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

backend/internal/service/gateway_waiting_queue_test.go

@@ -0,0 +1,120 @@
+//go:build unit
+
+package service
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestDecrementWaitCount_NilCache 确保 nil cache 不会 panic
+func TestDecrementWaitCount_NilCache(t *testing.T) {
+	svc := &ConcurrencyService{cache: nil}
+	// 不应 panic
+	svc.DecrementWaitCount(context.Background(), 1)
+}
+
+// TestDecrementWaitCount_CacheError 确保 cache 错误不会传播
+func TestDecrementWaitCount_CacheError(t *testing.T) {
+	cache := &stubConcurrencyCacheForTest{}
+	svc := NewConcurrencyService(cache)
+	// DecrementWaitCount 使用 background context，错误只记录日志不传播
+	svc.DecrementWaitCount(context.Background(), 1)
+}
+
+// TestDecrementAccountWaitCount_NilCache 确保 nil cache 不会 panic
+func TestDecrementAccountWaitCount_NilCache(t *testing.T) {
+	svc := &ConcurrencyService{cache: nil}
+	svc.DecrementAccountWaitCount(context.Background(), 1)
+}
+
+// TestDecrementAccountWaitCount_CacheError 确保 cache 错误不会传播
+func TestDecrementAccountWaitCount_CacheError(t *testing.T) {
+	cache := &stubConcurrencyCacheForTest{}
+	svc := NewConcurrencyService(cache)
+	svc.DecrementAccountWaitCount(context.Background(), 1)
+}
+
+// TestWaitingQueueFlow_IncrementThenDecrement 测试完整的等待队列增减流程
+func TestWaitingQueueFlow_IncrementThenDecrement(t *testing.T) {
+	cache := &stubConcurrencyCacheForTest{waitAllowed: true}
+	svc := NewConcurrencyService(cache)
+
+	// 进入等待队列
+	allowed, err := svc.IncrementWaitCount(context.Background(), 1, 25)
+	require.NoError(t, err)
+	require.True(t, allowed)
+
+	// 离开等待队列（不应 panic）
+	svc.DecrementWaitCount(context.Background(), 1)
+}
+
+// TestWaitingQueueFlow_AccountLevel 测试账号级等待队列流程
+func TestWaitingQueueFlow_AccountLevel(t *testing.T) {
+	cache := &stubConcurrencyCacheForTest{waitAllowed: true}
+	svc := NewConcurrencyService(cache)
+
+	// 进入账号等待队列
+	allowed, err := svc.IncrementAccountWaitCount(context.Background(), 42, 10)
+	require.NoError(t, err)
+	require.True(t, allowed)
+
+	// 离开账号等待队列
+	svc.DecrementAccountWaitCount(context.Background(), 42)
+}
+
+// TestWaitingQueueFull_Returns429Signal 测试等待队列满时返回 false
+func TestWaitingQueueFull_Returns429Signal(t *testing.T) {
+	// waitAllowed=false 模拟队列已满
+	cache := &stubConcurrencyCacheForTest{waitAllowed: false}
+	svc := NewConcurrencyService(cache)
+
+	// 用户级等待队列满
+	allowed, err := svc.IncrementWaitCount(context.Background(), 1, 25)
+	require.NoError(t, err)
+	require.False(t, allowed, "等待队列满时应返回 false（调用方根据此返回 429）")
+
+	// 账号级等待队列满
+	allowed, err = svc.IncrementAccountWaitCount(context.Background(), 1, 10)
+	require.NoError(t, err)
+	require.False(t, allowed, "账号等待队列满时应返回 false")
+}
+
+// TestWaitingQueue_FailOpen_OnCacheError 测试 Redis 故障时 fail-open
+func TestWaitingQueue_FailOpen_OnCacheError(t *testing.T) {
+	cache := &stubConcurrencyCacheForTest{waitErr: errors.New("redis connection refused")}
+	svc := NewConcurrencyService(cache)
+
+	// 用户级：Redis 错误时允许通过
+	allowed, err := svc.IncrementWaitCount(context.Background(), 1, 25)
+	require.NoError(t, err, "Redis 错误不应向调用方传播")
+	require.True(t, allowed, "Redis 故障时应 fail-open 放行")
+
+	// 账号级：同样 fail-open
+	allowed, err = svc.IncrementAccountWaitCount(context.Background(), 1, 10)
+	require.NoError(t, err, "Redis 错误不应向调用方传播")
+	require.True(t, allowed, "Redis 故障时应 fail-open 放行")
+}
+
+// TestCalculateMaxWait_Scenarios 测试最大等待队列大小计算
+func TestCalculateMaxWait_Scenarios(t *testing.T) {
+	tests := []struct {
+		concurrency int
+		expected    int
+	}{
+		{5, 25},    // 5 + 20
+		{10, 30},   // 10 + 20
+		{1, 21},    // 1 + 20
+		{0, 21},    // min(1) + 20
+		{-1, 21},   // min(1) + 20
+		{-10, 21},  // min(1) + 20
+		{100, 120}, // 100 + 20
+	}
+	for _, tt := range tests {
+		result := CalculateMaxWait(tt.concurrency)
+		require.Equal(t, tt.expected, result, "CalculateMaxWait(%d)", tt.concurrency)
+	}
+}