From fe6043aec746eea7eb80e55e6d40617de3766fa7 Mon Sep 17 00:00:00 2001 From: MohammadErfan Jabbari Date: Mon, 5 Jan 2026 18:45:25 +0100 Subject: [PATCH] fix(antigravity): preserve finish_reason tool_calls across streaming chunks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When streaming responses with tool calls, the finish_reason was being overwritten. The upstream sends functionCall in chunk 1, then finishReason: STOP in chunk 2. The old code would set finish_reason from every chunk, causing "tool_calls" to be overwritten by "stop". This broke clients like Claude Code that rely on finish_reason to detect when tool calls are complete. Changes: - Add SawToolCall bool to track tool calls across entire stream - Add UpstreamFinishReason to cache the finish reason - Only emit finish_reason on final chunk (has both finishReason + usage) - Priority: tool_calls > max_tokens > stop Includes 5 unit tests covering: - Tool calls not overwritten by subsequent STOP - Normal text gets "stop" - MAX_TOKENS without tool calls gets "max_tokens" - Tool calls take priority over MAX_TOKENS - Intermediate chunks have no finish_reason Fixes streaming tool call detection for Claude Code + Gemini models. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude --- .../antigravity_openai_response.go | 36 +++-- .../antigravity_openai_response_test.go | 128 ++++++++++++++++++ 2 files changed, 154 insertions(+), 10 deletions(-) create mode 100644 internal/translator/antigravity/openai/chat-completions/antigravity_openai_response_test.go diff --git a/internal/translator/antigravity/openai/chat-completions/antigravity_openai_response.go b/internal/translator/antigravity/openai/chat-completions/antigravity_openai_response.go index 24694e1d..35de1a3d 100644 --- a/internal/translator/antigravity/openai/chat-completions/antigravity_openai_response.go +++ b/internal/translator/antigravity/openai/chat-completions/antigravity_openai_response.go @@ -21,8 +21,10 @@ import ( // convertCliResponseToOpenAIChatParams holds parameters for response conversion. type convertCliResponseToOpenAIChatParams struct { - UnixTimestamp int64 - FunctionIndex int + UnixTimestamp int64 + FunctionIndex int + SawToolCall bool // Tracks if any tool call was seen in the entire stream + UpstreamFinishReason string // Caches the upstream finish reason for final chunk } // functionCallIDCounter provides a process-wide unique counter for function call identifiers. @@ -78,10 +80,9 @@ func ConvertAntigravityResponseToOpenAI(_ context.Context, _ string, originalReq template, _ = sjson.Set(template, "id", responseIDResult.String()) } - // Extract and set the finish reason. + // Cache the finish reason - do NOT set it in output yet (will be set on final chunk) if finishReasonResult := gjson.GetBytes(rawJSON, "response.candidates.0.finishReason"); finishReasonResult.Exists() { - template, _ = sjson.Set(template, "choices.0.finish_reason", strings.ToLower(finishReasonResult.String())) - template, _ = sjson.Set(template, "choices.0.native_finish_reason", strings.ToLower(finishReasonResult.String())) + (*param).(*convertCliResponseToOpenAIChatParams).UpstreamFinishReason = strings.ToUpper(finishReasonResult.String()) } // Extract and set usage metadata (token counts). @@ -102,7 +103,6 @@ func ConvertAntigravityResponseToOpenAI(_ context.Context, _ string, originalReq // Process the main content part of the response. partsResult := gjson.GetBytes(rawJSON, "response.candidates.0.content.parts") - hasFunctionCall := false if partsResult.IsArray() { partResults := partsResult.Array() for i := 0; i < len(partResults); i++ { @@ -138,7 +138,7 @@ func ConvertAntigravityResponseToOpenAI(_ context.Context, _ string, originalReq template, _ = sjson.Set(template, "choices.0.delta.role", "assistant") } else if functionCallResult.Exists() { // Handle function call content. - hasFunctionCall = true + (*param).