refactor(backend): update handlers, utilities and core modules after models restructure

src/api/handlers/gemini/converter.py

@@ -70,7 +70,7 @@ class ClaudeToGeminiConverter:
             return [{"text": content}]
 
         if isinstance(content, list):
-            parts = []
+            parts: List[Dict[str, Any]] = []
             for block in content:
                 if isinstance(block, str):
                     parts.append({"text": block})
@@ -249,6 +249,8 @@ class GeminiToClaudeConverter:
             "RECITATION": "content_filtered",
             "OTHER": "stop_sequence",
         }
+        if finish_reason is None:
+            return "end_turn"
         return mapping.get(finish_reason, "end_turn")
 
     def _create_empty_response(self) -> Dict[str, Any]:
@@ -365,7 +367,7 @@ class OpenAIToGeminiConverter:
             return [{"text": content}]
 
         if isinstance(content, list):
-            parts = []
+            parts: List[Dict[str, Any]] = []
             for item in content:
                 if isinstance(item, str):
                     parts.append({"text": item})
@@ -524,7 +526,7 @@ class GeminiToOpenAIConverter:
             "total_tokens": prompt_tokens + completion_tokens,
         }
 
-    def _convert_finish_reason(self, finish_reason: Optional[str]) -> Optional[str]:
+    def _convert_finish_reason(self, finish_reason: Optional[str]) -> str:
         """转换停止原因"""
         mapping = {
             "STOP": "stop",
@@ -533,6 +535,8 @@ class GeminiToOpenAIConverter:
             "RECITATION": "content_filter",
             "OTHER": "stop",
         }
+        if finish_reason is None:
+            return "stop"
         return mapping.get(finish_reason, "stop")
 
 

src/api/handlers/gemini/stream_parser.py

@@ -10,7 +10,7 @@ Gemini API 的流式响应格式与 Claude/OpenAI 不同:
 """
 
 import json
-from typing import Any, Dict, List, Optional
+from typing import Any, Dict, List, Optional, Union
 
 
 class GeminiStreamParser:
@@ -32,18 +32,18 @@ class GeminiStreamParser:
     FINISH_REASON_RECITATION = "RECITATION"
     FINISH_REASON_OTHER = "OTHER"
 
-    def __init__(self):
+    def __init__(self) -> None:
         self._buffer = ""
         self._in_array = False
         self._brace_depth = 0
 
-    def reset(self):
+    def reset(self) -> None:
         """重置解析器状态"""
         self._buffer = ""
         self._in_array = False
         self._brace_depth = 0
 
-    def parse_chunk(self, chunk: bytes | str) -> List[Dict[str, Any]]:
+    def parse_chunk(self, chunk: Union[bytes, str]) -> List[Dict[str, Any]]:
         """
         解析流式数据块
 
@@ -111,7 +111,10 @@ class GeminiStreamParser:
             return None
 
         try:
-            return json.loads(line.strip().rstrip(","))
+            result = json.loads(line.strip().rstrip(","))
+            if isinstance(result, dict):
+                return result
+            return None
         except json.JSONDecodeError:
             return None
 
@@ -216,7 +219,8 @@ class GeminiStreamParser:
         """
         candidates = event.get("candidates", [])
         if candidates:
-            return candidates[0].get("finishReason")
+            reason = candidates[0].get("finishReason")
+            return str(reason) if reason is not None else None
         return None
 
     def extract_text_delta(self, event: Dict[str, Any]) -> Optional[str]:
@@ -285,7 +289,8 @@ class GeminiStreamParser:
         Returns:
             模型版本，如果没有返回 None
         """
-        return event.get("modelVersion")
+        version = event.get("modelVersion")
+        return str(version) if version is not None else None
 
     def extract_safety_ratings(self, event: Dict[str, Any]) -> Optional[List[Dict[str, Any]]]:
         """
@@ -301,7 +306,10 @@ class GeminiStreamParser:
         if not candidates:
             return None
 
-        return candidates[0].get("safetyRatings")
+        ratings = candidates[0].get("safetyRatings")
+        if isinstance(ratings, list):
+            return ratings
+        return None
 
 
 __all__ = ["GeminiStreamParser"]