fix: gracefully catch error if streamed json does not meet schema val…

…idation (fixes #14)

PiperOrigin-RevId: 711449980

google/genai/tests/models/test_generate_content.py

@@ -404,6 +404,60 @@ def test_json_schema(client):
   assert isinstance(response.parsed, dict)
 
 
+def test_json_schema_with_streaming(client):
+
+  response = client.models.generate_content_stream(
+      model='gemini-2.0-flash-exp',
+      contents='Give me information of the United States.',
+      config={
+          'response_mime_type': 'application/json',
+          'response_schema': {
+              'properties': {
+                  'name': {'type': 'STRING'},
+                  'population': {'type': 'INTEGER'},
+                  'capital': {'type': 'STRING'},
+                  'continent': {'type': 'STRING'},
+                  'gdp': {'type': 'INTEGER'},
+                  'official_language': {'type': 'STRING'},
+                  'total_area_sq_mi': {'type': 'INTEGER'},
+              },
+              'type': 'OBJECT',
+          },
+      },
+  )
+
+  for r in response:
+    parts = r.candidates[0].content.parts
+    for p in parts:
+      print(p.text)
+
+
+def test_pydantic_schema_with_streaming(client):
+
+  class CountryInfo(BaseModel):
+    name: str
+    population: int
+    capital: str
+    continent: str
+    gdp: int
+    official_language: str
+    total_area_sq_mi: int
+
+  response = client.models.generate_content_stream(
+      model='gemini-2.0-flash-exp',
+      contents='Give me information of the United States.',
+      config={
+          'response_mime_type': 'application/json',
+          'response_schema': CountryInfo
+      },
+  )
+
+  for r in response:
+    parts = r.candidates[0].content.parts
+    for p in parts:
+      print(p.text)
+
+
 def test_function(client):
   def get_weather(city: str) -> str:
     return f'The weather in {city} is sunny and 100 degrees.'

google/genai/types.py

@@ -2453,7 +2453,10 @@ class GenerateContentResponse(_common.BaseModel):
       default=None, description="""Usage metadata about the response(s)."""
   )
   automatic_function_calling_history: Optional[list[Content]] = None
-  parsed: Union[pydantic.BaseModel, dict] = None
+  parsed: Union[pydantic.BaseModel, dict] = Field(
+      default=None,
+      description="""Parsed response if response_schema is provided. Not available for streaming.""",
+  )
 
   @property
   def text(self) -> Optional[str]:
@@ -2503,12 +2506,21 @@ def _from_response(
         response_schema, pydantic.BaseModel
     ):
       # Pydantic schema.
-      result.parsed = response_schema.model_validate_json(result.text)
+      try:
+        result.parsed = response_schema.model_validate_json(result.text)
+      # may not be a valid json per stream response
+      except pydantic.ValidationError:
+        pass
+
     elif isinstance(response_schema, dict) or isinstance(
         response_schema, pydantic.BaseModel
     ):
       # JSON schema.
-      result.parsed = json.loads(result.text)
+      try:
+        result.parsed = json.loads(result.text)
+      # may not be a valid json per stream response
+      except json.decoder.JSONDecodeError:
+        pass
 
     return result