(*convertCliResponseToOpenAIChatParams).SawToolCall = true // Persist across chunks toolCallsResult := gjson.Get(template, "choices.0.delta.tool_calls") functionCallIndex := (*param).(*convertCliResponseToOpenAIChatParams).FunctionIndex (*param).(*convertCliResponseToOpenAIChatParams).FunctionIndex++ @@ -190,9 +190,25 @@ func ConvertAntigravityResponseToOpenAI(_ context.Context, _ string, originalReq } } - if hasFunctionCall { - template, _ = sjson.Set(template, "choices.0.finish_reason", "tool_calls") - template, _ = sjson.Set(template, "choices.0.native_finish_reason", "tool_calls") + // Determine finish_reason only on the final chunk (has both finishReason and usage metadata) + params := (*param).(*convertCliResponseToOpenAIChatParams) + upstreamFinishReason := params.UpstreamFinishReason + sawToolCall := params.SawToolCall + + usageExists := gjson.GetBytes(rawJSON, "response.usageMetadata").Exists() + isFinalChunk := upstreamFinishReason != "" && usageExists + + if isFinalChunk { + var finishReason string + if sawToolCall { + finishReason = "tool_calls" + } else if upstreamFinishReason == "MAX_TOKENS" { + finishReason = "max_tokens" + } else { + finishReason = "stop" + } + template, _ = sjson.Set(template, "choices.0.finish_reason", finishReason) + template, _ = sjson.Set(template, "choices.0.native_finish_reason", strings.ToLower(upstreamFinishReason)) } return []string{template} diff --git a/internal/translator/antigravity/openai/chat-completions/antigravity_openai_response_test.go b/internal/translator/antigravity/openai/chat-completions/antigravity_openai_response_test.go new file mode 100644 index 00000000..eea1ad52 --- /dev/null +++ b/internal/translator/antigravity/openai/chat-completions/antigravity_openai_response_test.go @@ -0,0 +1,128 @@ +package chat_completions + +import ( + "context" + "testing" + + "github.com/tidwall/gjson" +) + +func TestFinishReasonToolCallsNotOverwritten(t *testing.T) { + ctx := context.Background() + var param any + + // Chunk 1: Contains functionCall - should set SawToolCall = true + chunk1 := []byte(`{"response":{"candidates":[{"content":{"parts":[{"functionCall":{"name":"list_files","args":{"path":"."}}}]}}]}}`) + result1 := ConvertAntigravityResponseToOpenAI(ctx, "model", nil, nil, chunk1, ¶m) + + // Verify chunk1 has no finish_reason (null) + if len(result1) != 1 { + t.Fatalf("Expected 1 result from chunk1, got %d", len(result1)) + } + fr1 := gjson.Get(result1[0], "choices.0.finish_reason") + if fr1.Exists() && fr1.String() != "" && fr1.Type.String() != "Null" { + t.Errorf("Expected finish_reason to be null in chunk1, got: %v", fr1.String()) + } + + // Chunk 2: Contains finishReason STOP + usage (final chunk, no functionCall) + // This simulates what the upstream sends AFTER the tool call chunk + chunk2 := []byte(`{"response":{"candidates":[{"finishReason":"STOP"}],"usageMetadata":{"promptTokenCount":10,"candidatesTokenCount":20,"totalTokenCount":30}}}`) + result2 := ConvertAntigravityResponseToOpenAI(ctx, "model", nil, nil, chunk2, ¶m) + + // Verify chunk2 has finish_reason: "tool_calls" (not "stop") + if len(result2) != 1 { + t.Fatalf("Expected 1 result from chunk2, got %d", len(result2)) + } + fr2 := gjson.Get(result2[0], "choices.0.finish_reason").String() + if fr2 != "tool_calls" { + t.Errorf("Expected finish_reason 'tool_calls', got: %s", fr2) + } + + // Verify native_finish_reason is lowercase upstream value + nfr2 := gjson.Get(result2[0], "choices.0.native_finish_reason").String() + if nfr2 != "stop" { + t.Errorf("Expected native_finish_reason 'stop', got: %s", nfr2) + } +} + +func TestFinishReasonStopForNormalText(t *testing.T) { + ctx := context.Background() + var param any + + // Chunk 1: Text content only + chunk1 := []byte(`{"response":{"candidates":[{"content":{"parts":[{"text":"Hello world"}]}}]}}`) + ConvertAntigravityResponseToOpenAI(ctx, "model", nil, nil, chunk1, ¶m) + + // Chunk 2: Final chunk with STOP + chunk2 := []byte(`{"response":{"candidates":[{"finishReason":"STOP"}],"usageMetadata":{"promptTokenCount":10,"candidatesTokenCount":5,"totalTokenCount":15}}}`) + result2 := ConvertAntigravityResponseToOpenAI(ctx, "model", nil, nil, chunk2, ¶m) + + // Verify finish_reason is "stop" (no tool calls were made) + fr := gjson.Get(result2[0], "choices.0.finish_reason").String() + if fr != "stop" { + t.Errorf("Expected finish_reason 'stop', got: %s", fr) + } +} + +func TestFinishReasonMaxTokens(t *testing.T) { + ctx := context.Background() + var param any + + // Chunk 1: Text content + chunk1 := []byte(`{"response":{"candidates":[{"content":{"parts":[{"text":"Hello"}]}}]}}`) + ConvertAntigravityResponseToOpenAI(ctx, "model", nil, nil, chunk1, ¶m) + + // Chunk 2: Final chunk with MAX_TOKENS + chunk2 := []byte(`{"response":{"candidates":[{"finishReason":"MAX_TOKENS"}],"usageMetadata":{"promptTokenCount":10,"candidatesTokenCount":100,"totalTokenCount":110}}}`) + result2 := ConvertAntigravityResponseToOpenAI(ctx, "model", nil, nil, chunk2, ¶m) + + // Verify finish_reason is "max_tokens" + fr := gjson.Get(result2[0], "choices.0.finish_reason").String() + if fr != "max_tokens" { + t.Errorf("Expected finish_reason 'max_tokens', got: %s", fr) + } +} + +func TestToolCallTakesPriorityOverMaxTokens(t *testing.T) { + ctx := context.Background() + var param any + + // Chunk 1: Contains functionCall + chunk1 := []byte(`{"response":{"candidates":[{"content":{"parts":[{"functionCall":{"name":"test","args":{}}}]}}]}}`) + ConvertAntigravityResponseToOpenAI(ctx, "model", nil, nil, chunk1, ¶m) + + // Chunk 2: Final chunk with MAX_TOKENS (but we had a tool call, so tool_calls should win) + chunk2 := []byte(`{"response":{"candidates":[{"finishReason":"MAX_TOKENS"}],"usageMetadata":{"promptTokenCount":10,"candidatesTokenCount":100,"totalTokenCount":110}}}`) + result2 := ConvertAntigravityResponseToOpenAI(ctx, "model", nil, nil, chunk2, ¶m) + + // Verify finish_reason is "tool_calls" (takes priority over max_tokens) + fr := gjson.Get(result2[0], "choices.0.finish_reason").String() + if fr != "tool_calls" { + t.Errorf("Expected finish_reason 'tool_calls', got: %s", fr) + } +} + +func TestNoFinishReasonOnIntermediateChunks(t *testing.T) { + ctx := context.Background() + var param any + + // Chunk 1: Text content (no finish reason, no usage) + chunk1 := []byte(`{"response":{"candidates":[{"content":{"parts":[{"text":"Hello"}]}}]}}`) + result1 := ConvertAntigravityResponseToOpenAI(ctx, "model", nil, nil, chunk1, ¶m) + + // Verify no finish_reason on intermediate chunk + fr1 := gjson.Get(result1[0], "choices.0.finish_reason") + if fr1.Exists() && fr1.String() != "" && fr1.Type.String() != "Null" { + t.Errorf("Expected no finish_reason on intermediate chunk, got: %v", fr1) + } + + // Chunk 2: More text (no finish reason, no usage) + chunk2 := []byte(`{"response":{"candidates":[{"content":{"parts":[{"text":" world"}]}}]}}`) + result2 := ConvertAntigravityResponseToOpenAI(ctx, "model", nil, nil, chunk2, ¶m) + + // Verify no finish_reason on intermediate chunk + fr2 := gjson.Get(result2[0], "choices.0.finish_reason") + if fr2.Exists() && fr2.String() != "" && fr2.Type.String() != "Null" { + t.Errorf("Expected no finish_reason on intermediate chunk, got: %v", fr2) + } +}