修复代理与日志链路的可靠性问题

tests/proxy/sse_capture_test.go

@@ -643,6 +643,58 @@ func TestGeminiStreamPreservesFunctionCallParts(t *testing.T) {
 	}
 }
 
+func TestGeminiStreamPreservesMultiplePartsByIndex(t *testing.T) {
+	upstream := newSSEUpstream([]string{
+		`data: {"candidates":[{"content":{"parts":[{"text":"hello "},{"functionCall":{"name":"lookup","args":{"q":"weather"}}},{"text":"world"}],"role":"model"},"index":0}]}` + "\n\n",
+		`data: {"candidates":[{"content":{"parts":[{"text":"again"},{"functionCall":{"name":"lookup","args":{"q":"weather"}}},{"text":"!"}],"role":"model"},"finishReason":"STOP","index":0}]}` + "\n\n",
+	})
+	e := requestStreamEntry(t, upstream, "/v1beta/models/gemini-1.5-pro:streamGenerateContent")
+
+	var captured struct {
+		Candidates []struct {
+			Content struct {
+				Parts []map[string]any `json:"parts"`
+			} `json:"content"`
+		} `json:"candidates"`
+	}
+	if err := json.Unmarshal(e.ResponseBody, &captured); err != nil {
+		t.Fatalf("unmarshal assembled Gemini response: %v; body=%s", err, e.ResponseBody)
+	}
+	parts := captured.Candidates[0].Content.Parts
+	if len(parts) != 3 || parts[0]["text"] != "hello again" || parts[2]["text"] != "world!" {
+		t.Fatalf("multiple Gemini parts not preserved: %+v", parts)
+	}
+	if _, ok := parts[1]["functionCall"]; !ok {
+		t.Fatalf("middle functionCall part missing: %+v", parts)
+	}
+}
+
+func TestGeminiStreamAppendsDifferentPartKindsAcrossChunks(t *testing.T) {
+	upstream := newSSEUpstream([]string{
+		`data: {"candidates":[{"content":{"parts":[{"text":"answer"}],"role":"model"},"index":0}]}` + "\n\n",
+		`data: {"candidates":[{"content":{"parts":[{"functionCall":{"name":"lookup","args":{"q":"weather"}}}],"role":"model"},"finishReason":"STOP","index":0}]}` + "\n\n",
+	})
+	e := requestStreamEntry(t, upstream, "/v1beta/models/gemini-1.5-pro:streamGenerateContent")
+
+	var captured struct {
+		Candidates []struct {
+			Content struct {
+				Parts []map[string]any `json:"parts"`
+			} `json:"content"`
+		} `json:"candidates"`
+	}
+	if err := json.Unmarshal(e.ResponseBody, &captured); err != nil {
+		t.Fatalf("unmarshal assembled Gemini response: %v; body=%s", err, e.ResponseBody)
+	}
+	parts := captured.Candidates[0].Content.Parts
+	if len(parts) != 2 || parts[0]["text"] != "answer" {
+		t.Fatalf("different Gemini part kinds were merged: %+v", parts)
+	}
+	if _, ok := parts[1]["functionCall"]; !ok {
+		t.Fatalf("functionCall part missing: %+v", parts)
+	}
+}
+
 func TestUnknownSSEKeepsRawBody(t *testing.T) {
 	e := requestStreamEntry(t, fakeUnknownStreamUpstream(), "/v1/chat/completions")