fix: None value handling of flattened generation kwargs for AmazonBedrockChatGenerator (#2752)

* fix: None value handling of flattened generation kwargs for AmazonBedrockChatGenerator

* fmt

* apply feedback

Author: tstadel

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

@@ -423,27 +423,31 @@ def _prepare_request_params(
 
     def _resolve_flattened_generation_kwargs(self, generation_kwargs: dict[str, Any]) -> dict[str, Any]:
         generation_kwargs = generation_kwargs.copy()
-        if "disable_parallel_tool_use" in generation_kwargs:
-            disable_parallel_tool_use = generation_kwargs.pop("disable_parallel_tool_use")
-            tool_choice = generation_kwargs.setdefault("tool_choice", {})
-            tool_choice["disable_parallel_tool_use"] = disable_parallel_tool_use
 
-        if "parallel_tool_use" in generation_kwargs:
-            parallel_tool_use = generation_kwargs.pop("parallel_tool_use")
+        disable_parallel_tool_use = generation_kwargs.pop("disable_parallel_tool_use", None)
+        parallel_tool_use = generation_kwargs.pop("parallel_tool_use", None)
+
+        if disable_parallel_tool_use is not None and parallel_tool_use is not None:
+            msg = "Cannot set both disable_parallel_tool_use and parallel_tool_use"
+            raise ValueError(msg)
+        elif parallel_tool_use is not None:
             disable_parallel_tool_use = not parallel_tool_use
+
+        if disable_parallel_tool_use is not None:
             tool_choice = generation_kwargs.setdefault("tool_choice", {})
             tool_choice["disable_parallel_tool_use"] = disable_parallel_tool_use
+            tool_choice.setdefault("type", "auto")  # default value
 
-        if "tool_choice_type" in generation_kwargs:
-            tool_choice_type = generation_kwargs.pop("tool_choice_type")
+        tool_choice_type = generation_kwargs.pop("tool_choice_type", None)
+        if tool_choice_type is not None:
             tool_choice = generation_kwargs.setdefault("tool_choice", {})
             tool_choice["type"] = tool_choice_type
 
-        if "thinking_budget_tokens" in generation_kwargs:
-            thinking_budget_tokens = generation_kwargs.pop("thinking_budget_tokens")
+        thinking_budget_tokens = generation_kwargs.pop("thinking_budget_tokens", None)
+        if thinking_budget_tokens is not None:
             thinking = generation_kwargs.setdefault("thinking", {})
             thinking["budget_tokens"] = thinking_budget_tokens
-            thinking["type"] = "enabled"
+            thinking.setdefault("type", "enabled")
 
         return generation_kwargs
 

integrations/amazon_bedrock/tests/test_chat_generator.py

@@ -409,21 +409,68 @@ def tool_fn(city: str) -> str:
             ]
         }
 
-    def test_prepare_request_params_with_flattened_generation_kwargs(self, mock_boto3_session, set_env_variables):
+    @pytest.mark.parametrize(
+        "generation_kwargs,additional_model_request_fields",
+        [
+            (
+                {
+                    "parallel_tool_use": False,
+                    "tool_choice_type": "any",
+                    "thinking_budget_tokens": 1024,
+                },
+                {
+                    "tool_choice": {"disable_parallel_tool_use": True, "type": "any"},
+                    "thinking": {"budget_tokens": 1024, "type": "enabled"},
+                },
+            ),
+            (
+                {
+                    "parallel_tool_use": True,
+                    "tool_choice_type": "all",
+                },
+                {
+                    "tool_choice": {"disable_parallel_tool_use": False, "type": "all"},
+                },
+            ),
+            (
+                {
+                    "parallel_tool_use": True,
+                },
+                {
+                    "tool_choice": {"disable_parallel_tool_use": False, "type": "auto"},
+                },
+            ),
+            (
+                {
+                    "disable_parallel_tool_use": True,
+                },
+                {
+                    "tool_choice": {"disable_parallel_tool_use": True, "type": "auto"},
+                },
+            ),
+            (
+                {
+                    "thinking_budget_tokens": None,
+                    "parallel_tool_use": None,
+                    "tool_choice_type": None,
+                },
+                {},
+            ),
+        ],
+    )
+    def test_prepare_request_params_with_flattened_generation_kwargs(
+        self, mock_boto3_session, set_env_variables, generation_kwargs, additional_model_request_fields
+    ):
         generator = AmazonBedrockChatGenerator(model="anthropic.claude-3-5-sonnet-20240620-v1:0")
         request_params, _ = generator._prepare_request_params(
             messages=[ChatMessage.from_user("What's the capital of France?")],
-            generation_kwargs={
-                "parallel_tool_use": False,
-                "tool_choice_type": "any",
-                "thinking_budget_tokens": 1024,
-            },
+            generation_kwargs=generation_kwargs,
         )
 
-        assert request_params["additionalModelRequestFields"] == {
-            "tool_choice": {"disable_parallel_tool_use": True, "type": "any"},
-            "thinking": {"budget_tokens": 1024, "type": "enabled"},
-        }
+        if not additional_model_request_fields:
+            assert "additionalModelRequestFields" not in request_params
+        else:
+            assert request_params["additionalModelRequestFields"] == additional_model_request_fields
 
 
 # In the CI, those tests are skipped if AWS Authentication fails