From e156b8fcb8538276c532000f7a218bd8a282d7fd Mon Sep 17 00:00:00 2001
From: Fabio Mora <17892293+Fuabioo@users.noreply.github.com>
Date: Tue, 15 Jul 2025 20:59:05 -0600
Subject: [PATCH] fix(openai): handle empty responses from OpenAI API in send
 and stream methods

---
 internal/llm/provider/openai.go      | 16 ++++-
 internal/llm/provider/openai_test.go | 91 ++++++++++++++++++++++++++++
 2 files changed, 106 insertions(+), 1 deletion(-)
 create mode 100644 internal/llm/provider/openai_test.go

diff --git a/internal/llm/provider/openai.go b/internal/llm/provider/openai.go
index 51baaf3a27a0596483bef18663cd2ded2ead0af9..ed5d95ed909124219ef9b5f093153de9ab55d6c1 100644
--- a/internal/llm/provider/openai.go
+++ b/internal/llm/provider/openai.go
@@ -224,6 +224,10 @@ func (o *openaiClient) send(ctx context.Context, messages []message.Message, too
 			return nil, retryErr
 		}
 
+		if len(openaiResponse.Choices) == 0 {
+			return nil, fmt.Errorf("received empty response from OpenAI API - check endpoint configuration")
+		}
+
 		content := ""
 		if openaiResponse.Choices[0].Message.Content != "" {
 			content = openaiResponse.Choices[0].Message.Content
@@ -324,7 +328,9 @@ func (o *openaiClient) stream(ctx context.Context, messages []message.Message, t
 					}
 					if choice.FinishReason == "tool_calls" {
 						msgToolCalls = append(msgToolCalls, currentToolCall)
-						acc.Choices[0].Message.ToolCalls = msgToolCalls
+						if len(acc.Choices) > 0 {
+							acc.Choices[0].Message.ToolCalls = msgToolCalls
+						}
 					}
 				}
 			}
@@ -336,6 +342,14 @@ func (o *openaiClient) stream(ctx context.Context, messages []message.Message, t
 					slog.Debug("Response", "messages", string(jsonData))
 				}
 
+				if len(acc.ChatCompletion.Choices) == 0 {
+					eventChan <- ProviderEvent{
+						Type:  EventError,
+						Error: fmt.Errorf("received empty streaming response from OpenAI API - check endpoint configuration"),
+					}
+					return
+				}
+
 				resultFinishReason := acc.ChatCompletion.Choices[0].FinishReason
 				if resultFinishReason == "" {
 					// If the finish reason is empty, we assume it was a successful completion
diff --git a/internal/llm/provider/openai_test.go b/internal/llm/provider/openai_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..c11e8ff14d7995859cccd3c95eeae4008fb20ac9
--- /dev/null
+++ b/internal/llm/provider/openai_test.go
@@ -0,0 +1,91 @@
+package provider
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/charmbracelet/crush/internal/config"
+	"github.com/charmbracelet/crush/internal/fur/provider"
+	"github.com/charmbracelet/crush/internal/llm/tools"
+	"github.com/charmbracelet/crush/internal/message"
+	"github.com/openai/openai-go"
+	"github.com/openai/openai-go/option"
+)
+
+func TestMain(m *testing.M) {
+	_, err := config.Init(".", true)
+	if err != nil {
+		panic("Failed to initialize config: " + err.Error())
+	}
+
+	os.Exit(m.Run())
+}
+
+func TestOpenAIClientStreamChoices(t *testing.T) {
+	// Create a mock server that returns Server-Sent Events with empty choices
+	// This simulates the 🤡 behavior when a server returns 200 instead of 404
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/event-stream")
+		w.Header().Set("Cache-Control", "no-cache")
+		w.Header().Set("Connection", "keep-alive")
+		w.WriteHeader(http.StatusOK)
+
+		emptyChoicesChunk := map[string]any{
+			"id":      "chat-completion-test",
+			"object":  "chat.completion.chunk",
+			"created": time.Now().Unix(),
+			"model":   "test-model",
+			"choices": []any{}, // Empty choices array that causes panic
+		}
+
+		jsonData, _ := json.Marshal(emptyChoicesChunk)
+		w.Write([]byte("data: " + string(jsonData) + "\n\n"))
+		w.Write([]byte("data: [DONE]\n\n"))
+	}))
+	defer server.Close()
+
+	// Create OpenAI client pointing to our mock server
+	client := &openaiClient{
+		providerOptions: providerClientOptions{
+			modelType:     config.SelectedModelTypeLarge,
+			apiKey:        "test-key",
+			systemMessage: "test",
+			model: func(config.SelectedModelType) provider.Model {
+				return provider.Model{
+					ID:    "test-model",
+					Model: "test-model",
+				}
+			},
+		},
+		client: openai.NewClient(
+			option.WithAPIKey("test-key"),
+			option.WithBaseURL(server.URL),
+		),
+	}
+
+	// Create test messages
+	messages := []message.Message{
+		{
+			Role:  message.User,
+			Parts: []message.ContentPart{message.TextContent{Text: "Hello"}},
+		},
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	eventsChan := client.stream(ctx, messages, []tools.BaseTool{})
+
+	// Collect events - this will panic without the bounds check
+	for event := range eventsChan {
+		t.Logf("Received event: %+v", event)
+		if event.Type == EventError || event.Type == EventComplete {
+			break
+		}
+	}
+}