Sub2API v1.0 - AI API 网关（二开初始版本，基于上游 Wei-Shaw/sub2api）

backend/internal/handler/openai_gateway_first_output_timeout_test.go

@@ -0,0 +1,51 @@
+package handler
+
+import (
+	"context"
+	"fmt"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/Wei-Shaw/sub2api/internal/service"
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/require"
+)
+
+func TestOpenAIForwardMayFailoverOnlyAfterNonSemanticWrite(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	before := service.OpenAICompactKeepaliveAdjustedWrittenSize(c)
+
+	_, err := fmt.Fprint(c.Writer, ":\n\n")
+	require.NoError(t, err)
+	c.Writer.Flush()
+
+	require.True(t, openAIForwardMayFailover(c, before, &service.UpstreamFailoverError{
+		SafeToFailoverAfterWrite: true,
+	}))
+	require.False(t, openAIForwardMayFailover(c, before, &service.UpstreamFailoverError{}))
+}
+
+func TestOpenAIFirstOutputFailoverStopsAfterOneAccountSwitch(t *testing.T) {
+	failoverErr := &service.UpstreamFailoverError{SafeToFailoverAfterWrite: true}
+	count := 0
+
+	require.False(t, openAIFirstOutputFailoverExhausted(failoverErr, &count))
+	require.Equal(t, 1, count)
+	require.True(t, openAIFirstOutputFailoverExhausted(failoverErr, &count))
+	require.Equal(t, 1, count)
+}
+
+func TestOpenAIRequestAllowsFailoverReplayStopsCanceledClient(t *testing.T) {
+	require.False(t, openAIRequestAllowsFailoverReplay(nil))
+
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	requestCtx, cancel := context.WithCancel(context.Background())
+	c.Request = httptest.NewRequest("POST", "/v1/responses", nil).WithContext(requestCtx)
+
+	require.True(t, openAIRequestAllowsFailoverReplay(c))
+	cancel()
+	require.False(t, openAIRequestAllowsFailoverReplay(c))
+}