Fix GoogleAIGeminiChatGenerator to_dict and from_dict

integrations/google_ai/src/haystack_integrations/components/generators/google_ai/chat/gemini.py

@@ -2,9 +2,10 @@
 from typing import Any, Dict, List, Optional, Union
 
 import google.generativeai as genai
-from google.ai.generativelanguage import Content, Part, Tool
+from google.ai.generativelanguage import Content, Part
+from google.ai.generativelanguage import Tool as ToolProto
 from google.generativeai import GenerationConfig, GenerativeModel
-from google.generativeai.types import HarmBlockThreshold, HarmCategory
+from google.generativeai.types import HarmBlockThreshold, HarmCategory, Tool
 from haystack.core.component import component
 from haystack.core.serialization import default_from_dict, default_to_dict
 from haystack.dataclasses.byte_stream import ByteStream
@@ -159,7 +160,14 @@ def to_dict(self) -> Dict[str, Any]:
             tools=self._tools,
         )
         if (tools := data["init_parameters"].get("tools")) is not None:
-            data["init_parameters"]["tools"] = [Tool.serialize(t) for t in tools]
+            data["init_parameters"]["tools"] = []
+            for tool in tools:
+                if isinstance(tool, Tool):
+                    # There are multiple Tool types in the Google lib, one that is a protobuf class and
+                    # another is a simple Python class. They have a similar structure but the Python class
+                    # can't be easily serializated to a dict. We need to convert it to a protobuf class first.
+                    tool = tool.to_proto()  # noqa: PLW2901
+                data["init_parameters"]["tools"].append(ToolProto.serialize(tool))
         if (generation_config := data["init_parameters"].get("generation_config")) is not None:
             data["init_parameters"]["generation_config"] = self._generation_config_to_dict(generation_config)
         if (safety_settings := data["init_parameters"].get("safety_settings")) is not None:
@@ -179,7 +187,15 @@ def from_dict(cls, data: Dict[str, Any]) -> "GoogleAIGeminiChatGenerator":
         deserialize_secrets_inplace(data["init_parameters"], keys=["api_key"])
 
         if (tools := data["init_parameters"].get("tools")) is not None:
-            data["init_parameters"]["tools"] = [Tool.deserialize(t) for t in tools]
+            deserialized_tools = []
+            for tool in tools:
+                # Tools are always serialized as a protobuf class, so we need to deserialize them first
+                # to be able to convert them to the Python class.
+                proto = ToolProto.deserialize(tool)
+                deserialized_tools.append(
+                    Tool(function_declarations=proto.function_declarations, code_execution=proto.code_execution)
+                )
+            data["init_parameters"]["tools"] = deserialized_tools
         if (generation_config := data["init_parameters"].get("generation_config")) is not None:
             data["init_parameters"]["generation_config"] = GenerationConfig(**generation_config)
         if (safety_settings := data["init_parameters"].get("safety_settings")) is not None:

integrations/google_ai/tests/generators/chat/test_chat_gemini.py

@@ -157,33 +157,16 @@ def test_from_dict(monkeypatch):
         top_k=2,
     )
     assert gemini._safety_settings == {HarmCategory.HARM_CATEGORY_DANGEROUS_CONTENT: HarmBlockThreshold.BLOCK_ONLY_HIGH}
-    assert gemini._tools == [
-        Tool(
-            function_declarations=[
-                FunctionDeclaration(
-                    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. San Francisco, CA",
-                            },
-                            "unit": {
-                                "type_": "STRING",
-                                "enum": [
-                                    "celsius",
-                                    "fahrenheit",
-                                ],
-                            },
-                        },
-                        "required": ["location"],
-                    },
-                )
-            ]
-        )
-    ]
+    assert len(gemini._tools) == 1
+    assert len(gemini._tools[0].function_declarations) == 1
+    assert gemini._tools[0].function_declarations[0].name == "get_current_weather"
+    assert gemini._tools[0].function_declarations[0].description == "Get the current weather in a given location"
+    assert (
+        gemini._tools[0].function_declarations[0].parameters.properties["location"].description
+        == "The city and state, e.g. San Francisco, CA"
+    )
+    assert gemini._tools[0].function_declarations[0].parameters.properties["unit"].enum == ["celsius", "fahrenheit"]
+    assert gemini._tools[0].function_declarations[0].parameters.required == ["location"]
     assert isinstance(gemini._model, GenerativeModel)