is available on both
LegacyAPIResponse and APIResponse. Update test mocks to match.

Author: ArkaD171717

integrations/mistral/src/haystack_integrations/components/generators/mistral/chat/chat_generator.py

@@ -387,7 +387,7 @@ def run(
             completions = self._handle_stream_response(chat_completion, streaming_callback)
         else:
             raw_response = getattr(self.client.chat.completions.with_raw_response, openai_endpoint)(**api_args)
-            completions = _convert_mistral_response_to_chat_messages(raw_response.json())
+            completions = _convert_mistral_response_to_chat_messages(raw_response.text)
 
         for message in completions:
             _check_finish_reason(message.meta)
@@ -457,7 +457,7 @@ async def run_async(
             raw_response = await getattr(self.async_client.chat.completions.with_raw_response, openai_endpoint)(
                 **api_args
             )
-            completions = _convert_mistral_response_to_chat_messages(raw_response.json())
+            completions = _convert_mistral_response_to_chat_messages(raw_response.text)
 
         for message in completions:
             _check_finish_reason(message.meta)

integrations/mistral/tests/test_mistral_chat_generator.py

@@ -1,11 +1,9 @@
 import json
 import logging
 import os
-from datetime import datetime
 from unittest.mock import ANY, patch
 
 import pytest
-import pytz
 from haystack import Pipeline
 from haystack.components.generators.utils import print_streaming_chunk
 from haystack.components.tools import ToolInvoker
@@ -21,8 +19,7 @@
 from haystack.tools import Tool, Toolset
 from haystack.utils.auth import Secret
 from openai import OpenAIError
-from openai.types.chat import ChatCompletion, ChatCompletionChunk, ChatCompletionMessage
-from openai.types.chat.chat_completion import Choice
+from openai.types.chat import ChatCompletionChunk
 from openai.types.chat.chat_completion_chunk import Choice as ChoiceChunk
 from openai.types.chat.chat_completion_chunk import ChoiceDelta, ChoiceDeltaToolCall, ChoiceDeltaToolCallFunction
 from openai.types.completion_usage import CompletionUsage
@@ -103,23 +100,25 @@ def mock_chat_completion():
     Mock the OpenAI API completion response and reuse it for tests
     """
     with patch("openai.resources.chat.completions.Completions.create") as mock_chat_completion_create:
-        completion = ChatCompletion(
-            id="foo",
-            model="mistral-small-latest",
-            object="chat.completion",
-            choices=[
-                Choice(
-                    finish_reason="stop",
-                    logprobs=None,
-                    index=0,
-                    message=ChatCompletionMessage(content="Hello world!", role="assistant"),
-                )
-            ],
-            created=int(datetime.now(tz=pytz.timezone("UTC")).timestamp()),
-            usage={"prompt_tokens": 57, "completion_tokens": 40, "total_tokens": 97},
+        mock_response = type("MockRawResponse", (), {})()
+        mock_response.text = json.dumps(
+            {
+                "id": "foo",
+                "model": "mistral-small-latest",
+                "object": "chat.completion",
+                "choices": [
+                    {
+                        "finish_reason": "stop",
+                        "index": 0,
+                        "message": {"role": "assistant", "content": "Hello world!"},
+                    }
+                ],
+                "created": 1234567890,
+                "usage": {"prompt_tokens": 57, "completion_tokens": 40, "total_tokens": 97},
+            }
         )
 
-        mock_chat_completion_create.return_value = completion
+        mock_chat_completion_create.return_value = mock_response
         yield mock_chat_completion_create
 
 
@@ -857,7 +856,7 @@ def mock_reasoning_response():
     """Mock that returns a raw-response-like object with reasoning array content."""
     with patch("openai.resources.chat.completions.Completions.create") as mock_create:
         mock_response = type("MockRawResponse", (), {})()
-        mock_response.json = lambda: json.dumps(
+        mock_response.text = json.dumps(
             {
                 "id": "test-reasoning",
                 "model": "mistral-small-latest",

integrations/mistral/tests/test_mistral_chat_generator_async.py

@@ -1,20 +1,16 @@
 import json
 import logging
 import os
-from datetime import datetime
 from unittest.mock import AsyncMock, patch
 
 import pytest
-import pytz
 from haystack.dataclasses import (
     ChatMessage,
     ChatRole,
     StreamingChunk,
 )
 from haystack.tools import Tool
 from openai import AsyncOpenAI
-from openai.types.chat import ChatCompletion, ChatCompletionMessage
-from openai.types.chat.chat_completion import Choice
 
 from haystack_integrations.components.generators.mistral.chat.chat_generator import (
     MistralChatGenerator,
@@ -60,27 +56,24 @@ def mock_async_chat_completion():
         "openai.resources.chat.completions.AsyncCompletions.create",
         new_callable=AsyncMock,
     ) as mock_chat_completion_create:
-        completion = ChatCompletion(
-            id="foo",
-            model="mistral-small-latest",
-            object="chat.completion",
-            choices=[
-                Choice(
-                    finish_reason="stop",
-                    logprobs=None,
-                    index=0,
-                    message=ChatCompletionMessage(content="Hello world!", role="assistant"),
-                )
-            ],
-            created=int(datetime.now(tz=pytz.timezone("UTC")).timestamp()),
-            usage={
-                "prompt_tokens": 57,
-                "completion_tokens": 40,
-                "total_tokens": 97,
-            },
+        mock_response = type("MockRawResponse", (), {})()
+        mock_response.text = json.dumps(
+            {
+                "id": "foo",
+                "model": "mistral-small-latest",
+                "object": "chat.completion",
+                "choices": [
+                    {
+                        "finish_reason": "stop",
+                        "index": 0,
+                        "message": {"role": "assistant", "content": "Hello world!"},
+                    }
+                ],
+                "created": 1234567890,
+                "usage": {"prompt_tokens": 57, "completion_tokens": 40, "total_tokens": 97},
+            }
         )
-        # For async mocks, the return value should be awaitable
-        mock_chat_completion_create.return_value = completion
+        mock_chat_completion_create.return_value = mock_response
         yield mock_chat_completion_create
 
 
@@ -270,7 +263,7 @@ async def test_run_async_with_reasoning(self, chat_messages, monkeypatch):
         monkeypatch.setenv("MISTRAL_API_KEY", "fake-api-key")
 
         mock_response = type("MockRawResponse", (), {})()
-        mock_response.json = lambda: json.dumps(
+        mock_response.text = json.dumps(
             {
                 "id": "test-reasoning-async",
                 "model": "mistral-small-latest",