修复邀请码普通兑换错误

backend/internal/service/redeem_service.go

@@ -374,6 +374,13 @@ func (s *RedeemService) releaseRedeemLock(ctx context.Context, code string) {
 	_ = s.cache.ReleaseRedeemLock(ctx, code)
 }
 
+func unsupportedRedeemTypeError(codeType string) error {
+	if codeType == RedeemTypeInvitation {
+		return infraerrors.BadRequest("REDEEM_CODE_UNSUPPORTED_TYPE", "invitation codes can only be used during registration")
+	}
+	return infraerrors.BadRequest("REDEEM_CODE_UNSUPPORTED_TYPE", fmt.Sprintf("unsupported redeem type: %s", codeType))
+}
+
 // Redeem 使用兑换码
 func (s *RedeemService) Redeem(ctx context.Context, userID int64, code string) (*RedeemCode, error) {
 	// 检查限流
@@ -407,9 +414,15 @@ func (s *RedeemService) Redeem(ctx context.Context, userID int64, code string) (
 		return nil, ErrRedeemCodeUsed
 	}
 
-	// 验证兑换码类型的前置条件
-	if redeemCode.Type == RedeemTypeSubscription && redeemCode.GroupID == nil {
-		return nil, infraerrors.BadRequest("REDEEM_CODE_INVALID", "invalid subscription redeem code: missing group_id")
+	// 验证兑换码类型的前置条件。邀请码属于注册流程，不能通过普通兑换接口使用。
+	switch redeemCode.Type {
+	case RedeemTypeBalance, RedeemTypeConcurrency:
+	case RedeemTypeSubscription:
+		if redeemCode.GroupID == nil {
+			return nil, infraerrors.BadRequest("REDEEM_CODE_INVALID", "invalid subscription redeem code: missing group_id")
+		}
+	default:
+		return nil, unsupportedRedeemTypeError(redeemCode.Type)
 	}
 
 	// 获取用户信息
@@ -483,7 +496,7 @@ func (s *RedeemService) Redeem(ctx context.Context, userID int64, code string) (
 		}
 
 	default:
-		return nil, fmt.Errorf("unsupported redeem type: %s", redeemCode.Type)
+		return nil, unsupportedRedeemTypeError(redeemCode.Type)
 	}
 
 	// 提交事务

backend/internal/service/redeem_service_redeem_test.go

@@ -0,0 +1,102 @@
+package service
+
+import (
+	"context"
+	"testing"
+
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
+	"github.com/stretchr/testify/require"
+)
+
+type redeemRejectRepo struct {
+	code      RedeemCode
+	useCalled bool
+}
+
+func (r *redeemRejectRepo) Create(ctx context.Context, code *RedeemCode) error {
+	panic("unexpected Create call")
+}
+
+func (r *redeemRejectRepo) CreateBatch(ctx context.Context, codes []RedeemCode) error {
+	panic("unexpected CreateBatch call")
+}
+
+func (r *redeemRejectRepo) GetByID(ctx context.Context, id int64) (*RedeemCode, error) {
+	if r.code.ID != id {
+		return nil, ErrRedeemCodeNotFound
+	}
+	clone := r.code
+	return &clone, nil
+}
+
+func (r *redeemRejectRepo) GetByCode(ctx context.Context, code string) (*RedeemCode, error) {
+	if r.code.Code != code {
+		return nil, ErrRedeemCodeNotFound
+	}
+	clone := r.code
+	return &clone, nil
+}
+
+func (r *redeemRejectRepo) Update(ctx context.Context, code *RedeemCode) error {
+	panic("unexpected Update call")
+}
+
+func (r *redeemRejectRepo) BatchUpdate(ctx context.Context, ids []int64, fields RedeemCodeBatchUpdateFields) (int64, error) {
+	panic("unexpected BatchUpdate call")
+}
+
+func (r *redeemRejectRepo) Delete(ctx context.Context, id int64) error {
+	panic("unexpected Delete call")
+}
+
+func (r *redeemRejectRepo) Use(ctx context.Context, id, userID int64) error {
+	r.useCalled = true
+	r.code.Status = StatusUsed
+	r.code.UsedBy = &userID
+	return nil
+}
+
+func (r *redeemRejectRepo) List(ctx context.Context, params pagination.PaginationParams) ([]RedeemCode, *pagination.PaginationResult, error) {
+	panic("unexpected List call")
+}
+
+func (r *redeemRejectRepo) ListWithFilters(ctx context.Context, params pagination.PaginationParams, codeType, status, search string) ([]RedeemCode, *pagination.PaginationResult, error) {
+	panic("unexpected ListWithFilters call")
+}
+
+func (r *redeemRejectRepo) ListByUser(ctx context.Context, userID int64, limit int) ([]RedeemCode, error) {
+	panic("unexpected ListByUser call")
+}
+
+func (r *redeemRejectRepo) ListByUserPaginated(ctx context.Context, userID int64, params pagination.PaginationParams, codeType string) ([]RedeemCode, *pagination.PaginationResult, error) {
+	panic("unexpected ListByUserPaginated call")
+}
+
+func (r *redeemRejectRepo) SumPositiveBalanceByUser(ctx context.Context, userID int64) (float64, error) {
+	panic("unexpected SumPositiveBalanceByUser call")
+}
+
+func TestRedeemRejectsInvitationCodeBeforeTransaction(t *testing.T) {
+	ctx := context.Background()
+	redeemRepo := &redeemRejectRepo{
+		code: RedeemCode{
+			ID:     1,
+			Code:   "INVITE-001",
+			Type:   RedeemTypeInvitation,
+			Status: StatusUnused,
+		},
+	}
+	redeemService := NewRedeemService(redeemRepo, nil, nil, nil, nil, nil, nil, nil)
+
+	got, err := redeemService.Redeem(ctx, 2, redeemRepo.code.Code)
+
+	require.Nil(t, got)
+	require.Error(t, err)
+	require.True(t, infraerrors.IsBadRequest(err))
+	require.Equal(t, "REDEEM_CODE_UNSUPPORTED_TYPE", infraerrors.Reason(err))
+	require.Equal(t, "invitation codes can only be used during registration", infraerrors.Message(err))
+	require.False(t, redeemRepo.useCalled)
+	require.Equal(t, StatusUnused, redeemRepo.code.Status)
+	require.Nil(t, redeemRepo.code.UsedBy)
+}